The Bentley 4 1/2 liter came into existence to fill a void left by the 3-liter and the 6.5-liter variants. The 3-liter suffered from underperformance while the 6.5-liter was unsafe for the roads. The 6.5-liter was powerful, and with poor road-conditions often caused tires to fail quickly. The solution was the Bentley 4.5-liter; a vehicle that had enough power to carry the vehicle down the road at a good pace. The chassis consists of channel-steel, front and rear suspension by semi-elliptic leaf springs, and 4-wheel drum brakes.
Production amounted to a total of 733 cars of all body styles. Fifty-four cars were equipped with the famous supercharged engine, 'Blower Bentleys,' built by the race driver Sir Henry 'Tim' Birkin as a private venture - against W.O. Bentley's wishes.
The 4.5-Liter Supercharged Bentley, better known as the 'Blower' Bentleys, is a sporting automotive icon that earned its place in history as an engineering marvel and powerhouse. Only 50 examples, plus an additional five racing prototypes, were created. In the modern era, they are among the top rank in collector cars throughout the world.
Engineer and founder W.O. Bentley was hesitant to adapt a supercharger to his 4.5-liter engines. Rather, the development was financed by a woman, the Honorable Dorthy Paget, who provided the funds necessary to complete the project. It was for Henry R.S. 'Tim' Birkin, one of the 'Bentley Boys' who campaigned the Bentleys at many venues and various competition events bringing recognition and victories to the Bentley marque. The list includes Brooklands with its closed oval course, and the other extreme, LeMans, with his challenging road course.
Birkin had intended to race the supercharged 4.5-liter Bentley at LeMans in 1929, but lubrication problems on the early cars halted those plans. Instead, Woolf Barnato (Bentley's chairman and fellow factory team racer), Birkin, and Glen Kidston drove the Bentley Speed Six Models in 1929 to victories at LeMans.
Birkin was able to convince Barnato to enter the 'blower' Bentley in the 1930 LeMans race. In order to do so, homologation requirements had to be satisfied. The rules stated a minimum of 50 examples had to be built. Bentley officially introduced their production versions of the cars at the 1929 Olympia Motor Show, with the fist cars on sale in April of 1930.
With homologation requirements satisfied, Bentley entered two blowers and three Speed Six models. Birkin's LeMans blower was co-drive by Jean Chassagne. The Blower Bentley showed great promise early in the race, and by the fourth lap had passed a highly-competitive supercharged Mercedes at 126 mph. In the process it shredded a tire and was forced to stop. At the time, they had been averaging 89.66 mph per lap, which was a new lap record for the course.
The other Bentley's were given the job of chasing down the Mercedes. Their job became much easier when the Mercedes was forced to retire when their battery died. The Blower Bentley's would endure similar fate, as they were forced to retire in the 20th hour. The Speed Six models went on to secure a 1-2 Bentley victory.
1930 was the last year the Bentley factory team would compete at LeMans, as the company had fallen on very difficult economical times. Dorothy Paget eventually withdrew her support for the Birkin blowers as the cost to compete continued to escalate. This brought an end to the short-lived saga of the Bentley blower era.By Daniel Vaughan | Apr 2008