Hi,

FWIW for a sparkplug the helicoil has to go in from a given side,
I suspect it will go in a lot easier from the reverse side of a crank.

The job is far, far, far easier on a bicycle than for a engine, I don't
know how they do it without dropping a load of crap into the cylinder.

9/16"s seem more motorbike than car engine size, and motorbike
shops might be more fruitful than car shops regarding helicoiling.

rgds, sreten.

A 30 degree pedal sounds like a pretty chewed up crank.
A nice and straight new hole for tapping might be the
the most difficult thing to achieve, just analysing.

10 turns is too much for my folders steel cranks *, but
would be fine for my road bikes much wider alloy cranks.

* Unless I just left them sticking out a bit on the inside.