What year is my motor?

ASSISTANCE Stock Engine-Bay Components
1

i have asked this question before but didnt really get much of a response. i have a 1990 acura gs i just bought, the motor has been replaced in it before i got it. it has b18a1 stamped on it, then HM then the block number 2xxxxxx.

now i do not think it is a 1990 because i have 2 other motors out of 1990 integra’s with an A stamped then b18a1 then 1xxxxxx. so if anyone could help me find out what year integra this motor is out of i would like to know. i am hoping it is a 92 or 93 cause in the specs it says they have 10 more hp … thanks for any help i you guys can give.

2

Did you look at the head stamping? not sure if anyone knows what the serial numbers mean.

3

Yeah you should look at the head. Even if the block is from 92-93 it’s not any different from 90-91. The year is shown on the exhaust side, right about the heat shield. There will be a row of numbers inside circles with slashes in between them. The first two are the year. For example on my P74 head from a CR-V it says (9/7).

4

i have looked on the head

on the head it says 9/4 in one spot i didnt think that was right though i thought i was looking in the wrong spot. so i guess that means its a 94 conversion? but it is not obd 1 it is obd0 so maybe i am wrong again… geez i dont know

i was looking at the spec chart and saw that the 94’s make 142 hp and i think 126 torque if this is a 94 engine with 90 injectors and 90 distributor WOULD IT HAVE THE SAME SPECS? also it doesnt have the 94 exhaust manifold so i would think that would choke it down some too. i dont think the manifold would fit between the crossmember and the block though. thats why its not on there .

5

if it says 9/4 that is actually from a 95, the heads are always stamped a year earlier for whatever reason. The gains were from the cams, intake manifold, header, and ECU, so you have more power than a stock 90, but not as much as a 95.

6

just a correction the 3rd generation integras had a B18B not a B18a that was in the 2nd gens.

7

Your motor is a 1991 Motor.

If you look at the engine model number and then the Hm number the first number tells you the year of your motor.

i.e. in this case the b18a1 was first in production in 1990 hence the 1xxxxxx and in 1991 it would be 2xxxxxx. So a 94 GSR motor would be b18c1 HM 1xxxxxx and a 99 would be b18c1 HM 6xxxxxx.

Hope this clarifies things