Compression

Not sure but pressure test it as it is, and compare one barrel to the other, then add some oil through each plug hole, if you get a temp uplift in pressure the there is a pressure leak between piston and barrel. Either wear or damage (prob ring) I think you said that the top end has been overhauled, so presumably you know the valves are ok?

Dan

Previously stephenjohn_ball wrote:

Hi on a navigator can anyone tell me what the compression pressure should on a rebuilt engine in PSI

Thanks

Atmosphere is roughly15 PSI.Compressionration isamultiple of that. Thereforeif its 8.25:1 ratio its 123 psi... roughly...