[ovrtaxt]

It appears there is some mechanism to smoothe out the motion into a continuous rotation, it also likely regulates the movement of the two piston assemblies.

There are these counterweight things that spin with the piston assemblies- kind of reminds me of a rotor/ timing advance assembly in a distributor.

The way this works appears to eliminate a lot of the wasted motion (and thus power).

There are only 22 moving parts, I think, in the prototype.

Couple areas of concern - not sure how you would seal the combustion chamber when there are three pieces rotating against each other - I suppose it could be done with rings like pistons have.

Yes, the seals are apparently the issue with longevity. I think there's some info on that on the site- but with automakers involved, they may have something that meets the challenge.

[-YYZ-]

"Yes, the seals are apparently the issue with longevity."

The seals are almost always the deal-breaker in these new IC engine designs. That's assuming outright complexity and manufacturing hurdles don't kill the concept first.