Excellent job! I've designed one of these types of generators when was doing my degree in Russia in 2003 being inspired by the automatic diesel pole hammer that uses gravity to compress the fuel on the down stroke, didn't have money to produce it though unfortunately. You are absolutely right about all of the advantages and with the camless valves from koenigsegg it will be a piece of cake to make it work!

Useful in EV as well.

But is it better than a Stirling motor?

I thought power was produced by coal and steam turbines (on the large scale at least). Are you talking about small generators?

You'll need to get the valve timing better or it's junk.

Where can İ buy ? 😅

Only one drawback - not applicable in practice due to vibration

Same as haskel electric supercharger