W.O. registered Bentley Motors Ltd. in August 1919, and in October he exhibited a car chassis, with a dummy engine, at the London Motor Show. Ex–Royal Flying Corps officer Clive Gallop designed an innovative four-valves-per-cylinder engine for the chassis. By December the engine was built and running. Delivery of the first cars was scheduled for June 1920, but development took longer than estimated so the date was extended to September 1921. The durability of the first Bentley cars earned widespread acclaim, and they competed in hill climbs and raced at Brooklands.