Rebuilding a B20A???????

[hammer3rd]

Just bought one myself and have to do a rebuild. It was bought in pieces but I think it is complete. Guys I am a little new and could use a little guidance here. Rob has helped a good bit but he is building a boosted motor. Carotman seems to have a solid build and I may follow just new to this and don't want to have to do it twice. Some of my questions are what compression is best to have with a dependable motor and what about b18 cams, what do you have to do to make them work. Thanks for any input guys Mike C in NC.

[MessyHonda]

im also rebuilding my block as we speak

[hammer3rd]

Whats your plans. Any little secrets you can pass on to help a newbie. I know there is a wealth of info on here but the fact is there is so much is can be an overload at times. And then sometimes some of the small important little details get left out. Thanks for the respond and any thing you are willing to offer.

[MessyHonda]

https://www.3geez.com/forum/showthread.php?t=70305

my budget is around ~2500

[hammer3rd]

Hi Messy. Mike here and I finally had a chance to go through your thread and I have a few q's. Did you use your stock crank and if so what did you do to it. I like the rods and pistons will probably go the same rout. I called colt cams and really like the tri flow cams they make. Look at the wab site http://www.coltcams.com/html/tri_flo...logy/index.cfm and see for your self. And let me know what you do with your head. I want to get it p&p but I am scared to send it off (took me one and a half years to find) but I would like some parameters to go by. Looking foward to seeing more.

[hammer3rd]

just bought an 87 hatchie. Going to b20a b2k5 her. Want a little input on the 87 wireing/fuel injection. I read on here 88 and newer is better. Is this true or can I just stay 87. Thanks for any input Mike C.

[hammer3rd]

Well I talked to a few people today about building my b20a and got sone very good news and prices lol.

[2ndGenGuy]

Stock crank will be fine. Not much you can do with it really. You can buy an Eagle forged crank, but the stock crank is forged as well, so there's no knowing if it will be any better. You can run H23 rods which are cheap, and are the same length and end bores, so basically are a direct replacement but are quite a bit beefier. You can run any B20A5 (3g Prelude) pistons or any B-series pistons but the piston pins won't match up, so you'll have to get the rods or pistons modified if you want to run regular B-series pistons.

B18 cams will work but you have to chop off the ends of them I guess. There are lots of great cam selection threads over on Prelude Power in the 3g Prelude section. The 3g Prelude B20A5 can fit the same cams as the JDM B20A so anything that applies as far as valvetrain and cams applies to our B20A motors. The detailed info there is great with lift and duration charts overlaid on eachother. Great info! Plenty to read. :)

Also check out B20A.org :D

[hammer3rd]

Thanks for the info. Just not wanting to go 5speed. I do just dont want to loose the highway manners I have now. You know 3000 rom at 75 mph. But am more than likely going b2k5 with lsd.

[RobT5580]

The B20A has a pretty close gear ratio so forget about 3k rpm at 75mph mine is closer to 4k.

[hammer3rd]

How close to 4k. I am also baseing my rpm off an auto. I do belive they have a little lower overdrive 4th gear as compared to the 5 speed 5th gear. Does anybody what a stock 5speed runs at 75 mph.

[RobT5580]

I can check next time i take my accord out but its up there for sure.

Do yourself a favor and figure out what you need for stock parts and track them down because parts are scarce these days. Not everything will work from other cars so you really need to read some of the main builds like Carot and YK to see what you need.

And your lucky we all pitched in and posted this stuff because back when i started mine the three of us were all in the dark doing tons of leg work. YK and Carot have put in a lot of time to get this stuff on the web.

[hammer3rd]

Thanks man. I am going to need all the help I can get. I thought all the parts were pretty much B20A5 with a very few coming from over seas. Please tell me if otherwise. I have finally got a plan now all it is going to take is blood,money,sweat,money,and tears did I say money. I am pretty much going to follow carotmans. I like the way he did things including the quit muffler from an sei. And I really like colt cams. Have spoken with then 2 times and the triflow seems to be what I will go with. Stock rods high cp pistons and I think I found someone to p&p my head. A b2ks with lsd and 9lb flywhaal should about do it. Oh does anyone have a obd1 setup on a b20a. I read in pp where a b20oa5 gained like 25 to 30 horsepower with a good tune. Does this soubd right to you guys or a bunch of bs. Well its off to start so wish me luck and thanks for all your help so far and I am sure in the future.

[mykwikcoupe]

yeah Im running obd1 on my b20a. It cleans up the engine bay well and I was able to swap out a few other items to really make it look mmuch better.

[hammer3rd]

Cool thanx for the info. Do you have ant pics. And did you have it tuned if so how much did you gain.

[RobT5580]

My car was OBD-1 but i was boosted and running a AEM EMS so my car is not comparable.

Not all parts are interchangeable and it is been hard even getting them overseas. I use to order from Japan but have not been able to get stuff lately. So do your homework and figure out what parts you will need to hunt down. Carot went a better route using as much USDM parts as possible but i stayed JDM because i have adjustable cam gears that cost a lot and have not been easy to sell so i could convert.

[hammer3rd]

Yeah that is my plan to go us. And I belive most will swap that way but if not I will do what is nessary to do to make it run. Does any one what hp #s are possible out of a high cp b20a.

[rjudgey]

I'm starting a build on a B20A have Eagle steel billet crank, with Karillo lightweight Rods and Forged Wiseco flat top pistons oversize .5mm, ACL race series bearings oversize rings hand gapped and engine fully blueprinted.
Head I'm working on some nice port shapes, have bronze guides with SI blank valves which will be machined with new head sizes of 30mm exhaust and 34.5mm maybe just squeeze 35mm inlet valves in, then will be looking at some Cat cams camshafts with duration off around 270 degrees and 12mm lift. Will be running from some ITB's probably as the Webers will be topped out i think probably go for some 45mm bodies running Emerald ECU. Exhaust will be custom made with 2.5" collector with Long primaries and 2.5" mandrel bent system.
This should get pretty close to the Mugen spec B20A5's which use to run 240bhp with a 26mm restrictor place in the intake system. But we will just have to see! I'm not planning on running crazy Compression should be around 10.5:1 or 11:1 depending on howmuch i decide to take off the block and head.

[MessyHonda]

I'm starting a build on a B20A have Eagle steel billet crank, with Karillo lightweight Rods and Forged Wiseco flat top pistons oversize .5mm, ACL race series bearings oversize rings hand gapped and engine fully blueprinted.
Head I'm working on some nice port shapes, have bronze guides with SI blank valves which will be machined with new head sizes of 30mm exhaust and 34.5mm maybe just squeeze 35mm inlet valves in, then will be looking at some Cat cams camshafts with duration off around 270 degrees and 12mm lift. Will be running from some ITB's probably as the Webers will be topped out i think probably go for some 45mm bodies running Emerald ECU. Exhaust will be custom made with 2.5" collector with Long primaries and 2.5" mandrel bent system.
This should get pretty close to the Mugen spec B20A5's which use to run 240bhp with a 26mm restrictor place in the intake system. But we will just have to see! I'm not planning on running crazy Compression should be around 10.5:1 or 11:1 depending on howmuch i decide to take off the block and head.

sweet...my goal is 180whp...i know the head will cost me alot to get it ported and polished...i dont plan on pushing it over 7200rpm

[RobT5580]

If i am not mistaken the intake valves Ferrea use H22 blanks because the stem sizes were that diameter.

[hammer3rd]

Thanks guys. Sounds like what I am going to run. I dont want the ITBs but what hp#s can you make with a b16 intake and some tb mods. Has anyone ran the colt cams triflo grind. They sound really powerfull and very streetable. But other than that I am going to drop some serious coin on the head. Bigger valves p and p speings and so on. what is a good rpm to build for. Never owned one of there so have no clue. 7500,8000 just dont know.

[2ndGenGuy]

Choosing your RPM is the same for any motor. It's going to depend on your camshaft selection mainly, because that's going to be the major factor in determining where you're making power. The more duration/overlap you choose typically the higher up in the RPMs you'll be making your power. If you choose Colt, they should be able to tell you where up in the RPM range that thing should be getting it's power. Well, same for any camshaft manufacturer actually. Good news is, you have lots of options with all the B18 cams out there.

[hammer3rd]

Thanks 2nd but I was actually meaning a safe rpm range for these motors. You know what they can turn without tossing a rod through the block. Maxium safe rpm. Sorry for the confusion but thanks for the info. So any got real good hp#s from a stock type fuel injection system without haveing to go to the ITB s

[MessyHonda]

Thanks 2nd but I was actually meaning a safe rpm range for these motors. You know what they can turn without tossing a rod through the block. Maxium safe rpm. Sorry for the confusion but thanks for the info. So any got real good hp#s from a stock type fuel injection system without haveing to go to the ITB s

these engines dont make that much hp at high rpms...the bore and stroke ratio says that 7200rpm

[hammer3rd]

Cool. Thanks messy. On another note is there any difference worth worring about between the B2k5 and the F2k5. I know about the gear ratio differences between 2nd and 3rd but is it really enough to worry about for a street car.