difference between b18a1's

i have the chance to pick up a b18a1 but there is supposed to be a 10 hp difference between the 90-91 and the 92-93. How can i tell visually what year it is?

look by the exhaust manifold, there numbers there like a circle with a line in the middle and a number on each side, there will be either a 9/0 or a 9/1 or a 9/2 etc and thats teh year

Originally posted by 88ReX
i have the chance to pick up a b18a1 but there is supposed to be a 10 hp difference between the 90-91 and the 92-93. How can i tell visually what year it is?


Theres no difference. The only different ones are the 94 and up ones (b18b)

90-91 are OBD0. 92-93 are OBD1. you can tell a difference by looking at the block numbers, or by looking at the intake manifold. the obd0 ones has a dashpot and also an air boost valve, which were some "old looking" sensor type things on the manifold. the OBD1 B18A1 didnt have these. Also, look at the wiring. a 92-93 engine will have a 4 wire O2 sensor

arnt the numbers on the front of the head diffrent like pr3 or pr4