1929→1931 Bentley 4½ Litre ‘Blower’
With it's front mounted supercharger, the 4½ became one of Walter Owen Bentley's quintessential British sportscars. It was the vision and product of Sir Henry Ralph Stanley 'Tim' Birkin who persuaded Bentley to produce 50 examples of the model.
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 racing.
The first prototype was initially built in 1929 with racer racer Mike Couper. They established Birkin & Couper Ltd. where the first Blowers were made. W.O. Bentley said "They would lack in their preparation all the experience we had built up in (our own) racing department over 10 years. I feared the worst and looked forward to their first appearance with anxiety..."
The first appearance of the car was the Brooklands 6-Hour race on June 29,1929. Later in the year more 4½ Litre Bentleys were fitted with Birkin's blower system and one placed second in the RAC Tourist Trophy, but they never won a race.
Bentley described the model at the end of the season "The supercharged 4½ never won a race, suffered a never-ending series of mechanical failures, brought the marque Bentley disrepute and incidentally cost Dorothy Paget a large sum before she decided to withdraw her support in October 1930..."
Despite the lack of results, Wolf Barnato allowed Birkin to try the cars again at Le Mans but none of them endured to finish. This meant Bentley was obliged to produce 50 road going examples of the model which they did.
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.
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
1931 Bentley 4½ Litre ‘Blower’ Sports 2/3 Seater Boattail SM3916 - did not sell for $7,100,000
Among the Finest of the 50 Factory Blowers. Exceedingly Rare, Matching-Numbers, Original-Bodied Example. Exceptional Provenance Including a 54-Year Stewardship. One of Very Few Vintage Bentleys with Original Fabric Covering. Ideal International Driving and Concours Event Entrant. One of the Most Significant Bentleys in Existence
Gallery: 2012 Pebble Beach Auctions by Gooding & Company
1931 Bentley 4½ Liter Supercharged Le Mans MS 3944 - sold for $4,647,500
One of three Original Le Mans Specification production Supercharged cars built. Owned by the Noble family for more than 55 years. Original components and numbers as delivered new from Bentley. Documented by Bentley Expert Dr. Clare Hay. Eligible for Mille Miglia and more.
Gallery: 2013 Quail Lodge Auction by Bonhams