Re: Normal Compression Test Values for 1931 Super 8

Posted by Tim Cole On 2022/5/18 10:55:06

Static compression is cranking compression. Dynamic compression is with the engine idling, which always is lower, unless those labels are wrong of course.

The variation isn't so hot either and I would expect that should be fixed as it is poor enough to affect idle quality and cause overheating.

Freeing up the valves can be done with the valve cover off and a pair of water pump pliers if you are lucky, but only is a temporary fix. Running Gumout through the thing might help a little.

The least expensive route is pull the head, take out each valve, and polish the stems with crocus cloth or whatever. Clean the guides out, clean the oil pan, crankcase, and start running Risolone with detergent oil.