Read that Porsche has filed for patents on a 6 stroke engine design, adding a second compression/power stroke to the traditional sequence - intake, compression, power, compression, power, exhaust. And to make it even MORE confusing, it's variable compression, with two TDC and BDC crank positions with the crankshaft operating in a planetary gearset!
I need to see a video representation of the crank & piston travel through the cycle! Makes my brain hurt trying to visualize how it works!! There are several articles out talking about it. Here's one - https://www.roadandtrack.com/news/a6...ent-documents/