Rolls-Royce R engine was invaluable in the subsequent development of the Rolls-Royce Merlin engine and the Spitfire. A de-rated R engine, known as the Griffon, was tested in 1933, but it was not directly related to the production Rolls-Royce Griffon of 1939, of the same exact bore/stroke and resultant displacement figures as the "R" design. Three examples of the R engine are on public display in British museums as of 2014. Rolls-Royce realised that the Napier Lion engine used in the 1927 Supermarine S.5 Schneider Trophy winner had reached the peak of its development, and that for Britain's entrant in the next
Rolls-Royce Falcon unusual feature of this engine was the epicyclic propeller reduction gear which contained a clutch designed to limit the maximum torque, thus protecting the reduction gears. The Falcon was notably used in the Bristol F.2 Fighter and Blackburn Kangaroo bomber. "Note:" "List from Guttery and Lumsden:" Bristol F.2B Fighter, "D-8096", is based at the Shuttleworth Collection and is powered by a Falcon III, this aircraft flies regularly throughout the summer months. Rolls-Royce Falcon The Rolls-Royce Falcon is an aero engine developed in 1915. It was a smaller version of the Rolls-Royce Eagle, a liquid-cooled V-12 of 867 cu in (14.2