When doing a compression leak down test does the piston absolutely have to be at top dead center? With the valve covers off i can confirm both valves are closed if I can spin both pushrods per cylinder with my fingers. So does it matter where the cylinder is in the stroke as long as both valves are closed?
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I vote No, it shouldn't matter where the piston is as long as the valves are closed. :alan2cents:
If you put enough air in the cylinder it might just push the piston down that's all.
Most of the cylinder wear is at TDC