Coventry Climax was a British manufacturer of specialty engines and Machinery. It was founded in 1903 as Lee Stroyer, and was created to provide simple and low cost piston engines. The company also manufactured a limited number of cars. In 1905, after the departure of Stroyer, Henry Pelham Lee renamed the company as Coventry-Simplex, to reflect the location and the concept of simple piston engines. An early client was GWK, who produced over a thousand cars with Coventry-Simplex two cylinder engines in the period 1911-15. When civilian auto production shut down for the war, the company sold thousands of engines to the military to power searchlights. In 1917 the company name was changed to Coventry-Climax.
Throughout the 1920s and 30s the company provided engines to manufacturers of lighter cars, including GWK, Morgan and Triumph.