Roberts Model 4X
This 37 kw (50 shp) Model 4X engine was built by the Roberts Motor Company of Sandusky, Ohio about 1911. An important design objective of this engine was light weight which was achieved through the extensive use of aluminum and magnesium alloys in the cylinders and crankcase, a hollow crankshaft, and two-stroke cycle operation (to reduce parts count). Between 1911 and 1912, Roberts engines were used by many noted exhibition pilots, and more engines were said to be built than by Hall-Scott and Curtiss combined.
This Roberts engine powered a Curtiss-type, float-equipped aircraft (hydroplane) built by Harry H. Ford in 1911. Mr. Ford was a self-taught pilot and did most of his flying between 1912 and 1913 in the area of the Bridgeport, Connecticut harbor.
Gift of Harry H. Ford.
Country of Origin: United States of America
Length 103 cm (40.5 in)., Width 61.0 cm (24.0 in)., Height 63.5 cm (25.0 in).
Type: In-line, 4 cylinders, water-cooled, two-stroke cycle
Power rating: 37.3 KW (50 hp) at 1,400 rpm
Displacement: 5.2 L (318 cu in)
Bore and Stroke: 114 mm (4.5 in) x 127 mm (5 in)
Weight: 77 kg (170 lb)
Condition: Has carburetor, magneto, accessory gears, ignition harness, and 4 reproduction spark plugs; data plate on forward cylinder; missing grease cups; has painted silver (non-original) finish; on stand.