break in

Mechanic putting a field overhauled engine on a shared plane didn’t put mineral oil in (because he didn’t have any, idk why he didn’t just order some, we would have paid for it and gladly waited…) and he told us that it was fine with "modern" oils (I am pretty sure aviation oil hasn’t changed in...

I'm reading the break-in instructions for my Superior Millennium 0-320 cylinders and everything makes sense so far except: "At no time should cylinder head temperature be allowed to exceed original airframe equipment manufacturer recommended maximum cruise limit." Its one hell of a sentence...