I have question that's not GC related but that GC some fans might have a decent chance of addressing, and it is regarding some exotic engine types (which clearly aren't part of GC, but perhaps some day an exotic engine category could be added, perhaps via GC extension DLC).

So about almost a year ago I recall seeing in some popsci article an actually really promising new engine concept made by an aerospace parts CEO (or founder, or other company VIP). There were two methods central to this engine. 1. Instead of the reciprocating motion of pistons to do work, it entailed a piston that circulated (winding) in a circle; the annulus was the cylinder. Certain valves opened and closed at the right moment, such that the energy from the combustion of a compressed air fuel mixture was directed to do work during a nearly full rotation. 2. Secondly it was a split-cycle type engine, and you had two paired annular pistons (side by side, in an infinity shape fashion) doing some division of labor, such that a full rotation in one of the chambers was the equivalent of two strokes (comparing to reciprocating piston). For split cycle concept see: https://en.wikipedia.org/wiki/Scuderi_engine

So in one rotation of the pair, the work of a four cycle engines single workcycle was done.

I haven't been able to find this startup again via news and we searches. I do come across other interesting ideas, such as this two-stroke opposed piston in an annular chamber concept: https://www.youtube.com/watch?v=MiEy_KcZHak It's a pretty interesting crankshaft design which still don't really understand by looking at the animation. The compact size advantage of this is apparent---like the wankel engine in GC, or a V2.

Well, that's the end of my question and rant. Happy motor simming to you all.