On leak down tests in automotive engines if you start with #1 cylinder at TDC on the firing stroke it won't push the rod and piston down After #1 is done rotate the crankshaft 90 degrees to get #8 at TDC and test it and go from there through the rest of the firing order
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)