If that's the case, just turn it down in your lathe there until its round, then once you turn the top portion down, turn it around in your lathe and machine the bottom portion. Just make sure you turn the bottom portion a touch smaller than the top to keep it from hanging up in a port. Should have less friction that way as well. I see this sort of thing all the time, piece of cake really. While you have it chucked in the lathe, you can go ahead and cut a small dish shape in the top of the piston. After you turn your piston round and remove all that extra mass from it, install your helo starter, your expansion chamber and at least a 15 pin, I would stand back, that's gonna be one mean machine. I think with the rotating mass you are removing from the piston though, you could probably bump up to a 20 pin if you're running those carbon fiber rims cause the weight is gonna be about the same. Also you could grind a little off of the rod beams to reduce weight on the rod and add it to the rim. I think you're ON to something here.
