In 1929, the French Salmson company started a British branch company, Moteurs Salmson in Raynes Park, London, as a radial aero engine maker for the British Empire market.

[1] As aero engine sales proved slow, the company extended the licence deal to include local production of cars from 1934.

The British S4C had the same twin-overhead-camshaft, 1471 cc, four-cylinder engine and chassis as its French parent, but the gearbox was updated to include synchromesh on the top two ratios.

The new car was heavier than the superseded S4C and in spite of the larger engine, there was no significant increase in performance.

Car production did not restart after the war, but a few small 31 cc engines for converting bicycles were made.