In 1932, the Air Ministry declined to fund a new engine and Rolls-Royce decided to develop one using their own funds. Designated the P.V.12 (private venture), this engine first flew in 1935.
Named the Merlin, this engine was made famous by the Spitfires and Hurricanes that won the Battle of Britain.

The Rolls-Royce Merlin was license-built by Packard in the U.S. These Merlins were designated the V-1650.
 

models

• Merlin XX: 1,280 hp (954 kW)
• Merlin 25: 1,620 hp (1208 kW)
• Merlin 45: 1,478 hp (1102 kW)
• V-1650-7: 1,695 hp (1264 kW)

specifications

• V-12 piston engine, two-stage supercharger
• Liquid cooled
• Displacement 1,649 cubic inches (27 litres)

used by

• de Havilland D.H.98 Mosquito
• Hawker Hurricane
• North American F-82 Twin Mustang
• North American P-51 Mustang
• Supermarine Spitfire