The Bentley 3 Litre was a car chassis manufactured by Bentley. The company's first, it was developed from 1919 and made available to customers' coachbuilders from 1921 to 1929. The Bentley was very much larger than the 1368 cc Bugattis that dominated racing at the time, but double the size of engine and strength compensated for the extra weight. The 4000 lb (1800 kg) car won the 24 Hours of Le Mans in 1924, with drivers John Duff and Frank Clement, and again in 1927, this time in Super Sports form, with drivers S. C. H. "Sammy" Davis and Dudley Benjafield. Its weight, size, and speed prompted Ettore Bugatti to call it "the fastest lorry in the world", which was regarded as a compliment. Built in 3 main variants, Blue label, Red Label Speed models all carrying a 5-year warranty, and the coveted and rare Green Label 100 mph cars, which only carried a 12-month warranty reflecting the high state of tune. Coachwork The 3 Litre was delivered as a running chassis to the coachbuilder of the buyer's choice. Bentley referred many customers to their near neighbour Vanden Plas for bodies. Dealers might order a short cost-saving run of identical bodies to their own distinctive design. Most bodies took the simplest and cheapest form, tourers, but as it was all bespoke or "custom" coachwork there was plenty of variation. Customers included Prince George, Duke of Kent, Gertrude Lawrence, and Beatrice Lillie. Engineering The 3.0 L () straight-4 engine was designed by ex-Royal Flying Corps engineer Clive Gallop and was technically very advanced for its time. It was one of the first production car engines with 4 valves per cylinder, dry-sump lubrication and an overhead camshaft. The four valve SOHC Hemi design, with a bevel-geared shaft drive for the camshaft, was based on the pre-World War I 1914 Mercedes Daimler M93654 racing engine. Just before the outbreak of the war Mercedes had placed one of the winning Grand Prix cars in their London showroom in Long Acre. At the suggestion of W.O. Bentley, then being commissioned in the Royal Naval Air Service, the vehicle was confiscated in 1915 by the British army, dismantled at Rolls-Royce and subjected to scrutiny. A notable difference to both the Mercedes and the aero engines was the cast-iron monobloc design, and the fully Aluminium enclosed camshaft, which greatly contributed to its durability. But having the valve-head