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Clerget 9B Aero Engine Manual (1915)

Price $363.00 Sale


Le Montage, Le Reglage, 
Et L'Entretien Du
Moteur Rotatif

Type 9B 130 HP

CLERGET-BLIN & Cie, Levallois-Perret, 1915

A very rare original WW1 edition of the Clerget-Blin manufacturer's instruction manual for the Clerget 9B 130 hp rotary aero engine. Undated, but published by Clerget-Blin c.1915 (the 9B engine was introduced in that year, and revised models such as the 9F were developed later in 1915). During WW1 the Clerget 9B was fitted to many successful RFC and RAF aircraft, including the Sopwith Camel, Sopwith Triplane and Avro 504.

The manual, written in French, includes a general description of the 9B engine, its components and its operation. There are also instructions for assembling and mounting the engine, and making any necessary adjustments to valves, magnetos, oil supply, etc. A comprehensive illustrated list of parts and tools is included, along with various useful technical appendices, and a number of blank notes pages for any amendments that would have been added. The manual is illustrated with plates, a folding plan of the engine, detailed drawings, and diagrams of various components.

The book is signed in pencil on the front endpapers by 'J. H. Cheese, 2340, R.F.C.' John Harold Cheese (1895-1970) was born on 14 February 1895 in Wolverhampton, the son of John C. and Catherine Cheese. He attended Holy Trinity School in Heath Town and by 1911 he was working a pump fitter. He later worked at the Sunbeam Motor works in Wolverhampton. On 23 November 1914 he joined the Royal Flying Corps, becoming one of its earliest members, with the service number 2340. He became an aeroplane fitter, working on aero engines at Brooklands aerodrome and later at Le Bourget airfield in France. Le Bourget, 13km north east of Paris, was established as a military airfield by the French Army at the start of WW1. After the War John Cheese returned to Sunbeam Motors, working as a fitter for their Grand Prix racing team. He also played football for the Sunbeam works team, as well as semi-professionally for Wellington, and in the England junior league team in 1921-22.

Clerget-Blin & Cie: was founded in 1913 when Pierre Clerget (1875-1943) joined forces with the industrialist Eugene Blin. From their premises at 37 Rue Cavé, Levallois-Perret, on  the banks of the Seine about 4 miles from the centre of Paris, they produced a succesful range of aero engines. Clerget-Blin were best known for the air-cooled rotary engines which were built and licensed during WWI, and which powered some of the RFC’s most famous aircraft, including the Sopwith Pup, Sopwith Camel and Avro 504K. Gwynnes Ltd held the British manufacturing rights for Clerget designs during the first world war. Clerget designed air-cooled rotaries with seven, nine, and eleven cylinders. Their cylinders, machined with integral cooling fins from solid steel billets, were gripped between the two steel crankcase halves. The crankcase nose piece carried the propeller hub.

Clerget 9B: was a nine cylinder 130HP rotary engine designed by Pierre Clerget. During WW1 it was produced in France and also under licence in Britain by Gwynnes of Hammersmith, Gordon Watney (Weybridge), Ruston Proctor of Lincoln, and Humber-Bentley (Coventry). What distinguished the Clerget rotary engine from rival engines made by Gnome and Le Rhone was that the Clerget had normal intake and exhaust valves, unlike the Gnome, and the connecting rod arrangement was much simpler than the Le Rhone. A source of failure among the Clerget engines were the special-purpose piston rings, or obturator rings. These rings were often made from brass and only had a lifespan of a few hours. The Clerget engines were considered reliable but they cost more per unit to produce than their rivals. Unlike other contemporary rotaries in which the ignition system was either switched on or off to provide a rudimentary form of engine speed control, the Clerget featured a throttle. The 9B was considered to be one of the best WW1 aero engines, and was used extensively by aircraft manufacturers such as Sopwith, Avro and Vickers, powering iconic aircraft including the Sopwith Camel, Vickers Gunbus, and Avro 504.


In very good condition. The cloth-covered stiff card cover is in very good condition, with a few minor marks marks. The binding and hinges are very good and secure. The text and illustrations are in very good condition. The folding plan of the 9B is in very good condition. The book is signed in pencil on the front endpapers by 'J. H. Cheese, 2340, R.F.C.'

Published: c.1915 
Maroon cloth-covered card cover with silver gilt titling
Illustrated with plates, line drawings, and a folding plan
Dimensions: 100mm x 150mm
Pages: 158 (plus blank notes pages)