“Why is dimpling not standard practice in commercial ICEs?”
Cost of manufacturing and maintenance, and probably warranties.
An imperfection in the cylinder wall, or “dirt,” could machine a button and thus, the piston skirt is offset a bit. Whereas, without the buttons, the engine would run longer.
Teflon in this case, not physically durable in the long run of an engine. Probably somewhere, there are a few test engines laying outside, rusting away in a junkyard. A stack of those, not getting past 1,000 or 5,000 or 15,000 miles, would end the project.
BTW, may interest:
Cummins Crankshaft grind n polish
https://www.youtube.com/watch?v=FuVPx9kC2Yk
Cummins Crankshaft grind n polish
https://www.youtube.com/watch?v=FuVPx9kC2Yk
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JUST WOW! At this man’s intelligence and expertise.