Bentley · racing automobile model · 1927–2020

Bentley 4½ Litre

The Bentley 4½ Litre is a British car based on a rolling chassis built by Bentley Motors. Walter Owen Bentley replaced the Bentley 3 Litre with a more powerful car by increasing its engine displacement to 4.4 litres (270 cubic inches). A racing variant was known as the Blower Bentley. Bentley buyers used their cars for personal transport and arranged for their new chassis to be fitted with various body styles, mostly saloons or tourers. However, the publicity brought by their competition programme was invaluable for marketing Bentley's cars. At the time, noted car manufacturers such as Bugatti and Lorraine-Dietrich focused on designing cars to compete in the 24 Hours of Le Mans, a popular automotive endurance course established only a few years earlier. A victory in this competition quickly elevated any car maker's reputation. A total of 720 4½ Litre cars were produced between 1927 and 1931, including 55 cars with a supercharged engine popularly known as the Blower Bentley. A 4½ Litre Bentley won the 24 Hours of Le Mans in 1928. Though the supercharged 4½ Litre Bentley's competitive performance was not outstanding, it set several speed records, most famously the Bentley Blower No.1 Monoposto in 1932 at Brooklands with a recorded speed of 222.03 km/h (137.96 mph).

Text from Wikipedia (CC BY-SA 4.0).

Predecessor: Bentley 3 Litre · Successor: Bentley Mark V

All Bentley 4½ Litre data: UK builds, safety, recalls, model years →

Background and development

=== Bentley at the 24 Hours of Le Mans === The 24 Hours of Le Mans endurance race is a 24-hour race around the Circuit de la Sarthe. The inaugural race was held 26–27 May 1923, and attracted many drivers, mostly French. There were two foreign competitors in the first race, Frank Clement and Canadian John Duff, the latter winning the 1924 competition in his personal car, a Bentley 3 Litre. "Made with precision and the finest material," and with recent success, the luxurious Bentley cars attracted attention. After two years without success, Bentley convened a group of wealthy British men, "united by their love of insouciance, elegant tailoring, and a need for speed," to renew Bentley's success. Both drivers and mechanics, these men, later nicknamed the "Bentley Boys", drove Bentley automobiles to victory in several races between 1927 and 1931, including four consecutive wins at the 24 Hours of Le Mans, and forged the brand's reputation. It was within this context that, in 1927, Bentley developed the Bentley 4½ Litre. Two cylinders were removed from the 6½ Litre model, reducing the displacement to 4.4 litres. At the time, the 3 Litre and the 6½ Litre were already available, but the 3 Litre was an outdated, under-powered model and the 6½ Litre's image was tarnished by poor tyre performance. Tim Birkin and the Blower Bentley. Sir Henry "Tim" Birkin, described as "the greatest British driver of his day" by W. O. Bentley, was one of the Bentley Boys. He refused to adhere strictly to Bentley's assertion that increasing displacement is always preferable to forced induction. Birkin, aided by a former Bentley mechanic, decided to produce a series of five supercharged models for the competition at the 24 Hours of Le Mans; Mercedes-Benz had been using superchargers for years. Thus t

Specifications

Although the Bentley 4½ Litre was heavy, weighing 1,625 kg (3,583 lb), and spacious, with a length of 4,380 mm (172 in) and a wheelbase of 3,302 mm (130.0 in), it remained well-balanced and steered nimbly. The manual transmission, however, required skill, as its four gears were unsynchronised. The robustness of the 4½ Litre's lattice chassis, made of steel and reinforced with ties, was needed to support the heavy cast iron inline-four engine. The engine was "resolutely modern" for the time. The displacement was 4,398 cc (268.4 cu in): 100 mm (3.9 in) bore and 140 mm (5.5 in) stroke. Two SU carburetters and dual ignition with Bosch magnetos were fitted. The engine produced 110 hp (82 kW) for the touring model and 130 hp (97 kW) for the racing model. The engine speed was limited to 4,000 rpm. A single, crossflow, overhead camshaft actuated four valves per cylinder, inclined at 30 degrees. This was a technically advanced design at a time where most cars used only two valves per cylinder in a side-valve cylinder head. The camshaft was driven by bevel gears on a vertical shaft at the front of the engine, as on the 3 Litre engine. The Bentley's tanks – radiator, oil and petrol – had quick release filler caps that opened with one stroke of a lever. This saved time during pit stops. This 4½ was equipped with a canvas top stretched over a lightweight Weymann body. The hood structure was very light but with high wind resistance (24 Hours Le Mans rules between 1924 and 1928 dictated a certain number of laps for which the hood had to be closed). The steering wheel measured about 45 cm (18 in) in diameter and was wrapped with solid braided rope for improved grip. Brakes were conventional, consisting of 17-inch (430 mm) drum brakes finned for improved cooling and operated by rod. Sem

Competition performance

Between 1927 and 1931 the Bentley 4½ Litre competed in several competitions, primarily the 24 Hours of Le Mans. The first was the Old Mother Gun at the 1927 24 Hours of Le Mans, driven as a prototype before production. Favored to win, it instead crashed and did not finish. Its performance was sufficient for Bentley to decide to start production and deliver the first models the same year. Far from being the most powerful in the competitions, the 4½ Litre of Woolf Barnato and Bernard Rubin, raced neck and neck against Charles Weymann's Stutz Blackhawk DV16, setting a new record average speed of 111.12 km/h (69 mph); Tim Birkin and Jean Chassagne finished fifth. The next year, three 4½ Litres finished second, third, and fourth behind another Bentley, the Speed Six, which possessed two more cylinders. The naturally aspirated 4½ Litre was noted for its good reliability. The supercharged models were not; the two Blower models entered in the 1930 24 Hours of Le Mans by Dorothy Paget, one of which was co-driven by Tim Birkin, did not complete the race. In 1930, Birkin finished second in the French Grand Prix at the Circuit de Pau behind a Bugatti Type 35. Ettore Bugatti, annoyed by the performance of Bentley, called the 4½ Litre the "fastest lorry in the world." The Type 35 is much lighter and consumes much less petrol. Blower Bentleys consume 4 liters per minute at full speed. Despite the Blower's record of poor reliability, Mildred Bruce, a British female racer, achieved a 24-hour distance record at Montlhéry in one, attaining an average speed of 89.4 mph (143.9 km/h). In 1930, the Daily Herald offered a trophy for the fastest driver at an event at Brooklands. The first year, Tim Birkin and Kaye Don competed and Kaye Don won with a speed of 137.58 mph (221.41 km/h). In 1932,

End of production

In November 1931, after selling 720 copies of the 4½ Litre – 655 naturally aspirated and 55 supercharged – in three different models (Tourer, Drophead Coupé and Sporting Four Seater), Bentley was forced to sell his company to Rolls-Royce for £125,175, a victim of the recession that hit Europe following the Wall Street crash of 1929.

Current status

As of 2013, Bentley 4½ Litre automobiles from this inter-war period – the "Belle Époque" of the automobile for some – sold for around €1,000,000. Blowers can fetch more than €7 million and are coveted by collectors despite never winning a single race. For many, the 4½ Litre is to automobiles what the Spitfire is to aircraft.

Popular culture

James Bond drives a 1930 Blower Bentley in Ian Fleming's first three novels featuring the character, Casino Royale, Live and Let Die and Moonraker. In the books, Bond drives one of the last Blower Bentleys built, a battleship grey Convertible Coupé, with French Marchal headlamps.

Sections adapted from Wikipedia (CC BY-SA 4.0); text is shortened. Read the full article for the complete history and citations.

Specifications

name: Bentley 4½ Litre
Related: Blower Bentley (supercharged model)
Manufacturer: Bentley Motors Limited
Assembly: United Kingdom: Cricklewood
Production: 1927–1931, (supercharged model from 1929), (720 units), 2019–2020, (12 units)
Class: Sports car chassis
Body style: as arranged with coachbuilder by customer
Layout: FR layout
Predecessor: Bentley 3 Litre
Successor: Bentley 6.5 Litre
Engine: 4.4 L SOHC I4, 4.4 L supercharged SOHC I4
Transmission: 4-speed manual
Designer: Walter Owen Bentley
Wheelbase: Standard: 10 ft, SWB (8 made): 117.5 in
Kerb weight: 4½ Litre: 1625 kg, Blower: 1727 kg
Length: 4380 mm
Width: 1740 mm
sp: uk