Agreed.

Also, how does it get started? Seems like the only force pushing the piston against the axial cam is the fuel explosion. (Perhaps extra springs to retract the piston for intake?)

> Also, how does it get started? Seems like the only force pushing the piston against the axial cam is the fuel explosion. (Perhaps extra springs to retract the piston for intake?)

In lieu of combustion you still have the air spring rebound from the compression... (at least until the exhaust opens)

Presumably an electric starter, much like a traditional engine - only it’ll turn the driver shaft instead of a cam shaft.