Trying to calculate new compression
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
Trying to calculate new compression
1989 stock, automatic trans
I’m trying to calculate my current compression. The reason why is because I think the local counter man at GM dealer might have sold me an incorrect head gasket. I blew a head gasket a while back and decided to replace both sides myself. Corvette Shop wanted over 3000.00 to do it. I had never done it before
Not knowing that much and not doing my homework, I took the ones he said were correct, that being .051 thick.
I used a scope and looked inside chamber and I can see they are what I would call dish pistons. This is the original engine and doesn’t appear it was ever rebuilt. The mileage is 53,000 miles, 47000 when I bought it. Anyway, they are a little bit dished with valve reliefs
I can’t figure up compression without knowing piston dome volume. Anyone know? The engine is already back together and runs fine. I just want (NEED) to know If I’m leaving any horsepower behind due to low compression
I’m trying to calculate my current compression. The reason why is because I think the local counter man at GM dealer might have sold me an incorrect head gasket. I blew a head gasket a while back and decided to replace both sides myself. Corvette Shop wanted over 3000.00 to do it. I had never done it before
Not knowing that much and not doing my homework, I took the ones he said were correct, that being .051 thick.
I used a scope and looked inside chamber and I can see they are what I would call dish pistons. This is the original engine and doesn’t appear it was ever rebuilt. The mileage is 53,000 miles, 47000 when I bought it. Anyway, they are a little bit dished with valve reliefs
I can’t figure up compression without knowing piston dome volume. Anyone know? The engine is already back together and runs fine. I just want (NEED) to know If I’m leaving any horsepower behind due to low compression
Last edited by mlm0; Apr 2, 2020 at 11:40 PM.
