Roberts 4X, In-line 4 Engine
date: label: Date
content: 1911
name: label: Manufacturer
content: Roberts Motor Company (Sandusky, Ohio)
notes: label: Physical Description
content: Type: Reciprocating, in-line, 4 cylinders, water-cooled, two-stroke cycle
label: Physical Description
content: Power rating: 37.3 kW (50 hp) at 1,400 rpm
label: Physical Description
content: Displacement: 5.2 L (318 cu in.)
label: Physical Description
content: Bore and Stroke: 114 mm (4.5 in.) x 127 mm (5 in.)
label: Physical Description
content: Weight: 77 kg (170 lb)
label: Summary
content: The Model 4X engine was built by the Roberts Motor Company of Sandusky, Ohio. An important design objective was light weight, which was achieved through the extensive use of aluminum and magnesium alloys in the cylinders and crankcase, and a hollow crankshaft. Also like all Roberts engines it operated on a two-stroke cycle operation to reduce parts count. Between 1911 and 1912, Roberts engines were used by many noted exhibition pilots, and more Roberts engines were said to be built than by Hall-Scott and Curtiss combined during this period.
label: Summary
content: This engine artifact was manufactured about 1911 and powered a Curtiss-type, float-equipped aircraft (hydroplane) built by Harry H. Ford. 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.
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 Harry H. Ford
dataSource: label: Data Source
content: National Air and Space Museum
identifier: label: Inventory Number
content: A19480187000
objectType: label: Type
content: PROPULSION-Reciprocating & Rotary
objectRights: label: Restrictions & Rights
content: CC0
physicalDescription: label: Materials
content: Metal
label: Dimensions
content: 3-D: 102.9 × 61 × 63.5cm, 77.1kg (40 1/2 × 24 × 25 in., 170lb.)
label: Dimensions
content: Support: 114.3 × 58.4 × 39.4cm (45 in. × 23 in. × 15 1/2 in.)