You dont want to skim the whole piston, you want to be opening up the bowl, to keep the engine's det characteristics.


from memory the crown thickness is 7mm at lowest point of bowl.



i just measured a new 4wd mahle +0.5mm piston.

top of 1st ring to top of crown = 8.3 mm,
bowl deepth = 6.1 mm,
top of bowl diameter = 73.3 -75.3 mm, matters on the part of radias is measured,
Bottom of bowl = 51.4 - 52.9 mm