[RealDeal]

I bought a complete motor , fresh rebuild but don't have the compression ratio. I have a compression tester but it's in psi. Dous any one have a way of converting psi to static compression?

[JimM]

The compression tester shows the dynamic compression in psi at cranking speeds. It's a very useful diagnostic tool, but doesn't really tell you much about "what's in there" only "how well it's working."

Now if you know (exactly) what cam is in it, there are people here who could give you a close guess from a cranking compression test.

The cam has a huge effect on dynamic and cranking compression.

[RealDeal]

Thanks Jim, I was trying to get away from taking it apart , but I guess i'll have to buy a gaket set. I guess it's better that way so I know whats what.

[Larger Dave]

Spend the money you were going to spend upon the gasket set to buy a degree wheel and a one inch travel dial indicator with a means of attaching it to your head (magnetic bases do not work well on aluminum heads).

You will never be mystified by a what cam do I have question again (and if you ever build a motor you can always degree your own cam). With the cam information you can choose what piston you have (dished, flat top, or domed from the cranking psi divided by 15)

Larger Dave