Stock 383 cylinder compression??

[Fummins]

Recently performed a cylinder compression test on my stock 1964 383/4 barrel motor, wondering what "average" numbers should be, and what others have seen on similiar motors? Thanks

 

[Cranky]

Never checked a 64 but a healthy engine shouldn't vary more than 10% between any cylinder and the less it varies the better but according to a Motor's Repair Manual it should be 160 for a 64 model year 4 bbl engine. Of course this can be different if the engine has ever been rebuilt or has had a different cam installed or is worn...

 

[lewtot184]

the actual number could vary from 130-180lbs, depending on pistons and cam timing. like cranky said; being within 10% is more important.

 

[1967coronet]

I just checked my 1965 383 this spring, no problems but I just wanted to see.
High reading was 132, lowest was 125 all others were in between. seems to run just fine, no blow by ect.

 

[Meep-Meep]

I'd say in the 150 range within 10% would be great. 125-132 is a bit low IMO but they are even so it will run smooth.

 

[lewtot184]

in my experience around 130 usually indicates 8:1 pistons in a stock build.

 

[Fummins]

Thanks for the input guys, im about 135# average, she runs pretty good.