General Motors X-250, Radial 4 (8) Engine
date: label: Date
content: Circa1940
name: label: Manufacturer
content: GM Corp, Chevrolet Division
notes: label: Physical Description
content: Type: Radial, 4 (8) cylinders, supercharged, liquid-cooled
label: Physical Description
content: Power rating: 168 kW (225 hp) at 2,500 rpm
label: Physical Description
content: Displacement: 4.1 L (252 cu in)
label: Physical Description
content: Bore and Stroke: 78 mm (3.0625 in.) x 109 mm (4.281 in.)
label: Physical Description
content: Weight: 125 kg (275 lb)
label: Summary
content: A direct-drive, liquid-cooled, supercharged, two-stroke cycle engine, this General Motors engine was a very unusual design incorporating four cylinder blocks, each containing two cylinder bores with a common combustion chamber. At least one application was a small radio controlled target aircraft, and it also powered an Oldsmobile Eight automobile. Flight testing by famed racing and test pilot Tony LeVier successfully continued through 1940 as high as 7.6 km (25,000 ft.) in a Cessna Airmaster C-165, but other pressing war priorities led to termination of the project.
label: Summary
content: A 1942 engineering report written by GM's Research Laboratories, led at the time by its highly regarded director Charles F. Kettering, stated that the engine had excellent power/displacement and power/weight ratios, low fuel consumption, and very low vibration characteristics.
label: Summary
content: Removed from the Cessna in June 1946, the aircraft was later refurbished and flown again.
place: label: Country of Origin
content: United States of America
setName: label: See more items in
content: National Air and Space Museum Collection
creditLine: label: Credit Line
content: Gift of L.T.I. Corporation
dataSource: label: Data Source
content: National Air and Space Museum
identifier: label: Inventory Number
content: A19820086000
objectType: label: Type
content: PROPULSION-Reciprocating & Rotary
objectRights: label: Restrictions & Rights
content: CC0
physicalDescription: label: Materials
content: Steel, Aluminum, Ceramic, Copper, Paint, Rubber, Glass, Phenolic
label: Dimensions
content: Overall: 31 x 27 11/16 x 41 7/16in., 275lb. (78.7 x 70.4 x 105.2cm, 124.7kg)
label: Dimensions
content: Other: 31 x 41 7/16 x 27 11/16 x 60 x 38 x 46in. (78.7 x 105.2 x 70.4 x 152.4 x 96.5 x 116.8cm)
label: Dimensions
content: Approximate (Weighed with Stand by Cat Forklift): 298.5kg (658lb.)