PDA

View Full Version : Swap - ET2 / A18 / B20A (JDM) / B20A5 / B21A : Head - A20A : Block



Hoshizakido
06-30-2002, 10:48 PM
What heads will swap on to tha A20 block?


I know someone that put a B20A3 head on a A18.... it worked but had coolant problems
I posted 1 year ago that someone installed a B20A3 head on an A18A... the problem was the cooling passages and the timing gear location. He said in the other thread the he shimmed the bottom gear... fine, I can beleive that.
However, the distributor and crank sensor are NOT from a B16A... they are from a D16 (Integra 86-87 engine)
The major problem I see with this setup is that you need a custom intake manifold to make it work... or a monster hood
Like sean said, for all the trouble involved, you could use a VTEC head instead... no need for a custom intake with that head since the engine leans in the proper way.
Nice work tough... I wonder if it actually runs.
That's because of the exhaust valve location isn't at the same place on cylinder #1-2 and #3-4. This way honda can make only 1 model of piston instead of making 2 different pistons for the same engine...
The F23A head isn't bad but I would prefer to have the DOHC F22B head on it. Interesting project tough.
It sure seems to line up properly.
Once the head is bolted to the engine, the rest would be fairly easy.
However, the JDM B20A head would be a better option to mod in my opinion. The intake manifold wouldn't need to be modified to fit in the car since the B20A uses the same mani as the A20A.
The problem is findind a B20A head in North America, which leaves us back to square 1.
With the B20A5/B21 head, you would need to mod the intake mani so it fits inside the enginebay. Just a cut N weld thing.
I would run the PK2 ecu with that setup but the PJ0 could also run it.
For the Manifold, I was refering to the Accord B20A. The Accord B20A will not bolt to the B21A or 88+ Prelude B20A
The A20A has a 82,5mm bore if I remember.


I finally logged into 3geez after being gone for a few months, and saw a few PMs asking about this project. Here is a quick summary:

Here is what you would need (Mostly from memory):

B21A1 (from 1990 - 91) or B20A5 (from 1988 - 91) head from a Prelude. B21 head lowers compression just a bit, B20 head bumps it up just a bit. B20A5 heads are much more common in the junkyards around here.

Custom lower timing gear (Modify a B20/B21 gear to fit A20 shaft)

Some other timing belt - Unsure of what is needed

Tap and plug the extra oil drain holes in the new head

Redo the one head bolt that does not line up. Probably make the hole in the head a little bigger and oval shaped, and then make a special washer for it.

Redo the oil feed, since the head bolt that doesn't line up is used with the head's oil system.

Upper timing belt pulleys do not quite align with the tensioner and bottom pulley. Probably has to have some shimming done.

You need the B21A1/B20A5 intake.

I remember that the A20 distributor had a different number of teeth than the B20A5/B21A1. You will probably need to switch to one of the OBD1 ECUs to make tuning simpler. Look for the instructions on what distributors fit on the B20A5/B21A1 head on preludepower.com. The ECU swap is a project in itself...

My suggestion: Do the head swap if you are looking for a challenge, if you want cheap power go turbo. I am sure that the head swap could be done, but it will not be easy.

I am currently (slowly) working towards going turbo. College has been keeping me very busy, but I am slowly making progress.

meanaccord
09-05-2002, 03:45 PM
My friend has a 2.0 with DOHC F.I. . I have an 2.0 SOHC with carburation. He is getting rid of his car so would his DOHC fit on my car, i mean anywayz possible?Thanks

I found an a20a1 DOHC head running to a carb. . I have an a20a1 with SOHC carbed.....will that head fit on my block and bolt to my intake? If so then what else would i need for the conversion.

AZmike
09-06-2002, 12:33 PM
Sounds like he has the B20A. You can't just switch the heads. You have to swap the whole engine and transmission. Then you'd need a few other parts to get it all to fit and work properly.
You may consider buying his car and selling yours unless you've already done a lot of work or yours is in much better shape.

I think Sean was going to use some shift light feature of the GM ECM to control the VTEC, switching it on at around 4k.

88boy
10-19-2002, 01:38 PM
is it possible to put k20a from an rsx heads on the a20a3. or even the f20 heads off the s2000?

dXsquared
10-19-2002, 02:19 PM
HAHAHAHA are u on glue??? they are DOHC... and the block is soooo different! not even close to a swap there... try a 2 gen lude head...

Travis

flamed89
10-19-2002, 06:52 PM
try a 2 gen lude head
sorry to let you know this but that is the same head as what is on the 86-87 accord!

my suggestion is to go to a machine shop and have yours ported and polished!

1989 DX R
10-21-2002, 03:35 PM
There were never any DOHC A20a1's. You might have a B20a1 or something else.

KMS, would you be able to make a manifold for some Weber 40DCOE carbs and how much would one of those headers cost?
Also, how much should a good rebuild of my whole motor cost? I want everthing regasketed and reground to make it smooth.

I'm just looking for an estimate on a price for a rebuild...I'm in Texas so the work is going to be done locally.
For the DCOE manifold, I'm sure you can get your paws on the flanges and stuff, if not, then I can probably get that stuff done here as well.


Originally posted by KMS
Sure we can make the manifolds you need. I just need the set of carbs you want to run and they would be in the price range of $200.00 to $300.00
Ok, so I can get my hands on some Weber 40DCOE carbs and the flanges, and then ship em to you, and then you can get it all hooked up correctly, including the tilt angle? I will do the carb tuning myself, but need the manifold to connect it to my block.

Well $200-300 is a good deal for a manifold anyways. No group buy, but KMS could have like a mold or something so he can make more if he wants.
Would it be possible to have it tapped for the PCV valve?

socal3rdgen
12-04-2002, 11:11 AM
I think this should go in the performance section since that what he does. This thread is a Q/A Thread. 3geez. members and KMS were off to a bad start. So these are pics of his work. Hopefully this can be a good thread for him and for us.
***Warning- dail-up users***
this will take a while for you.
IS THIS AN ACCORD ENGINE BAY?
More pics below
IS THIS A ACCORD HEAD. IT HAS 4 VAVLES. THE ACCORD ENGINE AS I UNDERSTAND IT HAS 2 INTAKE 1 EXHAUSTING MAKEING IT ONLY 3 VALVES PER CYLINDER.
That all the pics. Please post Questions and comments.
so i still have to ask even if you dont have a dyno sheet. (i would like to see one but oh well). the engine in the civic is N/A right? what quarter times have you gotten with this and what torque/ horsepower have you gotten.


Originally posted by quagmire
And are the time slips for a single cam, or is it with the DOHC head?
good question. to add to that. is it a
the A20 engine with a20 head. and modifications? otherwise those slips are for a hybrid engine.
i think most of us want to know how far are a20's will go.
yeah ide like to see the twin cam. what kind of dohc head are you using. from what engine.
oh ok.

Originally posted by Sean
problems with your head swap plans.
both the intake and exhaust vavles are gonna hit the cylinder walls. the shrouding form the valves being so close to the cylnider walls is gonna screw up airflow. secondly why not work on getting the a20a head to flow.
btw from your ET i derive 198hp in an accord but i feel that these times slips are in the civic which works out to 155hp.
have a good day.
thats what i was getting at when i was talking about the engine bay. how much of a weght didference is there between the 2 cars.


Originally posted by KMS
I have been answering questions for 2 days and all the ones that step up to talk have not said one thing that makes them an expert nor have I seen their success.
kms this thread was started to test your knowledge and no one elses without fighting. i think its going good so far. we want to see your skill since as far as i know no one has your products. late
Joel

yeah im thinking i want to do that also site.

swim

read your pm's

KMS
12-04-2002, 11:53 AM
This cyl head is a conversion that i am working on to convert to a dule overhead cam Note the accord head gaskit it is starting to come together the pistion is for the orignal accord that i run in the singel cam
No this is a civic engine bay i run the accord engine
Yes the header bolts right up. with no mods its an ok design we have better but it dosent pay for us to build them for the old cars
the block in the cnc is to an old school 1200 civic this is adam mallys car http://www.scca.org/amateur/club_racing/runoffs/photogal/hp-7.jpg
Price ? the cam in my car is a weld cam it gives a better base circle and more overlap
List price on the cams for a grind and than re hardend is$185.00 and a hard weld That being in my opinion the Best because you can change the overlap for real power$550.00
I dont have a dyno sheet on this engine anymore and i have just started tuning agian this year . this car is old and i havent used it to much if i can get it to hook up it will run 12s best so far 13.5 but i have both time sheets if you need them and thay will show that it will hit 12s
Knifeedge and balance crank shaft $350.00 and micro polish
Who can i send these time sheets to?to post
Let me know if you got them
An 88 prelude. regrinds are cheap. the only reason thay are welded is that nowon maks a billet cam cores.When thay are welded you can change duration and overlap And it also gives you better rocker geometry.
Thanks
a 4-2-1 builds low end torque 4 into one would be for top end power but i have found that having 1 exoust valve all ready controles torque.And WOW have you seen the exoust ports on the s2000? all i can say is wow thay are huge.
Yes that is the price unless it is a volum deal.
forgot the E
Yes for a hardened grind.$185.00
It will pass EMI but it could add a littel more emissions but as long as you werent on the edge to begin with . but as for specs i have several i can use. I try to use customer info to decide but i have cam lifts and durations that would Never pass
The time slip is a single over head cam. No it would be crazy fast twin cam
I have not run a twin cam head yet. But i should be Fun
Got to go. leave questions i will Check in periodically through the night. Or i will be here all day tomorrow
Thanks
88 pralude
Prelude
Sure stop buy . Did you see the 89 lxi head gaskit siting on the head? the combustion chamber is small but thay line up fine.
Get of on exit 82 turn right go 6 miles to browns brige turn left go 3 miles after brige turn right first black fence on right
No its not finished but its not a rush for me I build new engines every day. The block needs nothing but a larger timing gear and buy larger i mean wider gear and an oil pump adaptor all the work is in the head lots of welding.
I believe that this head flows more than it should but please look at the picture before talking .The head is on the table the head gasket is on the head the gasket is from an 88 accord lxi do you see that the combustion chamber is smaller than the accord bore size? and what do you think the normal head on an accord flows ? and what do you think a prelude head flows ?and how much can you port an accord till you see day light and not loose velocity?
FPR? I can give you lingth in the morning just Email me I like the super coil and a 6AL
Ok WOW what a pain but the carbs i run are gravity fed and thay love to leak that why on my street car i used CBR 1100 carbs . yes the FPRs are a pain the ASSSS Thay are built buy Holly
That was the point I was looking for power and that helped .you don’t want the water pump to spin as fast as you rev it starts to cavatat and you loose cooling
The compression ratio is about 13.7 to 1 I havent CC the head sense I cut it for a new head gaskit the cam lift is .465 duration.284 springs have a seat pressure of 100 pounds oversized valves with narrow shafts and titanium retainers. and you have seen the pistons thats what i was holding.
Cool
I Owen a flow bench what is the water drop in with your test were done ? Be careful I will call Bull Shit my bench will pull 1000 cfm At 28 inches of water.
And do remember there is a point in witch a head will stall so if you are talking over your head stop now .This is for a No BULL SHIT talk .
PIC. http://www.honda-performance.com/pics/swap/flowbench300.jpg i can provide beter pics in the morning . when I open my shop.
And sean have you been DRINKING?you no talk so good
Point taken on the typing skill. And my spelling sucks also . But it just upsets me when someone jumps in and won't stay around to talk about the subject .I have been answering questions for 2 days and all the ones that step up to talk have not said one thing that makes them an expert nor have I seen their success. BUT back to the subject. See it is right to ask about the lift but has anyone asked about rocker ratio but there is just to much to talk about and we haven't talked about lobe centers yet .
On timing belt line up I just spaced the timing gear on the block and we are using adj cam pullys to dial in the cam card . and using one extra adjuster .
On the front side like the mugen to take the belt slap out. the car weight is about 1800 pounds .
Thank you for your support and I have enjoyed it. Sorry I get a little bent out of shape some times but there's nothing like being in rapid fire discussions.
Thank you for your support and I have enjoyed it. Sorry I get a little bent out of shape some times but there's nothing like being in rapid fire discussions.
Thanks and I didnt mean to piss everybody off at the begining .:stick: :beer:
What?
I get it now sorry kinda slow. Had A Bad day $
Now how are you going to fit that much lift under the rocker assy?And there is a little thing called coil bind But I am just asking. With the lift in the head now I had to notch the back side of the rockers.
1989 DX R Call me770-784-1801 we need to find out Just what you want.
Sean so What do you have for a car ? Just Wondering you sound like you have a clue . No when I Get serous I will build A Billet Head Thats why I have a CNC . But this old school stuff dosen't make me any money so I won't be spending alot of my time on it .So When you reduce your base circle do you find you'r losing overlap?But Sean if we talk to much we will lose the people Watching the thread. So drop me an email and I will give you a call to talk.

Ok but we will have to start explaining LOT'S See What hapens now is we go into theory and no one wins except on the track . And it gets real Boring But whatever.

Sean what times do you run?What do you have for a set up?

Sure we can make the manifolds you need. I just need the set of carbs you want to run and they would be in the price range of $200.00 to $300.00

Sean what center line were u using On the cams I have few that have worked well ?

If thats what you want Thats what you get.

Site
12-04-2002, 01:19 PM
I'll post them. Send them to [email protected]. Let me know if you want me to post them in this thread or create a new thread for them.
Here ya go:
http://www.riverhillscc.com/lighthouse/kms_pics/mally019.jpg
http://www.riverhillscc.com/lighthouse/kms_pics/mally020.jpg
http://www.riverhillscc.com/lighthouse/kms_pics/mally021.jpg
http://www.riverhillscc.com/lighthouse/kms_pics/mally022.jpg
http://www.riverhillscc.com/lighthouse/kms_pics/mally023.jpg


Originally posted by KMS
I have been answering questions for 2 days
I for one am glad you're here and are taking the time to answer so many questions. Like you don't have others things to do, if you so wished. I know you're hoping to get some business from this forum sent your way. I'd say you're establishing yourself well enough to accomplish that. Results speak, you know?
Personally, after Christmas I'm planning to send a crankshaft to you for balancing. I like the results you've posted so far.

quagmire
12-04-2002, 01:24 PM
Ok, its $550 for a hard weld regrind? And what motor is that DOHC head from?
I'm aware of what goes into a hard weld, but wanted to be sure of the price. So is it $185 or $550? You didnt say. Its hard to read these posts that are one or two long run-on sentences.
So what is involved in the DOHC head swap? Redrilling the head bolt holes? What about modifications to the timing chain? Does the Prelude combustion chamber match up to the A20 cylinder bore? And have you done hard weld cams for the Prelude head? Are the valves the same size? And are the time slips for a single cam, or is it with the DOHC head?
So its $185?
Cool, what are the specs on the regrind? And since I get inspected in Houston, does it increase emissions significantly?
Cool, 'cause right now I'm looking to mainly improve my power with stock head and intake manifold. I don't know exactly when I'll be able to do it, probably over spring break (early March) or during the summer. Over Christmas break, I'm going to try and get all of my cars little problems( brakes and other little shit) worked out, along with a header, cat( probably Catco) and muffler( Dynomax). So thats probably what I'd be camming the motor for.
He said an 88 Prelude, so whatever DOHC motor came in a Prelude in 1988.
KMS-
Have you finalized the conversion process yet? You didn't say what you had to do to get it work on the A20 block.

Sorry, I was afraid the thread was dead. Mea culpa, mea culpa. Thanks for the specs.

Pretty salty going up against Sean. Anyway, I'm sure most of us on the board would be most interested on your work on the A20 head. Sean is right, .465 is pretty low lift. But anyway, is that 284 degrees duration, is that at .5?
P.S. Not to be a bitch or anything, but you dont type very well either. Lack of periods and such.

I didn't mean anything by the typing comment. And I think Sean was just making sure you weren't some random douche who didn't know what he was talking about. But you've satisfied me that you're qualified, for what that's worth. I also plan to send some business you way next year, but most likely a cam. Thanks for the info. Later.

I find your conversation quite stimulating. I'm learning a lot.

Sean
12-04-2002, 04:00 PM
question how in the hell do you plan on swapping on a prelude head. the bore centers are further apart. ?
problems with your head swap plans.
both the intake and exhaust vavles are gonna hit the cylinder walls. the shrouding form the valves being so close to the cylnider walls is gonna screw up airflow. secondly why not work on getting the a20a head to flow.
btw from your ET i derive 198hp in an accord but i feel that these times slips are in the civic which works out to 155hp.
have a good day.
i did look at the overlay ofr the lxi headgasket onto the preulude b20a5 head. the intake vales are gonna hit the cylinder wall. please done tell me your gonna notch cylinder youll hit water for sure.
and ive gotten the a20a head to 220cfm intake and 190cfm exhaust. without welding or dropping alot of port velocity. it can be done but do you want to invest the time on the flowbench to make it sing like that is the question
also thats a .450 lift. im sure it could do more at 500 0r even more lift. and yes the prelude head is a bad idea. it not gonna work right. you should do a bit of reasearch on head flwo dynamics when being modled in a cylinder. the srouding your gonna introduce there is gonna reall bunch flwo up alot. use the a20a head and make it flow.
hmm the prelude engine is aluminum and has a wider bore spacing. not every intake valve will hit but every other valve will hit.i found this out trying to fit a b20a5 crank into a a20a block.its the same reason wever never tried to swap the accord b20a head. look at the headgaket ovehanging the intake valves. that the give away. then again even if you do get the head on the engine and fix the valve contact issues you still have to do alot with piston shape. you cant just up the compression and expect good results you need to work at qunech and using the flame front to propogate good combustion. ive seen plenty of high compression engines get beatne by a lowe compresion engine using the same specs. combustion efficency is whee its at.
and KMS if you would like to talk to me about head porting fine. but stop putting that head on that motor. how much flwo do you need. come at me with a cfm number and i should be able to help you.
as for port stall the factory ports stall a 550 lift. the last head i did stalled a .675 roughly. ive spent alot of time modeling cylinder head flow with this motor. but then ive been porting heads in general for the better part of the last 10yrs. i dont do it proffesioanlly cuase the aint no jobs paying what i need to make. i turn a wrench day in and day out.
ps 28inch of water the normal
well i used a reduced base circle to prevent this very issue. with the the follower being hit by the cam lobe. then i used ford small block valve springs and had the spring pockets cut out. ive run .500 lift cams. its nto hard. but what exactly do you need for airflow. ?send me a head.
actually i found that reducing base circle has zero effect on overlap. you can just grind off center to split the difference. and the a20a head is easy to port. just have to know where. ive spnet lots of time on the where and alot of heads. ive cut 4 into sections i know where the water is.

those motors are gone. i ran a 15.1 in a 4dr full stock bodied accord once. which i figured was good for about 185hp. i didnt know then what i do now about the head either. i was turning around 8200rpm. im confidendt i could make more power now a 6500rpm then i used to at 8200rpm. ive learned much about this engien and its like and dislikes.
anyways id rather talk about head porting and flow dynamics.


----
im going to get started on this soon is there any interest??
ok gotsome issue to work out but it looks feasable. not saying im 100% sure i can make it work but i cant see why it wont. alot of things fell into place. my biggest issues right now are oil returns, and oil feeds. aside from that it looks like itll work.
yes it uses the same bore centers spacing as an a20a. it has an 81mm not a 82.5 im not sure why they keep publishing it in all the headgasket catalos that way. anyways yes im getting my hand on a head soon so i can start making it al work. i plan to make this an integral part of the GM ecm project for sevral reasons.
first the stock computer cant switch the vtec on period. second i found the shift light parameters in the GM ecms can. third its easier to tune EFI for this then try and hack a stock system in the GM ecm is more flexiable and easier to program.
all in all i got lots of homeworks to do but i think forging so new ground and brining in technologys like Vtec to the older a20a could really change the way the import scene treats us and looks at our cars.
think about how powerful a b16a would be if it was poked and stroked ?? pretty TQ'e with a good bit of high end power.
im not waining whats killing me is developing parts for me as well as everyone else. i always try to make things kit able in term that means that if you want it i can sell it inexsepsnsively
would you like to send me a b16 head ?? i could really use one. the one i got is all fubared and ai need a good one to get moving. plus i need the timing gears etc. if you can do that email me thanx a bundle.
im gonna use the whole b16 head.
the R/R is 1.51:1 its pretty good that explain why the a20a has such a long ring life. that better then alot of the damn motors including the b16. which is 1.5. im not to worried plus with our bigger enignes the head will run out of air at about 7100rpm plenty enough rpm for me.
1,3,2,4 but that dont matter much the b16 is 1,3,2,4 and thats becuase there both 180 throw crankx.
Well as dandy as all this is. heres a startling factiod. intake to exhuast flow ratio in most high end racing applications shoots for 100/75-80 ratio. and as dndy as 16 valves is you can get enough flow out of te single exhuast valve with little to no trouble to no make the troube of fitting that big cubersome head on this engine.
Just a FYI. if i was gonna go 16 V id defiantely go vtec because the dual profile cams would make it a worthwhile venture.

pric
12-06-2002, 06:12 AM
Sean: I'm not an expert but the A20A has a larger bore than the B20A so I was wandering if you could explain to me why the intake valves of the B20A would hit the cylinder walls of the A20A? Thanks.
KMS: My question for you is how do you plan on insinking the timing of the B20A cams with the A20A crank detailed explantion would be appreciated? Thanks.


On timing belt line up I just spaced the timing gear on the block and we are using adj cam pullys to dial in the cam card . and using one extra adjuster .
That makes sense but were are you mounting the extra adjuster at? Oh BTW your input is appreciated and I want to thank you for you time.

2old_honda
12-09-2002, 12:45 AM
I know a few people want a manifold for dual DCOE 40's. Would you be willing to do a group buy of say 5 manifolds? I know that I would buy one if it was in the $200-$300 range. thanks:)

Originally posted by 2old_honda
I know a few people want a manifold for dual DCOE 40's. Would you be willing to do a group buy of say 5 manifolds? I know that I would buy one if it was in the $200-$300 range. thanks:)

Originally posted by KMS
Sure we can make the manifolds you need. I just need the set of carbs you want to run and they would be in the price range of $200.00 to $300.00
so you would do a group buy of 5 manifolds? these would be for dual weber 40 DCOEs. and I am sure you know about how the manifold needs to tilt back 10-12 degrees. If we could get 5 people to buy them, how much could you make them for? Also, I would be able to organize the group buy, I would get the 5 people for you and all you would have to do is collect the money, make the manifolds, and ship them out. you can email me at [email protected] if you would like to get something started.
thank you!


Originally posted by da6integra
wouldnt a d16 sohc vtec swap seem more of an acheivable feat... just a thought
no, I highly doubt the bores would even be close
the header will fit but the down pipe will either have to be modified, or a custom one wil have to be made.

carotman
01-04-2003, 04:09 PM
Ok let me explain a little story that happened to a friend and that might apply to our cars
A guy I know owns a 1.8L Prelude 2nd gen.
He went to the junkyard to buy a head for his 1.8L with the Idea of rebuilding it with performance parts. He bought the head and took it to the performance shop.
When he brought the head back home, the head wouldn't fit, some things were different. All the bolts lined up except one on the back of the engine. He took the head back to the junkyard for some explanation, it turned out that he got a 2.0L head instead of a 1.8L, up till 30 mins ago, I had never seen the head myself and thought it was an A20A head. But when I saw the head, I instantly realised that this was in fact a B20A dual carb head (from the SOHC 3rd gen lude)
The guy didn't know that and since he put money into modding the head, he wanted to make it fit anyway, (thinking he had a A20A head on a A18A) he machined the bolt hole that didn't fit and modded some coolant passages,
The head bolted to the engine like a charm after that, the only problem was that the cam sprocket didn't alogn with the crank sprocket. He took care of that and installed everything else.
Beleive it or not I saw the engine running like a charm. SOHC B20A head on a A18A!!!!!! He had little coolant problems but he blew the bottom end of the engine before he could take care of that. (9000 RPM isn't that great for the A18A)
--------------------------------------------------------
Ok, the story ends..... now I hopw you see where I'm going..!!!
The SOHC B20A (B20A3 I think) and the B20A5 (DOHC) share the same head gasket, this means that the same modifications would be needed to put the B20A5 head on the A18A, That's something huh!!!!
Now I'm sure that the A20A could use the B20A5 head. If not, then we could just swap an A18A in our car with a B20A5 head....
I'll try and get pictures of this soon.

I doubt it will work with the A20A sinec the bore size of the A20A is 82.5mm while the B20a5 is 81mm, the combustion chamber will need to be resized (if this can be done) the bore of the A18 is 80 mm, so this can be Ok
I definetly need to check more on that, I was so astonished to see that the SOHC B20 head was used on a A18 that I forgot to take pics :)

I think there is a little problem with the coolant passages (from what the guy told me and rfom what I saw on the head)
I'm sure that coolant lines could be plumbed to patch for that.

PhydeauX
01-05-2003, 08:52 AM
The bore size won't make a diference. Infact it would be better to have the head on the a20 block then the a18. No part of the piston comes past the deck of the block so there will be no interference. the outside of the piston will also come very close to the head giving it some quench, something that the stock a20a head lacks. What you need to worry about is that the chambers and bores have the same spacing and that the coolant and oil passages can be made to line up.
andy

------------

Did the bores actually line up?
andy

------------
Kinda like a crvtec but with a block that can hold up to the power.
andy

------------
I remember lude speed trying to put a b16a head on a b20a block, I think they managed to get that one to work. I also seem to remeber them trying to put a b16a head on a a20a block and having a bitch of a time with it. I don't remember if it ever ran. I've never heard of some one actualy trying it with a b21a head on the a20 block. Though there was talk of trying to put a jdm b20a head but I don't think anyone ever tryed it. Does anyone happen to know if the b20a3/5 heads are the same as the b21a. Those heads are alot easier to come by.
andy

------------
Well, now that I'm home from work I can look it up.
a20aX 3.25"
b20a3/5 3.19"
b21a1 3.27"
If this is possible I'd choose the b20a3/5 head. You might pick up a little quench around your ring lands from the smaller cc and it should add some squeeze too to help the mix. Plus it leaves room for oversized valves. That is if the head has the proper bore spacing and the bolts are close enough to allow the mod.
andy

------------
He probably had some of the coolant and oil passages welded and re-shaped so they would line up with the passages on the a20 block, then he had some of the head bolt holes redrilled.
andy

KaMiKaZeE
01-05-2003, 11:18 AM
you might need to do a custom oiling setup as in b20b/b18c hybrids. It could be made to work with a little ingenuity provided the bore spacing is correct as phydeaux said.

SQ is the SQUAD
02-10-2003, 11:33 AM
arew you going to do the oil feed lines and return like on a ls/vtec with tapped oil lines. i got a b16 block in my basement so yuo need any parts off it, i tihnk it might have oil squirters

i just happen to hav ea d16z6 head and a b18c1 head

markmdz89hatch
02-10-2003, 07:22 PM
Sean, if it helps at all, I think that OpenLoop did a ITB setup on an A20A3. 'Least that's what I think I remember about it. And, if I'm not mistaken, they used a B16 kit and made a few modifications to it.


Originally posted by AccordEpicenter
if you wanna spin the a20 engine well past 7 or 8 k you need valvesprings, lighter valves, rods, entire engine balanced, and pistons. BTW the a20 block doesnt have sleeves, the bores are cast in. Youll have an easier time making the engine take the 20psi then you will making it reliably rev to 9k. From what i hear, all you need to do to the bottom end of the a20 is get the forged pistons (for turbo), because the stock honda rods are strong as long as you dont overrev the engine. How you prevent it from blowing head gaskets is another problem.
...and Johnny-O can certainly vouch for that one. He's melted head gaskets like there's no tomorrow in his 11.8sec Turbo A20A3-powered 3G Hatch down at Englishtown.

da6integra
02-10-2003, 08:35 PM
wouldnt a d16 sohc vtec swap seem more of an acheivable feat... just a thought

Grant2k
02-10-2003, 08:42 PM
Originally posted by PhydeauX
Kinda like a crvtec but with a block that can hold up to the power.
andy
in that swap isn't it the rods that become the weak link?

Originally posted by 2old_honda
as someone stated before, will the a20 rods hold up to the power?
what i was thinking was that the LS or whatever block people use for this swap usually is strong enough to withstand it, the problem is they change the R/S and the rods get all stressed out and become the weak link. i imagine that anybody willing to do all this work is going to pay for forged rods and do it right. Andy just commented that now it'll have a block that can stand it, and it will, but i just never thought the block was the issue. it must also become hard on the rings too if they are getting pushed into the cylinder wall all the time. i would guess that none of these swaps have been around long enough for people to study ring wear though. but i would factor it in in the long run.

actually i think his best was an 11.9 and he ran it in New York somewhere. 11.8, now that's just silly.

Scorpion88LX
02-11-2003, 08:37 AM
if there is a chance in hell that sean can make a vtec then couldn't you we use a latter sohc vtec cam and acces.
One ques could we even use the whole head.

two ques. if you get this done (hoping) how will you get the timing belt right and what type will you use. the second is will b16 exhost headers and down pipe fit under the a20 block.

AccordEpicenter
02-14-2003, 12:20 PM
ynot, unless you overrev the engine. For example, A20 rods couldnt withstand b16 rev limiter of 8000 or 8100 rpm or whatever it is, youd have to stay at the stock rev limit
why would you do that? If yore looking for power, go with the gold, the b16. In any event, controlling the vtec is easy, its just a solenoid. Most guys when they do a mini-me conversion use one of those msd rpm switches to mess with vtec.
i believe the b20A head is better than the B20A5/B21A1 etc... not sure though
hey, which intake is better for power, the 88-89 intake, bypassed maybe, or an 86-87 intake (both efi) im looking to make the car pull harder past 3 or 4k. I have my bypass open all the time in my 88 lxi and that gave me a boost of power past 4k but I also have a spare 87 lxi manifold and an 88lxi manifold around here somwhere but i was wondering which is better for speed? Also how much power can be had with intake and head porting, and which is worth the most power?
if you wanna spin the a20 engine well past 7 or 8 k you need valvesprings, lighter valves, rods, entire engine balanced, and pistons. BTW the a20 block doesnt have sleeves, the bores are cast in. Youll have an easier time making the engine take the 20psi then you will making it reliably rev to 9k. From what i hear, all you need to do to the bottom end of the a20 is get the forged pistons (for turbo), because the stock honda rods are strong as long as you dont overrev the engine. How you prevent it from blowing head gaskets is another problem.

did you say 11.8?

lol.... those are scary times for an accord. I think he could improve on those actually from what ive heard (wheels spinning all the way down the track)

wprocomp
02-14-2003, 02:39 PM
will the ignition firing order be the same?I think its diff on the b16.the intake size on the a20 is1.52,1.51,1.52,so the b16 head should work well with the better valve diameter.and you can always concrete the head or block to seal off unused oil passages.good luck Id like to see this work.

iiviasterp
03-31-2003, 03:49 PM
it seems as though you would have to have a vtec controller too to switch over to vtec at a lower rpm, because im pretty sure b16's switch over pretty high, and if your sayin that the motor would only be able to rev to about 7100, thats not alot of vtec to play with......just something i was thinkin about......

Justin86
03-31-2003, 04:38 PM
The does make since, but even if you can't use the full benefits of the VTEC head the fact the you have one is reason enough to do it. Saying that it is possible to make the switch.

Well it looks close but I don't see any big machine work so I guess this is pretty much bolt on?

Low Tek
03-31-2003, 09:56 PM
this is a question for sean or kms - I am wanting to do a new cam, but I want the higher rpm range... I want something like 9grand for the new red line.. and I want it to be an agressive pull for street/strip..
I am goint o run the stock a20 block and head - boring it out 40 over and then resleeving it, I have the b16 intake manifold, and a 87 prelude distributer/ecu and a 20 psi t3 turbo.. I have done some research, but I need the cam to pull it all off

you guys both seem to know what you are talking about, so what do you think??

oh yea.. and what compression should I run to get the hard 20psi hit??

thanks

Vanilla Sky
04-01-2003, 12:15 AM
he needs a head that he can cut apart and see how much room is in there... i've tried to sorce one, but the only ones i found were either trashed (severely) or would only be sold with the rest of the running engine...

he also thinks that this is not a needed swap, that you can make the same power using some common sense with upgrading the a20... talk to him for more details... andy says he's looking to be into the 14's in his 2gee wiht the a20a1 and some other mods... i'm looking into getting a JDM b20a and modding it in the same manner as sean suggests the a20 be modded... he has gotten me into looking for a frame for my car because i have learned that i can do something with the motor i already have (i refuse to drop in a POS a20a1 without modding it any[it runs just fine])

dammit... sorry for the long post, i was just hoping to help with some info since it seems to be something that may be done widely, even though most are on tight budgets

1988starter
04-01-2003, 04:20 AM
First off you can onle bore 30 over or you will have too thin walls.. Second 9000 redline go buy an s2000 because A20A1 has about what the max you should go and that is 7500 adn for 20 PSI no more than 8.5 is my guess

buzzbomber88lx
04-05-2003, 05:19 PM
i wouldnt drive long distances because of compression reasons from the decreased flow rate. Like when you put 289v8 heads on a 302 it reduces flow but enhances compression. putting 351w heads on a 302 gives it more flow but a little less compression. the smaller the head the greater the compression. going down from an a20 to a b16 is asking for trouble i'd say unless you are only making quarter mile passes and dont want a daily driver. just my .02
-Ryan

damnit....brings back mameries of my dads pimpin 90 lude b21a1 with 4ws and an si. nice job getting that all done. should be hella faster.
pogi is right. turbo is an easy way and actually pretty cheap way to get performance. but nitrous is the cheapest and safest on the motor.

phrenology
04-24-2003, 09:46 PM
I have a quick inquiry, sorry if I'm not up on the tech curve with you G3 Accords, but I'm doing the best with what I got. I have a G2 1984 Accord Hatchback LX. I love my car, the body and undercarridge is in excellent shape. I want to give it a new lease on life but I'm working on a shoe string budget. I'm trying to get 120 HP into it. The original motor has 160k miles and only gives a meager 86 rated HP. I'm about ready to rip that ES2 out. I need some advice on an engine swap that will be cheap and require little or no modifications. Will an ES2 manual 5 speed tranny fit with an A20A and will it take the torque? Anyone have torque ratings? This maybe a stupid question but will a B20A DOHC head bolt up to a A20A block? If you know anyone who has done a similar swap with a G2 Accord can you let me know. I need to know engine mount matchups and engine bay clearances for the motors. Whatever motor I swap to I'm using a pair of Weber DCOEs to power it. I only want to have to build one intake manifold for one engine. My biggest concern is that the G2 Accord is about 3" narrow wheel to wheel distance when compared with a G3 Accord. If I switch engines/trannies will I have to get special CV joints to keep the wheels clear? Any help or sugeestions would be much appreciated. Email me with comments: [email protected]

I have an 84 Accord LX Hatchback and I'm planning on going with an A20 engine swap. I have a pair of Weber DCOE 40s to power it, and I'm ready to toss out my ES2 1.8 Cvcc engine. I'm just trying to get the most aftermarket compatible and reasonable to install engine to swap into my ride. I've been told by many that my best bet is an A20. I'm interested to know if anyone has done an A20 swap with a modified head or if it is possible to mount a B20 DOHC head on an A20 block? I'm also concerned that putting too much power on my current stock manual tranny will be too much torque for it to handle. Any suggestions? If I swap transmissions I will have a problem with CV joint distances. The G2 Accord is about 3" more narrow, measured middle tire to tire than the G3 Accords. Help!

Tref_LXI
04-25-2003, 08:17 AM
i dont know about a lot of the questions you asked, but these are the stats for the a20a3 which should fit in your car, 120 hp/122 torque at 3000rpms, so its a very good engine because it reaches its max torque very fast.

Mike's89AccordLX
04-25-2003, 07:26 PM
Um... think you'd be fine with SOHC with dual 40's. I don't think you will gain too much with a head swap but hey I don't know too much about head swaps.

I'm shocked b/c I didn't know that b18's had carbs. I think that's awesome though.

CARBurn
04-25-2003, 09:09 PM
Phydeaux could help you there, he took an 2nd generation Accord hatchback and mounted an 88-89 a20a3 motor with DCOE's. He also helped me with my weber installation on my 87 Accord. He very knowledgeable about the weber conversion in our Accords.

That B20 head on A20 block question has been posed before, I thought the findings were this is not possible, am I right anyone?

If you want to go DOHC, there is always the B18A, it's a dual carburetor and makes 130 hp and 119 ft-lbs of torque, I planning on beginning this swap on in the summer. The only drawback is aftermarket support which I know you are looking for as well, but I am currently attempting to remedy that by trying to contact some import suppliers.

89LXIHATCH
06-09-2003, 06:17 PM
my friend was telling me i could put a prelude 2.0 si head and computer on my car and i im ready to port, polish, and grind my injectors and if i could get this head for my car over working on the stock head from a junkyard cause my head is done but yea would it work or would it not bolt up is the question and do you think their might be any other compliactions thanks.

Jareds 89 LX-i
06-09-2003, 08:36 PM
Well it all depends on which year Prelude you're talking about. If it's 2nd gen Si, then it has the same A20 as our 3geez, but if it's the 3rd gen Si, then it has the DOHC B20. Of course the A20 head would swap cuz it's the same engine, but I doubt the B20 head would be swappable. You never know until you try though... just need a guinea pig!


Originally posted by 3rdGenFanatic
Hey Jared, out of that lineup, which car is yours. I'm looking at those clear corners... o.0
Mine is the completely stock one on the far left. The one with the clear sidemarkers belongs to Rooz (SiR)

3rdGenFanatic
06-09-2003, 11:42 PM
Hey Jared, out of that lineup, which car is yours. I'm looking at those clear corners... o.0

Brettmans5
06-11-2003, 01:42 AM
figure if the prelude DOHC head bolted up to a a20 block there would be a lot of accord running around with that already done :D , but hey it is worth a try, if it works there will be a run on DOHC heads from b20's.

nvrenf
06-17-2003, 08:10 PM
sound kewl any info on a 93-94 del sol single cam vteck head on a a20a

i got a b18c5 head onmy girls civc 18ls block i use nos switch to activate, them both (nos and VTECH)

gofast
07-14-2003, 11:38 AM
guys i'll show more later the two heads pic. is a n a20a head beside an b21a head you can have a b21a head fix to fit an a20a block more soon
heres some more info for you guys to have head welded up it cost me 40.00$ & to shave it ti was 30.00$
the bottom timing gear you have to use is the b20a one i'm having to have it shimmed to fit the a20a crank
i'll post a pic of both heads one welded and one thats not welded
how i did this by placing an a20a headgasket on a b20a head
well the heads im using is a b20a .
im puting it on an a20a and for not much money
im going to use a distributer out of a 1987 integra
i think dose any have any info
perlude
idon t have a com . on line right now . so i use the neighbor 's com
slow BUT REAL!!!! so when i can i do OK. i'm sorry about the spelling
more pic.http://images.cardomain.com/member_img_b/284000-284999/284796_13.jpg
that pic. sucks on car domain the pic can be enlarged
its so much better. i did not use a metal head gasket. i sent the head to the machine shop with a head gasket they welded head
to match more later sorry
IT RUNS !!!!!!!!!!!!! and damm good
my computer has been down
i'll post more pictures tomorrow. the motor is in the car now.
i'll try . i'm having timing belt problems . i can't find one the right size
who will post some picfor me
i ll send them tomorrow some time ok ? please reply
heres a list of parts i used in my motor
block A20A3
head B21A3
intake B21A3
exhaust B21A3
cam s B21A3
camgears B21A3
timing gear on the crank B21A3 ****
distributer B16
cranksensor B16
now . the bottom timing gear needed to be shimed to fit the A20A3 crank
its in my car and running now
ok there they are ill get more later
i like your lude . i have an 87si
the reason for the shim in the bottom timing gear is the a20a crank is smaller in diameter
i have another B20A3 head
it runs good i let a machine shop make the shim.
they used brass
pogi lxi
i spent a whole year or more try to get this motor to work!
just tell me where you live 'i'll drive it right over. while i'm there i'll
anwser all your clutch pedal & cable questions!!!

if you ask any motor builder the head is where the HP. is
if you look at all the engine specification charts in the chiltons
book. the b21 has the most HP for a non v-tec inline 4 honda
the two heads when compared are so close to each other .
why not?
now with my car im still tuning it pulls real hard from 4000 to 7200 . i think that my crank sensor is retarded to much.
i need to thank all you guy here. with out ya' ll iprobably wouldn't
run now
i live right next to bristol drag way . in the spring i ll run at thursday night street fight . i don't think i know of a dyno. around here.
im righting it up now. it will be ready later this week pic. and all
now my car the first timming belt i use broke well it bent every
valve in it . i have another set of valves . ill change them soon
heres some more info.
what needs to be welded up on the B21 head? If you take an A20 head gasket and place it on an B21 head you should be able to see what needs to welded up its not much at all. i have some pic. at cardomain and i still dont know how to get then here.
know lets talk about the thing that i had to do that i didn't think about but i found out as i whent along
there's an oil jet in the a20 and b21 the oil jet in the b21 is level with the block.
the oil jet in the a20 sticks out of block about 1/8" of an inch. the a20 head has a place for it . the b21 head dosen't . the oil jet in the a20 is made of aluminum so i ground it off level with the block.
hey check this out
http://images.cardomain.com/member_image/8/web/284000-284999/284796_14_full.jpg
you guys want more?
timing gear
if you look at the A20 or B21 bottom timing gear you will see that they both have keyway made into them. A20 has smaller crank diameter then the B21. to make the shim they had to remove the keyway notch and then they made the shim out of brass. after the shim was in place they cut a notch through the shim and into the gear. they also gave me some key stock to use.
intake
the intake is B21 so it fit the head.i had to adapt my vac. lines to that intake .if you need help there i just winged it. there's alot of stuff on the B21 intake that MY 86-87 FI. doesn't use ,if you have 88-89 FI it would work better.
lets try some pic
HAHAHA!!!
http://images.cardomain.com/member_images_/8/web/284000-284999/284796_12_full.jpg
http://images.cardomain.com/member_images_/8/web/284000-284999/284796_13_full.jpg
i just don't get it ?????
if it isn't a car i'm a dumbass.
the pic are cardomain . tell me what you need
see i'm a dumbass . i forgot the (at)in the last reply
nx racer
you cant make a link from cardomain.com?
nxracer
my cardomaim user name:cjs1234us
theres alot more on the other pages
nxracer
thank you if you post all of them it would help . and again thank you
i also have a turbo and im going to put boost on it one day.

NXRacer
07-14-2003, 11:39 AM
this has already been tried before and it turned out to be a huge bitch and the project never was finished. I'd be interested in seeing if this actually worked and ran and how much trouble they had to go to to get it to work.
what did you have welded on a head?!?!?!?
DAMN, so does this mean we can have a DOHC motor w/out having to go through the headache of trying to locate a JDM Accord b20a motor?? that would TIGHT. MORE INFO DUDE!
?? not understading ya. are you using a DOHC head on an A20 block? if so, which head? I'm getting conflicing info in the thread.
thanks
Is that the JDM Accord B20a or the prelude b20a?
Either this guy is REALLY excited when he posts his progress or he can't spell worth sh*t.
No offense gofast cause you're doing something that a LOT of people are interested in, but you'll get a lot fewer questions if you take a little time to spell things out somewhat more understandable and put together.
Thanks for the R&D and keep the info coming!!

email me the pics at [email protected] and i'll post em up for ya
are the pictures you're trying to show available on your cardomain site for anybody to see? I dont think i can use the links you provided above. If you have them up on your cardomain site, then i could link them up here, but the ones you have now won't work.
next time PM me that info. I'd edit your post before you have a ton of people logging on to your site and getting you in trouble or something.
here are the pictures it shows the head is on, but that doesnt really show it works and runs.
http://images.cardomain.com/member_images/8/web/284000-284999/284796_5_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_6_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_7_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_10_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_11_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_12_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_13_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_14_full.jpg
http://images.cardomain.com/member_images/8/web/284000-284999/284796_15_full.jpg

I've never noticed a truly significant VTEC change-over except in the H22. That is one hell of an awesome change in sound!!!
Other than that, the H17, nope. Can't even tell when it's in VTEC or not. My friend's B16, nope. My friend's friend's B18C1, nope.

either both motors are bone-ass stock or you're just deaf.
you make some good points, but you gotta realize that theres more into it than just boring out the cylinders so it makes more CI. The ports on the head have to match the passages on the block. If it would be just as easy as boring out the block and slapping any head on it, this wouldnt really be an issue.
Even LS/VTEC's have their problems that make them unreliable. And those are a helluva lot closer then the A20/VTEC head combo.
F23a is OBDII which could cause a problem. It came in the 98-2000 accords and is VTEC.
A better option would probably be the F22a/b head from the earlier accords simply because they're OBD1 and will cause a LOT less headaches then trying to put a VTEC head on our motors.

I think I'll just stick with the complete A20 and just boost the hell out of it. :cool2:
:werd: thats my plan. why go to all the hassle for DOHC? not worth it IMO.

pric
07-14-2003, 12:29 PM
The B21A had a large bore compared to the A20A and much larger than the B20A5. So I would expect that the valves will hit the cylinder wall.

carotman
07-15-2003, 09:08 AM
I know someone that put a B20A3 head on a A18.... it worked but had coolant problems

I posted 1 year ago that someone installed a B20A3 head on an A18A... the problem was the cooling passages and the timing gear location. He said in the other thread the he shimmed the bottom gear... fine, I can beleive that.
However, the distributor and crank sensor are NOT from a B16A... they are from a D16 (Integra 86-87 engine)
The major problem I see with this setup is that you need a custom intake manifold to make it work... or a monster hood
Like sean said, for all the trouble involved, you could use a VTEC head instead... no need for a custom intake with that head since the engine leans in the proper way.
Nice work tough... I wonder if it actually runs.

A20A4...my head sux.. but why the each piston of this engine has four cuts for valves?
That's because of the exhaust valve location isn't at the same place on cylinder #1-2 and #3-4. This way honda can make only 1 model of piston instead of making 2 different pistons for the same engine...
The F23A head isn't bad but I would prefer to have the DOHC F22B head on it. Interesting project tough.
It sure seems to line up properly.
Once the head is bolted to the engine, the rest would be fairly easy.
However, the JDM B20A head would be a better option to mod in my opinion. The intake manifold wouldn't need to be modified to fit in the car since the B20A uses the same mani as the A20A.
The problem is findind a B20A head in North America, which leaves us back to square 1.
With the B20A5/B21 head, you would need to mod the intake mani so it fits inside the enginebay. Just a cut N weld thing.
I would run the PK2 ecu with that setup but the PJ0 could also run it.
For the Manifold, I was refering to the Accord B20A. The Accord B20A will not bolt to the B21A or 88+ Prelude B20A
The A20A has a 82,5mm bore if I remember.

bobafett
07-17-2003, 04:21 PM
hmm this is pretty interesting. if you are using the prelude head then there will be some parts we can buy, this is pretty cool..
youve definetly got my attention

why not just bolt on a k20 head instead, its probably just as feasable.. lol...
fuggitaboutit guys.....
interesting. doesnt seem that close to me... but with enough work, who knows...
what vehicles did the f23a come in ?


good question, i would say for balance or equal compresion. mabie plug clearance?

spark plugs go in the head man, not the block :thumbdn:
lol
b20 spark plugs go into the center, through the valve cover, a20 spark plugs go in through the side, through the head. but they are both in the head. :D

PogiLXI
07-18-2003, 11:22 AM
I think Hes Welded an Metal headgasket on it, The ones people use to lower compression on Turbo Cars. Actualy I have no clue just giving out what I think.
I think the metal head gasket is the only way to go, cause the usual one will just Fall apart if trying to mate To difrent of passages, what do you all think???
I really thing the Metal head Gasket Is the way to go, What do you all think???
What did they Weld?
Bboi, u a Flip? I am, Phillipino. Thus the Pogi, Errr Pheneticly Poogie. heh, but yah.
Gofast! What Language do you speak? this dude must be a joke, Cause A person that cant Type or Spell, Sending a head off to a shop and say Weld, just doesnt add up. I HIGHLY DOUBT this is going to work, and you just spent money on NOTHING, I say BOOOOOOO!!!!! BOOOOO!!!!
88LXI DSM turbo there pritty much interchangable with Everything, only thing I think that has a pripority (I dont know how to spell that word) turbo is Sabb. now if it had DSM BLOCK with VTEC heads, NOW THATS NUTZ! Mitsu should come out with a VTEC type head, Would DEFNENTLY get its Boost in Sales, Turbo VTEC 2.0 From the FACTORY! oh shit, Ill be at the Dealership in a heartbeat. Also Mitsu has that AWD TURBO! honda Cant hang with a Mitsu, It would beat it in so many Catigorys STOCK.
Bah, There the worse though, Trannys Go on them all the time.
Back to the subject, I would Defnently like to do a head swap, if It isnt that Expensive, and its not problematic.
ztec, hahahahahahaha. I hate Fords. Ima Chevy man my self. Im build up a Chevelle 454 Twin Turbo FI, I like Superchargers, but Its been done so many times, Ive searched the internet for Turbo Kits for hotrods, and came up with nothing, I found Alot of Buick GN stuff. I can maybe mate GN stuff to a 454, mostly electronics.
anyway. WHATS GOIN ON WITH THIS HEAD THING!?!?!?!
Gofast Probly hasnt Come back to this thread, cause he Knows that it Doesnt Work!!!!

alright, there is STILL no proof this thing runs, for all we know Its just a head sitting on the block. need better pics, even a VID! gofast keep us updated.

peeps, for all we know, the head is just sitting on the motor, I still wont belive it till I get some better pics, even a Vid. Im hopeing for Gofast to prove me wrong. so Facking do it then!

Rendon LX-i
07-21-2003, 09:29 PM
is there any other head that would fit the stock motor. kinda like a LSVTECH. u know just putting the vtech head on a ls. will i was thinking we could do something like that to. prolly a dum ass questions but tell me what u all think:rolleyes:

so its gonna need serious work. so a b16a vtec head. thats cool

ok i guess that out of the storie and shit. does any one have there motor BORED OUT. if u did tell me what size did u bored it out to

Justin86
07-22-2003, 09:49 AM
. You can put a B16A VTEC head on but it requires some serious work and it is not safe cause some place have to be machined so thin. Things will break.


Originally posted by bobafett
go down to radio shack, and ask for either the 900mhz or the 2.4ghz vtech headSETS, they should have some in stock. i dont know if it will add that much power, but you can get a power inverted and run them off your battery and convert to 120vac. im not sure how you are going to hook up a phone line into it since you are in your car, but i think its worth a shot... but again, im not sure on the horsepower gain of this mod...
Dude then my friend have VTECH in his Dodge van. That thing is pimp.

Sean is the one how tried to put on a B16A head on. I guess if you could get a cast iron head it should be able to withstand all the milling and stil be strong enough, but it would be cheaper to swap a B16A engine.


Originally posted by MoonScryer
OK, I'm going to add to this thread, but don't shoot the messenger. I was at the track last night, and a dude I know told me he knows of a car like mine, yes a 3rd gen, that has the SOHC V-TEC head from a 5th gen on it. I made sure he was talking about mine, and not a 4th gen, and he said yes. He is trying to put me in contact with the guy who has said engine. I don't know if he was giving me shit or not, but I will find out either way.
Now, go away.
Shit that would be cool. I though the VTEC heads were only DOHC. Well talk to this guy and hope for the best.
Well when my brother gets home I will do some measurements on his Accord to see how close the F22 head is to the A20.
But isn't the h22a DOHC. The point was to get a SOHC to have a better match up.

Originally posted by sixgears
Hey JUSTIN86....you have no clue. Sorry, but it's not an issue of strength. Very rarely is there a problem of strength in a head. And, a CAST IRON head....what the hell? The issue with swapping any head to any other block is five different things, others can be worked around easily. Borespacing, water jackets, oil passages(this one is fairly easily covered), bolt pattern and valve clearance. I'm not sure which of these is the issue in Sean's trials, but I will almost guarantee it is one of these.
Well Sean didn't really talk about the other things you mentioned, but I don't think that he would have spnet soo much time on this to have the oil passages not match up. From what he said that it would be a strength issue. Inorder to get everything to match up correct he had to machine the shit out of it. He said that there probably would be a strength issue with it.
I brought up the cast iron head cause they would be stronger then the aluminum. But unless you could get the cast for the head and have some Iron poured in, it is not really possible.
(forestales :))

bboipinoy112
07-23-2003, 06:02 PM
the head to the block ? lol .. this guy is funny .. he needs to explain everything he has/is doing .. CUMMON MAN ! we need a FULL explination . . . like maybe at least . . 8 lines ? haha .. that will be amuzing to all


Originally posted by PogiLXI
Bboi, u a Flip? I am, Phillipino. Thus the Pogi, Errr Pheneticly Poogie. heh, but yah.
yea im filipino .. hence the "PINOY" in my user name .. ;)

sixgears
07-24-2003, 12:06 AM
This is what's going on, from what I can tell. He had the rim of the combustion chamber welded to create a chamber whose edge will line up with the A20 head gasket, therefore also the bore of the A20 block. The head is then milled to create the flat surface it needs to have (welds protrude). Welding is common in 4-cyl oval racing to increase compression. What I can't figure out is that PhydeauX mentioned that the bore on the A20 is in fact larger than the B20's, so why would welding be utilized? GOFAST....first you said it was a B21 head, then said B20, so which is it? More info please.......:)

I'm bumping this back to the top so we can all figure out :wtf: is up here.....this GOFAST guy gives us a little info that could possibly turn 3gee performance around and......laters. What, come on, you just don't do this. Sometimes I wonder about people.....

smufguy
07-24-2003, 06:25 PM
well seems like its likely for someone to get a bashin if he does not respond on time or say somethin clearly. For example im from a third world country for heavens sake and i can make some sense :confused:
well the mixed and matched heads are in the B series category, not a B series head on a A20. so i dont know. Besides steve if u do a search or talk to our moderator Sean and Carotman to name a few, u will know that this project for the A20 has been attempted before.
yo pogi i was about to say what the heck ur talkin about mitsu cars and shit. anywho, like i said if u had been on this board for long, u would know the deal with the head jobs. and not to mention that the bmw 7 series has a variable intake runner length so thats the awsome shit.


Gofast, so technically its not a bolt on. Its something that can be "Made" to work with lots of changes and money spent for what? More than just pictures, i wanna know what good it does performance wise.


Originally posted by gofast
pogi lxi
i spent a whole year or more try to get this motor to work!
just tell me where you live 'i'll drive it right over. while i'm there i'll
anwser all your clutch pedal & cable questions!!!
I believe in your word. It does not mean i stand by it. BUt like i mentioned it before, I wanna know the money u spent on your project and the performance you gained from it. I wanna know how hard it was and the availability of the parts that you used. Cause sure are hell i dont know if i can find a B21 around my junk yard. But u cant escape from the cost/benifit ratio. so I wanna know how big our benifit is and more over the COST. So give us that and pics and/or estimated performance boost just from the head swap (no internal motor work) and it should speak for itself.
That is sick. Purely A fruit of hardwork and you got my respect buddy. You are going on my website pretty soon.
:wave: :super:
I wish you guys made just one thread for this. This topic has taken 3 threads (which are all over the place).
i know starter, i was just saying it would have been much easier to follow up if everything concerning one thing was in one place.
::: echos ::: still waiting for the numbers ...............
hehehe gofast, it was your hardwork man. It does not matter who helped you but you came up with the idea, u looked for parts, u researched it, u went thru with it. Congrats to you and cant wait to see the numbers its running on the dyno and on the strip.

Originally posted by NOAHS88accord
so to do this, i need the b21 head, b21 intake, b21 exhaust, b21 gears, and what else, what do I tell the machine shop, I need a how-to with pictures,
MR. GOFAST, please post what all is needed, what we have the shop do, and any more pictures you have. Also please do a step by step walkthrough of what you did to get it to work please.
heres a list of parts i used in my motor
block A20A3
head B21A3
intake B21A3
exhaust B21A3
cam s B21A3
camgears B21A3
timing gear on the crank B21A3 ****
distributer B16
cranksensor B16
thats all he posted. Have fun finding em.
IS there gonna be a write up on this?? Explaining how everything was put together?? It cant be just a bolt on is it??
How does this B21 head flow compared to our A20. I dont remember it being mentioned.
cool stuff. Its defenitely one mod that im gonna put it on my website with links and pics. Whooohoooooo baby, ::: gets goosebumps ::::

pogi is right. turbo is an easy way and actually pretty cheap way to get performance. but nitrous is the cheapest and safest on the motor.
I highly doubt Nitrous is the safest. Besides, its the cheapest way to make HP but not all the time and yet be legal. For me, performance is being a streetable car with kick ass performance, thats why Sean is #1 in my book right now. If anyone can do that with either a forced Induction or NA i will be appauled. But Nitrous is a no no for me and even tho it makes good hp, and since its not worth it for my motor and money, i would say its a waste of my money. But i know a lot of people on the board run Nitrous, atleast 5 or 6 that i know of, but its just aint my thang. :cool2: :)
The A20 manifold fits on the B20A. Dont try it on any other B series, you are better of using the ones that are made for it. The A20 manifold does not flow as great as the B series.
There are Cars with Dual Carbed DOHC engines. There was a B16 or a B18 or even a Darn B20 that was carbed. I have a picture, but there was speculation that it was not a B20 like i thought it was.
if my memory serves right. there were two F20 versions, The F20 found in the euro Type R accord (Older generatrions) and the F20C from the S2000. They were both Dual Overhead valve design and dont fit on the A20 block.
The F22s and F23s on the other hand were found in the USDM 4g and 5g accords, (6g too?). They wont bolt up either cause they were open decks.
The only head that someone tried to bolt up was a B21 prelude head and they said it was sticking outta the stock hood, and buncha stuff needs to be replaced which is not even worth it.
As far as trying to mate a Vtec head on a A20 block, hit up the search or go thru the FAQ, there were threads couple of years back concerning them. Please do not start another discussion regarding this cause it WONT WORK. people who have tried do no post here, so we, members who know of them, can attest to it and take it for our word. Its just not gonna work. We always try to balance two things, cost and benefit. Choosing wisely will let u know where side of the scale u will be tipping.
yeah i mentioned the open deck for the bore spacing issues. I think our bore spacing is like 90mm center to center of cylinder bores. i am sure the Open Deck motors have greater bore spacing to include the coolant passage.
The B21 lude head was put on a A20 block by one of the guys here, but the hood clearance was bad. Sean was talking about the A20 with a V-tec head, but it was never done.
davke: You need to go to the FAQ section and also the HOW-To section and read all the Sticky threads. Also go to the Performance section and read all the stickies. You seem to have a lot of questions but faint knowledge of what you are talking about. Read them, understand them and probably you will have a better understanding of things.
We need some pics of the A20 gasket on a B20A5 head. Even tho its hard to believe that such a thing is possible, I know aside from the hood Clearance problems, nothing else will be much of a hurdle. The other thing to worry about is the sensors as mentioned, but most probably we can try and use the stock sensors from the lude head and have it work. This is the second thread i am looking at the B20/B21 head mentioned. I wanna know if the Bore spacing is the same as the a20 (which is 90mm i believe). Someone start crackin up the pics man.
i think the hardest part of getting this motor to run is getting the valve timing set right along with the stock crank gear (which determines the TDC for every single piston) and in relation sets the valve timing of when to open and close.
i dont know if the B20A5 used a water pump that ran off the timing belt or not and if it did not, we might be able to use the B20A5 timing belt and the crank gear. I wish i had time to go to the junkyard and compare these things or better, work at a Honda dealership.

88LXiHatchMOdifier
07-25-2003, 11:35 PM
I know some people around here that have mixed an matched heads an stuff. So, yes , it should work. There is some kid from around here, running 11s, with a Civic Hatch. He has a DSM turbo, VTEc heads, etc, etc., lots of motor work, its fast. There is also some other people around here. One girl, she has a 97 or 98 Civic with a Integra head, on a Civic motor, an yes, it works, an yes, its fast as hell(runs high 11s-to low 12s consistently). Maybe this swapping heads idea isn't all that bad. You can pick up a head for any car, really easily, plus, its relatively cheap(depending on where you go).
Peace
Steve

think about this people , ummmm, your block is a 2.0, if you bore it to a 2.2, then sleeve it, then match it to a vtec head with the vtec computer(not bad) , or with a hondata(decently priced) or stand-alone motec unit(expensive), or tec3 system management(expensive) then you would have vtec on a A20a. Its a highly potent engine as it is. It just needs to be modded. If done right you will piss so many people off, and they'll see what you've done , and be like damn, ya know. So, I'm going to do some more research. I'm definitely going to do this. Peace
oh, one more thing i want to add. It pays to do the research. With a hondata computer, a motec computer, or a tec3 system added to control the vtec once set up, it'll actually get the motor pretty much ready for a turbo, cause all those systems are programmable. The vtec computer could be used to, but if you want turbo down the line, it only makes sense to use either a stand alone system, or a hondata system. A Vtec computer could be used, but you'd need to reprogram it. I'm learning as I go, peace.
Sometimes I feel like a moron, lol. I went back ,and read through all that stuff from the beginning of the posts on this topic. Its a good concept, but the only hybrids that I know of that would really work an be consistent are all the B18s with Vtec heads on them, etc. . A good idea though, mentioned, would be a D series head. A friend of mine has a Single Overhead cam turbo, in a Civic, and I think his block is a D-Series, but I'm not sure. The head looks very similar to the A20. However, for right now I think I'll stick with my idea I previously had, which is motor swap. I am probably just going to do a swap, an stay with that idea from now on, the car is coming along, considering that there is more aftermarket backing for newer motors. However, Gude racing makes a lot of mean parts for the 86-89 Accords, if you like N/A power, but mine will be boosted. This car is taking me damn near forever to finish, cause I have too many bills, an two cars that I'm doing stuff to. So, once I get pictures , I'll post them. Peace

pimp86LX
07-25-2003, 11:57 PM
its not worth it. dont even bother trying.

bobafett
07-26-2003, 05:50 PM
Originally posted by Rendon LX-i
u know just putting the vtech head

go down to radio shack, and ask for either the 900mhz or the 2.4ghz vtech headSETS, they should have some in stock. i dont know if it will add that much power, but you can get a power inverted and run them off your battery and convert to 120vac. im not sure how you are going to hook up a phone line into it since you are in your car, but i think its worth a shot... but again, im not sure on the horsepower gain of this mod...

MoonScryer
07-26-2003, 07:14 PM
OK, I'm going to add to this thread, but don't shoot the messenger. I was at the track last night, and a dude I know told me he knows of a car like mine, yes a 3rd gen, that has the SOHC V-TEC head from a 5th gen on it. I made sure he was talking about mine, and not a 4th gen, and he said yes. He is trying to put me in contact with the guy who has said engine. I don't know if he was giving me shit or not, but I will find out either way.

Now, go away.

original2k
07-27-2003, 06:36 AM
Originally posted by PogiLXI
88LXI DSM turbo there pritty much interchangable with Everything, only thing I think that has a pripority (I dont know how to spell that word) turbo is Sabb. now if it had DSM BLOCK with VTEC heads, NOW THATS NUTZ! Mitsu should come out with a VTEC type head, Would DEFNENTLY get its Boost in Sales, Turbo VTEC 2.0 From the FACTORY! oh shit, Ill be at the Dealership in a heartbeat. Also Mitsu has that AWD TURBO! honda Cant hang with a Mitsu, It would beat it in so many Catigorys STOCK.

Bah, There the worse though, Trannys Go on them all the time.


Back to the subject, I would Defnently like to do a head swap, if It isnt that Expensive, and its not problematic.

many other car manufacturers have their own form of variable valve timing man, i don't know much about dsm's at all, but i'm assuming they've touched the subject before, then again, i don't know much about dsm engine :lol, but valve timing isn't something that honda holds true to their own, like bimmers for instance have their own form of "vtec"

NXRacer
07-28-2003, 03:18 PM
Originally posted by Justin86
Shit that would be cool. I though the VTEC heads were only DOHC. Well talk to this guy and hope for the best.
nope. the original Civic Si d16(?) was SOHC as well as the 94-97 Ex motors. I seriously doubt that either d16 or f22 head would fit on our motors. I raise the bullshit flag on this one. It probably has a motor swap if anything.

i've never heard about somebody swapping a vtec head on a 4th gen f22. A 5th gen would swap right in if somebody ever came across one though. But h22 would deffinately be a better choice.

bobafett
07-28-2003, 09:03 PM
d16z6 is the civic EX, sohc vtec engine. :)
d16a6 is the 88-91 civic/crx SI engine, which is the same just with the z6 vtec head. :)

f22 is garbage though right? there was no vtec or easy vtec head swaps for the 4g accord was there? they just put an h22 in and call it a day if they want to cruise~ :)

Chadroper
08-02-2003, 01:04 PM
Would it also be possible to build a head for the A20A3? The VTEC mechanism is only involved with the camshafts, rockerarms, and rocker shafts. It might be possible to build a head that will fit the A20A3 block then bolt the valve train, sprockets, etc from a B16 head to new head.

I just noticed that the bore pitch on the B20A is identical to the A20A. Has anyone tried to see if the B20A's head can be made to fit the A20A?

A B21 is not a B20A.

ill do that its probably cheaper

sixgears
08-06-2003, 12:30 AM
Hey JUSTIN86....you have no clue. Sorry, but it's not an issue of strength. Very rarely is there a problem of strength in a head. And, a CAST IRON head....what the hell? The issue with swapping any head to any other block is five different things, others can be worked around easily. Borespacing, water jackets, oil passages(this one is fairly easily covered), bolt pattern and valve clearance. I'm not sure which of these is the issue in Sean's trials, but I will almost guarantee it is one of these.

markmdz89hatch
12-06-2003, 06:01 AM
not necessarily smuf, I'm just about convinced now that this can be done. KMS out of Georgia looked into doing this, and if I'm not mistaken, he had just about worked out all the quirks. He stopped visiting this site b/c his every work was not only challenged, but attacked, so he saw it as not worth it. If anyone wants to get ahold of him, his name is John, and he owns, KMS Engine Development, his site is www.hondaperformance.com, just hit up the site and go under the contact link to find his number.

Mike's89AccordLX
12-06-2003, 12:28 PM
It's a Prelude motor. I never even thought about adapting my B21A1 head to the A20A1 motor. I just sold it and didn't think. Oh well I think it would be more headaches to mod this head to the Accord than to get a JDM b20a. B/c for one you won't get the same amount of power.

The B21A1 motor had a longer stroke and only came in the 90-91 preludes. The sleeves are really weak on that motor. Most people junk those motors and get a JDM B20 in their preludes.
I just decided to sell the parts off of my 91 prelude and junk the rest. I made more than what I paid for it.
And then I got my 94 prelude so it was all good I guess.
-Mike

Dibbs
12-08-2003, 02:02 PM
Why is it necessary to use the b21a3 timing gear instead of just leaving the A20A3 gear? Just curious...

what issues did you have with getting the header/downpipe to fit, if any?


Originally posted by gofast
pogi lxi
i spent a whole year or more try to get this motor to work!
just tell me where you live 'i'll drive it right over. while i'm there i'll
anwser all your clutch pedal & cable questions!!!
:lol
Try not to get mad at Pogi man. You gotta understand his suspisions for the fact that there's a history of guys trying to put b-series heads on a-series blocks, and either failed or just gave up for reasons of price or lack of practicality or both. Among those in this list is Sean. He's a bit of a hero to most 3geez members for all the work he has done toward the advancement of the A20A engine. If you were to take some time to browse the Project Central section, you would see all the work he has done.
I think most of those who are still skeptical of your project want to be proved wrong. I can't speak for Pogi but I know I feel that way. :D

1988starter
12-08-2003, 05:07 PM
http://www.3geez.com/showthread.php?s=&threadid=20759

http://images.cardomain.com/member_images/4/web/304000-304999/304085_36_full.jpg

http://images.cardomain.com/member_images/4/web/304000-304999/304085_34_full.jpg

http://images.cardomain.com/member_images/4/web/304000-304999/304085_35_full.jpg

Sabz5150
12-08-2003, 06:55 PM
Originally posted by gofast
no where going to customize it
A race manifold that comes straight off the head instead of curving up should cure that.
Not to mention the power increase that it'll give.


Originally posted by PogiLXI
alright, there is STILL no proof this thing runs, for all we know Its just a head sitting on the block. need better pics, even a VID! gofast keep us updated.
Give em a chance, Rome wasn't built in a day.

A20A1
12-08-2003, 06:57 PM
What did you use to shim the lower timing gear? Will it hold up under stress?


if my memory serves right. there were two F20 versions, The F20 found in the euro Type R accord (Older generatrions) and the F20C from the S2000. They were both Dual Overhead valve design and dont fit on the A20 block.
The F22s and F23s on the other hand were found in the USDM 4g and 5g accords, (6g too?). They wont bolt up either cause they were open decks.

Why is open deck a problem?
I just want to know. I was thinking of picking up a used F23 head, or at least gasket. I wonder about the bore diameter & spacing though.

http://i23.photobucket.com/albums/b351/Wendy_girl/A20A3.jpg
http://i23.photobucket.com/albums/b351/Wendy_girl/f23a.jpg
Is it worth a shot?
I figure the oil drains can be plugged from the vertical exit on the F23A Head and tapped horizontally from the side of the head then fed back into the block or oil pan diectly.
What about the cam gear diameter? Can we use the stock F23A gear and get the same camshaft rotation speed? The speed needs to be the same as the A20's to match the piston movement.

interesting. doesnt seem that close to me... but with enough work, who knows...
what vehicles did the f23a come in ?
Accord 1998-2002 ? I think... not sure what trim level, if it's DX EX LX ?

it seems to have an extra dowl in the middle that the a20 dosent have.
You mean the one that is used by the oil jet?
I have the oil jet installed on the A20A Block
I assume it wasn't on the F23A block when they took the pic.
is the base of the f22b the same? What year model and trim did the f22b come in?

is the b21 head vtec?? dohc?? has anyone actually seen this "swap" in person??
http://i23.photobucket.com/albums/b351/Wendy_girl/B21_head.jpg
No idea if it runs.
Nah oil is the big holes along the outer rim... the inner rim is the water holes, normally the water jackets outline the shape of the cylinder.
2"
thats good to know... I'd probably'd figure that out when I layed on the F23 gasket on the A20.

RED LXI
12-09-2003, 09:33 AM
This is awesome A20 DOHC, now I gotta have it, one question though, it seems like we will need to custom make an intake manifold because, at least from the pics, the hood wont be able to close properly.

88LXi68
12-09-2003, 10:29 AM
So if you go A20 Dohc you cant run a hood?

sns_vg
12-09-2003, 12:53 PM
why would you custom your intake when you custom your hood youself with some fuckin saw and fiberlass. also its cheaper even in a shop for a hood than an itake... ummm ok i have some questions......
this is what i think you have done.
you took the head, intake man. and exhaust man. from the b20 engine, but isnt the cylinder diameter on the b20 engine bigger, and therefore the valves will hit the wall of the smaller a20 engine cylinders, if they do not, which year and make did you get the b20 heads from ?
also for the cooland and oil lines, cant you just take the a20 gasket(not metal) spray paint on your cylinder head(the b20 one) with the gasket on, so that now you know how much you need to bore out on the oil and coolant lines. you can just do it with a dremel too.
also for the intake, did it match up nicley ? and which gear are you talkin about ? the one we are suppose to modify ? which one are we doin ?

questions:
for the cooland and oil lines, cant you just take the a20 gasket(not metal) spray paint on your cylinder head(the b20 one) with the gasket on, so that now you know how much you need to bore out on the oil and coolant lines. you can just do it with a dremel too.
also for the intake, did it match up nicley ? and which gear are you talkin about ? the one we are suppose to modify ? which one are we doin ?
[edit]
you are using the b21a engine right ? how do i know which one is b20a and which one is the 21, where is the code(still new to hondas) its between the years 88-91 preludes right? whats difference visually between the 20 and 21?

NOAHS88accord
12-11-2003, 03:12 AM
so to do this, i need the b21 head, b21 intake, b21 exhaust, b21 gears, and what else, what do I tell the machine shop, I need a how-to with pictures,

MR. GOFAST, please post what all is needed, what we have the shop do, and any more pictures you have. Also please do a step by step walkthrough of what you did to get it to work please.

thegreatdane
12-11-2003, 08:38 AM
What about the ECU?

asid_9
01-08-2004, 02:51 PM
wiould the intake manifold off the a20a fit on the b-series head? or do you need the b-series intake? could the a20a intake be modified to fit? If so it would solve the hood clearance problems and "i know it sounds silly" but you could have a dohc carborated motor?

youknowit62300
01-20-2004, 03:37 PM
if you ask me i think the b21 head looks a lot wider then the a20

'A20A3'
01-20-2004, 05:00 PM
I think I'll just stick with the complete A20 and just boost the hell out of it. :cool2:

I agree with you Caleb.
I mean, I see the point if you're trying to build an N/A monster, but, I'm not, so I figure it's too much time, effort, and money spent on what coul've been a built turbo engine.
Plus I like the fact that I have my entire ORIGINAL engine, as opposed to a hybrid, but I guess it's whatever floats your boat.

That's gonna be some hype shit gofast.
Just keep at it. Good work on the home-engineering.

mattalica
01-28-2004, 05:58 PM
I was recently looking through my Chilton's manual for timing specs and noticed that they give info on a DOHC head for both the Accord and the 'lude.However,I can't find info on matching it to my engine or if it's even available.I have no info at all except what's in the manual.Is it worth swapping if it exsists?Where can I find one and so onThanks for any info,Matt

racerx
01-28-2004, 07:22 PM
hmm, i haven't heard much on this topic.
your best bet though would be to get the specs of the B20A head. i dont know if it would match, but it might be worth looking into. of course, i dont know where you're going to find the JDM accord motor...
if you wanted to swap a head for some power, i would recommend swapping with the A18. it came out of the 88 and 89 prelude, non 2.0Si (obviously!!), i believe. it might have been earlier years though.
anyway, that head will raise your compression and should bolt right up.

hope that helps!

*edit* by the way, the A18 head is single cam

ET2
01-31-2004, 03:22 PM
The 86-87 et2 a18 head will bolt up to the a20 block

PhydeauX
01-31-2004, 05:39 PM
If you have the same chiltons book as I do, which I'm going to assume you do since I dont think they made more then one, then its covering all accords and preludes from 84-95. Thats a big span covering alot of modles and engines. The dohc engines in that book are the b20a b21a and h22a, all from preludes. The accord never got a dohc motor in the us market in any of those years. None of those heads swap on and no one yet has been able to find a dohc head that will bolt up to the a20a block.

andy

accordlxi2.0
03-13-2004, 07:26 PM
okay i was searching on our engine valve haed and a dohc valve head (like a prelude or integra). my question is can you just swap a dohc on our engine's?
and will it work for a carb a20?
and can it be from a teg or a lude?

oh shit . . . damn there's goes another idea . . . are you for real i thought this whould bolt on with very lil mod's.

so there's no acura/honda dohc head that would swap with our's without alot of money involved???

shepherd79
03-13-2004, 07:43 PM
it is possible, but you will spend over $1000+ on mashining the head to fit the block.

i am telling you, there are not DOHC heads that will bolt in.
one guy did the swap but ne spend tons of money trying to match the cooling ports. i don't even know if the car worked. he had pictures of it, but i don't think that setup reliable.

there was a guy who swaped 3G lude B20A5 head on A20A block. it took him a lot of work to get it done, he had to port and match every passage in the block with the head. he said it worked finem, but it looked like the cylinder head was on a wrong block.
if you want DOHC engine, i would recomend finding JDM b20A or swap B16 -B18 motor.

smufguy
03-23-2004, 05:12 PM
I know who did it, just cant get his id straight. He used actually the B21 head if im not mistaken, but he had to change a lot of parts and do all kinda crazy shit to it. Do know that if u change your head, u need different headers and manifold (possibily) and finding that B21 block would be fun cause seriously, i have not come across one in the local junkyard i go to. he had to machine off the oil jet on the B21 head to make it fit. or something.

okay found the thread http://www.3geez.com/showthread.php?t=20759&highlight=B21 have fun

Gregg86DX
05-12-2004, 06:11 PM
I hope you mean a B20A5 or B21 head, cuz if you have an Accord B20A head, then you probably have the block too and there is no reason not to use the B20A block unless it is cracked or something.
Anyway, there is a thread around here somewhere about a guy putting a B21 head on an A20 block. He supposedly got it to work, but I never saw a final conclusion. It generally is possible, but required quite a bit of work and would probably not be worth the effort. The A20 Head is not that bad and several folks have been working them over to improve flow (Sean and Openloop).
Gregg


What's a b21? or is that supposed to mean b20a1
A B21 is just a slightly larger bore version of a B20A5. It came in the 90-91 Preludes. It is very similar to the rest of the B20A family of motors.

carotman
05-13-2004, 08:48 PM
Actually the B21A has a larger bore...

train
10-06-2004, 06:50 PM
the b16 head isn't even the same size as an A20. right off the bat you couldn't even bolt it down. it wouldn't come close. on top of that, you'd need to redesign the oil galleys in the b16 head. whoever mentioned throwing in a little concrete to block off the oil galleys that don't line up... hahaha! an engine without oil flow won't be a working one for long. i'd give it about 1000 miles. sorry to say, the moment i read the first post in this thread, i knew it wouldn't work.
now, if the oil gallies lined up half way decent with a d16y8 or d16z6 head, that would be a better possibility. a lot of people shot down this idea, but i think this is a better idea than the b16 head. the A20 and D16 head are relatively the same physical size. yes, the D16 bore diameter is smaller (74.9mm or somethin like that), but the combustion chamber could be ported to more evenly match the A20's bore. combustion chamber diameter and cylinder bore diameter don't have to match up perfectly. this is obvious given that B20/vtec and 2.0L LS/vtec or GSR motors have an 84mm bore and an 81mm combustion chamber diameter. or that some race motors are bored to 86mm with an 81mm combustion chamber diameter. there is still a good amount of aftermarket support for the D16 head, so internals would be easy to come by, and D16 heads are dirt cheap. you can pick them up for 50 bucks. hell, sometimes you can find them free. i'd say the D16 head would be a better choice for an A20/vtec project.
EDIT: i know a block is skinnier than a head, i just thought about this. it might be possible that the bolt holes aren't as far off as i thought. maybe this is more feasible than i thought. afterall, b16 heads have been sold as a kit for B20a blocks. and the B20a block is very similar to the A20a, right?


B16 heads are not sold as kits for B20A blocks. They are for B20B and B20Z blocks.
they're not sold as a kit for B20B or B20Z blocks that i'm aware of. they're just used, but not sold in kit form. but there used to be a guy that sold a B16 head and kit for B20A blocks. he was the only guy to sucessfully and professionally get a B20A vtec going that i know of, and was very popular among 3rd gen prelude owners back in the day. he hasn't done this for several years tho and it was a whole hell of a lot of work. but it was done. i don't know his name either, so i can't provide that info.


his name was Tom.
Mr Ludespeed.
ie, B20A turbo kit.
and i checked today, the D head.... lets just say "no chance in hell"
yeah, that was it. ludespeed.

SteveDX89
10-11-2004, 11:24 AM
EDIT: i know a block is skinnier than a head, i just thought about this. it might be possible that the bolt holes aren't as far off as i thought. maybe this is more feasible than i thought. afterall, b16 heads have been sold as a kit for B20a blocks. and the B20a block is very similar to the A20a, right?
B16 heads are not sold as kits for B20A blocks. They are for B20B and B20Z blocks.


Dont laugh on the SOUND part because ive had many people ask me why
Vtec sounds so loud in my car............. and how they would love to hear that everyday................I dont know!
VTEC is pretty loud on my car too.


H17 is the motor that goes into the new civics
LOL. Funny shit. Try a D17.

That Chadroper dude claimed to have done this although no pics were posted. He claims the setup eats through timing belt and transmissions. Bottom line is it's cheaper to swap the whole B engine than just the head.

night
10-19-2004, 04:25 PM
his name was Tom.
Mr Ludespeed.
ie, B20A turbo kit.
and i checked today, the D head.... lets just say "no chance in hell"

dude, how would it possibly just be ecu :rolleyes:
it could be possible, but i just dont think its worth it.
the head bolts are pretty damn close. head could probly be modified to bolt on depending on the water jackets. but the B has large oil drains towards the corners that would have to be redirected.
and it will still not be that simple. the belt issue. probly gear/teeth count issue (i didnt count, so i dont know for sure) and very likely hood clearance issues. probly mani hood clearance too. ours dip down and come back up. B's more or less slope up from the head (cept with a gsr mani). it would still be a full wiring job as a regular swap.
by the time you did this shit you'd have a rigged ass motor that could hardly be called reliable. especially as most ppl on here have one car and cant even commit to a staight swap.

SlammedAccord89
10-31-2004, 07:46 PM
whats all the problems with the Vtec head, if its just ecu problems, why not run a b18a or b18b head, i put 190hp to the wheels with a LS motor in my crx with mostly stock parts with crower stage 2 cams, if its mostly ecu problems with not being able to engage vtec, trying a LS head would be a thought, mill the head to bump the compression and get stage 3 cams, the torque of the motor would be unreal and it would have the top end to back it up, as far as timing belts go, check with companies that make the belts themselves and see if they could make a custom one, Sean pm me all the problems that your running into and ill see what i come up with, just because the LS heads arent Vtec doesnt mean they dont make power. plus all the bolt patters and everything are the same sooo, all depending on whats your running into a LS head is a good thought

manifold clearance is not a problem, i ran a b18b manifold on my accord at one time, check nmodifiedracing.com they run integra mainfolds on their accord, as far as the wiring, if you know what your doing it wont be as hard as most think, i may have a idea for the teeth count, beeing that i havnt count those on a accord compared to a bseries, im working on the oil b/s right now, using a non-vtec head will save the headache, as soon as progress is made on the swap i will post info, i have a feeling that this will work. I plan on trying everything in my power to get this to work, as far as the only having one car thing, im sorry for that, i work my ass off to be able to afford funding multiple cars, its a trial and error on this swap that will only improve, if i make progress i will post step by step what i did

b8er
11-19-2004, 08:56 PM
alright im farily new to the 3gee's here but this thread defiantly has my attention, first thing i have to say is to the one guy( 'night' i believe), stop being so negative, ever post you've made so far has been no to this or no to that, dont count it out till sombody has tried everything they can,i personaly would like to see this swap done and am willing to help in anyway possible, iv been around cars forever and know what im doing, just new to the accords, who ever is spearheading this get ahold of me [email protected], i wanna get in on this, lets get it kicking

you can swap lude b20 heads? for real? how come i never heard this, i hope your not joking
thats what i thought, thats why i had to ask, i was pretty sure there arent any head swaps but that one post made me ask
o hot damn, im in the middle of pulling a sized motor out of a se-i i just bought, im definatly look into a custom leangth belt, o man am i excited
interesting, interesting, if i can get my hands on a cheap b20 head i think i might try this
i would have to use the b20 intake and exhaust mani's correct?
yup, this is whats getting me so stoked,
so racerx , all the passages are correct between the a20 and b20, do the bores line up correctly?, any other possible problems other then the dizzy and sensores?, how about the thermosate housing, would they match?
please do racerx, that would be awsome, do the head bolt holes line up? also we are talking the lude b20 no the jdm accord b20 right? or do they happen to be almost the same?
ok so theres alot of reading there and i dont have much time, plus im lazy, so will this or will this b20x head on a a20x block not work? i also thought of another problem, im pretty sure the ludes have a major getto slant on the motor, would we run into problems? anyways yea im not sure why you posted a link on DOHC VTEC as far as i know the lude b20 was never VTEC, aha
i gotta say i like you swap file, only 40 posts and your sumin up threads and looking for new mods, way to go, i would love to jump on this and try it see if it will all work but money just got tight so i dont think il be contributing anytime soon
i think the f23 even came in the cb7's (90-93), i know the f22 did and im like 30 percent sertian that the f23 did aswell, but dont count on me, 30% isnt that good, check out www.cb7tuners.com
yea there wouldnt be a problem with the sparkplugs

HondaSi88
11-19-2004, 11:10 PM
i have a few questions...............first what are yall goals with using a vtec head? to get a few extra ponies? better flow? the use of aftermarket parts? just the SOUND?
my point is this i had a b16, own a b17 and in the process of buying a b18c5 head
"just to resale"............since i haven't owned a 3g in almost 2yrs im kinda out of the loop
educate a once 3g lover!

Dont laugh on the SOUND part because ive had many people ask me why
Vtec sounds so loud in my car............. and how they would love to hear that everyday................I dont know!

h17? im guessing b17..........speak for the cars that you've been in! Because my b17 is so loud that i actually thought something was something wrong with the car. My 2 co-workers has a 98lude and a 94 both h22 and mine is def louder. I think no I KNOW
not having an exhaust and just a intake makes a difference.

im still looking for the H17.........D17 and B17 is understandable

racerx
11-21-2004, 04:40 PM
I've never noticed a truly significant VTEC change-over except in the H22. That is one hell of an awesome change in sound!!!
Other than that, the H17, nope. Can't even tell when it's in VTEC or not. My friend's B16, nope. My friend's friend's B18C1, nope.
All that to say, if you want to hear a "real" cross-over, listen to an H22 and stop kidding yourselves. (unless you WERE talking about the H22...)
H17 is the motor that goes into the new civics, and it's gay. Trust me. No power at all. (at least not at 6850 ft above sea level)
Anyway, I was talking about the VTEC crossover sound. In the H22, it's insane how much the sound changes from vroom, to WAAAAAAAAAAH! (deep, throaty WAA, that is).
I'm not saying other engines aren't loud, I'm just saying H22's cross-over is the most noticable in feel and sound, that I've noticed. And I actually have been in and heard all of the engines that I talked about.
My B20A is loud as all hell, especially with the CAI on. It scares little kids, and my exhaust blows chics' skirts up. ...oh wait, I don't have an exhaust... but if I did... :D
But yeah, I know there's a ton of engines out there that make all sorts of noise, but if you want to hear the cross-over, H22 is the best.

Prelude 2G: 85-87 --> B20A (same as 3G accord B20A), A18, A20 (i think?)
Prelude 3G: 88-91 --> B20A, B20A3, B20A5, B20A7, B21A1, B21A
4G: 92-96 F22, H22, H23
oh, btw, I'm gonna be taking the head off of my B21A1 and selling it. I'll tell you all what, I'll put that head on Dan's new short block (A20A1), and I'll see if it can fit.
I'll take pics, don't you worry.
and all the 3G prelude heads are swappable, so if this one fits, they all will.
you can swap your head for a B20A, B20A5, B20A7, B21A1 head.
(3rd gen prelude heads. DOHC)
Yes you can.
I put my B21A1 head on an A20A1 block. (didn't actually use it, just aligned bolt holes, head gasket, etc)
It'll work. You'll just have to deal with getting things like the sensors to all connect right.
It'd be a LOT easier if your car was already EFI
The B20A cams are more aggressive.
Yes, the B20xx (as mentioned above) WILL fit. No one's tried it yet, but I can promise the oil/water/gasket surfaces will mate.
When I put the gasket from a B20A5 on an A20A1, everything looked good. Oil chanels were open between head and block, and the correct spacing was there for water passages.
Yes, this will work. You'll just have to get a custom length timing belt. whoop-dee-do, any parts store can help you with that.
**edit** even the oil control jet was there, in the right place. :)
yeah, that'd be sweet to see. just remember you'll have to deal with all the sensors, plugs, etc. you might want to use the prelude ECU and wiring harness. Not sure though. Things just might connect right.
alright, i'll take a picture of a B20A5 head gasket next to and on top of an A20 head gasket if I must. (i have both)
90-91 prelude Si (not the 2.0Si)
yeah i will, later today probably. I'm finishing up my Prelude B20A rebuild. (I have a 3rd gen prelude, new head, 3-angle, new rings, bearings, etc etc etc)
:D
Watch out, ye of little doubt. You'll be eating your words very soon. (Do I look like the kind of person to go braggin about things like a fake H22 swap or something like that??)

maybe 90-91 prelude is SiR, not Si, Si is 2 litre, not 2.1 :dunno:
no.
88-91: 2.0Si, B20A5, 9.0:1
90-91: 2.0S, B20A3 SOHC 9.1:1
90-91: Si, B21A1, 2.1 liter, 9.4:1, Carbon Fiber Reinforced Sleeves. came ONLY in the 90-91 preludes.)
JDM: 88-91: B20A (what I now have, fully rebuilt with about 27 miles on the motor. :D :D )
A 2.0Si prelude is NOT an Si prelude. Those are 2 completely different cars.
The Si models were the only ones with available ALB (anti lock brakes) and 4WS (4 wheel steering, which is the model I have).
B20A5, B20A7, B20A. pretty much any 3rd gen prelude head.
and I have no idea what this SiR is all about. There was never an SiR 3rd gen prelude.
the JDM models were Si, 2.0Si and Si States. The european/canadian versions were 2.0Si, Si, and 2.0Si Efi or something funky like that. No SiR.
(isn't that just an Accord thing?)
.... well, there's the cost of the swap, engine, transmission, wiring harness, ECU, etc etc etc
(are you talking about swapping it in the prelude or the accord?)
3rd gen prelude's can accept an H22 or H23 without modification too.
uh, well i guess with a few engineers, machinists, mechanical geniuses, and loads of money it's possible.
you'd be better off doing a B16 or B18 swap. H22, no way.
you CAN put a DOHC 3rd gen head on your block.
oh yeah that's true. i didn't think about how the prelude's engine has that gansta slant.
if the B20A's manifold's will work, then the B20A5's and B21A1's will too.
right now, on my prelude, I have B21A1 manifolds on the B20A block. The port and bolt spacing is the same. The difference in the 2 is only the emissions.
the difference in bore of the B21 to the B20 is 2mm. B21 has an 83mm bore, the B20 has an 81mm.
The A20 has an 81mm bore too, if I'm not mistaken, so the A20 gasket would be a perfect match for the B20 head. It's kinda convenient how the A20 pistons are already recessed.
oh well then the B21 would be your best bet.
and you're right about the 82.7mm bore. I forgot about that.
btw, the B21A engine IS an actual engine, so it'd be good if everyone referred to the Si engine as the B21A1 or B21 to avoid confusion.
and, FYI, the B21A came in the JDM 3rd gen Prelude Si States model only. (yes, it was actually called the Si States) Extremely rare engine, extremely rare car.
only the 90 and 91 Si models had the B21A1. as stated before, this is NOT the 2.0Si
correct. Water is the little holes around the cylinder's on both engines.
Coincidentally enough, the oil holes are also in the same place, outer rim, so there'd be no modification necesarry.
Also, the B20 and B21 engines DID have a water pump run off the timing belt, unlike the A20.
However, all of this is completely useless information since the bending and routing of the belts would set off the length anyway.
What's going to be important is that the crank gear has exactly 1/4 as many teeth as the cam gears, which it should. however, if it does not, you'll need 2 A20 cam gears on the cam shafts. not a problem either way. and again, that could affect the timing belt length.
finally, someone who realizes B16's aren't all they're cut out to be, for heavier cars anyway.
H22's drop into 3G preludes with new mounts, which aren't made anymore, but you can always fab them yourself. that's beside the point though.
I don't think the accord and the lude's engine bay sizes are any different actually. if they are, it's only by half an inch or something... i could be wrong though.
i'm gonna take a picture of an A20 gasket on a B21A1 block. that should help sort things out a little more.
awesome! where are you located? maybe someone can donate a spare A20 short block for the project.

gsus
12-29-2004, 11:59 AM
im just wondering if it would be easy to swap the b20 head onto the a20 bottom or any dohc head for that matter:idea:? if so what kind of work would be required?

adams86lxi
12-29-2004, 12:03 PM
anything is possible with the right time and money! I wouldnt waste my time or money! Someone on here did swap a dohc head on a a20 but thats the only time i have ever heard of someone doing it. Its not worth it. Just swap or turbo it.

Doward
12-29-2004, 03:50 PM
I'm currently looking into the B20 from the '88-'91 Prelude motors... looks like it'll bolt up, but I gotta see what needs to be done about oil/coolant passages.

RobT5580
12-29-2004, 04:21 PM
Doward the prelude B20A from that year wont bolt up and has a hydraulic tranny. There is a JDM Accord B20A if you read these forums you can find the differences. It is a bolt in engine and fits the 2nd gen prelude also.

buds302
12-29-2004, 05:15 PM
yea someone tried it and said it ran but all we sw were pictures! nobodys heard it run or seen it in person! so we ruled it not running. we know what people can do with photoshop!

Accordtheory
01-10-2005, 05:20 PM
I had the same exact question. I will be looking into this at some point, although that would necessitate me building a new turbo header, quite the pain in the ass

a20a1, that whole thread was about a vtec b series head swap. ..which I'm not considering. has anyone actually set the a series head down next to the prelude head and visualized what would have to be done to make this work?

phrenology
01-10-2005, 06:18 PM
I'm currently looking into the B20 from the '88-'91 Prelude motors... looks like it'll bolt up, but I gotta see what needs to be done about oil/coolant passages.

I looked into this before doing my initial rebuild too. It is not really possible, look at the head gaskets from an A20A3 motor and the B20A5 from the 88-91 ludes. They don't match up, you can see for yourself go to Advanced Auto parts online and download the gasket images. I tried to convince my engineering friend whos been working on my project car. It really would be nice but I think if you're going to throw money at the issue than look for the elusive B20A from the JDM Accords, I saw one on ebay last week. I think I'll agree with everyone's sound advice to look for another swap either B16, B18, or JDM B20. The DOHC heads from early B18 tegs won't work either for a head swap. Side note there is a B20A3 from the 88 4w steering lude but its not DOHC despite being a B series. I saw it at the junkyard yesterday.

stickboy28210
01-20-2005, 11:32 PM
Proud owner of a '86 LXi here. Wanted to know if anyone knew if it were possible (and how hard it would be if it is possible) to swap a SOHC head for a DOHC head. Thanks for all the great info you guys leave on this site, this place is the greatest for exorcising the gremlins out of my baby.

A20A3inside
05-08-2005, 10:01 AM
OK, I have another A20A3 that i am trying to mod out. i already started a thread looking for some suggestions on best options for the rebuild. as soon as i can get ahold of a few different heads, i can check out the possibilities. the only problem is that here in NC especially around fort bragg, there are NO, i repeat NO heads to be found. the only thing that you can find in relation to import engines is eclipse gst and talon tsi engines. dirt cheap too. but as for the b, d, h, and f series engines, there are none. so anyone know where i can get a few heads...let me know

mouchyn
05-08-2005, 12:11 PM
OK, I have another A20A3 that i am trying to mod out. i already started a thread looking for some suggestions on best options for the rebuild. as soon as i can get ahold of a few different heads, i can check out the possibilities. the only problem is that here in NC especially around fort bragg, there are NO, i repeat NO heads to be found. the only thing that you can find in relation to import engines is eclipse gst and talon tsi engines. dirt cheap too. but as for the b, d, h, and f series engines, there are none. so anyone know where i can get a few heads...let me know

www.google.com

www.ebay.com

www.honda-tech.com

www.honda-acura.net

spanky
07-17-2005, 09:50 AM
hi, im new to my accord and any jdm cars. all i had so far was a EDM and domestics. ive been looking all over the forum and i didnt see any thing on switching a cylinder head for a diff honda/acura to put on mine. what i was thinking of doing if it's possible is putting a DOHC prelude engine gold or black top. Is this possible or not. also if it is i know i'll need a larger serpentine belt.were any of the dohc ludes carb? i think there were but again im not sure.

Ichiban
08-10-2005, 07:34 PM
why not adapt vtec components to an a20 head?
the vtec system is dirt simple, it just switches between 2 camshaft profiles depending on rpm. im sure even a 3 valve head would benefit from that.

oil feed is simple, tap into a gallery and use a solenoid control valve. the hard part is making a cam with 3 lobes fit. I m not sure but the lost motion rocker could be made to fit the intake rocker shaft somehow? the vtec oil feed is through the rocker shaft is it not? might be worth looking into perhaps

P|eszczoH
08-11-2005, 05:20 AM
I know that all of You can call me stupid,
but did anyone try to match our A20A block to the F20A head ?

it was SOHC also l but 16 valves, a little benefit from that i suppose.
and I'm not sure but there where some F engines sohc vtec i think.

I did not try this, and I have no idea that would it fit....
but F series engine looks more like A20 than any B series motor.

Doward
08-12-2005, 09:25 PM
So what happened with the Prelude SI B20a head on the A20 block? The bolt pattern is the same.

Correct, 3G Prelude head. If you're selling the head, let me know - I'd be interested in it. I matched up the head gaskets - looks like it'll bolt down fine - it's a matter of where the water/oil goes.

halxi
08-12-2005, 10:28 PM
What year doward?

if its a 86-93 (i think thats the end of the 3rd gen, 93) its not vtec. Thus canceling out the "a20 dohc vtec"

NotSeen2000
09-23-2005, 06:08 PM
i know this may seem stupid :slap: but r there ne frankinstien swaps i can do wit my A20? its fuel injected and its n an LXi. is there like a head swap i can do with like a B20 or another DOHC motor?

so head swap is out. i dont hav the money 4 a b16, b16, or b20 swap. i would like 2 put a turbo on my A20 but 4 right now what could i do just 2 raise the HP enough 2 b satisfied wit. by satisfied i mean, b on the street and b able 2 at least HANG wit a modded civic(I/H/E and other little things) or CRX, or CB7(90-93 accord)?

nice advise man. somethhin i needed. i got a good enough job its the time im worried about. i can stand watin and probaly my problem. lol. but i might b sellin it ne way.but ne other suggestions on HP and TQ gains would b appreciated

lol. good point. id rather hav I/H/E on my car than get the crap beat out of me by a a20 wit N2O on it. I/H/E it is then. custom exhuast though b/c i dont like pacesetters exhuast looks 2 stock. ill get the headers though

the muffler on the pacesetters exhuast system looks like a stock muffler. i kno its rice but id rather hav the muffler from APEXi or HKS or somethin like that. looks better 2 me

Swap_File
09-23-2005, 06:33 PM
I do not think any other heads fit on the A20, people have tried.

B series intake manifolds can be used with the A20, 2 of the bolt holes line up, but the other two need to be drilled (not a big deal).

bobafett
09-23-2005, 07:08 PM
yeah b series intake will work, and a18 head, if u felt so inclined, but i think that head is really the same as the a20 head... :(
your best bet would be custom b-series swap, or just work over your a20

yaeh its definetly nothing that is worth pursuing! ;-)

if you dont have money man, dont put yourself in a financial burden trying to mod your car.... seriously.. :( nothing wrong with having a slow car or a stock car... plus if u dont have money for these things, i know you dont have money for the tickets you get from racing cars on the street.

just take it easy until u have some cash saved up , get a better job, or whatever needs to happen so that u have some disposable income. :)

yeah ihe will help a lot, but its stlil not anywhere near swap power.. :( but its a start, and its what most people do... good mods for the money!

masterkillalw
09-24-2005, 06:35 AM
a18 head would have to be bored out to 2.0L...and a18 head would hurt more then help...

phrenology
09-24-2005, 10:37 AM
and a18 head would hurt more then help...

Not According to Rjudgey...ask him and do yourslef a favor...and search!!! :idea:

lostforawhile
09-24-2005, 10:55 AM
if you are going to go through that much trouble,why not swap a better fuel system onto the existing head? i mean bigger injectors and a different control system,you would have to swap more sensors and stuff but it could be done. if you get more fuel and air flow into the head you would be better off. i think the efi did has the top dead sensor and cyl position sensor in it these could be adapted to a different control system.

3G Jester
10-17-2005, 05:26 PM
which one? h0ndavtec? the kid from mass with that turquose franken-hatch?

the more i look at those pics i relize it was photochopped.

Electronic Fuel Injection not carburated.
but he has an Ex so hes not in america and it should be the equivalent to a USDM SE-i. which means hes fuel injected. and if your not in america...for example the b20 here doesnt fit in the engine bay as does the JDM b20...so would the heads differ greatly? or could he still do a b series head swap?
where you at davke? your english is actualy very good. we have a member in russia (paul) and the translating program he uses is not so good...and his english is even worse. but hes a good kid. we like him any way hahaha.
accords. you might want to talk to some of the boys in australia, malyasia or even the guy we have in japan. they migt be able to score you some parts that would work. us US boys wouldnt be much help at getting you the parts you would need.
here are threads started by people who might be able to help you:
england with a20a4: http://www.3geez.com/showthread.php?t=46382
chris in japan: http://www.3geez.com/showthread.php?t=46906
NZ http://www.3geez.com/showthread.php?t=47631
australia http://www.3geez.com/member.php?u=131
rehv from estonia but he hasnt be on in ages...you could try and use MSN messanger to get a hold of him http://www.3geez.com/showthread.php?t=36500

gfrg88
10-17-2005, 08:39 PM
is the b21 head vtec?? dohc?? has anyone actually seen this "swap" in person??

umm, which car came with a b21a1??
holy shit!! and this is the DOHC head right?? i might have to look into this pretty soon....
i think the h22/f22 exhaust manifold porta i think are the same for the jdm b20, atleast thats the turbo mani (h22) that adam has in his b20 :dunno:

FyreDaug
10-19-2005, 10:17 AM
I/h/e?

Nitrous is good power, you get about 10-15 from a full IHE when done properly, typical shots start at about 50. So putting 400 bucks into a full intake/header/exhaust isnt as beneficial as spraying. A system could cost you about the same 400 bucks, and nitrous isnt that expensive anyways. On a 50 shot you shouldnt go through it that fast. Get a 10lb bottle and youll be fine. With a stock a20 you got about 115hp, b20 obviously have more, rev easier and are a better motor to work with, but spend 2grand on a swap to be beaten by a juiced a20 isnt justifyable. Since your EFI, its much easier.
EDIT: And you can spray stock

Looks too stock? What?
http://memimage.cardomain.net/member_images/4/web/808000-808999/808617_33_full.jpg

On a side note: Someone should replace the rings on those pistons, that doesnt look too healthy.
(Now me and the mad scientist godda rip apart the block and replace the PISTON rings ya fried)

86hatch
10-19-2005, 11:39 AM
After I/h/e do some research on nitrous. I have a zex dry system on my 86 hatch and I love it. I can beat ls, b16 hatches all day long and bad too. I have a friend with a b16 in a eg coupe with toda spec A cams I/h/e and high comp head gasket. I can beat him by about 3 cars. Although I am building a 400hp b16 for nitrous to swap in my accord.

davke
10-25-2005, 11:38 PM
i have soch 2.0i ex 12V engine. it is possible to put the cilinder head with 16V from B series engines?

A20A4...my head sux.. but why the each piston of this engine has four cuts for valves?


Yes you can.
I put my B21A1 head on an A20A1 block. (didn't actually use it, just aligned bolt holes, head gasket, etc)
It'll work. You'll just have to deal with getting things like the sensors to all connect right.
It'd be a LOT easier if your car was already EFI
whats EFI? , anyway 2.0 i ex A20A4 engine, my head isn't good enough - the oil is coming out always from the head. i am going to change the head and also wondering or will 16V doch fit on my block?
so, racerx , does the only B21A1 from prelude 90-91 fit on my block?
ps : i am terrible at english, i hope you will understand :)
yes, its fuel injection - 90kW. I NEED MORE!!
i live in Lithuania :). The most bad thing in the east europe is RUSTING. 99% accords (86-89) are allready rusted :( and it is hard to find a good accord or performance parts.
anyway, i need more power :)! so i need b21a1 head (Si)?? but i haven't seen anything about prelude 2.1Si :((

90-91 prelude Si (not the 2.0Si)
maybe 90-91 prelude is SiR, not Si, Si is 2 litre, not 2.1 :dunno:
the head from B20A5?? would it fitt on a20 block???
mm, i dont know really, but i saw this http://hp3.lt/content.php?content.5.
anyway i need 16V, dohc. what head would fit on A20 block except B21A1? i can't get B21A1 head here.
in the accord! fuck damn, i got flustered totaly, i don't know what me to do.
v-tec? is it possible?
3rd gen of accords and prelude or only accords? anyway thanks

snoopyloopy
10-26-2005, 12:01 AM
is that the a20 engine you're talking about or the f22? well, doesn't really matter because it won't work for either one. you can frankenstein an f22 with an h22/h23 head, though.

so you i can go out and pick up a b20a5 head and bolt that on my a20a3?

go look. not really that much reading. there's speculation as to cooling issues, which heads work because of the different bores. one of the fellows says he used a b20a gear on the a20 crank, but it has to be shimmed. and pictures show that you have to either mod your hood or run with no hood at all.

snow_man_20
10-26-2005, 04:19 AM
good question, i would say for balance or equal compresion. mabie plug clearance?

rjudgey
11-03-2005, 10:30 AM
Ultimate piston would b custom with two left handed and two right handed sut outs to maximise the CR ratio without having to have such a high rasied section on top of the piston, but as you said maybe a balance issue but would have shout unlikely as the inlet valve cut outs are smaller than exhuast but the difference is very small maybe not enough to efect motion of piston. Cost of manufacturing on this one i think!!

accord_rcr
11-04-2005, 09:02 AM
i need, to know. can i swap out just my a20 head with a b20b head? is it a direct bolt on?

Legend_master
11-04-2005, 09:59 AM
i need, to know. can i swap out just my a20 head with a b20b head? is it a direct bolt on?
no

so you i can go out and pick up a b20a5 head and bolt that on my a20a3?
if this were true I think alot of people would have doen thsi already. Also what timeing belt would you use?


go look. not really that much reading. there's speculation as to cooling issues, which heads work because of the different bores. one of the fellows says he used a b20a gear on the a20 crank, but it has to be shimmed. and pictures show that you have to either mod your hood or run with no hood at all.
I think the dowls need to be relocated for the oil. From what I can understand he had to have the head machined just as I did to make my Vtec head fit on the LS block. The thread is kinda hard to fallow with all the opinions and the fact that the guy can't speak english very well.

Not to sidetrack the thread too much, but I thought for putting a VTEC head on LS engine you could just drill a hole and tap it for an oil feed line?
Edit: Like this http://www.sportcompactcarweb.com/tech/0411scc_hybrid/
yes but you have to tap a spot in the block for the GSR dowls to fit into the LS block then get the golden eagle head gasket. I am running the factory LS head-gasket(well actually comsetic 2 layer .20 bore headgasket but you get the idea), and all I have to do is tap a spot in the head and run it to the oil sandwitch on the block.
it seems to have an extra dowl in the middle that the a20 dosent have.
I wouldent be so worried abotu DOHC, I would try and find a SOHC vtec head that might fit on these blocks. I mean if you look at the bottem of the d16 vtec head they are very similer to ours. There are also F-series SOHC Vtec heads. With the added valve per cylinder and vtec we could pull some good HP # from our cars.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4588245570&indexURL=2#ebayphotohosting
according to This (http://cgi.ebay.com/ebaymotors/HONDA-2-3-ACCORD-F23A1-VTEC-REBUILT-CYLINDER-HEAD-98-01_W0QQitemZ8011353868QQcategoryZ33617QQrdZ1QQcmdZ ViewItem)the f23 is vtec and comes from the 98-00 odyssey.

ok i possibly missed this and will go look again but if somebody got this to really work what do you do with the spark plug holes? our plugs go in the side of the block but the B20 head has the plugs in the head its self sooo what do we do with the holes in the side of the block? :sad2:
I was thinking that myself, but when I pulled my head and put the new one on yesterday I noticed the plugs were in the head. This means that they would still work if you had them comeing down from the top.
I just tried a b18a head gasket and the bore was the exact same as the accord, but the head bolts and oil channels don't match up with the accords. So look away from any B18, B16, B17, B20. I think we will have to look at the F, H, D series motors.

We were talking about using the Prelude B20A/B21A head, It is different than the B20B and B20Z, B18, B16, B17.
From wikipedia : "Partially unrelated to the Honda B-series engines are the B20A and B21A. By some, these are not considered to be part of the B-series group of engines because they are not compatible with any of the other B-series parts or chassis. " http://en.wikipedia.org/wiki/Honda_B20A_engine
The Prelude B20A/B21A (and Accord B20A) shares alot more with the A20 series than with the "normal" B series.
I know all that, I was just letting you guy know.

F23a is OBDII which could cause a problem. It came in the 98-2000 accords and is VTEC.
A better option would probably be the F22a/b head from the earlier accords simply because they're OBD1 and will cause a LOT less headaches then trying to put a VTEC head on our motors.
You can change the Distributor and the Ecu and make it OBD-1

I just got back from the Northern U-Pull-R-Parts, they had one 1990 Prelude with a B20 or B21, but the head was gone. I will hopefully check out the Southern one next week.
After I looked at this Prelude, I got to thinking... Anyone know the easiest way to identify what Preludes have a B21A1? Junkyard cars can be pretty stripped...
The block code is your best method, but I think that motor was available in the SI model :dunno: .

HondaBoy
11-04-2005, 01:26 PM
i think the problem was completely because of the positioning of the cylinders, and the positions of the oil and water passages. no, not happening. or else yeah, me and everyone else with access to junk yard's would have a prelude head.

hey, if thats all true, i want in on it! i was just remembering stuff said before a few years back when someone asked this kind of question. i'd go for a custom lenth belt. i'm sure you could more or less use the stock prelude T belt, but use a different tensioner or modify one to work. i dunno, maybe we ought to look into it all?

adams86lxi
11-06-2005, 12:43 AM
if this was true then i would be buying a20 head gaskets. I am almost 100$ postive they way different and the problem isnt just the timming belt, otherwise tons of people would have this. But try it and find out.

Anyway. yes the h22 exhaust manifold works but its pretty far off and needs some modifying to fit. But the b20a5 is basically the same...

Swap_File
11-06-2005, 05:13 PM
I did see this post:

http://3geez.com/showpost.php?p=556444&postcount=120

Hood clearance wouldn't be that hard to fix :chainsaw:

Here's to hoping it works :beer:

I found more, still reading:
http://3geez.com/showthread.php?t=20759

Pictures:
http://www.3geez.com/showthread.php?s=&postid=320117

Edit: I guess the person who did it never had video of it running, and people assumed it could have been faked by just setting a different head on. Other people also said there was too much work involved for too little gain. I still wouldn't mind looking into it since the DOHC VTEC head idea did not work out. ( see here: http://www.3geez.com/showthread.php?t=13223 )

Edit AGAIN: This is why the DOHC VTEC project was scrapped: http://www.3geez.com/showpost.php?p=228741&postcount=58


I think the dowls need to be relocated for the oil. From what I can understand he had to have the head machined just as I did to make my Vtec head fit on the LS block. The thread is kinda hard to fallow with all the opinions and the fact that the guy can't speak english very well.

know lets talk about the thing that i had to do that i didn't think about but i found out as i whent along
there's an oil jet in the a20 and b21 the oil jet in the b21 is level with the block.
the oil jet in the a20 sticks out of block about 1/8" of an inch. the a20 head has a place for it . the b21 head dosen't . the oil jet in the a20 is made of aluminum so i ground it off level with the block."
Not to sidetrack the thread too much, but I thought for putting a VTEC head on LS engine you could just drill a hole and tap it for an oil feed line?
Edit: Like this http://www.sportcompactcarweb.com/tech/0411scc_hybrid/

This is a quick summary of the other threads for people who do not want to read it all:

1. Put the A20 headgasket on the B20 head see where something doesn't line up, and weld some stuff shut (unsure of what or how much) and get the head shaved (because of the welding).

2. Grind off the oil jet on the A20.

3. Have a shim made for the B20 crank timing gear to work on the A20.


if you look at the A20 or B21 bottom timing gear you will see that they both have keyway made into them. A20 has smaller crank diameter then the B21. to make the shim they had to remove the keyway notch and then they made the shim out of brass. after the shim was in place they cut a notch through the shim and into the gear. they also gave me some key stock to use.

4. Get a different intake, or bigger hood to make it fit.

5. These parts were used:


heres a list of parts i used in my motor
block A20A3
head B21A3
intake B21A3
exhaust B21A3
cam s B21A3
camgears B21A3
timing gear on the crank B21A3
distributer B16
cranksensor B16

So there is an ECU upgrade involved too it seems. I did check on preludepower and it seems the B16 distributor will work with the B20/B21 as long as you have a Integra/Civic ECU setup.

And we still do not know for sure if it all worked in the end.

I believe the A20 and Prelude B20/B21 intake manifold are interchangeable, so that should mean that the Prelude B20/B21 could take any B series intake with only slight modification (B16, B18, B20, aftermarket, etc). Maybe one would be low enough to not require major hood modification.

Edit: After reading up on preludepower and looking at some pictures, I see that the Prelude B20A has very different exhaust manifold spacing than the A20. The Prelude B20/B21 also has a slightly different bolt pattern than the Accord B20A. According to people on preludepower, a DSM or H22 manifold can be modified for use with the prelude B20/B21.

I will definately keep an eye out for these parts in the junkyard, but I do not see this as being a quick or easy project.

Edit: Adjustable cam gears are also easily available for the Prelude B20/B21 head, if you need/want them.

B16KILLA
11-09-2005, 01:23 AM
If you live in lithuania why dont you just swap a DOHC VTEC in it. No smog tests right??

Wuts the redline on that motor? Can you tell us atleast sum ballpark numbers on horsepower.Have you raced it yet?:bowrofl:

baby D
11-17-2005, 05:01 PM
i think the hardest part of getting this motor to run is getting the valve timing set right along with the stock crank gear (which determines the TDC for every single piston) and in relation sets the valve timing of when to open and close.
i dont know if the B20A5 used a water pump that ran off the timing belt or not and if it did not, we might be able to use the B20A5 timing belt and the crank gear. I wish i had time to go to the junkyard and compare these things or better, work at a Honda dealership.
check this out my dad tought me this and if im right you guys are on to something sweeeeeeeeet!!!!:bowrofl:


check this out my dad tought me this and if im right you guys are on to something sweeeeeeeeet!!!!:bowrofl:
look at these pics, and read the tabs if im right the most you will have to do is modify the gasket so that the oil and water flow the same, if there is no prob. then it will run, also see if you can use the timing sensors off of the b21, if you can and the cam timing matches the crank, you guys will have found the most usefull trick in the performence section, b ecouse the fact that it will breath the way the engin wants, but it would also make a turbo produce more ponies(horse power). so if you can please tell me and ill see if it runs, also can you find me more pics and email them and ill see if i cant ad to the knoledge you guys have found.:bowrofl: :rockon: but if you say that im right on the pic, then ill try it.http://img123.imageshack.us/img123/5364/works2kw.jpg




correct. Water is the little holes around the cylinder's on both engines.
Coincidentally enough, the oil holes are also in the same place, outer rim, so there'd be no modification necesarry.
Also, the B20 and B21 engines DID have a water pump run off the timing belt, unlike the A20.
However, all of this is completely useless information since the bending and routing of the belts would set off the length anyway.
What's going to be important is that the crank gear has exactly 1/4 as many teeth as the cam gears, which it should. however, if it does not, you'll need 2 A20 cam gears on the cam shafts. not a problem either way. and again, that could affect the timing belt length.
im on it ill talk to some friends of mine around here that do custom engines, maybe with the right set up we can tell people what they need for a 'kit':uh: but hopefully it will work, im always into trying, if i could do this i know of an 86 crx in need of horsepower, pulling thirteens stock.:rice: any way thanks.

Kabuki
11-21-2005, 10:43 PM
Well, I've been thinking about this from the 3G Prelude end of things. I have an extra head that came out of an Si, and was looking at what I could do with it. After poking around the shop holding the head gasket up to different blocks and heads, I ran across the B20A/21 Head & A20 block combo. Someone recently posted about attempting it on PreludePower.com, and said there was a conversation here.
First thing, I measured the A20 cam gears, and we will not be able to use two one the head. They are just too big. You can't use the B20 crank gear, because the shaft snout is smaller on the A20. I'm looking in to some others though, and hope to have this worked out soon. I suppose, though, that in the worst case, we'd just have a crank gear made or modified at a machine shop.
The type of engine build will very much depend upon which head is used. The B20A heads are designed for an 81mm bore, so the combustion chamber will actually be smaller, and better for a high compression, Naturally Aspirated build. The B21 head is designed for an 83mm bore, and thus will be a much better match for a turbo application. The B21 is what I plan on using.
As for the timing belt issue, I will be happy to help. But I need an A20 block to mock up and measure. I have access to whatever length of belt I need to try on.

Whoa... All SORTS of misinformation here.
The F and H engines are MUCH larger than the B and A series. The Pistons on the F20/22 engines are 85mm. The Bore on the F23 (98-2002 Accords, 98-99 2.3CL, and 98 Odyssey) is 86mm. The bore on the H23 and H22 are both 87mm. The F and H engines are a good 2 inches longer than the A20/B20, and there is NO way to make it work. The F22B1 and F23A1 are nearly identical. Same VTEC head design, but the F23 has a slightly larger bore, that's all. All of the H and F series heads and blocks have the same piston centering/positions, and the same bolt pattern. The oil galleries are a little larger on the H blocks, but that's pretty much it.
Sorry guys, but this one just can't work. I'm all for the B20A/A20A hybrid though... :)
Tidbits:
The JDM A18 has an 81mm bore too. Same for the 84-5 Accord engine (sorry, don't remember the US engine code on those).
We at Prelude Power have found that the later model B16 intake manifolds have the same port spacing as the B20A5/B21 units, and don't have the gangster lean to them.
Swap_File: Careful, the junkyard website may be referring to the B20A3 head, which is for the SOHC Dual-Carb unit. Which is a huge pain in the ass, and not worth your time.
Oh, jeez guys... B16s are only good for Civics and CR-Xs... The suck donkey balls in a 3G Accord or Prelude, because of the lack of torque. The B18/20B is better, but... There IS more space in a 3G Accord engine bay than the 3G Lude, and YES there are a few people who are running H22As in their 3G Ludes. It should work okay, and the weght difference changing from an Iron block to an Aluminum block will pretty much negate the additional engine size.

The junkyard's website just lists generic prices for all items, its $38 for any head you can find in their yard. And I did not find one. :(
Damn... May just have you find a bunch of heads and ship them! Haha... Well, good luck!
Okay, first... What the hell happened? There were three different threads that have apparently been converged in to this one? No I look stupid because I have three different posts in a row, that all refer to different parent posts... Ack...
I'm in Salem, Oregon. I run the front desk at the family Honda and Acura Service and Repair shop, Valley Specialists. I also order and distribute the parts, so if anyone needs anything, let me know. Memebers to any forum I frequent get at least 10% off of Honda list price, usually including shipping. Sometimes substantially lower prices than that.
Now I regret letting the techs toss the A20 engine core we had last year... Oh well... It WAS pretty bad, though.
Yeah... Shipping from minnesota would be a bit high... I may have one I can acquire... It's sitting in an '86 Accord that was brought in and left. The guy hit something, which broke the radiator, so it leaked all of the coolant out, and blew the head gasket on an engine we rebuilt less than a year ago. Dumbass...

A20A1
11-24-2005, 01:21 AM
Now there are 12 or so different threads converged here.

I titled the thread differently since all posts basicly cover available head swaps.

If it looks like your post is missing it isn't. I was trying to get all the images on the first two pages along with the posts... but with 12 threads to work with, it was too much. For those that quoted messages in their reposnses or made good replies, the merging of posts didn't do much harm.

Swap_File
11-25-2005, 12:20 PM
The 90-91 Preludes with B21 engines are OBD1, but their sensors and distributor do not work well with the Civic/Integra ECUs that are used with Hondata/Uberdata/Chrome.

This is what I found on PreludePower about the distributor/sensor upgrades that are needed to run a B21/B20 with a Civic/Integra OBD1 ECU (which we need to do for the head swap):


I'm using A P75 (LS) computer with Uberdata. The P75 doesn't like the [stock] B21 distributor. For one, the rotors are out of phase between the two distributors. And second, the tdc, cyl, and ckp sensors have different resistances. I measured my B21 sensors at about 1k ohms and the LS sensors at 250 ohms.

When I checked my ignition timing with the P75 and B21 distributor it was way off. It was impossible to set the timing near 15 BTDC. Probably because the rotors are out of phase.

It's been said that the LS distributor won't fit in the B21, but it will. Just installed 95 LS distributor in my B21 yesterday along with LS cams. What you need to do to make it fit is get a distributor end cam cap from a LS and switch it with the stock cap. Haven't been able to tune it yet (Uberdata) but I'll give my impressions after I do. Also removed the stock cyl sensor and replaced it with LS plug.

This should also work with stock B21 cams installed.

http://www.preludepower.com/forums/showthread.php?t=217600

Kabuki
11-28-2005, 04:57 PM
The 90-91 Preludes with B21 engines are OBD1, but their sensors and distributor do not work well with the Civic/Integra ECUs that are used with Hondata/Uberdata/Chrome.

This is what I found on PreludePower about the distributor/sensor upgrades that are needed to run a B21/B20 with a Civic/Integra OBD1 ECU (which we need to do for the head swap)

You shouldn't NEED to go OBD1 for this. You should be able to use the OBD0 ECUs from the Civics and Integras and not have to rewire as much stuff. The stock 3G Accord Distributors would all FIT, though bolting them in might be an issue.

racerx
11-29-2005, 12:15 AM
OBD1 and OBD0 ECU's in the 3rd gen prelude's have different pinouts. No idea why, but Honda likes to be special sometimes.

The B21 Preludes from 90 and 91 are the only OBD1 Honda's with injector resistor boxes. (that I know of)

Anyway, here's the run down:
If you want to use a B21A1 block/head/sensor combo, you'll need the OBD1 ECU and wiring harness.
I tried using an OBD1 civic ECU in my OBD1 prelude, didn't work right. It ran, but it ran weird; very lean. You'll need to chip the civic/teg ECU with uberdata to make it work right.

There IS an alternative, however.
The B20 head will bolt up to the A20 block as well, and those sensors and wires and OBD0, so there's a much better possibility that the A20 ECU would be able to manage it, or the B20 ECU might actually fit the wiring harness.

For everyone's information, swapping the B20 head on the B21 block increases compression and power by a little, so it should have the same effect on the Accord now that I think about it.

Next time there's a B20 OBD0 prelude in the junkyard here, I'll pull the ECU and see if it will run/fit in the 3G accord.

carotman
11-29-2005, 05:26 AM
Everything that relates to the wiring has been discussed in the engine swaps section when I made my PK2 How-to. It's also explained how to run a B20A with a PJ0 ECU (which shouldn't be done).

All you need to do is choose the ECU you want and install the distributor that will match that ECU. There is no such thing as an OBD-0 or OBD-1 head. Heads are heads, sensors are sensors and ECUs are ECUs. Every 88+ Honda engines use basicaly the same sensor between obd-0 and obd-1.

The BEST ecu to use without any doubt with the A20A/B20A hybrid is the P06. It's cheap, reliable and chippable by every tuning software around. Then, you install a B18B cam endcap to be able to use a B18B distributor and you plug the exhaust cam with the B18A/B endcap (for a better underhood look). You make an OBD-1 conversion harness and install a 4-wire O2 sensor.

If you're worried about emission controls, the P14 ECU is the thing to use but will make it run richer and doesn't allow you to use a Uberdata. It's only good because it will retain the EGR setup. Any OBD-1 Accord ECU would fit but you just need to choose the one you want. Remember, this is ONLY to keep the EGR functionnal.

A Stock P06 or P75 ECU doesn't work well on a B20A because of the fuel and timing curve. The B20A has a long stroke and needs higher timing to work fine. It's a 2L and will also need a little more fuel. This is why you need to chip it.

The B21A head gives less compression than the B20A because it has a bigger combustion chamber (bigger bore)
Anything that needs to be cleared out?

A20A1
11-29-2005, 02:32 PM
So carotman, did you ever see that b20/a18 car again?

carotman
11-29-2005, 03:10 PM
Nope, the dork junked it :(

It's one of those guys that will drop lots of money in a car and just cut corners. He had a coolant leak on one of the main hoses. The engine overheated.... and blew.

It was an ET2 with a B20A3 head I beleive.

Kabuki
12-01-2005, 11:51 AM
The 4G and 5G OBD1 Accords and 4G Preludes use resistor boxes as well.

Swap_File
12-01-2005, 05:04 PM
I got a crankshaft timing gear from the junkyard today (Still no head):

http://img227.imageshack.us/img227/4804/120105005large8iw.th.jpg (http://img227.imageshack.us/my.php?image=120105005large8iw.jpg)

Prelude B20A/B21 gear on left, A20 gear on right. A20 crank in the middle (the junk crank I have from the engine that spun a bearing).

Prelude B20A/B21 Shaft: 28mm
Accord A20 Shaft: 25mm

I will take this into the local machine shop sometime this month and see what they can do for a shim.

Also, I think this post got lost when the threads combined:

Mustardcat from preludepower tried to put the A20 cam gears on the Prelude B20A/B21 head:

http://mustardcat.brinkster.net/a18camgearonb20.jpg


Sorry the a20/a18 gear is just a hair too large, they will touch eachother. It does slip onto the b20 cam though.

After thinking about it a bit, I think you will be better off going with all the b20a/b21 gears. Since you will be able to pick up any b-series adj. cam gears, not to mention you may not be able to find a timing belt long enough to work with 2 a20 gears on there.

A20A1
12-01-2005, 06:03 PM
A smaller diameter B20A/B21 gear would be less rotational weight since the radius isn't as large... a big bonus aside from having the adjustable ones available.

The A20 gears would give more mechanical advantage to turn the camshaft against the rockers/valve springs... maybe if you had heavier springs that could came in handy perhaps?

Kabuki
12-01-2005, 10:37 PM
I was thinking... I need to check the size of the gears on my '89 Prelude B20A3 SOHC, Dual Carb. It's essentially the same design as the head from the dual carb 2G Ludes, but uses the B20A bottom end.

racerx
12-02-2005, 12:13 AM
that's definately worth looking into! could solve the problem right there!

Swap_File
12-02-2005, 06:16 PM
A smaller diameter B20A/B21 gear would be less rotational weight since the radius isn't as large... a big bonus aside from having the adjustable ones available.

I just put them on my scale, the B20A gear (without shim) is 6.7 oz and the A20 gear is 11.4 oz.

A20A1
12-02-2005, 09:46 PM
I was thinking cam gears not the crank. but thats just as good. :)

Swap_File
12-02-2005, 10:49 PM
I did some investigation in search of a 25mm crankshaft timing gear.

I limited my search to Hondas and Accuras that had adjustable cam gears available from AEM. (their site was easily searchable :) )

These are the different "Families" of camshaft cam gears (According to AEM):


AEM PN 23-800
38 Teeth
Camshaft Gear Fits - Yes (from Kabuki on PreludePower)
Crankshaft Gear Fits - ?

-Might be the same as the 23-804
-Most companies sell the same gear for 23-800 and 23-804 applications

Found in:
Honda Civic 1988-95 D15/D16 SOHC
Honda del Sol 1993-95 D15/D16 SOHC
Honda CRX 1988-91 D15/D16 SOHC

http://img321.imageshack.us/img321/3186/8f1b4ef.th.jpg (http://img321.imageshack.us/my.php?image=8f1b4ef.jpg)



AEM PN 23-801
42 Teeth
Camshaft Gear Fits - Too big for DOHC, gears will touch. Unsure of shaft size.
Crankshaft Gear Fits - Doesn't matter, the camshaft gear would be too big.

-Could possibly used for adjustable cam gear for the A20?
-See picture below of H22 belt with A20 gear

Found in:
Honda Prelude 1992-02 H22 DOHC

http://img451.imageshack.us/img451/677/fc26ecbbjpgorig4ue.th.jpg (http://img451.imageshack.us/my.php?image=fc26ecbbjpgorig4ue.jpg)http://img451.imageshack.us/img451/2628/359877133full3vb.th.jpg (http://img451.imageshack.us/my.php?image=359877133full3vb.jpg)



AEM PN 23-802
34 Teeth
Camshaft Gear Fits - Yes
Crankshaft Gear Fits - ?

Found in:
Acura Integra 1990-01 B17/B18 DOHC
Honda Prelude 1992-96 H23 DOHC
Honda Prelude 1988-91 B20/B21 DOHC (28mm Crankshaft)
Honda del Sol 1994-97 B16 DOHC
Honda Civic Si 1999-00 B16 DOHC
Honda CRV 1997-01 B20 DOHC

http://img526.imageshack.us/img526/5836/aem1camgear3kb.th.jpg (http://img526.imageshack.us/my.php?image=aem1camgear3kb.jpg)



AEM PN 23-803
40 Teeth
Camshaft Gear Fits - ?
Crankshaft Gear Fits - ?

Found in:
Acura Integra 1986-89 D16A1 DOHC
Honda Prelude 1992-96 F22 SOHC
Acura CL 1997-98 F22/F23 SOHC
Honda Accord 1990-02 F22/F23 SOHC (F22 30mm Crankshaft)
Honda CRX 1985-87 EW3/EW4/D15 SOHC
Honda Civic 1985-87 EW3/EW4/D15 SOHC
Honda Odyssey 1995-98 4 Cyl.

http://img126.imageshack.us/img126/7482/aemgears8pr.th.jpg (http://img126.imageshack.us/my.php?image=aemgears8pr.jpg)



AEM PN 23-804
38 Teeth
Camshaft Gear Fits - ?
Crankshaft Gear Fits - ?

-Might be the same as the 23-800
-Most companies sell the same gear for 23-804 and 23-800 applications.

Found in:
Honda del Sol 1996-97 D16 SOHC
Honda Civic 1996-00 D16 SOHC


AEM PN 23-805
38 Teeth
Camshaft Gear Fits - No
Crankshaft Gear Fits - ?

-If the Crankshaft gear would fit, it could maybe be used with 23-800

Found in:
Honda Civic 2001-03 D17 SOHC

http://img441.imageshack.us/img441/9592/6d18bt.th.jpg (http://img441.imageshack.us/my.php?image=6d18bt.jpg)

I would assume that the difference between each family is the number of teeth on the gears, or possibly the camshaft diameter.

According to Honda-Tech H22 and F23 crankshaft timing pulleys use the same shaft size.

I do not know if the crankshaft timing gear pully diameter has anything to do with the family the camshaft gear comes from or not.

If anyone wants to try to use pulleys from other families than "23-802", be sure that the camshaft pulleys will fit, as well as the crankshaft.

Feel free to post any of the measurements you can find, I will edit the list as I find more information.

racerx
12-03-2005, 01:27 AM
that is outstanding information!!! way to go!

Kabuki
12-08-2005, 08:14 AM
Okay, sorta bad news... The B20A3 (SOHC) uses a 40 tooth gear. So not really any help there. The two possibilities I see as the best possibilities are these: All three gears from the 1G Integra's D16A. I seem to remember that the crank gear from the D16Z6 was slightly larger than the shaft on the D16A crank that I bought to repair said D16Z6. If we need to, bore out the crank gear, but I'll bet either the crank gear from the D16A or D16Z6 will work for our application. Or we machine a sleeve/bushing for the B20A5/B21 crank gear. I'll look at my other D16Z6 sometime today.

smufguy
12-08-2005, 03:46 PM
From what i know you can use two Adjustable cam gears from the SOHC F22 (4g accords USDM) and use it on your B20A. Thats what Carotman (Jean) did.

Swap_File
12-11-2005, 09:32 PM
From what i know you can use two Adjustable cam gears from the SOHC F22 (4g accords USDM) and use it on your B20A. Thats what Carotman (Jean) did.

While the F22 camshaft timing belt pulleys would probably fit, the ratio would be incorrect with the stock A20 crankshaft timing belt pulley.

If the Accord B20A had the same size crankshaft pulley as the A20 it could be swapped over, but according to this http://www.3geez.com/showpost.php?p=59367&postcount=10 it does not. The Accord B20A has the same size diameter shaft as the Prelude B20/B21 ( 28mm ) which means it will not fit on the A20 crank.


Okay, sorta bad news... The B20A3 (SOHC) uses a 40 tooth gear...

They could (maybe) still work if the crankshaft pulley fits. We know that 40 tooth camshaft gears are on the Accord B20 (http://www.3geez.com/attachment.php?attachmentid=1426&d=1032502584) 40 tooth gears might also fit the Prelude B20/B21. I will measure the distance between the B20's camshafts the next time I am the junkyard.

The only other possible problem with using a 40 tooth gear would be finding a timing belt of the correct length.

Swap_File
12-11-2005, 10:35 PM
I asked around about the different ways to fill the 3 extra holes in the Prelude B21A1 block. Here are the suggestions I recieved:

Weld the holes shut - Would definately work. Would require head shaving. Most expensive option. Cannot be done yourself. Could warp the head if done improperly.

JB Weld - JB weld is rated to 500 degrees, which could be a problem. I would probably not trust it.

Liquid Aluminum Block Filler - Very strong, but can be tricky to use and apply properly. Head would have to be stripped down and cooked in an oven for proper curing.

Liquid Gasket - Can only be used when filling a hole that will be up against the block. Not a permanent solution. Not something that can be safely used for this head swap.

Thread the holes and install plugs - Just tap the holes and install some hex socket plugs (http://www.midwestsocket.com/HexKeys.jpg). Possibly use loctite red, and turn them in so they are deeper than flush. It was suggested that brass plugs would work the best. I do not know if loctite would be useful because it apparently starts to lose effectiveness at 500 F.

Most people I talked to seemed to think threading the holes for plugs would be the best solution. At this point I would agree.

phrenology
12-12-2005, 11:59 AM
Does anybody have a B20A3 (SOHC) crankgear for sale or do you know if it will fit the A20A crankshaft with little or no modification?

smufguy
12-12-2005, 12:39 PM
swap file. The first quote that you have of me is strictly for a B20A motor, not a hybrid one.

the second quote is not mine by the way. The tooth count is somehting i am unaware of.

Swap_File
12-12-2005, 04:46 PM
swap file. The first quote that you have of me is strictly for a B20A motor, not a hybrid one.

Yeah, I was just was hoping it would work for the hybrid also, but it turned out not to.


the second quote is not mine by the way. The tooth count is somehting i am unaware of.

Sorry about that, I had copied and pasted the quotes tags and while editing the post and forgot to change it to Kabuki. :uh: I fixed it now.

Kabuki
12-13-2005, 05:03 PM
Okay, I've got a 3G LX-i in for a head gasket, and the head is still at the machine shop till tomorrow. So tonight, after everyone else leaves, I'll go stick the B20A5 head on the block and try some timing belts. Now, since the A20 uses a 108 tooth belt, and the B20A5 uses a 124, I'm guessing that the belt will need to be somewhere in between. Something like the 112 or 113 tooth belts from the F series (VTEC and non-VTEC engines, respectively) should be pretty close. The F engines, of course, use the belt to drive the water pump, but are single cam. The PK1 belt from the SOHC B20A3 might work too, but it will all depend upon the gears we use.

baby D
01-25-2006, 04:44 PM
Okay, I've got a 3G LX-i in for a head gasket, and the head is still at the machine shop till tomorrow. So tonight, after everyone else leaves, I'll go stick the B20A5 head on the block and try some timing belts. Now, since the A20 uses a 108 tooth belt, and the B20A5 uses a 124, I'm guessing that the belt will need to be somewhere in between. Something like the 112 or 113 tooth belts from the F series (VTEC and non-VTEC engines, respectively) should be pretty close. The F engines, of course, use the belt to drive the water pump, but are single cam. The PK1 belt from the SOHC B20A3 might work too, but it will all depend upon the gears we use.


:bong: okay guys check this out the only problems you are gonna have is the belt, but i cant find a b 21 head, any way you need to use 2- a20a cam gears the cam and crank will be times perfict, how ever, i cant tell you about the water pump, belt routing, or how to get the tentioner to work, please pm me when you know, and tell me what f@#$ing car to get the head off of please:banghead: its p*%$ing me off!!, but it should be a bolt in.

A20A1
01-26-2006, 01:06 PM
I thought they said the A20 cam gear was too large and would hit eachother.

Swap_File
01-26-2006, 10:44 PM
They are too big, confirmed by members of preludepower.

I still haven't found a B21 head, so I have not done any more work on the head swap project yet.

Kabuki
01-28-2006, 12:11 AM
Sorry guys, the B21A1 was ONLY available in the USDM 90-1 Prelude Si (not 2.0Si). There was a B21A available in the JDM 3G Prelude SiStates (extremely rare), which was neat because it came with iron sleeves (happy!) instead of FRM (difficult to work with). I had planned on using my B20A5 head on my B21A1 engine, to up the compression, and then use the B21A1 head on an A20 block, so I can turbo that bitch. But if you want a naturally aspirated engine, just get the B20A5 head from ANY of the 88-91 Prelude 2.0Si engines. The compression will be a little higher too...

Swap_File
02-01-2006, 09:01 PM
I crunched some numbers, I think a B20A5 head on a A20 block with the fuel injected pistons should give about 9.6:1 compression.

The local junkyard finally got a second 3rd generation prelude in, it has a B20A5 in it but I am going in on friday to grab the head anyway. I scouted it out and started on removing it earlier today. I figure I can test fit it to my junk engine and see what happens.

smufguy
02-01-2006, 10:01 PM
keep me updated on that swap_file.

Swap_File
02-04-2006, 02:57 PM
I picked up a complete B20A5 head yesterday at the junkyard. I went to test fit it today, when I noticed that one of the head bolts do NOT line up. Check out these pictures:

http://img357.imageshack.us/img357/6315/badhead001large1lg.th.jpg (http://img357.imageshack.us/my.php?image=badhead001large1lg.jpg)
http://img357.imageshack.us/img357/2314/badhead004large8kr.th.jpg (http://img357.imageshack.us/my.php?image=badhead004large8kr.jpg)
http://img488.imageshack.us/img488/8408/badhead005large1ae.th.jpg (http://img488.imageshack.us/my.php?image=badhead005large1ae.jpg)

The intake side (upper in the picture) middle head bolt on the A20A3 is offset. All the head bolts on the B20A5 and B21A1 head are in straight rows.

I do not recall this problem ever being mentioned before in this thread.

Everything else does seem to line up fine.

Any ideas?

racerx
02-04-2006, 04:55 PM
uhm... i put all the head bolts through my B21A1 head into the A20A1 block once... no problems.

smufguy
02-04-2006, 05:18 PM
the best way to show the difference is to compare the head gaskets. The head is not realy making much sense to me, its soo much dirt there, im getting distracted. :eek5:

Swap_File
02-04-2006, 05:30 PM
Here are some more pictures:

B20A5 Exhaust Side Bolts
http://img355.imageshack.us/img355/1501/badhead2001large9iv.th.jpg (http://img355.imageshack.us/my.php?image=badhead2001large9iv.jpg)

B20A5 Intake Side Bolts
http://img355.imageshack.us/img355/6440/badhead2002large8fd.th.jpg (http://img355.imageshack.us/my.php?image=badhead2002large8fd.jpg)

A20 Exhaust Side Bolts
http://img476.imageshack.us/img476/2595/badhead2004large9sz.th.jpg (http://img476.imageshack.us/my.php?image=badhead2004large9sz.jpg)

A20 Intake Side Bolts
http://img476.imageshack.us/img476/8291/badhead2005large4ve.th.jpg (http://img476.imageshack.us/my.php?image=badhead2005large4ve.jpg)
(Note how the straight edge does not touch the farthest two bolts at all)

Here is one of gofast's pictures with the problem area circled:
http://img355.imageshack.us/img355/703/28479615full2fs.th.jpg (http://img355.imageshack.us/my.php?image=28479615full2fs.jpg)
(B21A1 head with A20 gasket)

Swap_File
02-04-2006, 08:03 PM
I went out to the shop and looked at it again. I can put all the other bolts in, and then look down the remaining hole, and I can see the offset in the block for the bolt hole. I measured the offset to be between 2mm and 3mm.

The only way I can think of to deal with this would be to drill the one hole in the head larger (an extra 2-3mm all the way around), and use a modified washer on top. Hopefully this would not cause any problems with weakening the head.

It will be a while before I try anything; maybe there will be an alternative by then.

While I was at the junkyard I also measured the B20A5/B21A1 intake manifold. As long as we do not use the B20A5/B21A1 intake (and stick with the A20 or B18, etc intake), I do not think hood clearance will be a problem.

smufguy
02-04-2006, 08:43 PM
THAT is a problem.

What i think is that we enlarge the existing head stud hole far enough to have the head stud to go all the way in to the block. then use the hole surface area and the head deck height and use a block of aluminun machined to the same area as an insert. engineers and anyone who uses CAD might understand this better. So basically u machine a piece of aluminum (6061) and then drill the proper whole into it for the head stud to go thru. That would be the better way of filling up the hole.

Any leeway in the headstud hole will distort and lift the head and cause it to leak or blow a head gasket. Filling up the hole with some kind of industrial filler (the ones that can patch a damn broken axle) also sounds tempting, but the reliability of it is a little sketchy. If that hole is the only thing thats gonna stop us from swapping the head onto this block, then it needs to be tackled in different ways by people with different experiences. I for one wlll defenitely undertake this and look into it more closely.

racerx
02-04-2006, 09:35 PM
I'd bet that any machine shop could move that hole. they'll probably just drill it down and fill in the other side, no problem. you should call a local place and see what they think.

Swap_File
02-04-2006, 11:27 PM
This problem bolt hole is special, because the oil from the block comes up around this bolt to feed the head. We really can't block it off unless we re-route the oil. We might be able to hook up at either end of the block (See picture below).

If I drop the head bolts into the head I can wiggle them all side to side. The holes are all atleast a millimeter or two larger than the bolts already. If the hole was drilled bigger, all the pressure would be spread out over a smaller area, so either the bolt could try to pull through the washer, or the head could try to deform (or both). I just do not know if the block or the washer could end up being a weak point.

Here is a picture of where the oil goes in the head:
http://img455.imageshack.us/img455/4364/badhead003large1fw.th.jpg (http://img455.imageshack.us/my.php?image=badhead003large1fw.jpg)

Red is where the oil comes up around the bolt from the block, blue is for the long holes bored through the head for oil, purple is for the plugs screwed into the head, and green is for the things that squirt out the oil onto the cams.

I am going to look at the head again tomorrow, and double check that everything else lines up.

Ichiban
02-06-2006, 04:17 PM
Anything new on this? maybe if you use a thick and wide washer on the head stud it would distribute the pressure evenly over the original "pad" for in the head it would clamp reasonably well

Ichiban
02-06-2006, 04:18 PM
THAT is a problem.
What i think is that we enlarge the existing head stud hole far enough to have the head stud to go all the way in to the block. then use the hole surface area and the head deck height and use a block of aluminun machined to the same area as an insert. engineers and anyone who uses CAD might understand this better. So basically u machine a piece of aluminum (6061) and then drill the proper whole into it for the head stud to go thru. That would be the better way of filling up the hole.
Any leeway in the headstud hole will distort and lift the head and cause it to leak or blow a head gasket. Filling up the hole with some kind of industrial filler (the ones that can patch a damn broken axle) also sounds tempting, but the reliability of it is a little sketchy. If that hole is the only thing thats gonna stop us from swapping the head onto this block, then it needs to be tackled in different ways by people with different experiences. I for one wlll defenitely undertake this and look into it more closely.

I don't believe the extra leeway in one or two of the bolt holes will cause distortion as the head is located side to side by the dowell pins, and remember the clamping force is down agains the deck of the block. the stock holes and bolts already have some clearance, especially this hole that flows oil past the bolt (right or am i mistaken here?). I say drill out the hole and use (or make) a thick washer/spacer/cap to distribute the force and keep the oil in. the only problem i could see is maybe interference with valve train parts as the washer/spacer/nut combo would take up slightly more space than it originally did.

smufguy
02-06-2006, 06:52 PM
after talking to some peopl i know who work on cars and engine builders, its what i thought before. The washer or spacer or anything wont help. alon with the hole being enlarged, it also needs to be filled and the stud needs to have the same clearance as the stock hole. obviously people are going to rebuild their motor/head when a project like this is undertaken and ARP studs will be used and they dont flex a bit. As long as there is no space for it to put side load on the head stud (in our case, a head bolt).

thegreatdane
02-07-2006, 08:14 AM
From what I recall the ET engines have an offset oil jet compared to the A20 engines. But I dont recall if the head bolt was offset too... I had a picture showing the difference but unfortunately deleted it the other day..

Ichiban
02-07-2006, 05:21 PM
so what you are saying is that the far side of the hole has to be brought closer to the stud even though it's still not making contact with anything? why? It's not that i don't believe it, i just can't see it making any difference, really. The head is gonna clamp just the same with that gap filled or not.

Ichiban
02-13-2006, 08:46 PM
so...the prelude B-series heads need a hole moved to fit on the A-block...so why not machine the bastard out and try it? or is the head of the bolt gonna hit the camshaft? That's probably why the factory moved that hole. Also, does the A20 block provide oil to that hole? I'm all for the project, but some questions need to be answered, and solutions found. Who doesn't want a 4 valve DOHC A20?

gfrg88
02-13-2006, 09:04 PM
ok so if it were possible too do something about the hole, what would you do about the cam gears and the belts????

Ichiban
02-13-2006, 10:06 PM
if i absolutly had to, i'd machine a crank pully to match the cam gears of the head. however, i'm sure there are stock parts somewhere that will work. i have a buddy who works at a bearing and transmission place, if i can get the required specs of that gear i'll contact him and find out. in terms of belts, i suggest trial and error. I'm seriously contemplating attempting this, and i'm not usually one to let crap details stand in the way.

Can we in fact use the A20A3 intake manifold on the B20A3/A5/B21 heads?

Ichiban
02-19-2006, 12:23 PM
Swapfile, if you can mike out the b20 crank gear and give me all the dimensions (width, tooth height/spacing/count) and the ID of the A20 crank gear, it would go a long way to trying to order something specific. like i said, i'll have my buddy check a massive database of industrial power transmission supplies, there has to be something...

any word on the A20A3 intake on the B20A5 head?

A20A1
02-19-2006, 01:26 PM
Can we fill in the bolt holes and have them redrilled along with redrilling the oil passages horizontaly to clean out any debris.

That Alumaloy may come in handy.


THAT is a problem.

What i think is that we enlarge the existing head stud hole far enough to have the head stud to go all the way in to the block. then use the hole surface area and the head deck height and use a block of aluminun machined to the same area as an insert. engineers and anyone who uses CAD might understand this better. So basically u machine a piece of aluminum (6061) and then drill the proper whole into it for the head stud to go thru. That would be the better way of filling up the hole.

so you mean make an aluminum cylinder and drill a hole in the cylinder to one side to accomodate the offset in the bolt spacing.

Or what about a half/half.

Drill the holes, add the insert but fill in some area that are close enough to the top and bottom of the hole to be heated by a torced and then fill it in with alumaloy.


I asked around about the different ways to fill the 3 extra holes in the Prelude B21A1 block. Here are the suggestions I recieved:
Weld the holes shut - Would definately work. Would require head shaving. Most expensive option. Cannot be done yourself. Could warp the head if done improperly.
JB Weld - JB weld is rated to 500 degrees, which could be a problem. I would probably not trust it.
Liquid Aluminum Block Filler - Very strong, but can be tricky to use and apply properly. Head would have to be stripped down and cooked in an oven for proper curing.
Liquid Gasket - Can only be used when filling a hole that will be up against the block. Not a permanent solution. Not something that can be safely used for this head swap.
Thread the holes and install plugs - Just tap the holes and install some hex socket plugs (http://www.midwestsocket.com/HexKeys.jpg). Possibly use loctite red, and turn them in so they are deeper than flush. It was suggested that brass plugs would work the best. I do not know if loctite would be useful because it apparently starts to lose effectiveness at 500 F.
Most people I talked to seemed to think threading the holes for plugs would be the best solution. At this point I would agree.

missed this post, sorry.

.
.
.

Legend_master
02-19-2006, 02:08 PM
having the hole filled and then re drilled would be the rout I would take. For my LS/Vtec I had this done. The filled the old oil passage hole on the head and redrilled a new one. YOu could have the passage on the block moved, but it is much more difficult to have this done. As for price, I paid $90.00 to have it done and they did a damn good job with it.

Ichiban
02-21-2006, 09:07 PM
I talked to the local engine builder/machinist today while i was picking up my 20R head, he says not to bother filling the other side of the hole once it's drilled out. if you really wanted to, he says, you could tig in some material before you drilled it, but there would really be no point. he says he'd be more concerned about adding material to the side of the "pedestal" that the bolt tightens on that you've moved the hole towards. But even if there's lots of material anyway again there's no point.

is someone gonna measure the B20A5 crank sprocket out for me? I found a company that will make every possible sprocket configuration conceivable. i also found a company that makes custom timing belts.

So there.

Swap_File
02-21-2006, 11:04 PM
I can measure everything this weekend (I am down at college for the week).

The last person I talked to thought it would be cheaper to machine a stock gear, and make a spacer, rather than having a whole new gear made.

If you want a basic idea of the size of the sprocket, look at this picture:

http://img227.imageshack.us/img227/4804/120105005large8iw.th.jpg (http://img227.imageshack.us/my.php?image=120105005large8iw.jpg)

Both gears are the same width. Teeth are spaced the same, and shaped the same. It's just less teeth means a smaller gear. The other difference is that the B20A5 shaft is 28mm, while the A20 shaft is 25mm.

Ichiban
02-22-2006, 05:45 PM
i'll try and get a price estimate for the off-the-shelf gear on Monday. I was thinking about just getting a piece of 1.5mm shimstock and welding it around the ID of the B20 gear, and using an oversize key. thoughts? what are the B20 gears made out of? steel? aluminum?

Swap_File
02-23-2006, 09:35 PM
Well, it turns out the information I got from preludepower was incorrect, the A20 intake manifold does NOT bolt up to the B20A5 head. Neither does my B18 intake manifold. The B20A5 bolt pattern seems to be much wider than anything else. Check out the pictures:

http://img160.imageshack.us/img160/8751/22306036large6jc.th.jpg (http://img160.imageshack.us/my.php?image=22306036large6jc.jpg)http://img160.imageshack.us/img160/7218/22306037large6vp.th.jpg (http://img160.imageshack.us/my.php?image=22306037large6vp.jpg)http://img66.imageshack.us/img66/1583/22306039large5vf.th.jpg (http://img66.imageshack.us/my.php?image=22306039large5vf.jpg)http://img66.imageshack.us/img66/7646/22306040large0jl.th.jpg (http://img66.imageshack.us/my.php?image=22306040large0jl.jpg)http://img66.imageshack.us/img66/5770/22306041large6de.th.jpg (http://img66.imageshack.us/my.php?image=22306041large6de.jpg)http://img160.imageshack.us/img160/6898/22306042large3iy.th.jpg (http://img160.imageshack.us/my.php?image=22306042large3iy.jpg)

A20A3 head on top, B20A5 head on bottom. I would have held the B20A5 gasket up to the A20A3 head, but it refuses to peal off the head in one piece.
http://img164.imageshack.us/img164/5828/head002large7jb.th.jpg (http://img164.imageshack.us/my.php?image=head002large7jb.jpg)

Next time I am at the junkyard I will grab the B20A5 intake that I left there. If I rip out the butterfly plate, it might make it low enough to clear the Accord's hood.

I am still not too worried about the intake, that can always be delt with later. I am more worried about the head bolt problem. While I am sure the hole could be moved, I just hope it will not end up costing an arm and a leg to do.

Swap_File
02-23-2006, 09:44 PM
I almost forgot, here is the information on the crankshaft cam gears.

A20A3:
http://img163.imageshack.us/img163/1626/a20a316dq.th.jpg (http://img163.imageshack.us/my.php?image=a20a316dq.jpg)http://img95.imageshack.us/img95/3118/a20a321wm.th.jpg (http://img95.imageshack.us/my.php?image=a20a321wm.jpg)
Thickness: 25mm
Shaft Diameter: 25mm


B20A5:
http://img95.imageshack.us/img95/5577/b20a518ia.th.jpg (http://img95.imageshack.us/my.php?image=b20a518ia.jpg)http://img163.imageshack.us/img163/4351/b20a529tx.th.jpg (http://img163.imageshack.us/my.php?image=b20a529tx.jpg)
Thickness: 25mm
Shaft Diameter: 28mm

For both gears, the keys are built into the gears themselves. The gears appear to be made of steel.

The images were scanned at 600dpi. By either tracing them in a CAD program or measuring them in a photo-editing software you should be able to get closer measurements than I could ever get with my cheap calipers. If you need more information (or better pictures), let me know.

Legend_master
02-23-2006, 11:54 PM
I almost forgot, here is the information on the crankshaft cam gears.

A20A3:
Thickness: 25mm
Shaft Diameter: 25mm


B20A5:

Thickness: 25mm
Shaft Diameter: 28mm

For both gears, the keys are built into the gears themselves. The gears appear to be made of steel.

The images were scanned at 600dpi. By either tracing them in a CAD program or measuring them in a photo-editing software you should be able to get closer measurements than I could ever get with my cheap calipers. If you need more information (or better pictures), let me know.


Looks good man, the intake should be no problem. I think your biggest problem will be the timing belt. Have you looked into the 86-90 integra belts. They are Dual cam, but are not very large motors 1.6L. There might be other swappable parts from that car also, just check it out.

A20A1
02-24-2006, 01:35 PM
Well I tried editing the gears in PS, the pics were taken at a bit of an angle so the measurements are off a tad. I tried to find the center of the gear then rotated it to even out the radius on all sides.

It's in 100 pixles/cm right now...

The outside diameter appears to be 62.5mm

http://i23.photobucket.com/albums/b351/Wendy_girl/a20a3_sgear.png


This picture measures the radii


http://i23.photobucket.com/albums/b351/Wendy_girl/a20a3_gear3.png

A20A1
02-24-2006, 03:21 PM
This is as best I could do with the B20A5

Again:
The thick lines represent the Radius

http://i23.photobucket.com/albums/b351/Wendy_girl/b20a5_measure.png

A20A1
02-24-2006, 03:31 PM
B20A5
- ID : Aprox. 28mm
-OD , TEETH : Aprox. 50mm ( Gear OD )
- ID , TEETH : Aprox. 44mm

A20
- ID : Aprox. 25mm
-OD , TEETH : Aprox. 62mm ( GEAR OD )
- ID , TEETH : Aprox. 56mm

Both A20 And B20 have a TOOTH Depth of 6mm



Here is a B20A5
not sure about the tooth degrees... I think they are spaced Somewhere between 21.1* - 21.25* degrees apart from eachother.

http://i23.photobucket.com/albums/b351/Wendy_girl/b20a5_ch.png

A20A1
02-24-2006, 03:56 PM
That drawing is not even/exact... so dont trace it and use it to make a gear.

smufguy
02-24-2006, 04:13 PM
if there are 17 teeth on the gear, then the teeth spacing deg would be 360/17 which is 21.1764 deg exact. so yes, ur right, they are a rounded 21.2 deg apart.

A20A1
02-25-2006, 10:51 AM
Hehe, I need to go back to school if I forgot something as simple as that. :(

Thanks Praveen :)

smufguy
02-25-2006, 04:25 PM
you are most welcome buddy. and you know i always get excited to see what you have to say, cause most of the time its something i never heard of.

PS: Your post count makes me wanna cry. lol

A20A1
02-27-2006, 04:14 PM
Swapfile, if you can mike out the b20 crank gear and give me all the dimensions (width, tooth height/spacing/count) and the ID of the A20 crank gear...


(B20A Gear OD 50mm /// Gear OD W/Out Teeth 44mm /// B20A & A20A Belt Width 25mm /// B20A & A20A Tooth Height 6mm /// B20A Tooth Spacing 21.1764 Deg. /// B20A Tooth Count - 17 /// A20A ID 25mm)



A20A3 head on top, B20A5 head on bottom. I would have held the B20A5 gasket up to the A20A3 head, but it refuses to peal off the head in one piece.
http://img164.imageshack.us/img164/5828/head002large7jb.th.jpg (http://img164.imageshack.us/my.php?image=head002large7jb.jpg)

Damn, looking at those pics I just realied that Carotman sent me his B20A5 Intake manifold Gasket when he sent me his old carbed A20 manifold.

Ichiban
02-27-2006, 09:37 PM
thanx eh for the specs...

huh...i didn't realise the teeth had rounded troughs like they do. i'm not sure if i saw that style in the catalogue i was looking at. I'm gonna print off the specs and see what i can dig up...any word on intakes, i was really hoping to use my BT1 non-EGR intake and computer.

A20A1
02-28-2006, 01:02 PM
I'n my drawings I left out the champher on the teeth...

the key And the little hole they drilled for the balancing.

Ichiban
02-28-2006, 09:17 PM
im hoping a few things here, but untill my buddy gets back off of holidays next week i won't know for sure:
-the tooth design and pitch is a standard "feature"
-the gear comes balanced
-a 17 tooth gear is availiable (most seem to be even numbers....)

next week i'll find out.

Edit:was it a balance hole or is it the timing mark, i noticed the timing marks on the A20 and B20 gears are opposite in swapfile's pictures. also, the integral key is a little strange.

A20A1
02-28-2006, 10:02 PM
hrm I thought it was for balancing... or maybe the gear + crank is balanced together but not apart?
I thought the flywheel was the timing mark.

rjudgey
03-08-2006, 09:40 AM
Well not sure what drugs Sean was on when he first posted i was bored yesterday and i'm off work for two weeks so i thought i'll have a play with my engine bits, so pulled out my B20A head and got a A20A head gasket just to see how close they were. To my amazement they weren't that far off, the bolt holes were all the same even the locating dowels fitted. The only downside was that the two oil drains at the front of the B20A head would need to be welded up a little as they widen out over the A20 head gasket, and also the oil feed on the back of the block was a little bit out but not by much, with some work it could be made to fit an A20, ET or ET2/A18 block, now the major set back as it stands is that the cam gears overhang all the A20 and ET geras by quite a bit at least an inch and a half which means that no belt is going to be able to fit on and drive all the different pumps etc. Even if you get round that problem your then left with sorting out pulleys to drive the whole lot. So to me this is a whole load of pain that for a little bit extra power that can easily be had by just fitting a whole B20A and tranny anyway?? If you guy;s are lacking engines and tranny's U.K. market only sold manuals and theirs still a few engines and box's knocking around in yards and as secondhand cars in both Accords and Preludes although the Accords are rarer sor some reason B20A accord never really sold well over here.
Can be done but with custom pulleys, belts and a little bit of welding but is it really worth the trouble i think i'll stick to my ET1 and A20 for now and leave my B20A in my 2G Lude SI where it belongs.

Swap_File
03-08-2006, 10:01 AM
If you just hold up the gasket, it looks like the B20A5 head will bolt up to the A20 block, but believe me, it does not. If you actually set the head on the block you will see that middle bolt on the intake side is offset in the block, and not offset in the head.

One of the biggest reasons I did not want to install an Accord B20A was the unavailability of parts in the USA and the cost (I won't be finding an Accord B20A at the local junkyard). Sadly, a Prelude B20A5 head swap will probably end up needing quite a bit of machine work, once again leading to a situation where it would be hard (and or expensive) to find replacement parts.

For now I have pretty much put my B20A5 head swap plans on hold. I am still looking into it, but focusing more on just getting a turbo installed in my Accord.

A20A1
03-08-2006, 10:59 AM
I thought he's saying the JDM B20A is the close fit not the B20A5 right?

Swap_File
03-08-2006, 11:40 AM
...i think i'll stick to my ET1 and A20 for now and leave my B20A in my 2G Lude SI where it belongs.

I thought he was refering to the B20A from the 88-91 Prelude SI (B20A5), but I may have mis-understood.

carotman
03-08-2006, 12:37 PM
Damn, looking at those pics I just realied that Carotman sent me his B20A5 Intake manifold Gasket when he sent me his old carbed A20 manifold.

Really? I don't remember having a B20A5 gasket honestly :D

A20A1
03-08-2006, 06:25 PM
hehe, well you must of, cause it's right next to me under my labarynth of DVD's
. :) I thoght I had asked you about it... when I first got the big box (rims) in the mail. or maybe it was someone else.

rjudgey
03-09-2006, 02:39 AM
UK 2G Lude SI came with B20A as standard and it's the same as the Accord B20A, Surprised about the fit not sure what the B20A5 3G lude SI head is like not seen any of those, was just playing with the spares that i had it's a shame that the cmap pully's didn't line up otherwise could have been a fiarly easy swap a JDM B20A head onto a ET/A20 especially with the larger bore and shorter stroke could have made quite an interesting hybrid i bet you wouldn't get any probs revving that to 9K apart from valve float from the weak springs in a B20A but Cat Cams do uprated springs of the shelf so not too much of a problem. But anyhow not worth the time i don't think better off spent on modding A20 Head.

Kabuki
03-15-2006, 05:39 PM
Well, it turns out the information I got from preludepower was incorrect, the A20 intake manifold does NOT bolt up to the B20A5 head.

Sorry about that, I try to dispel crappy information their, but I have been a little busy as of late. I'm still working on this from my end, but I'm also still waiting for a donor block.

Kabuki
03-31-2006, 11:11 AM
Okay, folks... I have an '87 LX coming in for an engine replacement on monday. So I finally will have a bolck to start this project with. I guess I better spend a little time this weekend and tear down the B21A1 that I'm getting the head from. This is the start of probably three long projects*, so we'll see how it goes.

* B21A1/B20A Rebuild for the '88 Lude, A20A/B21A1 for, uh, research, and Probable Turbo for the A20/B21.

Ichiban
04-19-2006, 09:00 PM
As far as a 17 tooth crank pulley with a 25mm bore, i can't find anything. most pulleys from the power transmission manufacturers have an even tooth count, so the best i could think of is a 16 or 18 tooth crank pulley and two 32 or 36 tooth cam gears. thoughts?

baby D
04-28-2006, 04:39 PM
As far as a 17 tooth crank pulley with a 25mm bore, i can't find anything. most pulleys from the power transmission manufacturers have an even tooth count, so the best i could think of is a 16 or 18 tooth crank pulley and two 32 or 36 tooth cam gears. thoughts?


yeeah as long as they fit in the place as the stock gears it should work, if you get this running could you give me a parts list, and does any one know if we can stroke an a20 to a 4 1/4 stroke, becose thats why im loseing, no torque.:cheers:

Ichiban
05-03-2006, 10:11 PM
change your gearing. trying to make a stroker crank will lead to nothing but problems...could someone with the B21 head post up some specs so i can look for timing gear that will come close to fitting? thanks.

Kabuki
05-04-2006, 03:21 PM
I'm looking in to possibility of the B20A3 Crank in the A20 block. Probably the rods too. In which case I may bump it up to the B20A5/B21 crank with the F22 rods. This should give us the extra length of snout that is needed to line up with the head. If it works, it may just be a goo stroker mod for the stock engine too. I've been rather busy at home lately, so I haven't been able to spend much time in the garage with this stuff.

Ichiban
05-05-2006, 01:04 PM
....i'm listening..:)

Sporno
05-09-2006, 01:59 PM
so i could get the B20A5 intake manifold , heads, and exhaust manifold and it would bolt on. i need some strait forward answers . does this project actually work?

or is it the B21A1 heads and all ... i need to know what to get

Ichiban
05-10-2006, 12:00 PM
you are gonna have to do a lot of reading to even begin to answer that question.

Kabuki
05-10-2006, 04:10 PM
Yep, you'll need to read the whole thread. But in a nutshell, no. Not without serious machine work.
The problems to overcome are:
1) The A20A crankshaft snout isn't as long as the B20/21 cams, so the timing belt won't line up.
2) The middle head bolt hole on the intake side is in a slightly different spot, and would need to changed somehow. Part of this issue is that the oil pressure channel runs through this hole near the top.
3) There are two oil drains in the head that need to be plugged, as they have no matching port on the A20 block.

Ichiban
05-24-2006, 10:11 PM
Yep, you'll need to read the whole thread. But in a nutshell, no. Not without serious machine work.
The problems to overcome are:
1) The A20A crankshaft snout isn't as long as the B20/21 cams, so the timing belt won't line up.

3) There are two oil drains in the head that need to be plugged, as they have no matching port on the A20 block.

1. Nobody else mentioned the cam/crank pully alignment issue yet? Is this a fact?

3. If the oil drains face the top of the block, won't the head gasket seal it off effectively enough? unless the hole overlaps the edge of the block, only then will oil pour all over the place. Im gonna check the pic's again....

Edit: i see the drainback ports there on the intake side, gofast welded his closed, also the oil drainbacks on the front of the head (exhaust side) need to be modified to keep the oil inside the engine

Kabuki
05-26-2006, 02:44 PM
1. Nobody else mentioned the cam/crank pully alignment issue yet? Is this a fact?
3. If the oil drains face the top of the block, won't the head gasket seal it off effectively enough? unless the hole overlaps the edge of the block, only then will oil pour all over the place. Im gonna check the pic's again....
Edit: i see the drainback ports there on the intake side, gofast welded his closed, also the oil drainbacks on the front of the head (exhaust side) need to be modified to keep the oil inside the engine
1) Yeah, they did... back in post #195 (http://www.3geez.com/forum/showpost.php?p=601897&postcount=195)

Kabuki
05-30-2006, 04:22 PM
Okay, I also found that the B series cranks (all of them) have a 55mm main journal, rather than the 50mm journal on the A20 block. So that's not going to work either. Then I was also thinking.... Even if we DID fix that, then the oil pump pulley would no longer be in line. So we'd have to mod that too, or replace it with a dry sump... :D

snoopyloopy
08-13-2006, 07:37 PM
so how does it look now? any more progress?

Ichiban
09-12-2006, 07:04 PM
Now that i'm going to school in a machine shop for 9 months I'm gonna make the 17 tooth 25mm ID gear. Who wants to try it?

Ichiban
10-03-2006, 04:46 PM
yeah if I can get ahold of a JDM B20A head I'll do it myself

Kabuki
12-01-2006, 12:24 PM
Sorry... No progress as of yet. Possibly soon.

stat1K
12-01-2006, 07:24 PM
this seems entirely too much work you could just swap one of these motors in for that... but i know that you guys just like tinkering so i'll only add those 2 cents.

MessyHonda
12-01-2006, 08:11 PM
this seems entirely too much work you could just swap one of these motors in for that... but i know that you guys just like tinkering so i'll only add those 2 cents.

yeah that is true..you can fit a b18 with just mounts....but the coolness factor of the a20 block and a DOHC head would be pimp...i will die a happy boy if it ever happens..hehe

Kabuki
12-04-2006, 01:53 PM
Just having 16 valves and dual cams for boosting with the iron block would be AWESOME.... Be like a DSM engine... :-/

Sporno
12-05-2006, 06:33 AM
if we could have DOHC heads that would be great for tuning.. with DOHC u can adjust the cams more than SOHC and valves and cam gears and everything it would make for way more power

Ichiban
12-15-2006, 08:18 PM
So, I'm going to school in the machine shop now...and I'm at the top of the class. My instructor is giving me free rein and backing for my final project, and I think this'd be a good one. What do you all think?

MessyHonda
12-15-2006, 08:30 PM
So, I'm going to school in the machine shop now...and I'm at the top of the class. My instructor is giving me free rein and backing for my final project, and I think this'd be a good one. What do you all think?


you will be my hero if you ever get it to work...lol

Legend_master
12-15-2006, 08:34 PM
you will be my hero if you ever get it to work...lol


:werd:

Swap_File
12-16-2006, 01:11 AM
I finally logged into 3geez after being gone for a few months, and saw a few PMs asking about this project. Here is a quick summary:

Here is what you would need (Mostly from memory):

B21A1 (from 1990 - 91) or B20A5 (from 1988 - 91) head from a Prelude. B21 head lowers compression just a bit, B20 head bumps it up just a bit. B20A5 heads are much more common in the junkyards around here.

Custom lower timing gear (Modify a B20/B21 gear to fit A20 shaft)

Some other timing belt - Unsure of what is needed

Tap and plug the extra oil drain holes in the new head

Redo the one head bolt that does not line up. Probably make the hole in the head a little bigger and oval shaped, and then make a special washer for it.

Redo the oil feed, since the head bolt that doesn't line up is used with the head's oil system.

Upper timing belt pulleys do not quite align with the tensioner and bottom pulley. Probably has to have some shimming done.

You need the B21A1/B20A5 intake.

I remember that the A20 distributor had a different number of teeth than the B20A5/B21A1. You will probably need to switch to one of the OBD1 ECUs to make tuning simpler. Look for the instructions on what distributors fit on the B20A5/B21A1 head on preludepower.com. The ECU swap is a project in itself...

My suggestion: Do the head swap if you are looking for a challenge, if you want cheap power go turbo. I am sure that the head swap could be done, but it will not be easy.

I am currently (slowly) working towards going turbo. College has been keeping me very busy, but I am slowly making progress.