Production cars had moved on, but racing for 24 hours continuously? Surely no-one would finish!

Arthur Donald Claude Thomas Thistlethwayte. That’s quite a clutch of names, but he became better known as ‘Scrap’ and, in 1924 when he was 21, Scrap Thistlethwayte came into a fantastic inheritance. It consisted of the family pile, Southwick House, along with some 8000 acres and a couple of villages in Hampshire. And in due course, Scrap would become known for entering a Bentley in a new French endurance race.

Like others of his era in similarly rarefied circumstances, Scrap had turned to motor sport, first racing a Vauxhall 30/98 – with a stylish two-seater open body by Martin Walter of Folkestone – in the Boulogne Automobile Week in September 1925. He also bought a 1500cc Frazer Nash, driven to first place in the Grand Prix de Boulogne by his friend Clive Gallop, a racing driver and engineer who had a hand in designing the valvegear for the 3 Litre Bentley.

But neither they nor a subsequent 1½-litre eight-cylinder supercharged ‘Flat Iron’ Thomas Special could satisfy Scrap. Influenced by Gallop’s Bentley 3 Litre Speed Model, Scrap had one specially built for a new and highly publicised French event. It was known as the Grand Prix d’Endurance de 24 Heures du Mans.

In its first year of 1923, the idea of a 24-hour race for production cars seemed absurdly ambitious. Cars had moved on from the early days of trembler coil ignition and acetylene lighting, but racing for 24 hours continuously? Surely no-one would finish! In fact, many of the entrants in that first haphazard race made it to the end, including John Duff, adventurer extraordinaire, and Frank Clement, the head of Bentley’s experimental department and an experienced racing driver, in Duff’s Bentley 3 Litre. If anything, the event proved harder on the road surface, and the French civil engineers responsible gained a crash course in road-building techniques.

Duff and Clement won in 1924 in a new Bentley 3 Litre so, the year after, WO Bentley himself entered a works-prepared 3 Litre driven by Bertie Kensington Moir and Dudley Benjafield – the former an experienced racing driver and the latter the owner of a tuned Bentley 3 Litre that he raced at Brooklands – alongside Duff’s privately entered but works-prepared car, again partnered by Frank Clement. It was a disaster, one falling foul of minimum distance refuelling regulations, the other retiring after a fire caused by a carburettor float chamber breaking off.

In those days Le Mans fired the imagination of the small, select motor-racing fraternity. Thistlethwayte was something of a loner, with particular views on how things should be done, and he insisted on a ‘Supersports’ 3 Litre rather than the standard Speed Model. The former was built on a very short 9ft wheelbase intended for open two-seater bodies, with a catalogue speed of 100mph. The standard Speed Model has a wheelbase of 9ft 9½in, the extra length giving enough room for a full four-seater body that met the stringent regulations laid down by the organisers, the Automobile Club de l’Ouest.

Bentley was already preparing two works 3 Litres and was happy to help Thistlethwayte and Gallop, and to run their 3 Litre alongside the two works entries – provided that, as WO made clear, Thistlethwayte could get a full four-seater body on the chassis that met the race regulations. The task was entrusted to his favourite coachbuilder, Martin Walter.

Walter shoehorned a four-seater body onto the very short chassis, with a long, semi-streamlined tail enclosing the back seats and a 25-gallon petrol tank. Back-seat passengers sit out over the axle, but then, the back of the car was only really intended to carry some of the ballast required by the Le Mans regulations. The rest went in front of the radiator, in the form of a lead-filled steel bar. The ballast was supposed to represent the weight of three passengers, Bentley having to point out to the race organisers that the regulations demanded a certain weight of ballast without specifying where it was to be located.

The Bentley mechanics and cars stayed at the Hôtel Moderne in Le Mans during the week before the race; the ‘above stairs’ crowd, who all knew each other, at the rather more grand Hôtel de Paris. The body was so tight on dimensions that, legend has it, a couple of the Bentley mechanics were detailed to distract the scrutineers and ‘bend’ the tape measure during scrutineering at the town hall. It passed, and three Bentleys – numbers 7 and 8 (the two works cars) and number 9 (the Thistlethwayte car – KM 4250, chassis 1179) took their place in the race line-up on 12 June 1926.

The race began with the classic Le Mans start, the cars lined up in front of the pits, the first driver for each car on the opposite side of the track. The starter dropped his flag, the drivers sprinted across, and raised the hoods on their cars before getting away for the first 20 laps (a shade over 200 miles). No petrol, oil or water could be taken-on other than at 20-lap intervals, and any work had to be carried out by the driver using only spares carried on the car. The pits could provide tools as well as oil, water and regulation petrol, and supply a spare wheel and tyre while changing a tyre and tube in the back of the pits. The regulations were strictly enforced by plombeurs with special pliers, wire and lead, who were present at every pit stop to cut off and replace the official seals.

Number 9 ran well right through the night but, at 9am on the Sunday morning, after 105 laps and while lying in joint third place, Gallop had to pull over with the engine running on three cylinders. One of the duralumin rockers had broken and the car was hors de combat. It proved to be another black year for Bentley, as number 8 had already retired with a broken valve, and Sammy Davis crashed number 7 into a sandbank at Mulsanne in the last hour of the race.

Thistlethwayte entered KM 4250 for the Boulogne race week later that year, for the speed trials and the hillclimb as well as the concluding Grand Prix de Boulogne on the Sunday. He finished third in the 3.0-litre class in the hillclimb, but Howey in a 5.0-litre Ballot got into a slide in the same event and crashed into a tree, killing himself and a spectator, and injuring four others. Thistlethwayte scratched his entry for the Grand Prix.

Soon after, the ballast bar was taken off KM 4250, along with the Le Mans reserve oil tank nozzle which protrudes below the dash; both have since been refitted. The tank is not small because, with hour-glass pistons and generous racing clearances, the oil consumption of a Bentley 3 Litre in racing conditions was around 100 miles to the gallon! Scrap went sailing in 1927, returning in 1928 with a supercharged 7.0-litre Mercedes S-36/220.

This car was entered for the 1928 Tourist Trophy race, carried across the Irish Sea as deck cargo on his yacht, the Schooner Charmian. In need of spares, he wired London and had them flown across in a specially chartered ’plane, causing a press sensation. Scrap Thistlethwayte set the fastest time of the day with a lap at 74.39mph but his co-driver ran off the road and then the head gasket failed. He put up impressive performances in the same car in 1929, in the Brooklands Six Hours race (fastest lap of the day), the Irish Grand Prix (Dublin) and the Tourist Trophy (Belfast).

In the Irish Grand Prix Thistlethwayte duelled for 26 laps with Tim Birkin in a blower Bentley before retiring with head gasket failure. Birkin said in his autobiography Full Throttle: ‘Thistlethwayte drove brilliantly; he had marked out his course as an expert before the race, and adhered to it with an expert’s regularity. He drove faster than anyone else.’ It was Scrap’s racing swansong. He died in 1956, aged 52, his later years uneventful.

As for KM 4250, after the war it had several enthusiastic Bentley Driver’s Club members as owners, one for almost 40 years, with minor changes to wings, lamps and windscreen along the way. It now has an unusual cylindrical fuel tank fitted, but the original mountings for the Le Mans tank are still there.

In 1988 KM 4250’s sound mechanical order was proven on a drive from John o’Groats to Land’s End on the centenary of WO Bentley’s birth. Gregor Fisken had known about this special Bentley for many years and, in 2010, negotiated its sale on behalf of a private client. The new custodian is a respected British collector and enthusiastic user of his old cars. Plans are already afoot to put bring KM 4250 back to its correct 1926 Le Mans guise. Looks like it could make much more history yet.


Thanks to Fiskens Fine Historic Automobiles of Kensington, London, where the Bentley is for sale, www.fiskens.com, tel: +44 (0)20 7584 3503.