Lycoming GO-435

 Lycoming produced a four-cylinder horizontally opposed engine in 1938 in addition to its radial engines. Introduced in 1942, the O-435 was a six-cylinder version of the four-cylinder O-290. These engines were also built as tank engines during the WW2 (Locust tank) and Korean War eras. Other models were fitted to helicopters (VO-435), or the turbocharged (TVO-435), as well as geared (GO-435) and geared, supercharged versions (GSO-435).

This engine was one of the huge family of Lycoming horizontally opposed engines and was used in the Stinson L-5, Helio Courier, Ryan Navion, Aero Commander 520, Beech B50 Twin Bonanza, Pilatus P-3 and the Piaggio P.136.
 

One of the Museum's examples of this engine is mounted on a test stand as used by engine overhaul companies to ground run an engine. The Museum's Bell 47J, that is awaiting restoration, is powered by a version of this engine modified for helicopters. An engine on display shows the vertical mounting structure and turbosupercharger of the TVO-435 model.

Technical Details:

Engine Type: air-cooled, horizontally opposed
Number of cylinders: 6
Power: 260 hp at 3400 RPM
Weight: 440 lb (200 kg)
Cylinders: bore 4.875 in (124 mm), stroke 3.875 in (98 mm)
Displacement: 434 cu in (7.1 liters)
Reduction gear ratio: 0.642