Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



Visit the new site at vcca.org

Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Apr 2014
Posts: 65
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: Apr 2014
Posts: 65
I have my 1931 Chevy sedan manifolds off for maintenance and while off I would like to check the cylinder compression. What is an acceptable pressure? I don't think I have a problem but worth checking while I have it apart this far.

Thanks

Filling Station - Chevrolet & GMC Reproduction Parts


Filling Station


Joined: Jan 2002
Posts: 30,701
Likes: 141
ChatMaster - 25,000
Offline
ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,701
Likes: 141
The compression should be in the 80 pound range. Actual reading can be determined by cranking speed and engine temperature. More important is the all cylinders should be even within a few pounds.


Gene Schneider
Joined: Apr 2014
Posts: 65
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: Apr 2014
Posts: 65
Thank You, Being that I have all manifolds off what can I expect with cold cranking?

Thanks Again

Joined: Nov 2001
Posts: 29,863
Tech Advisor
ChatMaster - 25,000
Offline
Tech Advisor
ChatMaster - 25,000
Joined: Nov 2001
Posts: 29,863
Quote
The compression should be in the 80 pound range

laugh wink beer2


The Mangy Old Mutt

"If It's Not Junk.....It's Not Treasure!"
Joined: Apr 2010
Posts: 734
Likes: 14
Oil Can Mechanic
Offline
Oil Can Mechanic
Joined: Apr 2010
Posts: 734
Likes: 14
Hello hopwooddon,
It appears that near 80 pounds is a good compression with a cold engine block. I do not know if your engine is brand new, but with wear and such, you might have lower readings. Leakage around rings and valve seats start happening over time. If you do a check on a warm engine, you should expect a little higher number, but not drastically higher. All cylinders should read about the same, within a few pounds. Any one or two cylinders that are significantly lower may indicate issues. Rings, valves, head gasket, that kind of stuff. Oil useage and smoking exhaust indicates worn rings and/or valve guides. Compression testers can be of different types. I think the screw into the spark plug hole style makes for a better seal and more accurate readings.


Link Copied to Clipboard
 

Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA.

Powered by UBB.threads™ PHP Forum Software 7.7.5