Spark plug angle

[otis71]

I need to time a xlch but not by the timing mark and want to determine the piston height without pulling the head. Does anyone know the exact angle of the spark plug so I can triangulate the measurement?

[T. Cotten]

I need to time a xlch but not by the timing mark and want to determine the piston height without pulling the head. Does anyone know the exact angle of the spark plug so I can triangulate the measurement?

Otis!

Math adds error.

Heres's a gutted sparkplug with a small vinyl tube installed.
Some oil and bubbles in the tube will rise and fall with the piston.
TDC can be precisely located, and your degree wheel set.

....Cotten