This is a great topic! I'd like to thank everyone for shedding light on this for me.

Although I do have some more questions if someone can help...


Do all 0.12 engine manufacturers use the same size ball mill for the button?

If they do, do all chambers have the same milling depth?

Considering different bore/stroke ratios between manufacturers, would "compression testing" be a more accurate way to determine the number for head shims?

My thanks for any help,