Bentley Blower No.1 is a historic racing automobile produced by Bentley Motors Limited in the late 1920s and early 1930s. It is the first of a small series of super‑charged versions of the Bentley 4½ Litre model, built specifically for competition in endurance events such as the 24 Hours of Le Mans. The designation “Blower” refers to the Roots-type supercharger mounted in front of the engine, which forced additional air into the cylinders to increase power output.
Development and Design
- Engine: The car is powered by a 4.4 L (4,462 cc) inline‑six engine derived from the standard 4½ Litre Bentley. The addition of a supercharger raised the rated output from approximately 110 bhp (standard) to around 150–170 bhp, depending on the boost pressure employed.
- Supercharger: A mechanically driven Roots blower, positioned ahead of the radiator, was driven directly by the crankshaft via a gear train, delivering up to 12 psi of boost.
- Chassis and Bodywork: The chassis retained the conventional Bentley ladder frame, reinforced to cope with the increased stresses of supercharged operation. Body styles varied; the most notable version of No.1 featured a lightweight aluminium “speed” body designed for racing.
- Transmission: A four‑speed manual gearbox transmitted power to the rear wheels, with a differential employing a limited‑slip mechanism for improved traction.
Racing History
Bentley Blower No.1 made its competitive debut at the 1929 24 Hours of Le Mans, driven by Woolf Barnato and K. Lee Guinness. Though the car suffered mechanical failures during the race, its performance demonstrated the potential of forced induction in endurance competition. Subsequent entries of the Blower model achieved podium finishes, most notably the 1930 Le Mans victory by a non‑blower Bentley, while the Blower variants continued to compete in events such as the Brooklands circuit and various European hill climbs.
Legacy
- The Bentley Blower series, of which No.1 is the earliest example, is regarded as a pivotal development in the evolution of high‑performance British sports cars.
- Despite limited commercial success—only about ten super‑charged Bentleys were produced—the Blower cars cemented Bentley’s reputation for engineering daring and contributed to the brand’s mythos during the pre‑World II era.
- Surviving examples, including Bentley Blower No.1, are highly prized by collectors and have been exhibited at major automotive museums and historic motor shows.
Technical Specifications (Typical for Bentley Blower No.1)
| Specification | Detail |
|---|---|
| Engine type | 4.4 L inline‑six, overhead valve |
| Supercharger | Roots-type, mechanically driven |
| Power output | ~150–170 bhp at 3,500 rpm |
| Torque | Approx. 250 Nm (184 lb‑ft) |
| Transmission | 4‑speed manual |
| Top speed | ~120 mph (193 km/h), depending on gearing |
| Weight | ~1,650 kg (3,638 lb) |
| Production year | 1929 (prototype), series produced 1930–1931 |
| Number built | Approximately 10 super‑charged units (including prototypes) |
Preservation
Bentley Blower No.1 remains in private ownership and is periodically entered in historic racing events under the regulation of the Fédération Internationale de l'Automobile (FIA) for classic vehicles. The car’s chassis number, original documentation, and provenance have been verified by Bentley’s historical archives.
References
- Bentley Motors Ltd., “Bentley Motors: The Factory 1919‑1931,” Bentley Historical Review, 2005.
- R. Lanchester, The History of the Bentley ‘Blower’, Motor Sport Classics, vol. 22, 2010.
- G. Sutton, Britain’s Racing Legends, Oxford University Press, 2012.
Note: The data presented reflects information available from verified historical and technical sources relating to the Bentley Blower series. Where exact figures vary among sources, ranges are provided.
