1931 24 Hours of Le Mans

9th 24 Hours of Le Mans endurance race

The 1931 24 Hours of Le Mans was the 9th Grand Prix of Endurance that took place at the Circuit de la Sarthe on 13 and 14 June 1931. With the demise of Bentley, the favourite for an outright victory was split between the Bugatti and Alfa Romeo works teams, with a lone privateer Mercedes as an outside chance. Once again it was one of the smaller fields, with only 26 starters. At the start of the race it was the Mercedes setting the pace from the Bugattis of Chiron and Divo. But tyre wear was a big issue, with many cars suffering tyre blowouts and punctures. This left Marinoni leading in the works Alfa. Coming up to the first refuelling stops, the rear tyre on Maurice Rost's Bugatti blew out at full speed on the Mulsanne Straight. Rost lost control of the car and went through a fence, hitting three spectators, killing one. When more tyre issues plagued Chiron's car, the Bugatti team withdrew their remaining two cars. Tyre troubles had also cost the Mercedes team eight laps. The Alfa Romeo of British privateers Howe and Birkin had been having a reliable race. As others were delayed they caught them up and took the lead after midnight. At 2.30am a sudden thunderstorm swept the track. Zehender went off at Indianapolis doing damage that eventually forced the works Alfa's retirement in the morning. The Talbots of the British Fox & Nicholl team were running third and fourth with the Mercedes closing in again. Ivanowski was able to source some Dunlop tyres. He and Stoffel were able to pick up their pace, and when the leading Talbot was waylaid in the morning by chassis damage, the Mercedes was up to second by noon. At the finish, Howe and Birkin won by seven laps from the Mercedes and the remaining Talbot. This was the first win at Le Mans for an Italian car, and in a record breaking run, they claimed all three trophies – including the Index and Biennial Cup – and broke the 3000km distance for the first time. Only six cars were classified, which has been the lowest ever number of finishers in the 24 Hour race.

This year there were no changes to the racing regulations of either the AIACR (forerunner of the FIA) Appendix C rules, nor those of the Automobile Club de l'Ouest (ACO). The biggest change this year was in the pits. Rather than refuelling with 10 litre cans, a series of 4 metre high reservoir towers were built holding 1000 litres. Three hoses from each allowed gravity replenishment at about 250 litres per minute. Shell once again had the fuel contract and again offered its three standard fuel options. The ACO also now allowed a mechanic to assist the driver with the refuelling. As usual, as engine power advanced, the ACO once again adjusted the Index target distances. Example targets included the following:
Engine size 1930Minimum distance 1931Minimum distance Equivalent laps Minimumvehicle weight Ballast 6000cc+ 158.9 laps 1820 kg 180 kg 3000cc 146.1 laps 875 kg 120 kg 1500cc 138.1 laps 670 kg 120 kg 1100cc 128.4 laps 430 kg 60 kg 750cc 109.1 laps 430 kg 60 kg

With Bentley in major financial strife, the works team had been disbanded and the Bentley Boys dispersed, marking the end of an era. Into this void came works teams from the two main powerhouses of current Grand Prix racing: Alfa Romeo and Bugatti. However, apart from Aston Martin, and a (non eventuating) effort from Ariès the remaining entries were from privateer teams and "gentleman drivers". There were still only 30 cars entered, not a great improvement on the record low number from the previous year. Of those, only four were entered in the final of the Biennial Cup – an Alfa Romeo, the two Talbots and the returning women in their Bugatti. Category Entries Classes Large sized engines 17 / 15 over 2 litre Medium sized engines 7 / 5 1.1 to 2 litre Small sized engines 6 / 6 up to 1.1 litre Total entrants 30 / 26
Note: The first number is the number of entries, the second the number who started. Daimler Benz had pulled out of racing officially in 1930 leaving privateers to run their cars. In the 1930 race, the Mercedes of Rudolf Caracciola had taken the challenge to Bentley in the first half of the race. This year, Paris based Russian Valériani Vladimir Tatarinoff, entered an SSK (Super Sports Kurz) on behalf of fellow émigré Count Boris Ivanowski. He had previously been denied an entry of a stripped down Alfa Romeo for the 1928 race. The SSK had a big 7.1 litre engine that could be augmented temporarily by a Roots supercharger up to 250 bhp. Along with his co driver, Le Mans veteran Henri Stoffel, Ivanowski entered the car in both touring and Grand Prix races. Bugatti had run almost exclusively in Grand Prix racing with great success in the late 1920s. This year marked its first foray to Le Mans with a works team. The new Type 50 was a development of the big engined Type 46. Its 5.0 litre straight 8 engine had a Roots supercharger and was capable of 250 bhp, and with a 3 speed gearbox, gave the car a top speed of 195 kp/h (120 mph). The team, managed by Bugatti's 22 year old son Jean, brought three short wheelbase versions for their works drivers Louis Chiron / Achille Varzi and Albert Divo/Guy Bouriat, joined by Maurice Rost/Caberto Conelli. Perhaps anticipating bad weather, they were running on a new, heavy tread Michelin tyre. Alongside the works team were three French privateer entries in smaller Bugattis, including wealthy Parisian bankers Pierre Louis Dreyfus / Antoine Schumann who raced together under the pseudonyms "Ano Nime"; and the women who charmed the media the previous year, Odette Siko and Marguerite Mareuse, returned. Alfa Romeo had achieved great success in recent years with the 6C model, in both its regular or supercharged format. Vittorio Jano's new design, the 8C, had a supercharged 2.3 litre engine that developed 155 bhp. It came in two styles: a short wheelbase, 2 seater corto adapted for Grand Prix racing and narrow, tight circuits like the Mille Miglia; and a 4 seater lungo (long) version for the ACO regulations for touring cars. Although the Scuderia Ferrari ran the car for Italian races, it was a works team that arrived at Le Mans with two cars. The driver pairings were team regulars Giuseppe Campari / Attilio Marinoni and "Nando" Minoia / "Freddy" Zehender. Two Englishmen were some of the early purchasers of the new model. Sir Henry "Tim" Birkin had given up his Blower Bentley project for the more reliable Alfa, and won his class first time up at the Irish Grand Prix the week before Le Mans. Earl Francis Howe had his delivered to replace his 6C that Achille Varzi had crashed in the 1930 Irish race. So in the 1930 Le Mans, Howe had run his Mercedes Benz instead, earning one of the four entries taken up for the Biennial Cup. For this race, he approached Birkin to be his co driver Since the previous race, the great brand had been sold to Rolls Royce. Unlike most other car companies, Talbot had been reasonably successful with sales of its 6 cylinder car range. Its latest version, the 105, now had a 3 litre capable of 120 bhp and 175 kp/h (110 mph), as well as a 4 speed gearbox and a bigger 160 litre fuel tank. Four cars were made available to the Fox & Nicholl team. Two were taken to Le Mans to race with another as a test vehicle. The drivers were team regulars Brian Lewis, Baron Essendon / Johnny Hindmarsh and Tim Rose Richards / Owen Saunders Davies. Henri de Costier had driven at Le Mans three times in the late '20s. This year he organised the entry of a pair of big Chrysler straight 8s. He, himself, drove the larger 6.3 litre, 125 bhp, CG Imperial Eight while the new model CD Eight (with a 100 bhp 3.9 litre engine) was entrusted to the new, young French talent, Raymond Sommer. La Lorraine Dietrich had not competed at Le Mans since 1926, after the company believed they were denied victory in the Biennial Cup by the ACO on a technicality. The team's four B3 6 Le Mans specials had been mothballed until one was sold to Henri Trébor, who got the car a few days before the race after a factory refit. Racing journalist Roger Labric submitted an entry on his behalf. Trébor engaged Louis Balart as his co driver, himself a veteran of the first four Le Mans races. The small Scottish car company of Arrol Aster arrived for its only foray at the race. The 17/50 had a 2.4 litre sleeve valve engine with a Cozette supercharger. The car was prepared at Tim Birkin's race garage in London. Voiturette racing was still popular and encouraged enthusiast engineers to make their own small customised specials. Yves Giraud Cabantous was one such. A mechanic and driver at Salmson, he adapted a Salmson chassis with the oft used 1.1 litre Ruby engine that put out 35 bhp. After successes in the Bol d'Or, Roger Labric encouraged him to enter the Le Mans race and offered to enter two under his name. After a disappointing race for BNC the previous year, when the new car didn't even turn a wheel, the team returned with the tried and tested 527 Sport, also with a Ruby engine. In 1930 George Eyston had approached Cecil Kimber, managing director of MG Cars, about developing the first 750cc car to break the 100mph barrier. In part, this was because his Land Speed Record rival, Malcolm Campbell was working with Austin for the same goal. With the resulting EX120 special, Eyston achieved the record in February 1931 at Montlhéry. Using the prototype's engine and frame, MG built the new C Type. Fourteen cars, already pre sold, were quickly built in time to take a clean sweep, first time out, at the Brooklands Double 12 (Britain's annual 24 hour event) in May. The result was repeated a month later at the Irish Grand Prix. A week later, two of the cars were entered for Le Mans, without superchargers. Sir Francis Samuelson returned with his regular co driver Fred Kindell, while Lady Joan Chetwynd ran her husband's car along with fellow C Type owner Henry Stisted. After their races the Bugatti team drove their cars across from Molsheim in eastern France, arriving on Thursday. In practice, one of the cars blew a rear tyre, so team manager "Meo" Costantini directed the drivers to not go above 4000rpm to limit their top speed for the first six hours. So, after three hours, at the first round of pit stops, Divo led from Marinoni and Stoffel, having all done 23 laps. Chiron was a lap behind with the two Talbots. This left the Mercedes to battle the Alfa Romeos. But when tyre delaminations struck them twice, the drivers decided to ease back and change tyres every hour to avoid further issues. The Caban of Labric/Giraud Cabantous got beached at Pontlieue after midnight, losing much time getting dug out. Class Winners are in Bold text. Class Team Drivers Chassis Engine Tyre Targetdistance* 1 3.0** 16 Earl Howe(private entrant) Francis Curzon, Earl Howe Sir Henry Birkin Alfa Romeo 8C 2300 LM Alfa Romeo 2.3L S8supercharged 147 [B] 184 2 8.0 1 V. Tatarinoff(private entrant) Boris Ivanowski Henri Stoffel Mercedes Benz SSK Mercedes Benz 7.1L S6 supercharged 159 177 3 3.0 11 Fox & Nicholl Tim Rose Richards Owen Saunders Davies Talbot AV105 Talbot 3.0L S6 146 [B] 173 4 5.0 9 Roger Labric Henri Trébort Louis Balart Lorraine Dietrich B3 6 Le Mans Lorraine Dietrich 3.4L S6 148 150 5 1.5 25 Aston Martin Ltd Augustus "Bert" Bertelli Maurice Harvey Aston Martin International Aston Martin 1495cc S4 138 139 6 1.1 29 Roger Labric Just Emile Vernet Fernand Vallon Caban Spéciale Ruby 1097cc S4 128 128 N/C*** 750 31 F. Samuelson(private entrant) Sir Francis Samuelson Fred Kindell MG Midget C type MG 746cc S4 109 ?

Pos Class No Team Drivers Chassis Engine Tyre Targetdistance* Laps Reason DNF 3.0 10 Fox & Nicholl Brian Lewis, Baron Essendon Johnny Hindmarsh Talbot AV105 Talbot 3.0L S6 146 [B] 132 Chassis(18 hr) DNF 1.5 26 Aston Martin Ltd Kenneth Peacock Sammy Newsome Aston Martin International Aston Martin 1495cc S4 138 126 Bodywork(22 hr) DNF 1.5 24 Aston Martin Ltd Humphrey Cook Jack Bezzant Aston Martin International Aston Martin 1495cc S4 138 111 Bodywork(18 hr) DSQ 1.1 27 C. de Ricou(private entrant) Gustave Duverne Robert Girod B. N. C. Type 527 Sport Ruby 1097cc S4 128 111 Prematurerefuelling (21 hr) DNF 3.0** 14 SA Alfa Romeo Attilio Marinoni Goffredo Zehender Alfa Romeo 8C 2300 LM Alfa Romeo 2.3L S8supercharged 147 99 Transmission(14 hr) DNF 1.5 23 J. Sébilleau(private entrant) Jean Sébilleau Georges Delaroche Bugatti Type 37 Bugatti 1496cc S4 138 96 Transmission(21 hr) DNF 5.0** 12 P. Hope Johnson(private entrant) Peter Hope Johnson Jack Bartlett Arrol Aster 17/50 Arrol Aster 2.4L S6supercharged 148 95 Electrics(16 hr) DNF 1.1 28 Roger Labric Roger Labric Yves Giraud Cabantous Caban Spéciale Ruby 1097cc S4 128 89 Engine(18 hr) DSQ 1.5 22 M. Mareuse(private entrant) Marguerite Mareuse Odette Siko Bugatti Type 40 Bugatti 1496cc S4 138 [B] 45 Prematurerefuelling (5 hr) DNF 1.1 30 C. Charrier(private entrant) Charles Charrier Camille Royer Lombard AL3 Lombard 1097cc S4 128 45 Engine(6 hr) DNF 750 32 Hon. Mrs J. Chetwynd(private entrant) Hon. Joan Chetwynd Henry Stisted MG Midget C type MG 746cc S4 109 30 Engine(8 hr) DNF 5.0 7 G. Bevan(private entrant) Gerald Bevan Mike Couper Bentley 4½ Litre Bentley 4.4L S4 156 29 Engine(6 hr) DNF 8.0** 5 Automobiles Ettore Bugatti Albert Divo Guy Bouriat Bugatti Type 50S Bugatti 5.0L S8supercharged 159 26 Withdrawn(4 hr) DNF 8.0** 4 Automobiles Ettore Bugatti Louis Chiron Achille Varzi Bugatti Type 50S Bugatti 5.0L S8supercharged 159 24 Withdrawn(4 hr) DNF 3.0** 19 A. Schumann(private entrant) Pierre Louis Dreyfus Antoine Schumann Bugatti Type 43 Bugatti 2.3L S8supercharged 147 22 Transmission(3 hr) DNF 8.0** 6 Automobiles Ettore Bugatti Maurice Rost Conde Caberto Conelli Bugatti Type 50S Bugatti 5.0L S8supercharged 159 20 Accident(3 hr) DNF 8.0 3 É. Brisson(private entrant) Édouard Brisson Joseph Cattaneo Stutz Model M Blackhawk Stutz 5.3L S8 159 19 Engine(2 hr) DNF 8.0 2 H. de Costier(private entrant) Henri de Costier Raymond Lussan Chrysler CG Imperial Eight Chrysler 6.3L S8 159 18 Radiator(2 hr) DNF 5.0 8 H. de Costier(private entrant) Raymond Sommer Jean Delemer Chrysler CD Eight Chrysler 4.0L S8 156 14 Radiator(2 hr)Sources:
Note *: [B]= car also entered in the 1930 31 Biennial Cup. Note **: equivalent class for supercharging, with x1.3 modifier to engine capacity. Note ***: #31 was not classified, for failing to complete the final lap of the race in under 30 minutes.

Pos Class No Team Drivers Chassis Engine Reason DNS 3.0 15 SA Alfa Romeo Giuseppe Campari Ferdinando Minoia Alfa Romeo 8C 2300 LM Alfa Romeo 2.3L S8supercharged Engine DNA 3.0** 18 C. Brunet(private entrant) Bugatti Type 43 Bugatti 2.3L S8supercharged Did not arrive DNA 1.5 20 Société des Automobile Ariès Ariès CB4 Ariès 1500cc S4 Did not arrive DNA 1.5 21 Société des Automobile Ariès Ariès CB4 Ariès 1500cc S4 Did not arrive

Pos 1930 31Biennial Cup Class Team Drivers Chassis IndexResult 1 1st 3.0 16 Earl Howe(private entrant) Francis Curzon, Earl Howe Sir Henry Birkin Alfa Romeo 8C 2300 LM 1.260 2 2nd 3.0 11 Fox & Nicholl Tim Rose Richards Owen Saunders Davies Talbot AV105 1.190 3 8.0 1 V. Tatarinoff(private entrant) Boris Ivanowski Henri Stoffel Mercedes Benz SSK 1.120 4 5.0 9 Roger Labric Henri Trébort Louis Balart Lorraine DietrichB3 6 Le Mans 1.016 5 1.5 25 Aston Martin Ltd Augustus "Bert" Bertelli Maurice Harvey Aston MartinInternational 1.015 6 1.1 29 Roger Labric Just Emile Vernet Fernand Vallon Caban Spéciale 1.002

Class Winning Car Winning Drivers Over 5 litre #1 Mercedes Benz SSK Ivanowski / Stoffel 3 to 5 litre #9 Lorraine Dietrich B3 6 Le Mans Trébort / Balart 2 to 3 litre #16 Alfa Romeo 8C 2300 LM Howe / Birkin * 1500 to 2000cc no entrants 1100 to 1500cc #25 Aston Martin International Bertelli / Harvey * Up to 1100cc #29 Caban Spéciale Vernet / VallonNote *: setting a new class distance record.