Bentley 4½ Litre 1927-1931

[Ferrer]

In this case the famous Blower Bentley (there were normally aspirated versions as well).

[csl177]

The truck that could. I love this model.

[Ecnelis]

Bentley 4.5 Litre 'Blower' Birkin Monoposto

1929 - 1931 Bentley 4.5 Litre 'Blower' Birkin Monoposto - Images, Specifications and Information

Sold for £5,041,500 inc. premium

Tim Birkin’s 4 ½ Litre Supercharged ‘Blower’ Bentley single seater sets new world best for a Bentley at Bonhams Goodwood auction

(Crewe and Goodwood, 29 June 2012) Just 35 miles away from the fabled Brooklands race circuit where it astonished thousands of spectators eight decades ago by sprinting its way into the record books, Sir Henry ‘Tim’ Birkin’s dramatic 4 ½ Litre Supercharged ‘Blower’ single seat racing machine returned to record-breaking form by reaching a sale price of £4.5 million when auctioned by Bonhams at the Goodwood Festival of Speed today.

This new world-best for Birkin’s striking 240bhp supercharged red racer now outstrips the previous record by a Bentley at auction when the Speed Six known as ‘Old No 2’ achieved £2.8 million at the Le Mans Classic in 2004.

At its racing zenith and with the famously fearless and dashing ex-fighter pilot and Le Mans winner Birkin behind the wheel, this unique Bentley was one of the undoubted stars of the high-risk Outer Circuit at Brooklands.

In March 1932 Birkin set a record 137.96mph (219.93kmh) at Brooklands, a feat even a man renowned for pushing back the limits in motor sport would describe as hair-raising: “there are bumps which jolt the driver up and down in his seat and make the car leave the road and travel through the air,” said Birkin.

Commenting on the exploits of Birkin and his 4 ½ litre at Brooklands, Richard Charlesworth, Bentley’s Director of VIP and Royal Relations comments:

“Birkin along with his Bentley racing friends like Woolf Barnato, Dudley Benjafield and Glen Kidston were true sporting superstars, renowned not only for their driving ability and courage but living life to the full and in some considerable style. They would create the enduring legend of the Bentley Boy racer at Brooklands and Le Mans and this new record price for a Bentley achieved by Bonhams reflects the enduring respect and admiration for their story and their cars.”

[Ecnelis]

Birkin Monoposto #2

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Birkin Monoposto #3

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Birkin Monoposto #4

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Birkin Monoposto #5

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Birkin Monoposto #6

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Birkin Monoposto #7

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Birkin Monoposto #8

[Ecnelis]

Tim Birkin / Brooklands

[Simi]

This is really a good thread where we can get a good pictures of Birkin Monoposto and some more models. Keep sharing such details.

[ScionDriver]

That's $7.8 million for us Yanks out there, according to Google.

[GaryM]

Does anyone know if a set of scale plans exist?
I presume the chassis and overall measurements are the same as for the Bentley 4.5 litre tourer.
Any help with the overall specifications would be most appreciated.

[Ferrer]

The Bentley 4½ Litre was a British car based on a rolling chassis built by Bentley Motors. Replacing the Bentley 3 Litre, it is famous for epitomizing prewar British motor racing and for its popular slogan "there's no replacement for displacement", created by the founder of Bentley, Walter Owen Bentley. Bentley sought to produce a more powerful race car by increasing engine displacement.

At the time, noted car manufacturers like 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 were produced between 1927 and 1931, including 55 models with a supercharged engine known as the Blower Bentley. A 4½ Litre Bentley won the 24 Hours of Le Mans in 1928. Though the 4½ Litre Bentley's competitive performance was not outstanding, it set several speed records, most famously in 1932 at Brooklands with a recorded speed of 222.03 km/h (138 mph).

Bentle 4½ Litre

Although the Bentley 4½ Litre was heavy, weighing 1,625 kg (3,580 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 latticed 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 double 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 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. 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. Semi-elliptic leaf springs were used at front and rear.

Blower Bentley

The essential difference between the Bentley 4½ Litre and the Blower was the addition of a Roots-type supercharger to the Blower engine by engineer Amherst Villiers, who had also produced the supercharger. W. O. Bentley, as chief engineer of the company he had founded, refused to allow the engine to be modified to incorporate the supercharger. As a result, the supercharger was placed at the end of the crankshaft, in front of the radiator. This gave the Blower Bentley an easily recognisable appearance and also increased the car's understeer due to the additional weight at the front. A guard protected the two carburetters located at the compressor intake. Similar protection was used, both in the 4½ Litre and the Blower, for the fuel tank at the rear, because a flying stone punctured the 3 Litre of Frank Clement and John Duff during the first 24 Hours of Le Mans, which contributed to their defeat.

The crankshaft, pistons and lubrication system were special to the Blower engine. It produced 175 hp (130 kW) at 3,500 rpm for the touring model and 240 hp (180 kW) at 2,400 rpm for the racing version, which was more power than the Bentley 6½ Litre developed.

Source: wikipedia.org