BMW Model IIIA In-line 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 Daimler-Benz company's virtual monopoly on the production of aircraft engines in Germany stifled research and development of other engines. As a result, when the Allies introduced a new generation of high-performance engines in 1916, Germany found itself without a suitable replacement for its now-obsolete standard aircraft power plant, the 119 kw (160-shp) Daimler-Benz Mercedes.

Believing that he had a solution to the crisis, Daimler-Benz designer Max Fritz proposed a new engine that used the same technology as the older Mercedes. But his ideas met with resistance, so Fritz left and joined Bayerische Motoren Werke (BMW). There he designed an engine that retained the 6-cylinder in-line configuration of the earlier Daimler-Benz engines, but was superior in many respects.

The BMW Model IIIa had unusually low fuel consumption and very good performance at high altitudes. This was the result of a choked down carburetor setting and a high compression ratio. It powered such aircraft as the Fokker D VII.

Collection Item Long Description:

Data Source

National Air and Space Museum

Restrictions & Rights

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

Credit Line

Transferred from the U.S. Navy




  • 3-D: 170.2 × 50.8 × 105.4cm (67 × 20 × 41 1/2 in.)
  • Support: 65.4 × 106.7 × 50.8cm (25 3/4 in. × 42 in. × 20 in.)

Country of Origin




Physical Description

  • Type: Reciprocating, In-line, 6 cylinders, liquid-cooled,
  • Power Rating: 134 kW (180 hp) at 1410 rpm
  • Displacement: 19.058 L (1,163 cu in.)
  • Bore and Stroke: 150 mm (5.9 in) x 180 mm (7.1 in)
  • Weight: 293 kg (644 lb)


PROPULSION-Reciprocating & Rotary

Inventory Number