Bentley 6.5 Litre Blower special, 1939
Bentley 6.5 Litre Blower special, year 1939. Colour green. Moss green interior with Connolly leather bucket seats and Wilton carpet. Black canvas soft top, tonneau cover and hood cover. This beautiful and impressive Bentley Special was built by the firm of Bob Petersen in the year 2003. This Bentley 6.5 Litre with supercharger (blower) was built on special order, it is the only Left Hand Drive 6.5 Litre blower Petersen has built. This Bentley Special is based upon a 1939 Rolls Royce 25/30 chassis (number GGR41). The engine is an impressive 8 cylinder in line Rolls Royce unit.
The famous Bentley make, erected by Mr. W.O. Bentley, existed as a independent firm for only twelve years (1919-1931) before the proud firm was taken over by the Rolls Royce motor company.
Those twelve exhilarating Bentley years were filled with racing successes and many victories. The Bentley name as manufacturer of large, heavy, powerful and rugged sportscars was imprinted in the human mind since the "roaring" twenties of the twentieth century.
Bentley motorcars won the famous 24 hours of Le Mans race in the years 1924, 1927, 1928, 1929 and 1930. The years they did not win the race they finished second or third.
Not only successes at Le Mans were counted but also many victories in the Brooklands 500 mile race.
The car presented here is a "Petersen Special" inspired on the Bentley 4.5 Litre which won at the Brooklands circuit in the year 1929.
To obtain more engine power Bentley added a blower (supercharger) to the 4.5 Litre in-line four cylinder engine. This increased power output from approx. 110 bhp. up to 240 bhp. maximum.
To get the Bentley 4.5 Litre blower accepted in racing at Le Mans Bentley had to built fifty production cars first. Twenty six of these cars were built with Van den Plas open tourer bodywork.
The addition of the supercharger did not make the rugged and reliable 4.5 Litre engine any more trustworthy during races. W.O. Bentley himself preferred a new engine with increased cylinder capacity. The supercharged 4.5 Litre engines were real "gas-guzzlers", the naturally aspirated 4.5 Litre engine used one Litre of petrol every 5.6 kilometers, the supercharged engine used one Litre for just 3.5 kilometers, a very large petrol tank was fitted additionally.
Another problem was that spark plugs in the supercharged engine wore out very quickly resulting in loss of power. Bentley engineer Nobby Clarke stated one day: "The blower eats spark plugs like a donkey eats hay"...
The Bentley 4.5 Litre Le Mans racer, with blower or without, is one of the top classic cars you can possibly dream to own. Collectors pay very high prizes for these, very scarce, Bentley racing cars.
Because the cars are very scarce and many people want to own one, many other Bentley models were modified to Le Mans specification and many replica's became available.
Sales prices of modified Bentley's and replica's are a fraction of the price asked for the real thing.
Talking about Bentley Le Mans replica's the specials built with Petersen bodywork and special manufactured parts are the finest around in quality and integrity. Much of the final quality however is in the hands, patience and precision of the private person or specialist who builds the automobile.
The featured Bentley 4.5 Litre Le Mans tourer Special is certainly one of the finest. This Bentley Special was built with love and care to absolute perfection.
Eight cylinder engine with supercharger
Cylinder capacity: 6.5 Litre
Carburettors: 2 x S.U.
Gearbox: 4-speed, manual
Electrical system: 24 Volts
Bodywork: aluminium sheet metal over an ash frame
Bentley history 1919 - 1931
The famous Bentley make, erected by Mr. W.O. Bentley, existed as a independent firm for only twelve years (1919-1931) before the proud firm was taken over by the Rolls Royce motor company. Those twelve exhilarating Bentley years were filled with racing successes and many important victories. The Bentley name as manufacturer of large, heavy, powerful and rugged sports cars has been imprinted in the human mind since the "roaring" 1920ies.
Bentley motorcars won the famous 24 hours of Le Mans race in the years 1924, 1927, 1928, 1929 and 1930. The years they did not win the long distance reliability race for production cars they finished second or third. Not only successes at Le Mans were counted but also victories in other long distance events like the Brooklands 500 mile race. The racing successes were mainly due to the rugged built of the cars and the meticulous preparation of the cars. In every race they learned and had the cars improved on small but important details (Head lamp covers, mesh gauze on the petrol tank, quick filler caps for engine oil and radiator, driver adjustable brakes.)
The Bentley 3 Litre was W.O. Bentley’s first design. The car was presented in 1919 but the first cars were sold in 1921. The four cylinder cars of rugged construction where in a class of their own for they combined the size and comfort of the big tourers and saloons with the road holding, and speed of the smaller sports- and racing cars. The Bentley was a true owner-driver car for the sporting motorist and connoisseur. The Bentley car could be had in three different types which were designated with three different radiator badges*. Red badge: short chassis speed model, Blue badge: the early short and then long chassis type for bespoke bodywork, Green badge: very rare and used for about eighteen 100 mph. These Green badge car won at Le Mans in 1924 and 1927 (Old Number Seven.) The 3-Litre was built from 1919 until 1929.
*The Bentley radiator and the logo were designed by the genius motoring artist Gordon Crosby. The logo is a ‘badge’ and not a ‘label’ as stated by AFC Hilstead in his book ‘Those Bentley Days’ (published 1953).
6.5 Litre and Speed Six
Then in 1926 the 6.5 Litre and the Speed Six were presented, these six cylinder models were in the eyes of W.O. Bentley the best cars the Bentley firm ever built. The bigger capacity was needed for many a customer had built a bespoke heavy saloon body on their chassis and thus eliminating the sporting element the chassis had to offer. The Speed Six brought Bentley the most racing successes and Le Mans victories. In the year 1929 the Speed Six came home first with Bentley 4.5 Litres second, third and fourth! In 1930 the same Bentley Speed Six 'Old Number one' came home a victor followed by another Speed six in second position!
Next came the upgraded four cylinder Bentley 4.5 Litre in the year 1927. The 4.5 Litre featured four valves per cylinder and two spark plugs per cylinder engine. Most of these cars were given open tourer and saloon bodywork and only nine short chassis were built.
4.5 Litre Supercharged (Blower)
The 4.5 Litre Blower was built in the ‘Barnato’ period. Financed by the Hon. Dorothy Paget Tim Birkin successfully experimented at Brooklands with his blower Bentley and even achieved the Brooklands lap record with his Blower Bentley. As Woolf Barnato was now in charge of the Bentley firm, and W.O. now only responsible for the development of the Bentley cars, Birkin convinced Barnato to enter a separate team of Blower Bentleys for the 1930 Le Mans race. This was against W.O. Bentley’s ideas for he was of the opinion that the supercharger would only add trouble to a perfectly good and reliable machine. The 1930 Le Mans race proved W.O. right as none of the blown cars finished and Barnato and Kidston won on a Speed Six model.
The supercharged 4.5 Litre engines were real "gas-guzzlers", the naturally aspirated 4.5 Litre engine used one litre of petrol every 5.6 kilometres, the supercharged engine used one litre for just 3.5 kilometres, a very large petrol tank was fitted additionally.
Another problem was that spark plugs in the supercharged engine wore out very quickly resulting in loss of power. Bentley engineer Nobby Clarke stated one day: "The blower eats spark plugs like a donkey eats hay". Only 55 Bentley 4.5 Litre ‘blower’ cars have been built by the firm of which 26 carried the Van den Plas open tourer bodywork.
In 1931 the most impressive Bentley model ever saw the light of day; the 8-Litre. This car can be regarded as a real ‘super car’. Only 100 of these big cars have been built.
Also in 1931 a down scaled 8-Litre was introduced, the 4-Litre. The car was designed to sell more cars to improve the cumbersome financial situation at Bentley’s. The 1929 Wall Street crash affecting the firm immensely. The 4-Litre featured the chassis, transmission and brakes of the 8-litre. The newly constructed 120 bhp ‘Ricardo’ engine proved underpowered for the chassis and as a result the 4-litre never became the success Bentley hoped for. Only 50 chassis were built.
1931 Rolls Royce take over
In 1931 business prospects looked very black and the firm went into receivership. Napier & Son were negotiating with Bentley's receiver to take over the company. Then another interested party arrived at the scene named British Central Equitable Trust. They outbid Napiers in a sealed bid auction. The Trust later was found to be a front for Rolls-Royce Limited. Rolls Royce had cleverly defeated the threat of a firm that could become a very unwelcome competitor.
From 1933 all Bentley cars were based upon their Rolls Royce counterparts and production was then moved from Cricklewood to Derby. Purists tend to name the Rolls Royce produced cars – Rolls Royce Bentley’s. Rolls Royce took good care of the Bentley ‘marque’. Many magnificent automobiles were built with a distinctively different character than the Rolls Royce models.
© Marc Vorgers