'It is extraordinarily difficult to explain in words or writing the exact fascination of a big, fast car of the type so ably represented by the big Bentley speed model.' The Autocar on the Bentley Speed Six, September 5th, 1930.

Although the 6½-Litre had been conceived as a touring car to compete with Rolls-Royce's New Phantom, in Speed Six form it proved admirably suited to competition: in 1929 Barnato/Birkin's Speed Six won the Le Mans 24 Hour Race ahead of a trio of 4½-Litre Bentleys and Barnato/Kidston repeated the feat in the following year's Grand Prix d'Endurance at the Sarthe circuit ahead of similarly-mounted Clement/Watney.

Small wonder then, that the fast yet refined 6½-Litre Speed Six was W O Bentley's favourite car.

Walter Owen Bentley established Bentley Motors in 1919 in the North London suburb of Cricklewood, though deliveries did not begin until 1921.

The first model, a 3-litre car, was powered by a four-cylinder, single overhead camshaft engine with four valves pe...