The rotary engine reduced rough the running and overheating of early air-cooled engines, namely. Disadvantages were gyroscopic forces, lubrication losses, low time-between-overhaul, air resistance to rotating cylinders, and limited rpm.

The first successful rotary engine is generally attributed to the American F.O. Farwell in 1896; but the French Gnome engine, developed by the Seguin brothers, was much more successful in bringing the rotary to a broad aviation market beginning in 1909. The original Gnome had two valves, with the inlet in the head of the piston and the exhaust in the in the cylinder head. The monosoupape, as the name signifies, had only one valve in the cylinder head, eliminating a weak feature of the earlier design, and was the most numerous model during World War I.

It powered the French Nieuport, Bleriot, and Pomier aircraft, the British Nieuport 28C.1 and Sopwith F.1 Camel, and was also built under license in England, Italy, and the U.S.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date Circa World War I Country of Origin France Type PROPULSION-Reciprocating & Rotary Designer Laurent Seguin
Louis Seguin
 Manufacturer Societe des Moteurs Gnome et Rhône
 Physical Description Type: Rotary, 9 cylinders, air-cooled, monosoupape Power rating: 123 kw (165 hp) at 1,350 rpm Displacement: 15.9 L (970.38 cu. in.) Bore and Stroke: 115 mm (4.53 in.) x 170 mm (6.69 in.) Weight: 132 kg (290 lb) Dimensions Diameter 102 cm (40 in.), Length 109 cm (43 in.)
 Inventory Number A19750202000 Credit Line Gift of the University of Connecticut Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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