The rotary valve head on this engine was invented by Herbert Scheel who, at one time, worked for Louis Chevrolet.
The patent for this head was filed on October 21, 1920, and approved on December 18, 1928. By that time, Scheel Motors, Inc., had moved from its original location in Maplewood, Missouri, to Delaware.
The head has one round bar-like “valve”, timed to the crankshaft via a chain. The head is a crossflow type and each of the four valve “cuts” works as both intake and exhaust.
The air/fuel mixture enters on the left side, then the same valve cut acts as the exhaust valve on the right side.