But all rings get 'squeezed'.... why does the contact radius get out of round once it gets squeezed a bit more than normal? If you were just pushing or pulling on the ring ends, like with a ring expander, then I agree; in that case, the bending force along the length of the ring will be uneven and will peak at a position opposite to the gap. But that is not what is going once in a cylinder. The ring is being pressed evenly inward all around, so I can't see what force would put it out of round. It is like a circular piece of spring steel with the forces being evenly distributed so I can't see anything that will put the circle out of round. And all rings have a gap so any end effects on radius and pressure would not change much... I would think. Honestly, not being obstinate, but the 'distorted contact radius' idea still does not make sense to me.
I would not put in oversized rings myself, but I am trying to understand what problems this situation will have. Very probably the ring drag goes up well beyond what it should be. That might in turn cause an issue with putting pressure on the lands. And the rings may drag and twist up and down more than they should, possibly causing rapid ring wear and/or rapid ring groove wear. That I can see. If this is a re-ring job done without checking ring side clearances or honing, there are bigger issues IMHO.
Admittedly, this is all academic.....
