--- title: W.O. Bentley · HICONIUM description: "Founder and chief engineer of Bentley Motors. Aluminium pistons, rotary aero engines, and four Le Mans-winning road cars — the 3 Litre, 4½ Litre, Speed Six and 8 Litre files in the HICONIUM register." canonical_url: https://hiconium.dev/people/wo-bentley image: https://hiconium.dev/og/people/wo-bentley.png --- > HICONIUM · Index: https://hiconium.dev/llms.txt · Every page: append `.md` or send `Accept: text/markdown`. > Path: [Home](https://hiconium.dev/) › [People](https://hiconium.dev/people) › W.O. Bentley > On this page: [The twenty-four hours](#the-twenty-four-hours) · [3 Litre](#3-litre) · [4½ Litre](#4½-litre) · [Speed Six](#speed-six) · [Speed Six](#speed-six) · [The 3 Litre to the 8 Litre](#the-3-litre-to-the-8-litre) · [Bentley 3 Litre](#bentley-3-litre) · [Bentley 4½ Litre](#bentley-4½-litre) · [Bentley Speed Six](#bentley-speed-six) · [Bentley 8 Litre](#bentley-8-litre) · [The piston, the head, the capacity](#the-piston-the-head-the-capacity) · [The aluminium piston](#the-aluminium-piston) · [The rotary engines](#the-rotary-engines) · [The fixed head](#the-fixed-head) · [Capacity over supercharging](#capacity-over-supercharging) · [Competition as proof](#competition-as-proof) # W.O. Bentley · HICONIUM ![W.O. Bentley in a tweed three-piece suit standing beside a Bentley Speed Six under a single spotlight](https://hiconium.dev/_derived/images/people/wo-bentley/hero.jpg.w1920.q75.webp) AI-generated People · Engineer · 1888–1971 Walter Owen a fast car, a good car, the best in its class | Label | Value | | --- | --- | | Born | Hampstead, 1888 | | Died | Woking, 1971 | | Company | Bentley Motors, 1919–1931 | | In the register | Four files | The constructor A railway apprenticeship, aluminium pistons proved at Brooklands, two rotary aero engines for the war — by 1919 Bentley had a method before he had a company. The cars that followed were engineered for strength, capacity and sustained speed; the racing record only confirmed what the road cars already were. Bentley Motors was his for twelve years, from the 3 Litre to the 8 Litre. After the 1931 collapse he served Rolls-Royce under the acquisition contract, then gave Lagonda a V12 and a post-war twin-cam six that outlived the company that commissioned it. The four files below hold the cars that carry his own name. Grand Prix d’Endurance · Le Mans ## The twenty-four hours He came to Le Mans a sceptic and left it the measure of his cars. The results below belong to the four files in this register. 1924 ### 3 Litre John Duff and Frank Clement give the marque its first outright win. Won outright 1928 ### 4½ Litre The naturally aspirated four takes the race — its defining result. Won outright 1929 ### Speed Six The Speed Six wins outright. Won outright 1930 ### Speed Six The Speed Six wins a second time. Won outright The register ## The 3 Litre to the 8 Litre [![Bentley 3 Litre staged in a darkened scene](https://hiconium.dev/_derived/images/cars/bentley-3-litre/hero-wide-2560.jpg.w1920.q75.webp) 1921 ### Bentley 3 Litre Founder and chief engineer · Bentley Motors The first production Bentley set the technical identity of the marque — the long-stroke four, twin ignition, the overhead camshaft. W.O. used competition to prove the production chassis; the endurance record gave the road car its public proof. Open the file](https://hiconium.dev/vehicles/bentley/3-litre) [![Bentley 4½ Litre staged in a darkened scene](https://hiconium.dev/_derived/images/cars/bentley-41-2-litre/hero-wide-2560.jpg.w1920.q75.webp) 1927 ### Bentley 4½ Litre Founder and chief engineer · Bentley Motors The 4½ Litre kept the fixed-head overhead-cam four and answered the call for more with capacity, not a supercharger. Its 1928 Le Mans win became its defining result. Open the file](https://hiconium.dev/vehicles/bentley/41-2-litre) [![Bentley Speed Six staged in a darkened scene](https://hiconium.dev/_derived/images/cars/bentley-speed-six/hero-wide-2560.jpg.w1920.q75.webp) 1928 ### Bentley Speed Six Founder and chief engineer · Bentley Motors The sporting 6½ Litre, developed through breathing, compression and camshaft rather than forced induction. It won Le Mans in 1929 and again in 1930. Open the file](https://hiconium.dev/vehicles/bentley/speed-six) [![Bentley 8 Litre staged in a darkened scene](https://hiconium.dev/_derived/images/cars/bentley-8-litre/hero-wide-2560.jpg.w1920.q75.webp) 1930 ### Bentley 8 Litre Founder and chief engineer · Bentley Motors His final Bentley enlarged the straight-six to eight litres, an Elektron magnesium-alloy crankcase containing the weight. It was built to move formal coachwork at a sustained hundred miles an hour — without noise, without strain. Open the file](https://hiconium.dev/vehicles/bentley/8-litre) Signature moves ## The piston, the head, the capacity ### The aluminium piston Developed for DFP competition engines before the war, proved by an 89.7 mph flying mile at Brooklands. The material lesson everything after was built on. ### The rotary engines The piston work applied to aero-engine reliability: the BR1 and BR2 rotaries, drawn for a war that needed engines to last, not merely to run. ### The fixed head The 3 Litre’s four-valve, overhead-camshaft four with its cylinder head integral to the block — an architecture stated once and kept through the 8 Litre. ### Capacity over supercharging When the cars needed more, he added litres, not a blower. The supercharged 4½ was built over his objection; it does not carry his credit. ### Competition as proof He opposed Le Mans at first, then made it the method: the race existed to confirm what the production chassis already was. ### The quiet hundred The 8 Litre closed the argument — a chassis for formal coachwork at a sustained 100 mph, engineered so the speed never announced itself. The archive ## Prints from the drawer Two portraits, a prototype, an aero engine and a Lagonda — choose a print and it pushes the others aside. W.O. Bentley, 1921. National Motor Museum, public domain. Beyond the register ## From the DFP to the Lagonda V12 ### '12–'19 #### DFP programme Import, preparation and competition with his brother H.M. — the aluminium-piston laboratory. #### Clerget 9J Wartime improvement work on the French rotary, the commission that led to his own. #### Bentley BR1 and BR2 The rotary aero engines of 1916–18, drawn for the Royal Naval Air Service. #### EXP1 and EXP2 The 1919 prototypes of the 3 Litre — EXP2 survives as the oldest Bentley. ### '26–'31 #### Bentley 6½ Litre The Big Six of 1926, the chassis the Speed Six was developed from. #### Bentley 4 Litre The company’s 1931 model, launched under his leadership in the final season. ### '35–'50 #### Lagonda LG45 The 4½-litre development line of his first Lagonda years as technical director. #### Lagonda V12 The 1937–40 twelve-cylinder programme — his grandest pre-war engine. #### Lagonda 2.6 litre The post-war twin-cam straight-six, later carried into the Aston Martin DB2. #### Armstrong Siddeley 3 litre A twin-cam sports-car project, 1947–50; prototype and development work only. In his words “We were going to make a fast car, a good car, the best in its class.” W.O. Bentley · on the founding, 1919