> 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.