Sphinx star wheel engine

A "Sphinx" star wheel engine built using the Alyn Foundry castings and design. The original contraption was conceived to circumvent Otto's 2:1 reduction cam gear, the star wheel alternately hits and misses the exhaust valve, inlet is atmospheric. Fascinating to watch working, although you're left with the impression that Otto got it right in the first place.

Base 26 x 8 inches
Flywheel 9 inch diameter
Weight 53 pounds