Soon my brother will be giving up his 1991 lude, and i am thinking about picking it up and turning it into a track-day car. the only problem right now is that the b21 engine is typically burning a lot of oil. so much that on start-up, oil spits out the exhaust. I know that in order to race it, i would have to rebuild the motor, but i know that even if i did, abusing the b21 would just bring me back to square one (burning oil). so what engines other than the h22 (too expensive) or the b20 (to weak) can fit into a 91 lude? would a f22 be a reliable and cheap option? could i get different cylinder liners on the b21 so they don't destroy the rings?

 

The B20 only has 5 less HP than the B21.

F22 also wouldn't be cheap because everything needed for an H22 is needed for an F22. Trans axles, mounts, ect.

 

if i swapped in a b20, would the transmission from the b21 bolt up to the b20? would i need a new ecu? would i need new mounts?

 

All that stuff would be the same from B20 to B21, except the ECU, even then an ECU isn't absolutely needed, fuel trimming between a 140 HP 2.1 Honda and 135 HP 2.0 Honda engines with the same heads aren't going to differ much.

 

It depends on which B20 you're talking about. The B20A5 and B21A1 are pretty much the same engine with a few minor internal differences. The B20B/B20Z are a completely different engine that'll require a lot of modification to fit.

 

If you swap in a b20 keep the intake and ecu from the b21.

b20a=0bd0
b21=0bdI

computer and intake must match

 

and the exhaust manifold too. ive done the complete swap once before and cleaned up a hack job on another car where the motor and the manifolds were b20's but the computer was b21

anything b21 should be stamped on it pk3

b20 parts will have pk2