[freebeard]

I guess it's a stretch. It seems to me that any 120PSI or greater compressed air source (like a Stirling engine) could be interpolated.

The Scuderi story is sad. The inventor burnt through his bankroll trying to make a proprietary inline four engine. Then his heirs were no help. So....15 years on a patent?

Were I he, I'd've started with a flat-four VW engine with two different paired cylinder displacements. The only proprietary parts would be the cam and cranshaft. Maybe a reassembled roller bearing crank.

I forsaw it in a shop truck tricycle that would roll as a two-cylinder street trike, or roll around the shop on compressed air from the shop air tank. maybe a big honkin' alternator for welding.