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With it's front mounted supercharger, the 4½ became the Walter Owen Bentley's quintessential British sportscar. It was shaped from the earlier cars such as the 3-Litre, but produced substantially more power with its blown engine. As such it was a stunning road car and a possible contender for endurance racing.

Unblown, the standard 4.5 liter engine put out 110HP. The use of a Roots supercharger offered an increase in power to 240 bhp. The power was necessary due to the massive size and weight of the car.

The overall design of the car was heavy and large. The tall engine forced the driver to sit with his head 63 inches above ground. To help compensate for a high center of gravity & weight Bentley employed the use of stiff and heavily damped springs. Excessive weight of the car due to huge brakes, large chassis & a bulky rear axle put the car in a class of its own. The Blower is one of the heaviest cars to compete in Grand Prix racing.

The number 9 car featured above, UU5872, is an original Birkin car known as 'Birkin Blower No.2'. This car made an appearance at the 1930 Lemans. The first car featured above is an unrestored 1928 works blower.

The Blower proved highly reliable on the track and nearly took victory at the 1928 and 1929 Le Mans 24 Hour races. In 1929 Bentley dropped the 4.5 liter engine and opted to race the more reliable Speed 6. At this time Tim Birkin saw the potential in the smaller displacement car and modified the 4½ for the 1929-30 race season. Three 'Birkin Blowers' competed against the Bentley Speed Sixes at the 1930 Lemans. The 4.5 blower was surpassed by the Speed 6 that went on to win the 1930 Lemans with a 72 mile lead.

Chassis & Sales

1929 Bentley 4½-Liter Supercharged DS3569 - sold for $722,000 The immediately preceding owner bought ‘DS 3569’ in the late 1980’s, the car having been in the previous ownership for some 24-or-so years. At that stage it was in driveable but weary condition, and a decision was taken to carry out a complete restoration, transforming the car as closely as possible to the specification of Birkin’s supercharged 4½-Liter Team Cars. This was to be a meticulously researched and expertly executed task taking some ... more
Gallery: 2009 Bonhams Exceptional Motorcars at Quail Lodge Resort

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