The Rolls-Royce R was a British aero engine designed and built specifically for air racing purposes. Nineteen R engines were assembled in a limited production run between 1929 and 1931. The experience gained from the R engine was invaluable in the subsequent development of the Rolls- Royce Merlin engine and the Spitfire. Three examples of the R engines are on public display in British museums as of 2014.
About Rolls-Royce R in brief
The Rolls-Royce R was a British aero engine designed and built specifically for air racing purposes. Nineteen R engines were assembled in a limited production run between 1929 and 1931. It was a 37-litre capacity, supercharged V-12 capable of producing just under 2,800 horsepower and weighed 1,640 pounds. The R was used with great success in the Schneider Trophy seaplane competitions held in England in 1929 and 1930. The experience gained from the 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 R Griffon of 1939, of the same exact borestroke and resultant displacement figures as the R design. Three examples of the R engines are on public display in British museums as of 2014. The engine’s length was minimised by not staggering its cylinder banks fore and aft, which meant that the connecting rods from opposing cylinders had to share a short crankshaft bearing journal. The introduction of articulated connecting rods was regarded as a ‘nuisance’ by a RollsRoyce engine designer, as there were inherent problems with the complicated geometry. Later production R engines featured a revised blade and fork system which Arthur Rowledge had designed for the Merlin, but were not embodied in the later Merlin engine. A final R-powered water speed record attempt by Donald Campbell in 1951 was unsuccessful. The engine was a physically imposing engine designed by a team led by Ernest Hives and including Cyril Lovesey, ArthurRowledge and Henry Royce.
It featured a balanced oil gudgeon that carried over the exhaust valve stems for cooling, while additional modifications included a redesigned lower lower crankcase casting and the introduction of an oil ring pin below the ring piston. The engines were used to achieve various land and water speed records by such racing personalities as Sir Henry Segrave, Sir Malcolm Campbell and his son Donald, the last record being set in 1939. A pair of pair of connecting rods had to be lengthened to prevent the lower piston running out of the lower skirt of the Articulated Goshawk engine from running out from the lower ring of the upper piston. A new single-stage, double-sided supercharger impeller was designed along with revised cylinders and strengthened connecting rods. Because of the short life expectancy of these engines, forged aluminium was used to replace bronze and steel in many parts. A special fuel blend powered the winning Supermarine S. 6B aircraft to a new airspeed record of over 400 miles per hour in the 1931 competition. It is believed that the R was the first engine to be used in the World Series of Air Races, which took place in 1936 and 1937. The first production R engine is believed to have been built in the United States in 1938. The Rolls-royce R engine has been used in many of the world’s most successful air racing aircraft, including the F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, F13, F15, F16, F18, F20 and F3 and F4.