It is Hokum. He claims the pistons don’t touch the “cylinder”, only the rings. If this design were to actually run, the force pushing the pistons out axially would be tremendous. Think of the “shoot around a corner” rifle, same thing.
I dont see any robust coupling of the piston to the shaft. There appears to be a disk on the inside diameter of the piston/cylinder, perhaps there is a slot cut in the piston which engages the disk. Can’t tell from the videos. That would allow it to function as an air motor for short periods of time.
Combustion creates heat. There appears to be no provision for cooling except for some very abbreviated fins on the outside of an entirely aluminum combustion chamber/cylinder arrangement.
All the while claiming power to weight ratios better than a turbine? We should remember why titanium, monel, stainless, and so forth were invented; to survive the heat that comes out the back end of a jet engine.
It’s a scam.
Look again at the first video (here,) and you will see that there are two discs, each one holding 4 pistons. The pistons are attached to the inner or outter disk at 90 degree intervals. About 30 degrees or so of the circumference of the piston wall is attached to the disk, making for what should be a very robust mounting.
However, the big problem I see long term for this engine is the same one that plagued the Wankel, which is lack of piston ring lubrication. In a conventional piston engine, the cylinder walls are coated with oil during the piston's upstroke, and the piston rings ride a film of oil on the downstroke.
In a Wankel, the three seals ride along the chamber walls dry, causing extreme wear issues. Same for this motor, no place to introduce cooling and lubricating oil on the cylinder walls, which will lead to longevity problems.
Very ingenious engine, but lots of hurdles before it ever becomes practical.