Lycoming O-145-B2 Horizontally-Opposed Engine


Display Status:

This object is on display in the Boeing Aviation Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Lycoming O-145-B2 Horizontally-Opposed Engine

Collection Item Summary:

Lycoming traces its beginning to a mid-nineteenth century sewing machine manufacturer. In 1907 that company was sold and restructured as the Lycoming Foundry and Machine Company, which produced automobile engines, and later was a subsidiary of the Auburn Auto Company. Although its early aircraft engines were radials, Lycoming entered the light-aircraft engine field early in 1938 with the introduction of the air-cooled, four-cylinder, horizontally opposed O-145 engine.

Along with Continental and Franklin, Lycoming was a basic provider of engines for the ubiquitous bright yellow Piper Cub, which sold for less than $2,000 and was synonymous with small general aviation aircraft for many years.

Appearing in 1939, the O-145-B2 provided the highest power of Lycoming's three engine models. It powered such aircraft as the Piper J3L-65, Taylorcraft BL-12-65, and Mooney M-18 Mite.

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


Harold E. Morehouse

Credit Line

Exchange with the Cradle of Aviation Museum.


In 1989, this engine was given an overall finish of black lacquer with the propeller hub finished in aluminum powdered acrylic enamel paint.


Length 62.6 cm (24.63 in.), Width 75.1 cm (29.56 in.), Height 52.3 cm (20.59 in.)

Country of Origin

United States of America



Physical Description

  • Type: Reciprocating, Horizontally-opposed, 4 cylinders, Air-cooled
  • Power rating: 48 kW (65 hp) at 2,550 rpm
  • Displacement: 2.4 L (145 cu in)
  • Bore and Stroke: 92.08 mm (3.625 in.) x 88.9 mm (3.5 in.)
  • Weight: 75.3 kg (166 lb)


PROPULSION-Reciprocating & Rotary

Inventory Number