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 Turbomeca Adour Rolls-Royce Turbomeca Adour The Rolls-Royce Turbomeca Adour is a two-shaft low bypass turbofan aircraft engine developed by Rolls-Royce Turbomeca Limited, a joint venture between Rolls-Royce (UK) and Turbomeca (France). The engine is named after the Adour, a river in south western France. The Adour is a turbofan engine developed primarily to power the Anglo-French SEPECAT Jaguar fighter-bomber, achieving its first successful test run in 1968. It is produced in versions with or without reheat. As of July 2009 more than 2,800 Adours have been produced, for over 20 different armed forces with total flying hours reaching 8 million in December