[PeteVS]

There's a problem with finding Top Dead Center by finding it AT top dead center. When the piston is AT top dead center, the crankshaft can rotate several degrees in either direction with either not moving the piston at all, or, moving it so slightly that perceiving the movement would be next to impossible with crude instruments. Seems to me, that the best way to ESTABLISH where the crankshaft is at top dead center is to have the head off, fasten a rigid bar between two studs and have a bolt thru the bar to stop the piston some distance below the uppermost point. Have a pointer down by the pulley and put a mark on the pulley when the crank is rotated in one direction and the piston comes to stop against the bolt. Then, rotate the crank in the opposite direction and put another mark on the pulley when the piston hits the bolt. Then, put a third mark half way between the other two marks. THAT will be crankshaft position AT top dead center.