Rolls-Royce aircraft piston engines test stand. The Buzzard was an enlargement of the Kestrel of Condor size, developed in its most extreme form into the Rolls-Royce R racing engine used for the Schneider Trophy competition. The Vulture of 1939 was essentially two Peregrines on a common crankshaft in an X-24 configuration, both of these types being deemed unsuccessful. The Rolls-Royce Merlin, and later the development of the Buzzard, the Rolls-Royce Griffon were the two most successful designs for Rolls-Royce to serve in the Second World War, the Merlin powering RAF fighters the Hawker Hurricane, Supermarine Spitfire, fighter/bomber de Havilland Mosquito, Lancaster and Halifax heavy
Rolls-Royce 25/30 Rolls-Royce 25/30 The Rolls-Royce 25/30 built between 1936 and 1938 is an updated version of the 20/25 with larger engine to provide more power, as often, over-large bodies had been fitted to the earlier model leading to complaints about its performance. The in-line 6-cylinder, overhead-valve 25/30 hp engine is similar to that used in the 20/25 but increased in capacity to by increasing the bore from to , with the stroke remaining at . The compression ratio is 6:1. A single proprietary Stromberg downdraught carburettor replaced the Rolls-Royce one, and magneto ignition was no longer fitted, but a standby coil