Need to take cylinder compression readings - Ford Forums

weetoots · 09-16-2008, 02:58

I am starting to notice I am using a little more oil than should be.
I want to do a compression test on each cylinder. What are the numbers I should be seeing on this 1978 400M?

Any help would be appreciated.

Al

847alexc · 09-16-2008, 11:06

Maybe someone could back me up here...

I'm not sure on the exact specs for this motor, but in general you want to see values above 90 psi after five cranks. More importantly look at the power balance, that is, how do each of the cylinders compare to each other. Low compression on only a couple of cylinders may be more of a problem.

Also, check the leak off. How long does it hold the pressure.

ymeski56 · 09-16-2008, 20:41

What C.I. engine? My 302 Dry tests 180-182 psi/cyl.