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 V8 engine later taken back by the factory and scrapped. The other two were used for factory transport or display purposes. Rolls ordered three more chassis for delivery in 1906 but there is no evidence these were ever made. No example of a 1905 V-8 car or engine is known to survive. Although the 1905 V-8 cannot be judged a success, lessons learned from the engine were used in subsequent Rolls-Royce engine designs. Having used straight six, straight eight and V-12 engines in the interim period, the need for another new engine was recognised in the early 1950s. Development of a totally