Re: Synthetic or mineral oil in low-hours motor
the idea of mineral oil on a brand new engine is it has lower shear stability than modern synthetic oils and so helps to break in the rings against the cylinder wall - so the statement of muc is basicly correct.
BUT at 41 hours that job is already done, so use any oil you want.
the crucial part of break in are the first 1-2 hours in its life , and to prevent people f**ck this completely up many manufacturers run the really new engine on a teststand for some minutes where it gets some hard bursts of throttle - so the opposite most people would believe is correct for break in.
that is done to build up cylinder pressures and pushing the piston rings hard against the cylinder wall to achieve an initial sealing.
cheers
Many car manufacturers "factory fill" their engines with synthetic right at the factory. Maybe they "break them in" before the dealers even get them.
When I used to work at an aircraft repair facility, we would break in the rings by flying the airplane around the local area at full throttle//max RPM for about 15-20 min.......
The rings would break in almost immediately. The owner insisted on using non-compunded (non detergent) oil. Later we used detergent (regular) oil and found no difference. You could see the break-in point happen because the cyl-head temp would quickly and obviously drop.
Can't do that with liquid cooled engine though. But we broke-in every other engine we rebuilt (including boat engines) the same way. max power/max RPM for 15-20 min or so. They never burned oil after that. It didn't seem to matter what type of oil we used.
The rings don't care how they're lubricated. like you said. It's all about cylinder pressures.