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The Rolls-Royce Crecy was an unusual British experimental two-stroke, 90-degree, V12, liquid-cooled aero-engine of 1,536 cu.in (26 L) capacity, featuring sleeve valves and direct petrol injection. Developed between 1941 and 1945 it was the most advanced two-stroke aero-engine ever built.〔Gunston 1986, p.143.〕〔Although similar comments were made about the Napier Nomad.〕 The engine was named after the Battle of Crécy; battles were the chosen theme for Rolls-Royce two-stroke aero engines. There were no other Rolls-Royce engines of this type, and jet engines were subsequently given the names of rivers.〔Nahum, Foster-Pegg, Birch 1994, p.40.〕 The Crecy was intended to power the Supermarine Spitfire after flight testing in a converted Hawker Henley, but neither aircraft type flew with this engine fitted. The project was cancelled in December 1945 as the progress of jet engine development overtook that of the Crecy and replaced the need for this engine. ==Design and development== Sir Henry Tizard, Chairman of the Aeronautical Research Committee (ARC), was a proponent of a high-powered "sprint" engine for fighter aircraft and had foreseen the need for such a powerplant as early as 1935 with the threat of German air power looming. It has been suggested that Tizard influenced his personal friend Harry Ricardo to develop what eventually became known as the Rolls-Royce Crecy.〔Nahum, Foster-Pegg, Birch 1994, p.26.〕 The idea was officially discussed for the first time at an engine sub-committee meeting in December 1935. Previous experience gained between 1927 and 1930 using two converted Rolls-Royce Kestrel engines through an Air Ministry contract had proven the worth of further research into a two-stroke sleeve-valved design. Both these engines had initially been converted to diesel sleeve-valved operation with a lower power output than the original design being noted along with increased mechanical failures, although one converted Kestrel was subsequently used successfully by Captain George Eyston in a land-speed record car named ''Speed of the Wind''.〔Nahum, Foster-Pegg, Birch 1994. pp.14–15.〕 The second engine was further converted to petrol injection which then gave a marked power increase over the standard Kestrel.〔Nahum, Foster-Pegg, Birch 1994, p.15.〕 Single-cylinder development began in 1937 under project engineer Harry Wood using a test unit designed by Ricardo. Although originally conceived as a compression ignition engine, by the time Rolls-Royce started serious development, in conjunction with the Ricardo company, the decision had been taken by the Air Ministry to revert to a more conventional spark-ignition layout, although still retaining fuel injection. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Rolls-Royce Crecy」の詳細全文を読む スポンサード リンク
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