Originally Posted by gimmemud

I see what WJ is trying to point out, in order for a vaccum pump to work properly the engine must be sealed up air tight. (With exception of the vaccum system plumbing)

When you do this, your vaccum pump must be up to the task of pulling more vaccum than the engine creates the oposite of (positive crankcase pressure). If that is not achieved, you will have problems with blown seals and pushed out gaskets.

IMO a pump that will only achieve 2" of vaccum will never do this.