The Fastest Lorries In The World
Nobody knows for sure who made the famous statement "Monsieur Bentley makes the fastest lorries in the world" - but many think it was the great Ettore Bugatti, and that he made the comment at Pau in 1930, after Tim Birkin's wild and wonderful drive. But were Bentleys really like lorries? And what was the secret of the great speed? The answers form part of a remarkable story - that of a motor firm that won undying fame, and yet was only in being for 12 years, and produced cars for barely 10 of those years.
The Bentley story begins in pre-1914 days, when the brothers W. O, and H. M Bentley were London agents for a French car, the DFP - a rather ordinary vehicle. One DFP model (made by Doriot, Flandrin & Parent), the 2 litre "12/15", appealed to the Bentleys as a potential sports car. They lightened the moving parts and experimented with light alloys, and the result was an astonishingly fast car. Hill-climb records followed, also wins at Brooklands and 2 litre class records at speeds of over 90 mph. The 1914 TT was for cars of up to 3 litres, but the small DFP finished sixth and won much praise. Brilliant though the work of W. O. Bentley was with the DFPs, his achiements with World War 1 aero engines were spectacular.
There was an untrue story circulating for many decades that he produced Gnome and Le Clerget aero engines under licence. At the time he was a serving officer in the technical and aircraft side of the Royal Navy, and first of all he introduced aluminium alloy pistons to the two engines. Later in the war he designed the Bentley Rotary (BR) Marks 1 and 2. These were developed with Admiralty approval as part of a drive to regain air superiority for the Allies. It had been said - and it could well have been true - that the BRs had a better power to weight ratio than the Rolls-Royce, Hispano, Napier and Packard-Liberty aero engines.
W. O. Bentley was one of the few engine designers with enough courage and faith in the products of his design to fly on operations with squadrons using his engine. This was something that considerably endeared him to the men who were continually risking their lives in the air. But he was not alone in this regard as, on the German side, Anthony Fokker, airframe designer, was doing the same thing. Good thing their designs were good, or the world may have been deprived of the race winning Bentleys of the vintage era, and also the Fokker "Southern Cross" of Sir Charles Kingsford-Smith.
Horace Millner Bentley
Although 30,000 Bentley rotary engines were built during World War 1, "W.O." gained no financial advantage, being a serving officer in the RNAS. One motoring writer claimed: "In addition to finding many of his ideas blocked by vested interests, or because they were not what 'the book' said were the correct ones from a service point of view, he finished the war not much better than at the start." In 1919, with his brother, H. M. Bentley, he started his own company, and the co-designer was T. F. Burgess, who had designed the 1914 racing Humber, and no doubt, met Bentley when his aircraft engines were being made at the Humber factory (among others).
The first Bentley cars and their successors had chassis similar to the Humber team cars, a fact that surprised nobody. The prototype 3-litre Bentley was completed in time for the 1919 Motor Show, but the first car to be sold, an open 4-seater, left the factory in September, 1921. It was surprising that the matter did not take a lot longer, given there was no design office, factory or machine shop. There was also very little in the way of capital. In the early days all parts were from outside firms, and made under contract, and this made for a very high price - about £1200. No other car in the world of 15.9 hp or less cost as much.
Success at Le Mans
In the early days, it was a struggle to make enough cars to pay the weekly wage bill. Production was kept down by a shortage of money until about 1926, when fortunes started to improve. However, the customers liked the cars, and the firm of Bentley became firmly established at a time when many of the new companies that had appeared like mushrooms in 1919 - 1920 had expired with the end of the post-war boom. Between 1926 and the 1930 - 1931 depression, Bentley was making very good progress, and the reasons were in no small part due to the resounding successes at Le Mans, such that wealthy financial backers were on hand.
The years just before these were difficult. It was not easy to sell the 3-litre to those who had not yet discovered the reliability, good gear ratios and excellent handling of this car, when rival machines were scoring heavily on sheer performance. The 72 bhp of the 1922 Bentley (the 1920 prototype mustered only 65 and did not impress). At that time the Vauxhall
company was selling the E type, a very light car powered by a 4.5 litre engine that could produce 90 bhp using side valves
. The later OE, with a 4.25 litre engine could produce an amazing, for the time, 108 to 112 bhp. Vauxhall
, and also Sunbeam
, with their famous 3-litre twin OHC sports car, had things their own way with regard to power and top speed. At the time, the 3-litre Bentleys could only produce 88bhp.
The first Bentley production
car was the 3 litre model, Ettore Bugatti
described it as the fastest Lorry in the
W.O. soon added
front wheel brakes, a move that would
bring much praise from commentators
of the day and quickly establish
the reputation of the marque...
It was a more
standard 130bhp un-blown 4.5 litre
that would win the Le Mans 24 hour
in 1928 – perhaps giving away
reliability issues associated with
Bentley was unashamedly
targeting Rolls Royce with the 6.5
litre, hoping to enter what was at
the time referred to as the ‘carriage
The 8 Litre was
a final roll of the dice for W.O.,
hoping to lure purchasers away from
body styles such as the Vanden Plas,
the 8 Litre was somewhat unrefined
when compared to the equivelant Rolls,
and a lack of sales would see the
receivers move in...
The 1951 Bentley
Mk.6 shared much with the equivelant
cars such as the Bentley Continental,
who would dare say the marque was
A Long Stoke 4 Cylinder With Non-Detachable Head
The 3 litre's engine was a long stroke four cylinder with non-detachable head. Bore and stroke were at the pre-war racing car ratio of about one to two - in this case 80 mm by 149 mm, giving 2993cc. There were four valves
per cylinder and two spark plugs, which created a clutteired combustion chamber and gas-flow problems, but good induction and exhaust
scavenging, and good ignition. Ahead of the engine, there were two independent magnetos for the two banks of plugs.
The early prototype was fitted with a Claudel-Hobson carburettor, but this soon gave way to a Smith with five jets. The famous "Speed Models" (1924 and later) carried twin SUs, one of the first cars to do so. The Bentley brothers were unashamedly old-fashioned in giving the 3-litre an inverted cone type clutch and a gearbox not in unit with the engine. Dry-sump lubrication was in the original design, but the scavenger pump was noisy and production cars were all fitted with wet sumps. Four-wheel braking was adopted in 1924.
The Bentley Radiator
The famous Bentley radiator deserves a mention, as W. O. obviously got his inspiration for the design from French manufacturers DFP (W. O. Bentley having been one of the original London agents) and the Lorraine-Dietrich. Later, two English firms, H.E. and Marendaz, were to adopt the same style. Decades later the Rolls-Royce-built Bentleys, from the 1960s, carried over the same radiator. In 1922, a special Bentley with a flat radiator was sent to America, and it raced at Indianapolis. As its dry weight was barely 20 cwt, the "fast lorry" tag could hardly be applied to this particular 3 litre. Soon after this, Bentley's early racing successes helped to establish the firm, though funds for expansion were still lacking.
Isle of Man TT
The 1922 TT was held on the Isle of Man, and Bentleys came in second, fourth and fifth. Bentley had been struggling fiercely against the faster Vauxhalls and Sunbeams, driven by top-ranking GP drivers such as Henry Segrave
and Jean Chassagne. In 1923, John Duff, a lone Le Mans entrant, finished fourth, and the following year provided a sensation by going back, again as a lone competitor, and wnning! This was, of course, still the period of the 3 litre model. Interesting and significant were the differences between the 1919-20 prototype and the 1921-1922 production model. Prototype: 2500 rpm and 65 bhp. Claudel-Hobson (and some Zenith) carburettor. Two cams per cylinder, operating pairs of exhaust
and inlet valves
. Some prototypes had one plug per cylinder from one magneto, and others, two plugs per cylinder from one double-sparking magneto; hour-glass shaped pistons; dry sump lubrication.
The early production models: 3500 rpm and 72 bhp; Smith five-jet carburettor; triple cams for four valves
per cylinder; two plugs per cylinder; two magnetos; pistons of ordinary shape; wet sump lubrication. The 3 litre Bentley was in full production from 1921 to 1927, and the model could be bought to order until 1931. Through this period various gearboxes could be chosen by the customer. Gearboxes for all Bentley models were labelled "A", "B" and so on. Certain boxes that gave top gear ratios of 3.53, 3.78, 3.92 (all for open models), and 4.23 (mostly sedans) were the options for the 3 litre. One feature of the car was the combination of very high gearing with an ultra-long stroke engine. The RAC hp rating was the lowest ever for a 3 litre - 15.9.
W.O. Bentley Engine Design
From the end of World War 2, to the mid 1950s, W. O. Bentley designed the engines for the DB Aston-Martins
, and during that time he held out against the post-war short stroke fashions, the dimensions chosen by him being 83 by 90. The post-W.O.Bentley Aston
, the DB4
, became the first "square" AM, with a bore and stroke of 92 by 92. W.O. Bentley had a long career as a designer - from 1912 to 1953 - and during that time arguably his biggest challenge was to be able to extract extra power from the 2996 cc engine. The main reasons were the long, narrow stroke and the complex roof of the combustion chamber with multiple valves and plugs. The 4.5 litre, on sale from 1928 had better scope for tuning, its shorter stroke engine measuring 100 by 140 mm, as against 80 by 149 mm.
The late 1920s were the great days for the Bentley marque. Numerous racing victories included the famous "hat trick" at Le Mans, performed for the first time (1927 - 1930). During these last pre-depression years, there is no doubt that Bentleys dominated sports car racing. Where the races were run on a handicap basis, the handicaps usually meant that if a Bentley was prevented from winning, a place or two was gained instead. Setbacks were few, consisting mainly of a 3 litre becoming stuck in a sandbank when leading during the last hour of the 1926 Le Mans
, the Carraciola wins for Mercedes-Benz in the TT of 1929, and the 1930 Irish Grand Prix (for sports cars).
Old No 7
A Bentley racing story that deserves to be told in some detail, concerns the Le Mans race of 1927, when the 3 litre cars were entered for the last time. A prototype 4.5 litre was also part of the team. The drivers of one 3 litre, S. C. H. Davis
and Dr J. D. Benjafield, performed deeds that have become legendary, contending against really intimidating odds. The "great crash" at White House Comer took place in darkness, and no less than six cars were wrecked. The road was blocked by the first two machines to crash, and the other four cars plunged into the wreckage. No driver sustained serious injury, but badly smashed were a French four-seater, three cars of the Bentley team, and two more French cars, a Schneider and a S.A.R.A. S. C. H. Davis
reversed his damaged 3 litre (the famous "Old No 7") out of the pile-up of wrecked cars and rejoined the race.
With Benjafield, Davis
battled on for hour after hour, with a bent front axle, one headlight, badly damaged steering
, a broken front shock absorber, brakes
barely working, a flapping mudguard, and a battery
box promenading about the running-board. Heavy rain, the lack of proper steering
and brakes, and shortage of lights (after a time some officials rung a lantern on the side of the car) did not stop the drivers from lapping at racing speed. The most fantastic part of the whole story is the fact that they won!
Davis and Benjafield could not, of course, come up on the leader the famous French driver Jean Chassagne, and pass him, but they did press him to the point that he was forced to keep speeding up until his engine blew up. A celebration dinner was held in London's Savoy Hotel, and "Old No 7" was driven into the room, engine roaring and one headlight blazing, in the same state as it had left the crash at White House Corner. All this was a complete surprise for the Bentley drivers. We would love to perpetuate the myth that Jack Daniels was the drink used to toast the drivers, thus the Old No 7 used to market the whisky - but then you would not believe anything else you read on the site. Or would you?
The Green Label Bentley
Identification of a Bentley can be seen in the separate sump cars, which are pre-1925, and those with two-wheel brakes, pre-1924. Some "Speed Models" were to be created in later years when owners shortened the chassis to imitate the rare genuine "Green Labels". Only 1620 3 litre Bentleys were made - and in the mid 1960s registration records indicate that some 300 were still on the road in Britain alone. As for warranty periods, all Bentleys carried a five year guarantee. Incredible given that many car makers today will not offer this. These days the famous 4.1 litre Bentley is widely regarded as the best Bentley of all - or that is what we have learnt from the few enthusiasts we have spoken with. These cars date back to 1927-28. The close-ratio four speed gearbox was excellent, and the final drive high for a car from this era, at 3.53 to 1.
The chassis was often described as built like a battleship, the 4.1 Bentleys manners at high speed and under all conditions have been accepted as above reproach for a pre-war car. It had first-class brakes, of the self-wrapping type put on to all Bentleys after 1928. The clutch was a less pleasant device than the antique cone-clutch of the 3 litre, and it was a modern single-plate type. The 100 by 140 bore and stroke, very large figures for a four cylinder car, gave a capacity of 4398cc. In standard form 110 bhp could be expected, and a speed of 90 mph. In 1928 such figures were sensational. Many of the 670 unsuper-charged 4.1 litre cars that were made found a good home and were preserved, however we have no numbers on what survives to this day.
The Bentley Speed Six
About a year after the coming of the 4.1 litre model, the Bentley brothers announced their magnificent monster, the "Speed Six", and this event came with the start of the great world depression. This huge sports car also had engine dimensions of 100 by 140 mm, but this was no 4.1 with two extra cylinders. It was not therefore true that the firm's cars just became bigger and bigger until something disastrous had to happen, as is generally supposed. The 4.1 litre model had been devised between the dates of the two versions of the large six-cylinder vehicle, and its design followed the idea of the standard 6.1 litre Bentley, with two cylinders taken away.
The great ''Speed Six" sports car was very fast, handled well and had a history of amazing reliability. W. O. Bentley never really approved of the project to supercharge
his cars, but allowed 54 of this type to be built to comply with the Le Mans regulations for eligibility. His associates urged the need for yet faster competition cars to rival those of a certain Kompressor-minded Mercedes-Benz
. These cars were heavy on fuel as they were fitted with very large Roots-type blowers and twin SU carburettors
. When in use on the road, they gave 10 mpg, as against 16 mpg for the unblown 4.1-litre cars. W. O. Bentley's fears concerning reliability were also justified, as the supercharged cars never won a pre-war major event, and did not finish in any long-distance race.
The Blower Bentleys
The "Blower Bentley" competition cars were financed and entered by a well-known eccentric racehorse owner, the Hon Dorothy Paget, and the drivers included Sir Henry Birkin and Dr Benjafield. One of the Paget ex-Le Mans cars was rebuilt with a "monoposto" body, radiator fairing and streamlined tail. It was claimed in the press years later that the fuel consumption of the Bentley Monoposto was not much better than 3 mpg, the blower and SUs being very large. Maximum speed was around 150 mph, which enabled Tim Birkin to hold the lap record at Brooklands
from 1931 until the coming of the 23-litre Napier-RaHton about three years later.
For the 1932 BRDC Brooklands 500, a body that looked the same as this Birkin-Paget car was put on to a Speed Six chassis, an 8-litre engine was used, and this promising young monster was driven by Jack and Clive Dunfee. A tragic disaster took place during Clive Dunfee's turn at the wheel, for the great car plunged over the top of the banking, killing its driver. A dramatic episode in Bentley history was the Le Mans race of 1930. A supercharged Mercedes-Benz SS was driven by Carraciola and Werner, and there were five Bentleys competing, three 61s of the works team, and two of the Paget supercharged 41s. In the opening stages, Birkin drove like a demon to force Carraciola's hand, and give the factory team the chance to press on at a less crazy pace to finish.
What happened is now history.. The great white challenger led the race for the first few hours at a cracking pace, while behind Carraciola, the bold Sir Henry set a new lap record, and then gave the German a shock by passing at over 130 mph - a fantastic speed for a 1930 sports car. Then Birkin blew up His engine. During the night, after six hours of furious dicing with Kidston and Barnato on Speed Sixes, the Mercedes-Benz withdrew with a burnt-out generator. In fairness to the Stuttgart firm, the rest of the car was in sound condition. Bentleys finished first, second and third.
The End of an Era
The Le Mans race of 1931
, however, told a vastly different story. Sir Henry Birkin
was back again, and this time he won, partnered by another title, Earl Howe, but the mount was a vastly different car from the "Blower Bentley", being an Alfa-Romeo
of a mere 2300cc. The era of the Bentleys and anything like them had suddenly ended. The 2.3-litre Alfa-Romeo was a machine with little affinity to the designs that had held sway in sports car racing for so long. Gone were the 1921 and pre-1914 ideas of single overhead camshafts, multiple valves
and large engines. This was also the finish of the long run of wins by the huge green cars.
The history of Bentley from 1928 to the end of 1931 is profoundly sad, but at the same time, interesting and dramatic. It is not really true that the models just became larger and larger, and then the firm went out of business. The great 6.5-litre touring model goes right back to 1925, and was brought in as a more suitable basis of "town carriage" style bodies than the 3-litre. In 1928-9, the Speed-Six version was introduced, and by this time the renowned, but now somewhat old-fashioned 3 litre was only being made to special order. The Bentley brothers (in the same way as the sponsors of the 30/98 Vauxhall
) never claimed that any of their cars were sports cars. They ware only ever meant to be fast touring cars.
The Greatest Bently of All Time - The 8 Litre Bentley
The 8-litre Bentley was one of the great engineering achievements of the vintage period. In 50 seconds the car would go from 5 to 100 mph with the smoothness of a turbine. It would carry heavy luxury coachwork at 100 mph without noise. The contemporary Rolls-Royce could only do this with special tuning, which the works viewed with disfavor, believing that the emergence of too many "Special Continentals" would injure the firm's reputation for absolute silence. The "Boulogne" Hispano-Suiza's performance was quite comparable to that of the Bentley, but this car had an alloy engine and different valve system and camshaft drive, and at speed was much noisier than the 8-litre.
With such cars in their stable, it seems strange that Bentley would fold - particularly given the like of Rolls-Royce
were also laying down cars of seven litres and over right through the world depression. One difference between Bentley and the competition was that the former was a small firm, while the competitors were large organisations producing machinery other than motor-cars, such as the production of industrial motors, aero engines, armaments and marine engines. Another obvious question is why did not its multimillionaire chairman, and also the other works team drivers, all noted for their great wealth, do more than they did to keep the firm from going under? It is easy to be wise after the event. The most likely explanation is that during the depression many believed things would continue to get worse, and that the larger car makers would soon follow.
Smaller for Bigger Luxury Cars
Rescue for the declining company not coming from investors, W. O. and H. M. Bentley made their own efforts to save the day. A pushrod 4-litre model was quickly designed and built - however this was not the work of W. O. Bentley, but of a consulting engineer from outside. His idea behind the whole scheme was to enter the "smaller for bigger luxury cars during the slump" market, and by having this pushrod engine, they were able to undercut the price of the 25 hp Rolls-Rovce. As a further economy, frames and bodies that had been intended for the 8-litre cars that could not be sold, were used. This made the failure of the project a certainty. The overweight 4-litre Bentleys had no performance at alL Fifty were made and very few actually sold.
The firm went into liquidation, and as the Napier company intended to resume car production it made a bid for the Bentley assets. A new W. O. Bentley designed 6.5 litre car was planned. At this point, however, Rolls-Royce put in a higher bid, and so Bentley became a division of Rolls-Royce. In 1934. the first tt the new-style Bentleys appeared. The Derby-built Bentley did not resemble the ears of the vintage era, and was, in fact, a more sporting 25 hp 3.5-litre Rolls-Royce with a Bentley radiator. But thats not to say this was a bad car. The isix cylinder RR-Bentley was destined to build its own reputation, being one of the best sports cars of the 1930-1940 era. The advanced design included features like power-assisted hydraulic brakes
and four-speed synchromesh. The new Bentley also achieved success in racing (semi-sponsored). E. R. Hall was twice second in the TT, and only fractional figures in the handicapping prevented him from winning.
Could Bentley Have Been Saved?
An intriguing "What If", much like what if Hitler had continued on to Moscow, and not turned his attention to the oil rich fields to the south. In Bentleys case, a change of policy could have steered the old Bentley company toward advances and prosperity instead of decline. One proposition is that instead of turning, in 1928, toward the mammoth 6.1 sports and the grand 8-litre, a medium-isized car should have been added to the range to replace the 3-litre. An engine with a normal number of valves
and a separate cylinder head
would have been modern and easy to service. Low-slung frame and light chassis and body could have been other features, also the most modern gearbox and brakes, and an engine of about 3.7-litre.
And we could argue the same applies today - as we witness the demise of Ford Australia and the iconic Falcon. Had Bentley had a smaller car, the firm could have put on the market in 1928-9 a model that would have been modern for many years to come. It would have been better positioned to survive the recession, and then been able to take on the likes of Alfa-Romeo, Bugatti, Alvis and Lagonda with their twin-cam, push-rod engines. Records kept by the Bentley company from 1921 to 1931 show the numbers of the various models that were made as follows:
- 3 litre. From 1921. All types. Blue, Red and Green labels -1639.
- 6.1 litre. 6 cyl. Touring. From 1925. Blue label - 374
- 4.1 litre-umS/Cd. 1928-31. Black label - 679
- 41 litre S/C'd. 1929-30. Black label - 54
- 6.1 litre Speed Six. From 1928-9.
- Green label - 170
- 8 litre-1930-31. Blue label - 100
- 4 litre 1931. Blue label - 50
W.O. Bentley married three times. In 1914 he married Leonie Gore, the daughter of the ninth baronet, she died in 1919 in the Spanish flu epidemic. He married Poppy (Audrey Hutchinson) in 1920, they divorced soon after the business was sold in 1931. He married Margaret Roberts Hutton nee Murray in 1934, although he had no children by any of his three wives. Bentley died at Woking, Surrey, on Friday the 13th August 1971
, shortly before his 83rd birthday. His widow, Margaret, survived him and died in 1989
. In this article, we have not touched on his time at Lagonda
, nor the Rolls-Royce merger. These topics are covered in other articles here on the Unique Cars and Parts website
Also see: Founding Fathers Of The Automotive Industry
| Bentley Car Reviews
| The History of Bentley
| The History of Bentley (USA Edition)