By disks, are you saying the two halves of the toroid are each one assembly, with four pistons each? Sort of two four-armed paddles, and that they oppose each others’ cumbustion pressures? To what do they react the combustion forces? Perhaps that is his cam arrangement opposite the toroid.
Regardless, there is no way that device is an internal combustion engine for very long. Imho.
Each disk assembly is spun on it's own concentric shaft by the cam and arm assembly behind the piston assembly. This gives each disc the staggered spin rate.
Then there are two torid halves that comprise the sides and top of the cylinder wall. The inner torid half is not installed on the demonstration model, giving the view of the internal piston action.