The Rolls-Royce Merlin is a British, liquid-cooled, 27-litre (1,650 cu in) capacity, V-12 piston aero engine, designed and built by Rolls-Royce Limited. Initially known as the PV-12, Rolls-Royce named the engine the Merlin following the company convention of naming its piston aero engines after birds of prey.
The PV-12 first ran in 1933, and a series of rapidly applied developments brought about by wartime needs improved the engine’s performance markedly. The first operational aircraft to enter service using the Merlin were the Fairey Battle, Hawker Hurricane and Supermarine Spitfire. More Merlins were made for the four-engined Avro Lancaster heavy bomber than any other aircraft; however, the engine is most closely associated with the Spitfire and powered its maiden flight in 1936.
An English icon, the Merlin was one of the most successful aircraft engines of the World War II era, and many variants were built by Rolls-Royce in Derby, Crewe and Glasgow, as well as by Ford of Britain in Trafford Park, Manchester. The Packard V-1650 was a version of the Merlin built in the United States. Production ceased in 1950 after a total of almost 150,000 engines had been delivered, the later variants being used for airliners and military transport aircraft.
In military use the Merlin was superseded by its larger capacity stablemate, the Rolls-Royce Griffon. Merlin engines remain in Royal Air Force service today with the Battle of Britain Memorial Flight, and power many restored aircraft in private ownership worldwide.
* Type: 12-cylinder, supercharged, liquid-cooled, 60° “Vee”, piston aircraft engine.
* Bore: 5.4 in (137.16 mm)
* Stroke: 6.0 in (152.4 mm)
* Displacement: 1,647 cu in (27 L)
* Length: 88.7 in (225.3 cm)
* Width: 30.8 in (78.1 cm)
* Height: 40 in (101.6 cm)
* Dry weight: 1,640 lb (744 kg)[nb 12]
* Power output:
o 1,290 hp (962 kW) at 3,000 rpm at take–off.
o 1,565 hp (1,167 kW) at 3,000 rpm at 12,250 ft (3,740 m) (MS gear)[nb 13]
o 1,580 hp (1,178 kW) at 3,000 rpm at 23,500 ft (7,170 m) (FS gear)