People keep saying an engine will loosen up with added miles...how many miles does this usually take? Why does it occur? What increases are common? I just don't see how or why it happens but I've been told this a half dozen times in the last week or so and I'm curious what this is based on?
its all the clearances between all the bearings and journals get slightly larger, therefore less friction and tis spins more easily. most bearings these days come with a coating that is suppose to wear off after a certain amount of use.
Yep, things are so tight in a new engine...and after some wear patterns are made and some friction of the rings against the walls, it increases the clearances (not so tight) and therefore is a bit easier to turn around...
Eventually it reaches a point where the clearances are to much (starts blow-by or piston knock) where the extra clearances hurt more than help. Lost compression is lost power...