Gnome Monosoupape

Gnome Monosoupape

The Monosoupape (French for single-valve), was a rotary engine design first introduced in 1913 by Gnome Engine Company (since 1915 called Gnome et Rhône). It used a clever arrangement of internal transfer ports and a single pushrod-operated exhaust valve to replace a large number of moving parts found on more conventional rotary engines, and made the Monosoupape engines some of the most reliable of the era. British aircraft designer Thomas Sopwith described the Monosoupape as "one of the greatest single advances in aviation".

Produced under license in Britain the engine was built in large numbers in both seven and nine-cylinder versions, the latter being produced with two different displacements.