b21a1 vtech

A friend of mine had 2 b21a1's fall into his lap so he decided to completely build up one of them with a b series VTEC head.

I know that most of you think that this is a bad idea considering the b21a1's reputation but the guy that will be building this engine has built motors for nascar, so he knows his shit and should be able to adress all the reliability problems with the b21a1.

I would like to hear your thoughts on this project or any stories you might have on people building this motor and what head you would recomend.

here's a thought. it's spelled VTEC :banghead: :banghead: :banghead:

typing faster than i was thinking :)

didn't the b21 come off of those older lude's?

i'm not sure its a strong block to be building off of, but if he does it. plz let us know about the results.

note to mods and admin: you guys should enable some kind of script on this forum that changes vtech and/or v-tech to: VTEC

They came out of a 91 quaalude si.

My friends brother got the car with a locked up motor and dropped another b21a1 in it, then got t-boned 3 days later when he pulled out infront of someone like a moron.

im pretty sure thats not gonna work. there totally different from the b20's in the crvs usdm and jdm im sure its not gonna work its a totally different motor hes be better off with b20b or b20z. im all dumb right now so excuse me i noticed i said the same basic thing twice lol :screwy: its gonna be a big head ach if he trys it.

He won't be talked out of building this motor, I've already tried it. He has alot of faith in his engine guy.

I have read everything I can find about the b21a1 and found only bad things about this motor other than its output. People say its the worst engine honda ever made.

He won't be talked out of building this motor, I've already tried it. He has alot of faith in his engine guy.

I have read everything I can find about the b21a1 and found only bad things about this motor other than its output. People say its the worst engine honda ever made.

i dont think everything would line up right. its like putting a dual cam head on a block made for a single cam head, it wont work.

and yea the older b20's aren't well known for there performance. i would look for a different b series block for the head. :2cents:

Does anyone know where I might find out if the head will bolt up?

I promise you that It wont work. I have a B21A1 in my garage, that is for sale (or give away), Come and get it or I'll ship it. It is useless scrap that takes up preacious room in my garage!! < that should tell you something. Plus after you put the money into a B21 and get it to a H22A4 swap w/ the same power and much more reliable.

Can you please tell me what exactly sucks about it?

Besides the thin cylinder walls, it is an over heater, starting problems, various mechanical problems, it just isn't a good engine.

AND NO THE VTEC HEADS DO NOT BOLT ON.

Alright, thanks for the info, I just wanted to hear some of your opinions on this project.

I'll let everyone know what happens after he takes it to the machine shop.

It doesn't have thin cylinder walls....It's cylinder walls are Fiber reenforced alloy walls which eat up piston rings. That's why they burn oil, the walls either eat the rings up, or opposite, the rings eat the walls up. The b21a1 or b20a5 for that matter will not have a b16a vtec head just bolt up, it takes a lot of custom fabrication and specially modified head gasket. Dont forget about the obd1 wiring conversion, have fun getting vtec to engage....
Only about 2 people have done this to thier Ba4 Preludes, it's not a common swap, it's very rare and hard. Not a good way to spend your money IMO...but good luck with it!