Tom,
Thanks for the explanation, I have a better picture of how it all works now except for the lifter/adjuster itself. I suppose it is pushed up by oil pressure when the engine is running and it holds pressure when the engine is off, and what we test is the ability to hold pressure.

Chuck,
I am not implying that it does not work. I guess I am not good at it. I just could not tell if there was any difference or not between lobe up and lobe down, probably because of the way I was doing it. Maybe I should have measured displacement with calipers or something. I misspoke, I should have said that I could not make sense of the results.

Jl