Monoposto! - the tale of the Birkin Blower
The Blower Bentley may be regarded as a racing failure but one very special single-seater did achieve success, lapping Brooklands faster than anything else had before. By Bill Boddy.
It would be invidious to debate which Brooklands outer circuit racing car was regarded as the most exciting to watch. It must lie mostly between the big and surprisingly fast Benz, Fiat and Napiers of the pre-1915 period, the post-war 350hp Sunbeam single-seater, the sensational Chitty-Bang-Bang Mercedes-Maybach and the stars of a later era, such as the Birkin Bentley, the Bamato-Hassan, and quickest of all, Cobb’s 24-litre Napier-Railton. I saw much of it, and must say Birkin, in the 4 1/2 singleseater, was my favourite from 1930-32, probably because his wins were an extension of Bentley’s Le Mans victories.
But lap-record holder though he was, Birkin did not like the Locke-King track. He wrote such criticism of it in his book Full Throttle that the BARC took action to get it withdrawn.
In 1929 Birkin shared the winning Le Mans Bentley with Woolf Barnato and persuaded WO that the 4 1/2-litre Bentley was too slow and outdated and should be replaced with a supercharged version. WO was against this, preferring to develop the Speed Six and the later 8-litre cars. But Sir Henry charmed him into allowing him to make the 50 supercharged 4 1/2-litres, possibly encouraged by the prospect of the Hon Dorothy Paget financing the resultant racing team.
But the supercharged cars hardly distinguished themselves, apart from a third in the 1929 Irish GP and Birkin’s second at Pau, beaten only by Etancelin’s GP Bugatti. Otherwise, from 1929 to 1933 the type chalked up 11 race retirements, and only another second in a 500-mile race driven by Dr Benjalield and Eddie Hall. The 50 production blowers were constructed and delivered between April 1930 and September 1931, fitted mostly with Vanden Plas open bodies.
Apart from these, there were four Birkin cars with Le Mans-type bodies, prepared at Birkin and Couper Ltd in Welwyn Garden City. Birkin’s partner was W M Couper, well versed in competition motoring and remembered for racing the famous Talbot 105 BGH23. Couper, who has been described as the sort of city gentleman for whom commissionaires called a taxi as soon as he appeared in the foyer, did not get on well with Sir Henry. Having got an unwilling agreement from WO over the blower 4 1/2 project, Birkin took on, to revise the engine, Raymond Mays’ friend Amherst Villiers and Col Clive Gallop who had been with Peugeot and on war-time aero-engines in France and then with Zborowski on the Chitty-Bang-Bang adventure.
Villiers produced a heavier crank and stronger con-rods, and his Rootes-type blower was mounted ahead of the cutdown radiator. Production s/c 4 1/2s did not have the balanced crank, which resulted in bearing wear. But the new car was shown at Olympia in 1929, £425 being added to the chassis price of the non-s/c 414, and the open blower car good for 98 to 103 mph for £1720. It is said that Amherst Villiers designed a badge to go on his supercharger and left Olympia in a rage when he saw that it had been removed!
The first of the Birkin blower 414s was given a four-seater body. Tim drove it in the 1929 BARC Six-Hour race but retired, was third in the Irish GP, 11th in the TT, WO, whatever he thought of the car, bravely riding with Birkin at Ulster. Tim could be wild, but only once did he crash, in the 1930 TT. For the 1929 BRDC ‘500’ a short-tailed two-seater body was used. It caught fire and Birkin retired.
For 1930 HB3902, engine SM3903, was provided with the blue single-seater body made by Compton’s. The engine now gave about 240bhp, and the axle ratio was raised to 2.56:1, with 3.50×32 tyres. The car in this form made its debut at the March Brooklands races. Tim was second from the first and won the third handicap from scratch, lapping at 126.73mph before the supercharger casing cracked.
After this start Tun and this blower were a centre of interest at Easter. Birkin did not disappoint his followers. Starting with a win and a lap at 134.24mph, a rehandicap of ‘owes 7sec’ was too much even for him, but on a clear run he broke the lap record held by Kaye Don, taking it to 135.33mph. That earned him an ‘owes 20sec’ handicap, and two race laps at the new record speed failed to give him a place. At the time, aged 17, I was on holiday with friends in the New Forest, in a vintage Renault, and had an agonising and abortive time trying to get a paper to see if the lap record had again fallen.
After slow lappery at the Clubs Meeting, the crowd-pulling Birkin/Bentley combination was fast on the August Bank Holiday Monday, the car snaking alarmingly at the Fork and leaping high from the bump on the Members’ banking, to roar flat-out down the Railway straight and round the long Byfleet banking – a stirring sight. Tim lapped at 137.38mph to third place, but a split fuel tank stopped him in the Gold Star race. At Whitsun Don had broken Tim’s lap record by 2.25mph in the VI2 Sunbeam but Birkin and the singleseater had caught the public imagination, especially as after his lap record, he had flown back that evening to Le Touquet for the promised celebration dinner with Bamato. Dramatic stuff! In the `500′ Tim, now in a crash helmet, drive with George Duller, but misfiring spoiled their race.
In mid-1930 Barnato’s Bentley Company withdrew from racing, and at the end of the year Dorothy Paget withdrew her sponsorship of Birkin’s team; but she bought the singleseater which she continued to enter for races for some time. Clive Gallop told me he’d drive it from Welwyn to Brooklands, stopping outside the KLG works on Kingston Hill if a plug needed changing, in order to get a rolling re-start.
Yearning for ‘proper’ racing, Tim, lacking a suitable British car, bought an 8C Alfa Romeo and a 2 1/2-litre GP Maserati, but he continued to use the Bentley at Brooklands. With the standard 10ft 10 1/2in wheelbase, the weight was mostly forward, so it used triple Hartfords and twin B&D hydraulic dampers at the back, but it was still tricky at speed. Birkin was awarded the 1930 BRDC Track Star.
At Whitsun 1931 he was third, and again in August, but the lap record eluded him. For the ‘500’ Eyston supplied a Powerplus supercharger, water-heated from the radiator, but Tim was unimpressed and it was soon changed. In practice vapour From the Ki-gass tank ignited and Tim had to stand on the seat to avoid the flames but still burnt his hands.
For 1932 the Bentley was painted red (to frighten the Sunbeam?) and in March won the ‘Lightning Long’ from Cobb’s old 10 1/2-litre Delage, which had been faster in 1931. The block had been bored out half a millimetre, taking it to 4442cc, but in the 100-mile Empire Trophy race this blew up when Birkin was leading the Delage.
At Whitsun there was another third, but retirement from the Gold Star handicap. I doubt if Tim much cared. He had at last broken the Sunbeam’s 137.96mph lap record, by 0.58mph, and in the August 100 Sovereign Match Race against John Cobb and the Delage, the Bentley won by 0.2sec.
During the season dry-sump lubrication was used with a scavenge pump on the nose of the supercharger. A further battle with the Delage had been at the JCC Guys Hospital Gala Day. The Bentley swept round to win the fastest race of 1932 (124.33mph) and equal its lap record. With 12lbs boost and 6:1 compression it was now capable of 145mph.
After Birkin’s sad death in 1933, the car remained in the hands of Dorothy Paget, unused until 1939, when Peter Robertson-Rodger acquired it with a lorry-load of spares. He later fitted a Northovers two-seater body to it,
It was at Bill Shortt’s London garage during the war, and John Morley took it over in 1946. By 1964 `Rusty’ Russ-Turner acquired it, and replaced the original single-seat body. I was asked to try it at Silverstone, but as I went off to a borrow a daughter’s crash helmet (used by her for delayed-drop parachuting), Rusty decided to do another lap, and the block cracked as he went out.
In 1973 I drove the car on the road, and was told I did 100mph but can’t believe it. Rusty continued with the car until his dying day in 1982, literally, for while racing it at Silverstone he suffered a fatal heart attack. The car coasted into the catch-fencing with barely a scratch. Today this famous car is owned and raced by horological ace George Daniels.