Finding TDC

A manometer can be used to find TDC.

A manometer is simply a U shaped  tube with a water or oil "indicator"  in it. Air pressure or suction at one end of the U causes the indicator to move.

For our Z application, a drilled out spark plug,  3' length of plastic tube,  and a few ml of coloured water is all that is needed.

Note that a one thousandth inch change in the piston is nearly 1/2 and inch of water change.

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