That is some incredible footage. I'm a little confused by it though. It does not look like that entire film came from one single intake/compression/power/exhaust revolution. It looks like a single picture was taken from hundreds of different strokes, as if the camera was put on a delay to capture a slightly more advanced location of the piston on each ensuing engine revolution. The only reason I say this is because I didn't see continuity of the incoming air flow or the flame front of the combustion. It really looked like pictures from different intake and combustion strokes.
Damned neat though, not trying to rain on your parade.
Camelman