First shown at the 1929 London Motor Show, the 'Blower' Bentley was developed as a private venture by 'Bentley Boy' Sir Henry 'Tim' Birkin in order to extract more performance from the proven 4½-Litre model, which was becoming outclassed by its rivals on the racetracks of Europe. His aim was to produce a British car that would enable British drivers to continue to win races as spectacularly as the 4½-Litre that had won the 1928 Le Mans 24-Hour race.
The supercharger installation was engineered by the brilliant Amherst Villiers, who modestly claimed that it was 'recognised in engineering circles as a definite landmark in automobile construction.' Unimpressed, W O Bentley never supported the development of the supercharged car and is quoted as saying how much he 'disliked the easy short cut provided by the supercharger,' preferring to increase engine capacity, as evidenced by the 6½-Litre and 8-Litre cars, while reducing front-end weight by using Elektron castings. However, 'W O' did not control the purse strings at Bentley Motors, and the influence of Birkin, backed by the fabulously wealthy Woolf Barnato, saw the supercharged 4½-Litre Bentley come to fruition.
Its potential was emphatically demonstrated when Tim Birkin took 2nd place in the French Grand Prix at Pau with his supercharged 4½-Litre tourer amid a field of monopostoGP racers. The production cars were fitted with an Amherst Villiers Supercharger Mark IV, of Roots type with twin paddle rotors, which drew mixture from twin SU carburettors and was driven off the front of the crankshaft, the latter having been substantially strengthened to accommodate the increased power. With 9½lbs boost at 3,500rpm, the blown Bentley developed 175bhp, a healthy increase over the production 4½-Litre's 110 horsepower, while with 10lbs boost at 3,900rpm, 182bhp was produced.
The first production model, chassis number 'SM 3903', a sporting four-seater bodied by VandenPlas, was exhibited on Stand 130 at The Motor Exhibition at Olympia in October 1929 and would be retained as the Company demonstrator. Although similar in many respects to the standard 4½-Litre car, the new model was immediately distinguishable by the massive supercharger protruding at the base of the radiator.
Just 50 production supercharged 4½-Litre Bentleys were built to support the homologation of five Birkin team cars: among the few cars of their day capable of 100mph on the open road, they have always been regarded as the supercars of their era. Motor Sport spoke of the Blower's 'remarkable acceleration' and 'ancestry of well-tried racers' and called it 'a car for the connoisseur of sporting cars...'
Known affectionately as 'Bertie Blower', the car offered here was built at W O Bentley's Cricklewood factory on the standard 10' 10" chassis and with engine number 'NT3131', the 81st of only 667 normally aspirated 4½-Litre models made. It was then sent to North London coachbuilders Harrison & Son who constructed a Weymann-type saloon body, as commissioned by the first owner Mr C A Cuthbert of Compton in Guildford, Surrey. The car was delivered in February 1928 and registered 'XV 1200'.
Mr Cuthbert kept the Bentley until 1929, selling it on the 4thJune to a Mr Paul Gibbons of St John's Works, Wolverhampton. In June 1931 Mr Gibbons sold it on to Mr James Dance of Mile Bush near Leighton Buzzard, Bedfordshire. The last pre- war owner is listed as Mr J A Barnett (in 1935) and the next owner as one P A Chalk (1953-1956) What happened subsequently is largely unknown but during this period many large saloons were scrapped and it would seem that this fate befell 'XV 1200'.
By 1982 the car had been reduced to a chassis, front and rear axles, and a quantity of other parts. The original Harrison body was missing, as were several other key components. Douglass Miller of Lundin Links, Lower Largs, Edinburgh, who had the parts in a shed at the back of his business premises, advertised them for sale in the BDC Advertiser of November 1982. Cedric Cook bought them and set about sourcing the missing bits. Provided with the sales receipt, and with the original chassis number established as 'NT3131', the DVLA duly issued a V5 registration document for the original 1928 registration number 'XV 1200'.
In 1986 Mr Cook sold the rolling chassis to a Mr George Dodds, who then sold it on to Mr Dennis Keen. It was Dennis Keen - an expert toolmaker from Chesham in Buckinghamshire - who eventually completed the three-year-long, 9,000-hour, ground-upwards restoration that resulted in 'Bertie' as you see him today.
Restoration works included shortening the chassis to the 'Birkin Le Mans' 9' 9½" wheelbase, upgrading the engine to full Amherst Villiers supercharged specification using a MkIV Roots-type blower, and extensively re-engineering the car to match the original Birkins specification as closely as possible. The engine was fully rebuilt with a new (Phoenix) crankshaft, connecting rods, pistons, valves, guides, rockers, camshaft, water pump, front closing plate, oil pump gears, damper and modern shell bearings to the mains and big-ends - all to 'Blower' specification - and the engine number correctly stamped 'NT3131S'. (It should be noted that the original engine 'NT3131' is recorded as being returned to and then renovated by the Cricklewoodfactory as a Service Engine, and passed onto chassis number 'SL3053'). The original 'C' type gearbox was replaced with the 'D' unit correct for a supercharged car.
A new 'Blower' pattern front cross member, dumb iron knuckles and cross tubes were fitted to the chassis, The magnetos and starter motor were rebuilt and the carburettors refurbished to original 'Birkin' specification. The fuel feed has been converted to twin electric pumps while the fuel tank is a new 35-gallon Le Mans unit. All other components were renewed and replaced as necessary. Messrs Metcalfe & Rosedale made and fitted a new VandenPlas Le Mans replica body to the shortened chassis. All instruments were overhauled or replaced and then set into a newly engineered aluminium racing dashboard.
By 1990 and following three years work, 'XV 1200' was finally fully restored. For the last 20 years its owner has travelled the world in 'Bertie' with the Bentley Drivers Club on many events including tours of Morocco, France, Australia, South Africa, Canada, New Zealand, the United Kingdom and Continental Europe. Offered with restoration invoices, current road fund licence, MoT to November 2012 and Swansea V5, the car continues to be maintained in tip-top condition regardless of cost by Elmdown Engineering and is ready to go anywhere in the world.
'Blower' Bentleys rarely come on the market and thus 'XV 1200' represents a possibly once-in-a-lifetime opportunity to acquire one of these charismatic cars, presented in immaculate condition throughout, 'on the button' and ready to drive away.