The Bentley Blower was a development of the 3 liter model produced in the 1920s. The 4.5 liter model was produced as a performance road car and a possible contender for endurance racing . The Blower proved highly reliable on the track and nearly took victory at the 1928 and 29 Lemans. 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 4.5 liter 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.
The Blower Bentley gets its name from the supercharger mounted up front of the radiator to give this car an appearance that means business. It was developed for racing thanks to the persistent efforts of Sir Henry ‘Tim’ Birkin who first mooted the idea of fitting a supercharger to enhance performance with the goal being to win Le Mans yet again. Just for the uninformed, Bentley is one of the winningest manufacturers at Le Mans with victories in 1924 and then made the Sarthe circuit its domain from 1927 to 1930, making this French classic its spiritual home.
The first Blower appeared at the Essex 6-Hour race at Brooklands on 29 June 1929 W.O. Bentley was not a believer in adding a supercharger to his cars claiming that, “there was no substitution for cubic inches” and that to supercharge a Bentley was “to pervert the design and corrupt the performance”. Birkin first raced and won at Le Mans in 1928 with the ‘Speed Six’ as co-driver to Woolf Barnato - one of the original Bentley Boys and who won Le Mans every time he entered in this race! Birkin was convinced that a supercharger was necessary for the car, which was huge: the wheelbase was 3.3 metres and the car weighed nearly 2 tonnes. The ordinary Bentley engine produced some 130 bhp. With help from supercharger specialist Armherst Villers and financial backing from Dorothy Paget, Birkin rebuilt the car, now sporting a huge Roots-type supercharger in front of the radiator, driven straight from the crankshaft and giving the car a unique appearance. Thus, was born the 242 bhp ‘Blower Bentley’.
The reason was, of course, to win Le Mans, but the rules stated that a minimum 50 cars of this type be produced to be eligible for the 1930 Le Mans 24-Hour race. Birkin somehow managed to persuade W.O. to build the requisite numbers and at the end a total of 54 Blower Bentleys were built. Whilst the Blower was very powerful, its Achilles heel was its fragile chassis and it was not expected to last the race. So, Birkin played the hare’s role to hary the works supercharged Mercedes SSK of Rudolf Caracciola. At one stage, he passed the SSK only to find his rear tyre shedding a tread but still managed to make the pass stick and pull away but a couple of laps later his tyre gave way completely, dropping him back to eventually finish fifth. But he succeeded in his quest and the Mercedes also retired, leaving the win to the Speed Six of Barnato and Kidston.
Sadly, the Blower never won at Le Mans - the very reason it was built - but it did win a GP race. This was truly ironic, as the Blower is perhaps the best-remembered example of its breed.