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I'm a novice, not an expert. I have a great interest in cars and engines in general, and I've pursued them to some degree, but I'm not an engineer. I have no where close to the level of expertise that the Duke engineers do.

> I thought you'd be right on board with speculating about where this went wrong. Sorry to have misjudged.

You've misread me. There's no thing wrong with asking questions. For example, take the question:

"Why can't we rotate the disc instead of the cylinders?"

Versus your statement

"The idea of valve-less cylinders via rotating ports can be done either way - rotating cylinders or rotating shaft - so reverse them."

You state this as if it's obvious, and it is obvious. It's also obvious (to someone with domain knowledge) that it's not a simple matter. I took us part way down the rabbit hole, and I'm always happy to do that, but it really gets under my skin when questions are states as presumptuous declarations such as, "so reverse them." Not to mention this one:

"Just wondering who got it wrong the first day and went down this path."

This presumes that the Duke solution is the wrong one, and your solution is the right one, but you aren't even familiar enough with ported engine designs to know the basic drawbacks. Again, I'm not an expert, but I know enough to know that I can't make these kinds of presumptions. You don't, and my suggestion is that you should recognize and start with questions rather than insulting someone else's work.

I know this comes across as a scolding, but I genuinely don't mean to be harsh. I just felt like I should say something because of the way your writing came across.




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.




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