Page 1 of 1

Compression for a 74 750s

Posted: Fri Jan 27, 2012 1:50 pm
by Aussie_bikerBob
Hi
I have pulled a 74 750S out of the shed and want to check the condition of the engine (without tearing it apart). A light probe down the intakes looked good but a compression test may tell me more. I need to know the approx compression for the 74 750S in psi. Thanks

Re: Compression for a 74 750s

Posted: Mon Jan 30, 2012 6:34 pm
by wdietz186
Compression figures are so variable because of quality and calibration of different gauges.Usually 120 or so is normal.The important thing is the readings are fairly close to each other. Looking down the intakes won't really tell you much,the conditions in which it has been stored will be the important factor. It is pretty moist here in the DC area and if it spent time outside rust in the bores and the valves is likely. If it turns freely and ran ok before it was put up I'd get it to run some before making any determination concerning compression numbers. You can PM me if you want.
Bill