i wouldn't say ralpg sarich's engine worked all that well, from what i read it "ran" but in the end he used a holden carby, and just got it working like that.
the problem was sealing the combustion chambers, not the mass production, he concentrated on 3 cylinder two strokes utilising lean burn air shear fuel injection after that.
i havent heard too much about them though, just a few vague references to a fleet of ford festivas.
id like to drive a car that uses tehse rotary valves though, and 15 grand is pretty cheap to get the work done, you would just want to be able to get as much power out of it as you would from a decent turbo setup though.
the final word in this is fuel cells, they don't even fck around with any moving parts.