What i'm am curious about is of the concept will proof to be an efficient way to harnes pressure difference.
The magnet, going around inside the torus shaped ring, in combination with the pick up coils. (How they are utalized best is the next challange).
The "input" does not have to be a combustion. Any kind of pressure difference will do. As long as you have a valve that blocks the pipe behind the magnet when the pressure input occures and will be out of the way when the magnet closes its loop.
This could be:
Heat (heated gasses or liquids)
Air pressure (wind difference, compressed air..)
And combustion.
( Maybe you could reverse it with an one magnet no baring bedini and create a small compressor ;-)