CarBrandLogos archive · Bentley · 1921

Bentley3 Litre

Four valves per cylinder in 1921, and the beginning of the Le Mans habit.

Photo: Mr.choppers · CC BY-SA 3.0

The story

A defining chapter in Bentley history.

Explore the ideas, engineering and context that shaped the Bentley 3 Litre, then continue into its specifications and place in the marque's lineage.

Origins

W.O. Bentley spent the First World War designing rotary aero engines, and the car he built afterwards brought that thinking down to the road. Its three-litre four had a single overhead camshaft, four valves per cylinder and twin spark plugs at a time when most British engines still had side valves and one plug apiece. Prototype work began in 1919; customer cars followed in 1921.

Bentley motif - Flickr - exfordy · Brian Snelson from Hockley, Essex, England · CC BY 2.0

Design and engineering

It was sold as a chassis, to be bodied by whichever coachbuilder the buyer preferred, and identified by the colour of the enamel behind the radiator badge, green, red or blue, according to chassis length and state of tune. On paper it was heavy and not especially fast. In practice it was strong, and strength is what wins long-distance races.

Bentley at Gunwalloe · Tim Green · CC BY 2.0

In production

A 3 Litre took Le Mans in 1924 with John Duff and Frank Clement, and won again in 1927 in the most famous circumstances the marque has: Old Number Seven, damaged in the multi-car pile-up at White House corner, was nursed to the finish by Sammy Davis and Dr Dudley Benjafield. The wealthy amateurs who drove these cars became known as the Bentley Boys, and for a company this small their publicity was worth more than the racing cost.

Chelsea Auto Legends 2012 · The Car Spy · CC BY 2.0