> I agree if for nothing else to be on the safe side. I'd like to
> hear from someone that works at an engine plant. Our engines are ancient
> but when they are rebuilt they have materials built to todays specs,
> unless of course as I said, someone has a bunch of old metal or whatever
> laying around and melts it down just for us.
> ...Art
>
I just found something that might shed some light on today's
less-stringent break-in requirements. One of the reasons I've always
heard for the break-in procedure was that neither the piston rings
or bores can be manufactured perfectly round, so some wearing has to
occur for them to fit snugly into each other, hence the warning in
the owner's manual that oil consumption may be high for the first few
hundred miles.
Well, in today's Sunday supplement, there was a review of all the
automakers' model introductions and changes. They did a little
sidebar on one company's new engine, and the tolerance for the
engine bores is .0000012 inches. (That's down in the angstrom range!)
If the "round" parts are closer to perfect coming from the factory,
it stands to reason that less effort on the purchaser's part will be
required to get everything seated.
Scott
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