Old Akro:
Thank you for posting that link. It's a very interesting and well done study.
In this study, Note:
1) at RPMs under 3000, no valve rotation was noted.
2) the components used to aid in this rotation are not part of the aviation engine.
We have tried to verify valve rotation via engine monitor data on a leaking valve. What we have found is that the leaking is not consistent with valve rotation as is assumed to be occurring. As I said, the jury is out, based on the data we have seen, that the valves rotate in an aviation engine at any consistent rate--if they are rotating at all. The assumption that aviation valves are rotating at higher than 15rpm as considered desirable in this study is simply not supported by the data.
There is more to study, for sure.