B_gentry14

I'm trying to do a motor swap from a 1993 honda prelude vtech with a h22a1 in it to a f20b. I'm not trying to get spoon fed I just want to know what all change is their to be made. I have roughly around 3500 to spend on the motor. My goal is to push 300 whp. Few upgrades I was thinking about was crowler stage 2 cams,crowler adjustable cam gears skunk 2 valve springs, low compression mahle pistons, and a turbo kit. I really just need to know if motor mounts line up, different axles, wiring harness, Ecu. Thanks for all your help and support

Sparksman

What transmission are you going to be using?

What is your current ECU?

The F20b will be 1K +/- pending where you source it. So that leaves say $2,500 or is that $3500 on top?

Im just taking the guess you have the factory ecu, which cant be tuned. So after you find a obd1 5spd ecu from a civic or integra you can either run Chrome, or get a actual tuning program like Neptune RTP or Hondata with a data-logger. I went Neptune myself, im only about $500 or so into it. I can keep my laptop hooked up to it at all times too. If you go cheap maybe $200 for ecu.

Then remember a street tune, and dyno tune cost money as well. "turbo even more". At least $300-$500 for a street and dyno tune, on your ecu.

You should source a turbo and other main parts separate. The only kit Id buy is a charge pipe/intake kit and inter-cooler.

Turbo header

Dont worry about cams, if you get the manual version F20b it comes with the H22a Type-S cams. Those will be plenty for boosting on a stock bottom end.

Building the bottom end would cost about your full $3500 said and done with no turbo parts. H22a pistons dont fit, there is almost no aftermarket pistons for the F20b other then bisi. You would have to sleeve at that point to run bigger pistons. Didnt know Mahle did for f series, I did for H series.

Get some new injectors and a bigger fuel pump.

As well as ARP head and main studs.

You should be able to get 300whp out of that.

If you still have money left over forged rods would be top on my list.

You reuse the h22A1 wire harness, and use same axles. I believe you may need F series engine mounts though, im not 100% on that but sounds right.

B_gentry14

Thanks a lot bro I can tell you done this before. on bisimoto web site they have 8.4:1 86mm compression pistons for 460 bucks, they also have have a bearing set for 169 dollars. the stock sleeves in the f20 should work right as for transmission goes I'm going LS. I do want a programmable computer so I will check into Neptune but, f20b is obd2 mine is obd1 what changes do I need for that and is 1000 cc injectors big enough to run that motor thanks for all your help

Sparksman

Honestly Id keep the stock pistons and get forged rods instead. Factory pistons and sleeves are good for well over 300whp.

Just reuse the alternator off your old car, as well as the distributor. Its easier to make obd2 to obd1 then the other way around.

LS trans, and in H2B?

1000cc's should be plenty fine but will need to be fine tuned.

B_gentry14

Thanks a lot I just herd lower compression for better boosting and the f20 has a pretty high compression I'll look for some forged rods do you know any good brands?

Sparksman

Lower compression is better, if you wanted you could get a thicker head gasket. That would lower the CR. Wiseco, Eagle, theres a few out there, just have balanced before installing. I would highly suggest getting better valve-springs too.

B_gentry14

Yea I forgot to mention that skunk2 has a nice set that I want to get with titanium retainers thanks a lot bud it seems like you do this for a living

Shadowcat

If you plan on boosting an f20b your going to need to lower the compression from 11:1 down to 8.5-9 or so. However only a few people have forged out an f20b for one good reason- no one makes forged internals for the f20b and b16b engines. Leaving you only a few options. Dont go with bisi. It is extremly over priced and you have to bore to 86mm which is not safe if you plan on leaving stock sleeves. Since no one else here on honda tech knows anything about the f20B i took the liberty to sit down and do all the math. I am not finished with my build. But have the bottom end together which is important. And it seems like this information is gold for the f20b guys lol. Basically it comes down to using an h22a4 55mm main bearing crank. H22a4 eagle rods. Weisco high comp f22a (or custom) pistons, f20b main bearings, f20b head gasket which is an 86mm bore. Main bolts and head bolts are a good idea. F20b/h22/h22a4 oil pump.