Originally Posted by
Hydro Junkie
Actually, something some do with boat motors to break them in is to run them on the bench without cooling, other than an oversized aircraft prop, and use the needle to actually regulate the engine's temperature. By running the engine rich, you actually cool the engine. .............
Yup, break in instructions for OS Max engines nowadays describe much the same. Except they do most of it in the first tank of fuel. And with the engine installed on the plane. Well, they've recommended it at least a decade actually. A 46AX bought back in 2010 or thereabouts is still running like a clock, a powerful one. They have you run it a minute or so rich, then needle it to full, then rich, then full, etc.
Having the right alloys and modern manufacturing works.