Camshafts and Compression

TT5.9mag said
But if you have to move it more than 4 or so degrees, to adjust where the installed centerline is compared to where the cam grinder wants it, then it’s probably the wrong cam.

Cam grinders can't take into account all the variables involved in the cylinder that affect the burn. They are only guessing at best.

Different fuels have different distillation temps so how can a cam grinder know where exactly to close the valve to best suit what you're using?