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 RB162 change from vertical to horizontal installation. With the RB162 fitted the Trident 3B had a 15% increase in thrust over the earlier variants for an engine weight penalty of only 5%. A design study for a turbofan version of the RB162 was designated RB175. Another projected derivative, the RB181 was to be a scaled-down version of the RB162 producing approximately 2,000 lbs of thrust. Seven of these lift engines were to power the unbuilt Lockheed/Short Brothers CL-704 VTOL variant of the F-104 Starfighter. Rolls-Royce RB162 The Rolls-Royce RB162 was a simply constructed and lightweight British turbojet engine produced by Rolls-Royce