Started by Walter Owen and Henry Bentley in 1919, Bentley Motors took their first Le Mans 24 Hours victory in 1924. The main reasons for this success were WO Bentley's determination and natural technical ability. He had worked as an apprentice at the Great Northern Railway and had designed airplane engines before he started his own company. By the time the company went into receivership in 1931, 3033 cars were produced and five Le Mans victories were scored.
The various engines produced were technically very similar to the 3 litre four cylinder engine of 1919. Characteristic features were the revolutionary aluminium pistons and an overhead camshaft operating 4 valves per cylinder. These features, together with dry-sump lubrication, were well ahead of the time and it would take decades before many other companies caught up. The cylinder block and head were cast as one piece to prevent gasket leakages. The extremely long stroke provided the slow running engine with plenty of torque.
In 1925 a new six cylinder engined model was announced. It displaced just under 6.6 litre and was equipped with all features that made the 3-litre unit special. More good news came in 1925 when millionaire Captain Woolf Barnato poured extra money in the company. On the track 1925 and 1926 were disaster years; two cars ran out of fuel and one caught fire in 1925, and engine maladies and a late crash took the 3 cars entered in 1926 out of the race. In 1927 a sole surviving 3-litre Bentley took the victory after the leading Aries dropped out of the race, one hour before the end of the race.
Work was started on a special high performance version of the 6 cylinder car, to ensure Bentley's racing future. Introduced in 1928, it was dubbed the Bentley 6 1/2 litre Speed Model or Speed Six. Meanwhile a group of young works racers was formed, with Woolf Barnato as the charismatic leader. Today they are the best known group works drivers and are commonly referred to as the 'Bentley-Boys'. The first success for the Bentley-Boys came in 1928, when the Barnato/Rubin driven Bentley 4 1/2 litre took a difficult victory at Le Mans.
Bentley's glory years at Le Mans were 1929 and 1930, with the Speed Six dominating both races. Barnato was the winning driver in both years, with Tim Birkin and Glen Kidston respectively as co-drivers. In competition specification the Speed Six engine was good for 200 bhp at 3500 rpm. Together with rock solid reliability this was more than enough to fight off the competition. Financial problems prevented Bentley from competing in the 24 Hour race in 1931 and after Rolls Royce purchased the remains of the company, the racing program was scrapped.
In 1930 Bentley launched a new model to take on Rolls Royce in the luxury market; the 8-Litre. As its name suggests the new car packed an eight litre version of the advanced six cylinder engine, which easily produced 220 bhp and bucket loads of torque. There were only very few contemporaries that could match the chassis' refinement, power and price. Due to the take-over by Rolls Royce production lasted for just two years in which 100 examples were built with both short and long wheelbase chassis.