MoNstER A20 All MoTOR !!

[247shuer247]

Ok guys So i have been Working non stop on my hatchie and have become so inspired with everyones mods and unique ideas on here so first of all thank you to everyone for the inspiration and thank you in advance to whoever posts on this thread . sorry in advance if i babble

so for starters i have a 1986 accord hatchback.

HERES WHAT I HAVE DONE TO DATE ....

Fixed all the mechanical parts the car is running great nice and strong
i replaced the entire cooling system clutch changed belts everything that would wear with age. my ac and power steering were already failing so i removed those and also the cruise control which freed up a bit of my engine bay

my next project was the body work getting rid of all of the dings and scratches not to many was able to get the body looking nice with very little bondo
looking on prelude power i found that alot of the 2nd gen guys were modifying there bumber to fit the 3rd gen. and i remeber that we could fit 2nd gen prelude bumpers with some modsso i took on the task of modifying the front bumber to fit the 3rd gen as far as i know mine is the only one with a 3rd gen bumper :cheers:

pics will be up soon


as of now the car has been primered I am holding off on the paint job until i get some work done on my engine heres where you guys come in i need your help.

I plan on rebuilding the engine not to many problems now just want a reliable engine... once the engine is out i will spray the engine bay and finish the paint..

heres my plans for the engine this is not set in stone and any advice would be appreciated


*FULL ENGINE REBUILD
port and polish the whole thing

*B16 INTAKE MANIFOLD AND THROTTLE BODY thinking after market on this maybe skunk2 ? would it make a difference?

* HEADERS im thinking obx because i have heard bad things about pacesetter. and ss and dc headers are really hard to find .

*Short Ram Intake weapon R heard alot of good things, can anyone say different maybe k&n

*Upraged ignition ??? i have no idea about this one

*4TH GEN INJECTORS most likely oem

*ALUMINUM FLYWHEEL again no idea any info would be appreciated

*NGK SPARK PLUGS AND WIRES pretty much

*BIGGER PISTONS ... would this make a difference? if so what size is good?

*Pelude A2k5 tranny

* Convert to obd-1

*Ehaust not to sure here ive seen that obx has an exhaust kit
but im a little skeptical and have no idea for a muffler

*Stage 2 cams and Gears thinkin colt where can i get them?

*Upgraded rods ? No idea where to start ....

like i said This is not set in stone open to any advice whether its negative or positive im just trying to get it right the first time ....:violin:

[88lxi-shortram]

obx utilizes the ss design. lost posted about that somewhere sometime. if your going all motor and obd1 you should look into either fabricating some itbs or buying a set. youll be able to tune easily so why not go all out? how much power are you looking to put out?

[247shuer247]

I was thinking that but i have no idea how much that would cost or if they would need to be custom made

im shooting for something like 200 but i would be happy as fuck with like 160
i dont think thats to farfetched

yeah i do remeber pete posting that

[nswst8]

I have a brand spanking new DC sport header, always entertaining offers.

[MessyHonda]

I have a skunk 2 manifold already drilled to fit

[247shuer247]

I have a skunk 2 manifold already drilled to fit

with or without the throttle body ?

[247shuer247]

I have a brand spanking new DC sport header, always entertaining offers.



:jaw:

really brand new ??

umm idk how much would it be just to ship to california ?

[MessyHonda]

with or without the throttle body ?

i can throw in a GSR throttle body if i can find it

[88lxi-shortram]

160 is easily doable without bottom end work. Build.the head,get a good cam,headers and an intake manifold and im sure you could get close to that.

[247shuer247]

i can throw in a GSR throttle body if i can find it

How much do you want for it bro ??

[247shuer247]

160 is easily doable without bottom end work. Build.the head,get a good cam,headers and an tintake manifold and im sure you could get close to that.

Just curious what can be done to the bottom end ??
And how much horsepower could be gained by doing that ?

[gfrg88]

bottom end. LS rods with some high comp pistons.. 12:1 if you're going all motor :)

something like THIS (http://www.ebay.com/itm/Wiseco-Pistons-Eagle-Rods-CRV-B20B-B20Z-12-0-1-84mm-/290580935544?pt=Motors_Car_Truck_Parts_Accessories&fits=Submodel%3ALS%7CModel%3AIntegra&hash=item43a7f93378&vxp=mtr)

[lostforawhile]

following this thread,


your only real choice on a header thats stainless is the OBX now or that DC if you can get it. I got one of the last S&S ones, the OBX is all right but may need some of the welds redone from what I've seen.

[247shuer247]

bottom end. LS rods with some high comp pistons.. 12:1 if you're going all motor :)

something like THIS (http://www.ebay.com/itm/Wiseco-Pistons-Eagle-Rods-CRV-B20B-B20Z-12-0-1-84mm-/290580935544?pt=Motors_Car_Truck_Parts_Accessories&fits=Submodel%3ALS%7CModel%3AIntegra&hash=item43a7f93378&vxp=mtr)

Does that one fit the a20 and yes I plan on staying all motor
Trying to bring n/a back

[lostforawhile]

Does that one fit the a20 and yes I plan on staying all motor
Trying to bring n/a back

same here all N/A old school

[obd0driver]

Yes LS rods and pistons will fit. You'll have bore the block to 83mm to get them to fit and get custom pistons made to match(thank messy for that info). Also your going n/a you may want to look in to ITB's you'll make power with them then a b16 intake manny. However you would have make your own ITB's. You also better get ready to run the bottle. A 75 shot should do the trick. A 5 angle valve job. Maybe even bigger valves. All this would be a nice start and get too your 200hp mark and maybe more.

[gfrg88]

Yes LS rods and pistons will fit. You'll have bore the block to 83mm to get them to fit and get custom pistons made to match(thank messy for that info). Also your going n/a you may want to look in to ITB's you'll make power with them then a b16 intake manny. However you would have make your own ITB's. You also better get ready to run the bottle. A 75 shot should do the trick. A 5 angle valve job. Maybe even bigger valves. All this would be a nice start and get too your 200hp mark and maybe more.

Don't have to get customs pistons.. Just get some off the shelf pistons with the bore you want. There's plenty of pistons out there in 83mm and 84mm that you can buy right off the shelf. Just make sure rods are LS. I believe all aftermarket pistons; itr, ctr, gsr, etc; will all fit aftermarket LS rods... This info has been around for YEARS. It's just recently that people have started using B series internals more often.. Check out the FAQ section...


In theory, you can use b16/b18 ITBs. I think 200 is pretty achievable without spray... Read Rich's(rjudgey) threads/post on head work, he's a god when it comes to that! I think it's all gonna come down to headwork to reach that power.. BIG valves, big cam, nice porting, etc...

[knifemind]

However you would have make your own ITB's.

http://www.extrudabody.com/servlet/the-306/KIT-cln--Honda-A20-Motor/Detail

[obd0driver]

Don't have to get customs pistons.. Just get some off the shelf pistons with the bore you want. There's plenty of pistons out there in 83mm and 84mm that you can buy right off the shelf. Just make sure rods are LS. I believe all aftermarket pistons; itr, ctr, gsr, etc; will all fit aftermarket LS rods... This info has been around for YEARS. It's just recently that people have started using B series internals more often.. Check out the FAQ section...


12:1 comp pisrons at a 83mm isn't some the u can just get "off the shelf". Most ls pistons are gonna be 10:1 with a 81mm or 84mm bore. The size needed is 82:7xmm.... so I would have to ask why would you run 84mm over and weaken your sleeves more then needed.

[Vanilla Sky]

Except we don't have sleeved blocks.

Service limit for these blocks according to the factory manual I just checked is 30 over, which would be close to a, 83mm piston. That's as large as I would go.

Diamond can make pistons to order. They have a file on hand for our engine, too. Give them a call.

[247shuer247]

So basically 12.1 83 mm with ls rods and the head bored to the same is crucial
Is diamond pricey with the pistons??

And lost I agree n/a all the way

And as for itb I'm gonna have to do some serious research on them first lol

[247shuer247]

Don't have to get customs pistons.. Just get some off the shelf pistons with the bore you want. There's plenty of pistons out there in 83mm and 84mm that you can buy right off the shelf. Just make sure rods are LS. I believe all aftermarket pistons; itr, ctr, gsr, etc; will all fit aftermarket LS rods... This info has been around for YEARS. It's just recently that people have started using B series internals more often.. Check out the FAQ section...


In theory, you can use b16/b18 ITBs. I think 200 is pretty achievable without spray... Read Rich's(rjudgey) threads/post on head work, he's a god when it comes to that! I think it's all gonna come down to headwork to reach that power.. BIG valves, big cam, nice porting, etc...


It's funny because I just recently found his thread and he is god at this lol

[247shuer247]

Yes LS rods and pistons will fit. You'll have bore the block to 83mm to get them to fit and get custom pistons made to match(thank messy for that info). Also your going n/a you may want to look in to ITB's you'll make power with them then a b16 intake manny. However you would have make your own ITB's. You also better get ready to run the bottle. A 75 shot should do the trick. A 5 angle valve job. Maybe even bigger valves. All this would be a nice start and get too your 200hp mark and maybe more.

Me is confused what do you mean by run the bottle what 75 shot ?

[ShyBoyCA6]

Nice can't wait for the outcome of this engine. im doing something similar but leaving room for more power. im trying to go for 140-160hp n/a for now, hope all goes well for your build. i suggest going obd1 for tuning.

[lostforawhile]

Nice can't wait for the outcome of this engine. im doing something similar but leaving room for more power. im trying to go for 140-160hp n/a for now, hope all goes well for your build. i suggest going obd1 for tuning.

I think he's going carb

[ShyBoyCA6]

I think he's going carb

Eww lol why downgrade?

[lostforawhile]

Eww lol why downgrade?

he's going FI and whats wrong with a carb setup?

[obd0driver]

Bottle=Nitrous.... 75 shot= it the amount of HP added when used

[ShyBoyCA6]

he's going FI and whats wrong with a carb setup?

what you mean he's going FI? he has an lx-i hatch....i just dont like the carb set-up lol

[lostforawhile]

what you mean he's going FI? he has an lx-i hatch....i just dont like the carb set-up lol

I think he's building a complete different Fi system from what I saw about his plans, the factory carb setup sucks, I'm talking about aftermarket setups, like webber, bikes carbs, even SUs :)

[gfrg88]

Eww lol why downgrade?

Downgrade?! lol

[lostforawhile]

there is something to be said for the sound of big carbs sucking air, that just isn't there on a FI setup, it's just old school, you may not get as much power out of it but it sure is enjoyable to drive. My inlets are six inched from the firewall so hopefully mine will make a lot of noise

[gfrg88]

12:1 comp pisrons at a 83mm isn't some the u can just get "off the shelf". Most ls pistons are gonna be 10:1 with a 81mm or 84mm bore. The size needed is 82:7xmm.... so I would have to ask why would you run 84mm over and weaken your sleeves more then needed.

http://realstreetperformance.com/store/je-forged-pistons-honda-acura-b18-b18a-b18a1-b18b-b18b1-b20-206.html

bam! Off the shelf ;)

[247shuer247]

To settle the debate I'm fuel injected and staying fuel injected . I do agree with pete about the sound
Of a carb but a weapon r intake sounds pretty beef as well

And shyboy thanks I wish you the same

[247shuer247]

Bottle=Nitrous.... 75 shot= it the amount of HP added when used

How often do you have to fill that bad boy

[gfrg88]

How often do you have to fill that bad boy

Depends how often you use it.. and how long you spray.. bottle size...



Btw, who the heck is pete? lol

[247shuer247]

Depends how often you use it.. and how long you spray.. bottle size...



Btw, who the heck is pete? lol



LOL sorry I was having this same conversation on preludepower
With my buddy Pete


But I was referring to what lostforawhile had said about the carb

[MessyHonda]

http://realstreetperformance.com/store/je-forged-pistons-honda-acura-b18-b18a-b18a1-b18b-b18b1-b20-206.html

bam! Off the shelf ;)

so almost 600 for pistons and another 300 on rods.

[247shuer247]

so almost 600 for pistons and another 300 on rods.

Plus the cost of those itbs lol :sad2:

Probably gonna save those for last lol

[247shuer247]

[QUOTE=gfrg88;1101585]


In theory, you can use b16/b18 ITBs. I think 200 is pretty achievable without spray...

i was thinking the same thing ...

if a regular b16 intake manifold could be fitted to fit
shouldnt the itb's be the same fit as the b16 mani ??

correct me if im wrong here because 1500 seems very steep for some itb's lol :)

[gfrg88]

It should! I don't see why they wouldn't work..

[MessyHonda]

for 1500 i would turbo

[247shuer247]

for 1500 i would turbo

i always wanted to go turbo but i just want to build an all motor
and see what i end up with.

im probably not gonna get that one most likely modify one
from a b18 lol depends how my budget is at the time

[247shuer247]

so these two should be a good fit and a pretty sturdy combination right ?

http://www.ebay.com/itm/Eagle-Forged-H-Beam-Rods-Integra-LS-B18A1-B18B1-CRV-CR-V-B20B-B20Z-CRS5394A3D-/270821504053?hash=item3f0e383435&item=270821504053&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

http://realstreetperformance.com/store/je-forged-pistons-honda-acura-b18-b18a-b18a1-b18b-b18b1-b20-206.html


Would I Need To Get Different cams and gear if im using these ?

[2oodoor]

for 1500 i would turbo

On an Lxi, I agree 100%...

The point of building the bottom end, or block, is to have a rotating assembly that can take forced induction or high rpms, and of course to raise compression but that can be done by shaving the head or just using different pistons.
A stock block A20 is pretty stout like it is so spending over a thousand just on the block seems radical to me. Ok, 250 + hp is radical for these :rockon:
You can boost AND build a bulletproof rotating assembly and achieve well over 300 hp, it has been done, but at what expense.
That is where the H22 swap makes a lot more sense.

[247shuer247]

On an Lxi, I agree 100%...

The point of building the bottom end, or block, is to have a rotating assembly that can take forced induction or high rpms, and of course to raise compression but that can be done by shaving the head or just using different pistons.
A stock block A20 is pretty stout like it is so spending over a thousand just on the block seems radical to me. Ok, 250 + hp is radical for these :rockon:
You can boost AND build a bulletproof rotating assembly and achieve well over 300 hp, it has been done, but at what expense.
That is where the H22 swap makes a lot more sense.

yeah i understand what you are saying. i personally would love to swap
my engine. but i want to let me see what the a block is capable of on its own.
if i ever got a second 3g i would definetly swap that. my dream is to drop a j series engine in this bitch lol.... maybe even a c series :wtf: lol

i can dream cant I ?

[obd0driver]

so almost 600 for pistons and another 300 on rods.

Messy the best thing is those still aren't 12:1 at 83mm lol and I'm sure if you call or email like it says to there not gonna have them in stock


84.0mm (+.120" Overbore) 12.0:1 (All Motor/Nitrous)
85.0mm (+.160" Overbore) 12.1:1 (All Motor/Nitrous)
84.5mm (+.140" Overbore) 12.2:1 (All Motor/Nitrous)
81.0mm (Standard Bore) 12.5:1 (All Motor/Nitrous)
81.5mm (+.020" Overbore) 12.5:1 (All Motor/Nitrous)
84.0mm (+.120" Overbore) 12.8:1 (All Motor/Nitrous)


I'm one for over building my motors. Just to be safe and have a long-lasting build that I can enjoy. Spending a $1000 on your whole block build wouldn't be that's bad. But spending over $1000 on pistons and rod is just dumb.

[cygnus x-1]

[quote=gfrg88;1101585]
if a regular b16 intake manifold could be fitted to fit
shouldnt the itb's be the same fit as the b16 mani ??

correct me if im wrong here because 1500 seems very steep for some itb's lol :)


$1500 is not expensive for ITBs (even remotely). Look up the price for a set from Jenvey or Kinsler. The cheapest ITBs that we could use off the shelf (with some minor modification) are these:

http://www.obxracingsports.com/products.php?pk=1469


The thing about these is that the bore size is huge and the runners are short so their effective power band will be in the 6000-8000RPM range. That's way too high for anything but a seriously built A20. The off idle throttle response will be awful and tuning will be an adventure. And forget about running any vacuum accessories unless you get a separate vacuum pump. ITBs are very cool when applied correctly but they are not easy to setup (VERY fussy and many things can go wrong).

I have a set of Extrudabody's that I've been playing around with for a couple years. I had them running for awhile but was having problems with keeping the throttle plates synchronized. They were sticking at idle and not closing all the way. Eventually I tracked the problem to the Bisimoto nylon insulating intake gasket. It was so squishy that the vibration and thermal expansion/contraction of the engine would cause the intake manifold nuts to loosen up. The loose nuts would create uneven clamping forces on the manifold, which caused it to warp and throw off the alignment of the throttle plates. I know it's crazy, but they really are that fussy. In the future I'll be using the normal thin paper gasket or just a very thin coating of silicone or RTV.


C|

[247shuer247]

Messy the best thing is those still aren't 12:1 at 83mm lol and I'm sure if you call or email like it says to there not gonna have them in stock


84.0mm (+.120" Overbore) 12.0:1 (All Motor/Nitrous)
85.0mm (+.160" Overbore) 12.1:1 (All Motor/Nitrous)
84.5mm (+.140" Overbore) 12.2:1 (All Motor/Nitrous)
81.0mm (Standard Bore) 12.5:1 (All Motor/Nitrous)
81.5mm (+.020" Overbore) 12.5:1 (All Motor/Nitrous)
84.0mm (+.120" Overbore) 12.8:1 (All Motor/Nitrous)


I'm one for over building my motors. Just to be safe and have a long-lasting build that I can enjoy. Spending a $1000 on your whole block build wouldn't be that's bad. But spending over $1000 on pistons and rod is just dumb.


You seem to have alot of insight

may i ask what kind of rods and pistons you are running ?

[247shuer247]

[quote=247shuer247;1101683]


$1500 is not expensive for ITBs (even remotely). Look up the price for a set from Jenvey or Kinsler. The cheapest ITBs that we could use off the shelf (with some minor modification) are these:

http://www.obxracingsports.com/products.php?pk=1469


The thing about these is that the bore size is huge and the runners are short so their effective power band will be in the 6000-8000RPM range. That's way too high for anything but a seriously built A20. The off idle throttle response will be awful and tuning will be an adventure. And forget about running any vacuum accessories unless you get a separate vacuum pump. ITBs are very cool when applied correctly but they are not easy to setup (VERY fussy and many things can go wrong).

I have a set of Extrudabody's that I've been playing around with for a couple years. I had them running for awhile but was having problems with keeping the throttle plates synchronized. They were sticking at idle and not closing all the way. Eventually I tracked the problem to the Bisimoto nylon insulating intake gasket. It was so squishy that the vibration and thermal expansion/contraction of the engine would cause the intake manifold nuts to loosen up. The loose nuts would create uneven clamping forces on the manifold, which caused it to warp and throw off the alignment of the throttle plates. I know it's crazy, but they really are that fussy. In the future I'll be using the normal thin paper gasket or just a very thin coating of silicone or RTV.


C|


yeah i have looked into the obx's not really sure if i want to go that way
but im having trouble finding info on anything else lol

[rjudgey]

Engine builds:

You don't need high compression forged internals for 200bhp.
I've built many blocks from stock rods, crank and cheap 3rd party piston makers that have run fine at between 160-200bhp from 7-8k rpm.

But I would make sure you have Honda/JIS pistons for A20A3/4 with the 9.4:1 CR ratio, so when you skim the head and deck the block removing between 1.5-2mm in total you can end up with a pretty decent CR ratio between 10.5-11:1 depending on howmuch you hog out to get the chambers nicely shaped up and flowing good.

Your power is in the head, cam, intake, exhaust the bottom end just has to try and keep up but unless your going for well over 200+bhp or 200bhp plus NOS forged pistons, uprated rods are just going to weigh down the rotational mass of the engine and give you you slower revving engine. Stock parts are not only strong but very very light compared to aftermarket ones.

One thing that I do with mine though is I use a much lighter wrist pin too which helps even more, if you got the monies having some custom titanium ones made would save huge weight but using federal mogul ones with come with their cheap rubbish pistons are very light and have never failed, the honda ones are overly heavy duty and heavy.

If you want the 200bhp or more don't mess around with stock plenum setups just get pair of weber DCOE's and convert to carb or go with ITB's injections equivalent of weber carbs. The ITB's will be better long term but to be honest in terms of setting up and getting you going on a budget the Webers can't be beat especially if they're new ones (won't go wrong as often).

Next up is a custom header with big long primaries and big fat secondaries leading up to a big 2.5" collector and main mandrel bent system, all headers that are available are only really designed for upto 180bhp, if your really on a budget get A20A3/4 exhaust manifold or A18 exhaust manifold which is 4 into 2 and have a custom downpipe made up with some big fat secondaries I think mine are 2" into 2.5" port and polish the hell out of the cast manifold and this can get you upto max 200bhp with 7600rpm peak power band. But a tubular equal length header without a CAT with 2.5" exhaust will get you 8000rpm peak and little bit more bhp I reckon 205-210bhp.

Once you have the exhaust sorted and the intake be it ITB's or Webers you really need to concentrate on the head, the block just needs to be hand built and blue printed with everything perfectly balanced (crank is by honda). Rods and pistons are the worst offenders, get flywheel and clutch balanced stock A18 flywheel can be lightened to 10lbs clutchnet for clutch kit red plate and sprung kevlar disk is best option. Beauty of A18/20 is the light weight bottom end the crank is half the weight of modern counterweighted ones so these engines love to rev and quickly too!! Only draw back is they rattle and shake like a tractor engine! lol! Mine sounds like a bag of nails at idle due to the slightly increased bore clearance and the un counterweighted crank but soon as your at WOT you won't be hearing anything but the most glorious noise you will have ever heard from a car engine!! Yes Webers/ITB's coupled with a Big valve pro head and 2.5" exhaust isn't for the faint hearted or the noise conscious!! Comes with a very big health and safety warning wear suitable ear protection!!

Ok so block taken care of you just need to concentrate on head work, I'm not talking bit of a clean up 3 angle vavle job. I'm talking full on radius valve seats, custom big valves with nice head design 1mm seat faces, worked chambers, reshaped ports and guide ends, bronze guides, perfectly matched intake and exhaust manifolds and gaskets, nice chunk of the head surface, double valve springs all round, upgraded titanium retainers nice little upgrade but not essential. If you went with the ITB/Carb route and seriously consider a A18 head with suitable manifold which are still available, the boost in CR ratio upto 11-11.5:1 combined with allowing valves upto 33mm intake and 37mm exhaust to be fitted, the unusual port layout giving excellent low down torque is seriously worth considering.

My current engine which is a A20A3/4 block std size pistons block decked just to flatten nothing major off it .10-15 mm at most, head 1mm off face, A18 head with 33mm custom SI valves on intake and 37mm exhaust all 7mm stems (could be way thinner next mod for new head), reshaped and hand finished by me with 1mm valve seats and faces all round, A18 exhaust double valve springs all round (can fit due to the thicker stems all round), bronze SI valve guides with worked guide ramps and the ends reshaped, pipercams regrind 285 degrees 10mm lift, the weakest part of this setup is the camshaft, the lift for the size of these valves is very conservative I'd like to get something custom made or look at hard weld from Bisi the lift on those is much more like it and could net me a 10-15bhp gain alone combined with exhaust header I think I'd be getting 230-240bhp with a power band of 4-8500rpm peak duration I think would be fine at 290 degrees and still keep it relatively driveable on the road it's the lift that is strangling the engine and the header. But point is with some nice valve and head work with a cheap old cam grind decent intake, and exhaust setup with stock A20A3/4 block you can hit 200-210bhp without too much effort hardest part will be finding someone to tune it for you and balance and set the idle and if you go for ITB's then mapping would need someone who is pretty hot as this ain't no vtec engine!! lol!! In UK there are excellent mappers that can cope with any engine from old school to new!!

[Tdurr]

^^ i love this man.

[86turbolude]

Yeah he is pretty awesome!

[obd0driver]

You seem to have alot of insight

may i ask what kind of rods and pistons you are running ?

I'm running anything right. I came from the D and H series motors. and im a boost man myself. rjudgey is right most of your power is coming from the head. I just happen to work from the saver then sorry point of view if you have two motors some time and money why not go fully built. my last D had standard bore vitara pistons, FJT Revolution custom lenght I Beam rods t3 turbo. more head work the I care to talk about. All said and done I was making 310whp at 17/18psi with a great tune form my DD. and thats what I'm hoping to do here with my A series.

[gtoman]

http://realstreetperformance.com/store/je-forged-pistons-honda-acura-b18-b18a-b18a1-b18b-b18b1-b20-206.html

bam! Off the shelf ;)

The off the shelf B series pistons that have been talked about are designed for a 4 valve per cylinder head, and it looks like the material between the two exhaust valve reliefs would come in contact with the exhaust valve in our 12 valve heads. I was thinking that I would have to get custom pistons made with 3 valve reliefs instead of 4. I would much rather use off the shelf pistons so someone please tell me that I'm worrying too much and B series pistons work great.:dunno:

[lostforawhile]

The off the shelf B series pistons that have been talked about are designed for a 4 valve per cylinder head, and it looks like the material between the two exhaust valve reliefs would come in contact with the exhaust valve in our 12 valve heads. I was thinking that I would have to get custom pistons made with 3 valve reliefs instead of 4. I would much rather use off the shelf pistons so someone please tell me that I'm worrying too much and B series pistons work great.:dunno:

just do some searching about what works you have a number of options even with the four reliefs that are proven to work

[rjudgey]

As said for N/A upto 200bhp engine stock honda pistons and JIS are good, but if you really want forged it is best to get them made to order doesn't really cost more JE and Diamond have patterns for our engines already. The B series ones will work worse case scenario if your using big valve like me is you'll have to have the crowns machined but the cost of this will end up probably the same as getting them made for the right fitment in the first place but it does allow you to use LS rods. You could try talking to JE or Wiseco and see if they'll do some B series with blank crowns and then have them machined to suit with just 3 reliefs with two exhaust on oneside and two on the other side this way you'll maximise your CR ratio try and stick to flat top pistons or ones with a very slight dish they produce better power and cause less stress on the head gasket chamber seals.

[247shuer247]

:help:
Engine builds:

You don't need high compression forged internals for 200bhp.
I've built many blocks from stock rods, crank and cheap 3rd party piston makers that have run fine at between 160-200bhp from 7-8k rpm.

But I would make sure you have Honda/JIS pistons for A20A3/4 with the 9.4:1 CR ratio, so when you skim the head and deck the block removing between 1.5-2mm in total you can end up with a pretty decent CR ratio between 10.5-11:1 depending on howmuch you hog out to get the chambers nicely shaped up and flowing good.

Your power is in the head, cam, intake, exhaust the bottom end just has to try and keep up but unless your going for well over 200+bhp or 200bhp plus NOS forged pistons, uprated rods are just going to weigh down the rotational mass of the engine and give you you slower revving engine. Stock parts are not only strong but very very light compared to aftermarket ones.

One thing that I do with mine though is I use a much lighter wrist pin too which helps even more, if you got the monies having some custom titanium ones made would save huge weight but using federal mogul ones with come with their cheap rubbish pistons are very light and have never failed, the honda ones are overly heavy duty and heavy.

If you want the 200bhp or more don't mess around with stock plenum setups just get pair of weber DCOE's and convert to carb or go with ITB's injections equivalent of weber carbs. The ITB's will be better long term but to be honest in terms of setting up and getting you going on a budget the Webers can't be beat especially if they're new ones (won't go wrong as often).

Next up is a custom header with big long primaries and big fat secondaries leading up to a big 2.5" collector and main mandrel bent system, all headers that are available are only really designed for upto 180bhp, if your really on a budget get A20A3/4 exhaust manifold or A18 exhaust manifold which is 4 into 2 and have a custom downpipe made up with some big fat secondaries I think mine are 2" into 2.5" port and polish the hell out of the cast manifold and this can get you upto max 200bhp with 7600rpm peak power band. But a tubular equal length header without a CAT with 2.5" exhaust will get you 8000rpm peak and little bit more bhp I reckon 205-210bhp.

Once you have the exhaust sorted and the intake be it ITB's or Webers you really need to concentrate on the head, the block just needs to be hand built and blue printed with everything perfectly balanced (crank is by honda). Rods and pistons are the worst offenders, get flywheel and clutch balanced stock A18 flywheel can be lightened to 10lbs clutchnet for clutch kit red plate and sprung kevlar disk is best option. Beauty of A18/20 is the light weight bottom end the crank is half the weight of modern counterweighted ones so these engines love to rev and quickly too!! Only draw back is they rattle and shake like a tractor engine! lol! Mine sounds like a bag of nails at idle due to the slightly increased bore clearance and the un counterweighted crank but soon as your at WOT you won't be hearing anything but the most glorious noise you will have ever heard from a car engine!! Yes Webers/ITB's coupled with a Big valve pro head and 2.5" exhaust isn't for the faint hearted or the noise conscious!! Comes with a very big health and safety warning wear suitable ear protection!!

Ok so block taken care of you just need to concentrate on head work, I'm not talking bit of a clean up 3 angle vavle job. I'm talking full on radius valve seats, custom big valves with nice head design 1mm seat faces, worked chambers, reshaped ports and guide ends, bronze guides, perfectly matched intake and exhaust manifolds and gaskets, nice chunk of the head surface, double valve springs all round, upgraded titanium retainers nice little upgrade but not essential. If you went with the ITB/Carb route and seriously consider a A18 head with suitable manifold which are still available, the boost in CR ratio upto 11-11.5:1 combined with allowing valves upto 33mm intake and 37mm exhaust to be fitted, the unusual port layout giving excellent low down torque is seriously worth considering.

My current engine which is a A20A3/4 block std size pistons block decked just to flatten nothing major off it .10-15 mm at most, head 1mm off face, A18 head with 33mm custom SI valves on intake and 37mm exhaust all 7mm stems (could be way thinner next mod for new head), reshaped and hand finished by me with 1mm valve seats and faces all round, A18 exhaust double valve springs all round (can fit due to the thicker stems all round), bronze SI valve guides with worked guide ramps and the ends reshaped, pipercams regrind 285 degrees 10mm lift, the weakest part of this setup is the camshaft, the lift for the size of these valves is very conservative I'd like to get something custom made or look at hard weld from Bisi the lift on those is much more like it and could net me a 10-15bhp gain alone combined with exhaust header I think I'd be getting 230-240bhp with a power band of 4-8500rpm peak duration I think would be fine at 290 degrees and still keep it relatively driveable on the road it's the lift that is strangling the engine and the header. But point is with some nice valve and head work with a cheap old cam grind decent intake, and exhaust setup with stock A20A3/4 block you can hit 200-210bhp without too much effort hardest part will be finding someone to tune it for you and balance and set the idle and if you go for ITB's then mapping would need someone who is pretty hot as this ain't no vtec engine!! lol!! In UK there are excellent mappers that can cope with any engine from old school to new!!


rjudgey :bow: . I for the most part understand why u mentioned to do all of those mods. except for converting to carb ? i always beleived that more power can be achieved with the fuel injection system. although i have heard of people using the a20a3 head with the a20a1 because the block is longer but i dont think thats what you are reffering to is it ?

also you mentioned custom headers i was looking into dc headers but you mentioned that they are probably only good to about 180 hp. so which brand should i consider and which way should i go ? 4:2:1 or 4:1?


now the head work is where you lost me :help: lol where can i get these bronze guides and double valve springs titanium retainers. i would have no idea where to start looking for these lol

like i said before any help is greatly appreciated

[gfrg88]

The off the shelf B series pistons that have been talked about are designed for a 4 valve per cylinder head, and it looks like the material between the two exhaust valve reliefs would come in contact with the exhaust valve in our 12 valve heads. I was thinking that I would have to get custom pistons made with 3 valve reliefs instead of 4. I would much rather use off the shelf pistons so someone please tell me that I'm worrying too much and B series pistons work great.:dunno:

There's more than one person running LS pistons.. Ryan(hondalude86), I believe is using pretty high CR pistons from Bseries. AND he has a big cam, revs the fuck out of it, with no problems.. well besides the HG issues :p

[MessyHonda]

There's more than one person running LS pistons.. Ryan(hondalude86), I believe is using pretty high CR pistons from Bseries. AND he has a big cam, revs the fuck out of it, with no problems.. well besides the HG issues :p

I think 89T also is using B series pistons that are 10:1 and he is still boosted.


now lets all be real. it all comes down to how much money you are going to spend. it might be cheaper to do all the work yourself if you know how. power cost money

[rjudgey]

Carbs versus FI:
Were not talking normal double barrel downdraught versus multi point injection.

Were talking racing sidedraughts with one choke per cylinder and Individual throttle body injection which is also one choke per cylinder.

Weber sidedraughts will allways be better than stock type or single plenum style injection setup for power, economy no injection wins there.

As for whether racing carbs v racing injection (ITB's) then ITB's will have a upper hand better low end and fuel atomization and also the bores can be had from 40-55mm carbs are limited to size and have lots of bits in the chokes to mix the air and the fuel up which ultimately looses velocity in doing so. But how big a difference is this not a huge amount depending on application 5-10bhp ITB's can gain on racing carbs on high power outputs of 180-230bhp. Whether this is worth the $1000 extra on decent ITB's and the $1000 more on rolling road sessions and tweaking is another thing racing carbs in UK are definately cost effective solution to big power if you don't care about economy (I still get 400miles to tank though on highway!). The carbs can be bought relatively cheaply compared to ITB's and don't need a computer tech to tune but someone who is skilled with a screwdriver and set of jets. If enough time spent tuning you can do this yourself like I have.

Exhaust manifold yes DC and others too restrictive for big power if you really want to get 180bhp + you need custom header there is no aftermarket support and to be honest most the home built fast motors out there will have custom headers too anyway. The pipes on the available headers are too restrictive you probably get better gains from stock cast one ported and polished with custom downpipe with 2" secondaries and 2.5" collector and main pipe which is what I use and get 200bhp from this no doubt a proper tubular 4-2 section with nice long primaries would get me 10bhp more and another 500rpm I'm hoping to get something made up when money allows but even with a good contact in racing exhaust fabrication still looking at about a £6-700 damage to have made. Also a lot damn lighter too! lol!

[gtoman]

Hearing that LS rods and B series pistons work makes me uber happy! Now to find a spare block...

:cheers: