Rolls-Royce Peregrine Rolls-Royce Peregrine The Rolls-Royce Peregrine was a , liquid-cooled V-12 aero engine designed and built by the British manufacturer Rolls-Royce in the late 1930s. It was essentially the ultimate development of the company's Kestrel engine, which had seen widespread use in military aircraft of the pre-war period. Due to the wartime priority of Rolls-Royce Merlin development and production, the Peregrine saw limited use and was cancelled with only 301 engines being built. During the 1930s the use of superchargers to increase "effective displacement" of an aircraft engine came into common use. Charging of some form was a requirement for high-altitude
Rolls-Royce Crecy the Ricardo E65 engine achieved the equivalent of for the complete engine. By June 1945 a total of 1,060 hours had been run on the V12 engines with a further 8,600 hours of testing on the V-twins. The fate of the six Crecy engines remains unknown. The Crecy proved a unique exercise and Rolls-Royce did not develop any other two-stroke aero engines, the whole concept of advanced piston engines at that time being overtaken by the advent of the practical jet engine. In the Summer of 1941 Supermarine Spitfire Mk II "P7674" was delivered to Hucknall and fitted with a