that's pretty cool.
the only sketchy part i noticed right now is the turbo bit where the left cylinder is fed compressed air to help the other cylinder along, but then the upstroke forces that air into the storage tank.... you're loosing energy having to shove it into the storage tank, unless its only a slight amount of resistance while it waits to go into the combustion cylinder. If it was vented to the atmosphere it would not use up energy on the upstroke.
however, as long as the tank isn't used to STORE energy during performance-turbo-mode..(lol) it sounds like a cool idea!
I'd like to see a real one....
and i'd hope that the relief valve system would be reliable. it would suck to blow the tank or cause the compressor cylinder to freeze if the tank got stuck shut
think of the possibilities of this though....maybe implement a "turbo" button that would let you apply boost air whenever you needed extra "go" and couldn't otherwise get it from a turbo or naturally aspirated power...]
OR for trail work...you could divert the energy gained from engine braking to an on-board air tank used for airtools and such. OR use the engine as a high-capacity air compressor...for whatever. at the least use it to air up your tires. i'm not really sure there are many needs for air tools on the trail....heh.
oh and a fucking LOUD air horn. just from shits and giggles