Curtiss Challenger R-600, 2-Row, Radial 6 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:

The Challenger engine, which followed the water cooled Curtiss V-8 OX-5 engine that powered the World War I JN-4 “Jenny” trainer aircraft, was designed as a lower-cost, medium-power engine specifically intended for small commercial cabin aircraft and open cockpit sport planes. The engine received its original Approved Type Certificate (No. 5) in 1928, which was revised and re-issued in 1930.

The small, compact configuration of two staggered rows of three cylinders was intended to provide better dynamic balance and, thus, smoother operation, as well as low frontal area for improved airframe streamlining and better pilot visibility. However, although being economical, the Challenger did not run smoothly, and was frequently replaced by aircraft owners because of a vibration problem.

The Challenger powered a variety of aircraft types including the Curtiss Robin, Curtiss Fledgling, Curtiss Tanager, Curtiss-Wright Sedan 15-C, Command-Aire Model 5C3, and Eastman Sea Rover E-2.

Collection Item Long Description:


Circa 1928

Inventory Number


Physical Description

  • Type: Reciprocating, 6 cylinders, two-row, radial, air-cooled
  • Power rating: 138 kW (185 hp) at 2,000 rpm
  • Displacement: 9.88 L (603 cu in.)
  • Bore and Stroke: 130 mm (5.125 in.) x 124 mm (4.875 in.)
  • Weight: 190.5 kg (420 lb)

Credit Line

Gift of Wright Aeronautical Corporation

Country of Origin

United States of America


  • HAZMAT: Magnesium
  • Aluminum, Steel, Copper, Rubber, Paint, Preservative coating


Diameter 108.3 cm (42.6 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