Freeze the video at the very last few seconds. The cylinders and pistons are reversed from the original. This is one of the basic modifications of my design which started out as an IC engine in 2004. This is a fixed displacement pump which could be used for a split cycle with on pump for intake, a combustion chamber, and one pump for power.
The present design is one with an adjustable stroke position through the fixed hub, with hydraulic fluid providing power to the outer rim, and variable displacement and neutral and reverse as well as forward positions. This would work as a drive system with an accumulator, the engine would only have to resupply pressure to the accumulator which would also serve to recover deceleration forces. A fully charged accumulator would be capable of providing the energy for a single 0-70 acceleration or a single 70-0 braking event.
regards
Mech