R-4090 Cyclone 22 An experimental 22-cylinder two-row radial intended to compete with the large Pratt & Whitney radial engines. Three prototypes are known to have been built, but development was abandoned to allow resources to be used for the R-3350 development program. See also Pratt & Whitney Wasp series – a comparable competing line of engines References Aircraft air-cooled radial piston engines 1920s aircraft piston engines Cyclone series