Hi All
I know that the prescribed procedure in to check engine compression with the engine warm.

I'm wondering why you can get valuable information by the checking compression with the engine at ambient temperature. After all, that's the compression the engine has when its first being started.

Shouldn't cold compression have a direct correlation with hot compression? Perhaps 50 psi less - or some other variable to the warm numbers?

Have any members checked their engine compression both warm and cold - and are willing to share the results?

When looking to buy a 123 that isn't running, it would be a great help to be able correctly interpet cold cylinder compression numbers.

All thoughts welcome!
Joseph