The rings do move around. I have read many studies by race engine builders discussing it. The only thing they seem do disagree on is at what speed they rotate.
90 degrees from the pin is the thrust sides. One side being the major thrust side the other the minor thrust side.
2 stroke engines pin the rings so they dont rotate. This is to keep the ring end from getting into the port. If the ring rotated so the end was at the port it would break the ring.
With a flat tappet cam you do want to break it in at a high idle. This is to increase oil splash and ensure the cam is getting enough oil during break in. Roller tappet cams don't need such break in proceedures.

 

just for sake of words here go dwn town at your local parts shop ,read what it says ,bet it says DO NOT IDLE. there i said it.( camshaft box)
now check out HOW TO DYNO FRESH eng. all th e BIG eng books say start ,look for leaks ,go to 20% shut dwn. start go to 30% or more depending ,repeat prosses...am i wrong??
exit stage left evven...

 

Looks like the best thing that could happen to an engine is the rings moving or rotating. The engine would last a lot longer and the bore would stay concentric. Without movement the rings could wear a bad spot and keep wearing it.

 

Thumper, if you are referring to my post of high idle. We are talking along the same lines. As a diesel engine tech my definition does not mean high idle as in the choke is closed and the engine is running around 900 rpms. My def is variable, it has to be. Like for instance Cat considers high idle to be WOT with no load. In the case of breaking in a flat tappet cam in a gas engine it would be about 2000 rpm. I work on two kinds of engines, diesel, and my own drag engines. So very seldom do I run across a flat tappet cam. Just every once in awhile in the smaller diesels.

 

you bet,
a high idle in a short stroke is a lot diff then in a long stroke..