and that would only work with flat top pistons.
Hi Musky - do you mean by those words that the tool would not work because the shape of the head would jam the rod in the tool I wonder.
I reckon as long as the thing goes up and down then the shape of the piston is irrelevant, take your point re the angle but that is calculable ( and probable well within the tolerance of my eyes and a pencil mark
).
I have used a dial gauge on pistons and the big advantage is that it will show movement right upto TDC and down again as opposed to my experience where my to eyes it appears the pistons don't move for a short period before and after TDC, hence the primary chain method of marking the travel at this point and dividing it.