I checked the compression on my 350 and I got 120? Is that low good or high?? Remenber it is completely stock.

 

https://www.thirdgen.org/techbb2/sho...mpression+test

https://www.thirdgen.org/techbb2/sho...mpression+test

 

but my question still stands.....is 120 too low. Although your links did answer a couple of my questions. THANKS

 

120 sounds low....you gotta do all 8 though, and compare them.

 

Ye I checked all of them and they are all about 120.

 

Moved to Tech/General Engine.

 

Sounds about right if you have a 7.8:1 smog motor. On the other hand my cammed 1983 9.5:1 305 has 185 psi in every cylinder. Are you fully opening the throttle while cranking the engine?

 

For a 350, 120 sounds low, I mean, my 350 (granted I built it to my own specs) was pulling 190-200PSI per cylinder. 120 just sounds low from what I've seen...most people are around or above 150, even with alot of miles. If the engine runs strong and doesn't gulp fluids though, maybe thats just your engine.

 

the number doesn't mean much it's the differance between numbers that matters

 

I agree you should not see more than a 10% difference between cylinders. 120PSI means that you should not be below 108 psi or abobe 132 psi in any cylinder. My 1983 305 has 170,000 miles on it and still puts out 185+/- 2 psi in every cylinder with a fair sized cam. Another check would be to put a teaspoon of oil in the cylinder then do the test. If the numbers come up alot you most likely need rings.