Quote:

Quote:

if the engine is at TDC, how far can the valve drop in?

rope version is simpler, and if you don't have an air compressor, than it's a moot point, but dropping a valve inside the engine isn't an issue.



When you use air, the piston is forced to BDC.



if you set it at exactly TDC, like doing a leakdown test, then you are fine. of course, you do have to be precise, just like doing a leakdown.