[eraser2005]

If you ran just 2 cylinders, the engine would definitely be seriously out of balance. My first impression is that a 4 cylinder version would not be nearly as smooth as conventional 4s, as you still could not balance the forces and moments as well. A flat 8 from this could potentially be pretty smooth, though, as that's the point in which you could balance forces well. A Y6 might be an option (not V, but Y)... but I haven't done any calcs....

[Nathan Zachary]

Download the video of the thing running. it sounds ok, meaning it "sounds" like it's revving at about 5 grand, but in reality it's barely hitting 1000 rpm. Looks like an 8 (4 sets of opposed piston assemblies) cylinder model they are testing. I think upper end wear is it's main problem, as well as too low of real rpm. Also the load on those "lobes" has to be tremendous.

[null and void]

More like an X-6, I think...