ORIGINAL: Gray Beard
An engine part hitting another part of the engine is not why you break in A new engine, there should never be anything like A rod hitting the case!!
Yep, I've been inside countless engines. All the way from RC stuff to lawn & garden to big blocks to twin cam, high performance engines. A rod hitting the block would be very, very bad. To be
really technical there should be no metal to metal contact of
any kind while running. Everything should ride on a lubricant film.