In the back of my '54 Motors Manual is a procedure for compression tests. I hadn't paid much attention to it until now. A interesting point...if all the plugs are removed for this test, it isn't necessary to hold the throttle plate open because there are always two or more intake valves open which provides a path to the intake manifold proper...who would have 'thunk it'.
I was always under the impression that the process of adding oil to the cylinder during this test was a way to differentiate between poor rings or valve seating problems. If the compression figures came up with the introduction of the oil, rings would be suspect. If the oil made no difference, then the valves might be the cause.
Stuart
