Rolls-Royce Limited its unreliable Rolls-Royce Vulture engines), Vickers Wellington (twin-engine); it also transformed the American North American P-51 Mustang into a competitor for the best fighter of its time, its engine a Merlin engine built by Packard under licence. Over 160,000 Merlin engines were produced, including over 30,000 by the Ford Motor Company at Trafford Park, Manchester. During the war most Rolls-Royce flight testing of engines was carried out from Hucknall Aerodrome. The Merlin crossed over into military land-vehicle use as the Meteor powering the Centurion tank among others. Many Meteor engines used engine blocks and parts that failed requirements for high
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