Curtiss K-12, 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:

In 1916 Curtiss engineer Charles Kirkham began designing an engine to compete with the Wright Corporation's Hispano-Suiza. By late 1917, the prototype K-12 (K for Kirkham) was bench tested. While it met its design objectives of high power, low frontal area, compact size, and low weight, the engine encountered technical difficulties during development. Kirkham left Curtiss in 1919, and Arthur Nutt took over the project, eventually producing the D-12, which became a highly successful racing and military power plant in the 1920s.

This engine is manufacturer's number 5 out of about 20 built. The K-12 powered the Curtiss Navy 18T Wasp triplane and the Army Curtiss 18B Hornet biplane. In 1919 Curtiss test pilot Roland Rholfs set a new world's altitude record of 10,641 m (34,910 ft) with the 18T.

Collection Item Long Description:


Circa 1918

Inventory Number


Physical Description

  • Type: Reciprocating, 12 cylinders, V-type, water cooled
  • Power rating: 280 kW (375 hp) at 2,250 rpm
  • Displacement: 18.8 L (1,145.09 cu in.)
  • Bore and Stroke: 114 mm (4.5 in.) x 152 mm (6 in.)
  • Weight: 307.5 kg (678 lb)

Credit Line

Transferred from the U.S. Navy

Country of Origin

United States of America


Steel, Aluminum, Paint, Preservative coating, Rubber, Ceramic, Copper, Brass, Phenolic


Length 152.4 cm (60 in.) (approximate), Width 70.8 cm (27.875 in.), Height 101.9 cm (40.125 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