Gnome Monosoupape
| Monosoupape | |
|---|---|
| A 1917 Gnome 9N 160 hp Monosoupape rotary engine, with dual ignition provision. Diameter is 95cm (37.4 in) | |
| Type | Rotary aero engine |
| National origin | France |
| Manufacturer | Gnome et Rhône |
| First run | 1913 |
| Major applications | |
The Monosoupape (French for single-valve), is a rotary engine design first introduced in 1913 by the Gnome Engine Company (renamed Gnome et Rhône in 1915). It uses an arrangement of internal transfer ports to replace the automatic centre-piston inlet valve found on earlier Gnome engines. The elimination of the inlet valve removed a common source of engine failure but also resulted in increased fuel consumption.
French aircraft manufacturers ordered relatively few Monosoupape engines preferring other types including Gnome et Rhône's own Le Rhône series. 2,188 Monosoupape engines were manufactured in Britain, with additional licensed production taking place in Italy and the United States.
British aircraft designer Thomas Sopwith described the Monosoupape as "one of the greatest single advances in aviation". However the type was also criticised for its poor reliability with Royal Flying Corps commander Hugh Trenchard describing it as a "beast of an engine".