This company made characteristic engines as they had rotary valves instead of normal valves.

-First we show a small motorcycle version, although it is an exhibition engine. It has a displacement of 348 cc and looks nice from the outside.

"Cross motorcycle engine"

-Now we present the 150 hp aero engine. The main characteristic of this engine made by Cross Manufacturing Co. Ltd. in Bath, is the rotary valve that is transformed into a shaft that crosses all the engine's four cylinder heads.

-The engine is air cooled, and has a gearbox in a front housing whose propeller gear also drives the rotary valve shaft. This is not a camshaft, but consists of conveniently perforated bodies to provide channels which, while rotating, connect with the intake or exhaust.

"Cross engine, cross-section"

"Longitudinal cross-section of the 4-cylinder engine"