Bolting a presumably aluminium piston running close to 300C with steel bolts through the crown is a recipe for disaster.
The gear will never work, not with normal profile deviations, bearing clearances and crank deflection. The load won't be shared evenly between the 2 sides. I'd also like to see how he plans on cutting the external teeth on the crank pin, particularly in between the webs - I don't think there is enough tool access.
Yes there aren't piston thrust loads but the friction losses in the big drum and the gear will be significantly higher compared to a normal plain bearing arrangement. Rotating and reciprocating inertias are surely higher too.
So the question is what does this design really achieve ?
nah pop no style