Bentley 4,5 Litre Le Mans Sport Vanden Plas
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Car producer : |
Bentley |
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Model: |
4,5 Litre Le Mans Sport Vanden Plas |
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Year: |
1929-1931 |
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Type: |
Tourer |
Sir Henry "Tim" Birkin, described as "the greatest Briton of his time" 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 de Le Mans Mercedes-Benz had been using superchargers for years.
Thus the 4½ litre Blower Bentley was born. The first supercharged Bentley had been a 3 litre FR5189 which had been supercharged at the Cricklewood factory in the winter of 1926/7. The Bentley Blower No.1 was officially presented in 1929 at the British International Motor Show at Olympia, London. The 55 copies were built to comply with 24 Hours de Le Mans regulations Birkin arranged for the construction of the supercharged cars having received approval from Bentley chairman and majority shareholder Woolf Barnato and financing from wealthy horse racing enthusiast Dorothy Paget Development and construction of the supercharged Bentleys was done in a workshop in Welwyn by Amherst Villiers, who also provided the superchargers.
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 4,200 rpm for the racing version, which was more power than the Bentley 6½ Litre developed
Despite representing the epitome of 'Boys Own' motoring and providing the heart and soul of the hobby, selling the requisite fifty cars that had needed to be built in the dire economic climate of the late 1920s proved hard work for Bentley Motors. As a result of this, though it may seem improbable today, not all were sporting tourers. Some 17 were delivered as drophead coupes and even closed Saloon cars.
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.
