can anybody give me info on an A20 motor I don't know what it is out of I bought a 1990 prelude and It has an A20 in it, and im pretty sure a 1990 prelude doesn't have that motor

 

not really the proper sub forum for this... try prelude or tech/misc, or even "classics".

a 1990 prelude should have some variant of the B20A. however, i believe this is the "black sheep" of the B-series family and is more of a twin cam version of the A20 than it is an early version of other B-series'. I'm no expert in these models but it would surprise me if an A20 were a direct bolt-in replacement for the B20A in your 1990 prelude.

oh, and according to wikipedia... the A20 came in the second gen preludes and contemporary accords through '89. both fuel injected and carb versions alike.

 

3rd gen Ludes came with variants of the B20, some SOHC some DOHC. I think some of the B20 SOHC are closely related to the A20 SOHC, so someone may have used the A20 as a replacement.

But this depends on one sub model you have and what market you are in or the car is from.