British Salmson (United Kingdom)

British Salmson Aero Engines Ltd. was established in 1930 in Kaynes Park, London, as a successor to the French-controlled Moteurs Salmson, with financial backing from the Martineau family. The company initially aimed to supply engines for the light aircraft industry, achieving limited success with some engines sold to British Klemm and powering at least one Cierva Autogiro. However, due to the need for alternative work, British Salmson began manufacturing the SALMSON S4C under license from the French firm in 1934.

The British version of the S4C featured a 1476 cc twin-overhead cam four-cylinder engine, which produced 55 bhp and allowed for a top speed of 70 mph (112 km/h). Notably, it included synchromesh on the third and top gears, a feature absent in the French model. The bodies were designed and manufactured in England, with saloons and tourers produced by Ranalah and Newns. Approximately 350 units of the S4C were produced.

In 1937, the S4C was succeeded by the S4D, which had an enlarged engine of 1596 cc. Despite the increase in engine size, the heavier bodies resulted in performance that was comparable to the S4C 12/55. The initial S4Ds featured an engine bored out to 1730 cc, but this was close to the block's limit, leading to most of the approximately 75 units produced being equipped with the smaller engine. The S4D maintained the transverse-leaf independent front suspension and hydraulic brakes found in the French Salmsons, and it was available in a curved back six-light saloon and a drophead configuration.

The final model produced by British Salmson was the 20/90, which featured a twin-overhead cam six-cylinder engine of 2580 cc, generating 90 bhp and achieving a top speed exceeding 90 mph (145 km/h). Only 12 units of the 20/90 were manufactured, available in four body styles, including a two-seater sports version and a two-door sports saloon. Production of four-cylinder models ceased in 1938, and the last car was delivered in 1939. The company later shifted its focus to general engineering, producing the 31 cc Cvclaid engine for motorizing bicycles between 1950 and 1952. Eventually, the factory transitioned to jam production, and British Salmson relocated to Glasgow, where it began manufacturing printing presses.