Rolls-Royce Merlin R.M. 14S.M. Mk 100 V-12 Engine


Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

Formed in 1906 to produce automobiles, Rolls-Royce was asked to begin designing and building aircraft engines at the outbreak of World War I in 1914. Design of the Merlin began in 1933 following the similar Kestrel design. Early Merlin Mk II and Mk III engines, which produced about 7,457 kw (1,000 horsepower), powered Hawker Hurricanes and Supermarine Spitfires in the Battle of Britain. Engine improvements and progress in supercharger performance increased the Merlin's rated power to over 1,715 kW (2,300 horsepower) by the end of the war.

This engine, a developmental prototype in the Merlin 100 series, was built by Rolls-Royce in Derby, England, sometime between June and July 1944. It was a new class of engine, built to higher performance standards for power and altitude. Merlin 100s powered the de Havilland Mosquito, Avro Tudor, and de Havilland Hornet and Sea Hornet. U.S. Packard-built Merlin 100s (V-1650-9 and -11) powered later versions of the North American Mustang.

Collection Item Long Description:



Inventory Number


Physical Description

  • Type: Reciprocating, V-type, 12 cylinders, pressure liquid cooled, supercharged
  • Power rating: 1,227 kW (1,645 hp) at 3,000 rpm
  • Displacement: 27 L (1,649 cu in.)
  • Bore and Stroke: 137.16 mm (5.4 in.) x 152.4 mm (6 in.)
  • Weight: 778 kg (1,715 lb)

Credit Line

Transferred from the United States Air Force, Park Ridge Facility

Country of Origin

United Kingdom


Aluminum and Steel


Length 225.3 cm (88.7 in)., Width 78 cm (30.7 in.), Height 101.3 cm (39.9 in.)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


PROPULSION-Reciprocating & Rotary