Lot details
Registration No: RR 4634
Chassis No: WB2567
Mot Expiry: May 2013

As production of Bentley's 3 Litre model gathered pace, it was apparent the chassis was being asked to support ever more voluptuous bodies, of a weight its designer had never intended. Needless to say, W.O. was never going to leave such a matter unattended, and by 1925 had instigated a prototype powered by an experimental six-cylinder engine of 4½ litre capacity. Rumour has it that while testing the car in France, its driver encountered Rolls-Royce's 'New Phantom' undergoing similar trials. Something of a race is said to have ensued, the outcome of which immediately led Bentley to increase the capacity of its embryonic engine to no less than 6½ litres - the size it then remained throughout its reign from 1926 to 1930. A stunning performer in its own right, it was of course the resulting 6½ Litre model that spawned the immortal Speed Six, which is said to have been W.O.'s favourite among all the illustrious motorcars he created. The engine of the 6½ Litre followed normal Bentley practice in having four tulip-shaped valves per cylinder and was fed by a single Smiths updraught carburettor. The overhead camshaft was driven by two tiny eccentrics coupled to triple connecting rods, the drive for which came from a helical gear at the rear of the crankshaft. The crankshaft itself featured a very effective multi-disc torsional damper. The compression ratio was 4.4:1 and the maximum output, 140bhp at 3,200rpm. Ignition was by two magnetos (later coil and single magneto) feeding a pair of sparking plugs per cylinder. The unit drove through a single-plate clutch to a modified gearbox of notably high ratios - the third gear of 1.278:1 was apparently the loftiest ever used in a standard W.O. Bentley.

With due deference to the problems encountered with the 3 Litre cars, the chassis of the 6½ Litre was a massive new creation featuring one tubular and four pressed-steel cross members for additional strength. There was a choice of three different wheelbases and suspension was by semi-elliptic leaf springs all round, for which there were three specifications depending on the chosen wheelbase and type of body. Damping was by Bentley and Draper Duplex or Hartford Duplex. Braking was mechanical to all four wheels and steering was by worm and wheels. The performance of the newcomer was deemed impressive and the road speed at 3,500rpm in top was 84mph, while a Motor magazine road test of September 1926 quoted a top gear acceleration time of 10-65mph in 30 seconds when carrying an all up weight of 2 tons and 8 cwt, including driver and two passengers - a remarkable level of flexibility for the period. In 1926, the cost of the chassis alone would have been circa £1,450 to £1,575, while that of a complete car would have been in excess of £2,000, depending on the chosen coachbuilder and design. It is understood a total of 363 6½ Litre chassis were produced between 1926 and 1930.

This particular example - chassis number WB2567 - was initially clothed as a Weymann Saloon by Gurney Nutting and delivered new to A.B. Spencer Esq. in August 1926. By 1930 the original engine had been changed under warranty, as had the front axle, steering arms and Perrot shafts. The saloon body was removed in 1935 and the car reconfigured as a breakdown truck, in which guise it remained for the next 10 years, until sold to a new owner who chose to convert the Bentley into a semi-racer (see black and white photo). It is at this point that the wheelbase appears to have been shortened from its original 12ft 6in to 12ft 2in. Acquired by Adrian Liddell in 1970, chassis WB2567 was despatched to the workshops of renowned marque specialist Tony Townshend shortly thereafter where it was restored and rebodied in the style of the 1929 Park Ward Speed Six.

Six years later, the engine was changed once more - this time for the current unit that emanated from chassis WB2554 which, according to Clare Hay's authoritative tome 'Bentley - The Vintage Years', had been 'completely stripped out in the February of 1931'. Since fitment, it has been uprated somewhat and nowadays breathes through a trio of SU carburettors.

It was in 1980 that 'RR 4634' was purchased by Steve O'Rourke, a successful historic racer, but still better known as the long term manager of the celebrated rock band Pink Floyd. While in his care, it was returned once more to Townshend's Elmdown Vintage Automobiles emporium, where the present Vanden Plas-style Le Mans replica body was fitted. The specification includes: a rear-mounted Auster screen (courtesy of P&A Wood); hood (but no sidescreens); folding windscreen with aeroscreens / sidelights; and lightweight cycle wings as supplied by Elmdown Vintage Automobiles.

Purchased by the vendor from Mr O'Rourke in April 1984, the 6½ Litre has been maintained by P&A Wood and Jonathan Wood ever since. Finished in traditional British Racing Green and trimmed in Green leather, this most imposing of vintage Bentleys was recently the subject of an independent inspection by marque enthusiast Philip Strickland that inspired the following summary: "A very appealing, long chassis 6½ Litre with good road manners, pleasant to drive, excellent brakes and light steering and controls, smooth gearbox and light clutch with smooth take up. Seemingly little work needed to keep this car in fully useable condition, ready for long distance touring."

The opportunities to purchase one of the mighty 6½ Litre cars are now few and far between, and especially so for one in this appealing condition. 'RR 4634' would unquestionably enhance any vintage collection and be the perfect partner for the many long distance touring events organised for W.O.'s masterpieces and their peers.

PLEASE NOTE: This vehicle has an MOT until May 2013.