[JoeAltmaier]

Cool, I apologize if I offended. But if we're talking radical engine design, then nothing is off the table. Including solving the existing problems with the Duke design. They haven't had 2 centuries of tweaking, so criticisms about where soot collects are getting ahead of things.

And also including turning the problem on its head. If shaft momentum is such a well-known and pernicious problem, then its not out of line to question why somebody went down that road at all. Obvious really. Its called returning to fundamentals, and anybody can do it.

So, what's the problem with using rotation to port air and exhaust, if the disk is turning instead of the now-stationary cylinder block? A mechanical linkage between the disk and a ported sleeve should do the trick. If its still desirable at all - a stationary cylinder block lets you do it the valve way too if desired.

Anyway, I'm actually astonished that anybody ever thought it was a good idea to rotate essentially the entire engine. Centripetal forces, heavier bearings, linkage issues - it invents all sorts of problems. Whereas the idea of pushing against a tilted disk doesn't require that at all. I can't get over that fundamental notion, and I'm sure its fair to ask "where did they go wrong" without being accused of backseat driving. If there's some obvious need to NOT rotate the disk, I'm all ears. But I didn't read that anywhere.