The 1924 24 Hours of Le Mans was the 2nd Grand Prix of Endurance, and took place on 14 and 15 June 1924. It was the second part of three consecutive annual races for the Rudge-Whitworth Triennial Cup, as well simultaneously being the first race in the new 1924-25 Rudge-Whitworth Biennial Cup.
With tougher target distances, as well as hot weather, the cars had to be pushed harder and this year only 12 of the 41 starters completed the 24 hours.Spurring 2011, p.92-3 The 4-litre Chenard-Walcker of the 1923 winners René Léonard and André Lagache had the early lead, for the first three hours, until it caught fire on the Mulsanne Straight. Thereafter it was a battle between the three-car Lorraine-Dietrich team and the British Bentley.
The first Lorraine-Dietrich had been delayed on Saturday night, the second went off the road during the night and the third was held up with two punctures then a blown engine trying to make up the lost time. The Bentley also had its problems but with two hours to go it had a significant lead when it pitted for a precautionary wheel-change. This soon became a big problem as one wheel could not be taken off and half an hour was lost. The delay meant its remaining laps would not be counted according to the new race-regulations, as the average speed would be below that achieved to reach their target distance. Although the remaining two Lorraines pushed hard they fell just one lap short.
The Bentley victory brought international acclaim and cemented the popularity of the race as a significant European event.Laban 2001, p.40
Regulations After the success of their inaugural 24-hour event, the Automobile Club de l'Ouest (ACO) set about making further improvements. Firstly, the race-timing was moved to the summer solstice in late June to make the best use of the extended daylight as well as the higher probability of better weather.Spurring 2011, p.92-3Clausager 1982, p.30 The ACO also recognised that the Triennial Cup format was unworkable after an unexpectedly large number of cars had qualified from the year before. The current trophy stayed active, but not renewed. Émile Coquille, co-organiser and representative of the sponsor Rudge-Whitworth was still keen on a multi-year format, so a compromise Biennial Cup was initiated instead. Teams had to nominate which of their cars would compete for the Triennial Cup, while all entries were eligible for the Biennial Cup.Spurring 2011, p.90Spurring 2011, p.98-9Spurring 2011, p.100-1
Specifications were tightened up on chassis features like windshields, running boards and seats to prevent abuse by manufacturers trying to save weight. It became compulsory to carry one spare wheel on board, exhausts had to be aligned to not blow dust off the road, and cars had to have functioning headlights between designated hours of darkness (8.30pm to 4am). In the original interests of furthering the advance of touring-car technology, convertibles had to come in after 5 laps and put up their hoods. Then after running for at least two laps with hoods up, they would come in and have them officially checked for robustness before dropping them back down. Failure would result in disqualification. Finally, the car companies also had to present written evidence of the requisite 30 production examples.
In the interests of driver safety, protective headgear now had to be worn. A minimum of 20 laps had to be driven before a car could stop to replenish fuel, water or oil fluids, still done solely by the driver.Clausager 1982, p.19 Cars did not need to complete the final lap at the end of the 24 hours if they had met their target distance, but any extra laps had to be done at or above the average speed of the rest of their race to be counted.Spurring 2011, p.96-7 After the lenient minimum target distances of the previous year, these were lifted significantly particularly for the smaller engined cars The distances included the following:
Engine size 1923Minimum laps 1924Minimum laps Requiredaverage speed 3500cc 82 119 85.6 km/h 3000cc 79 115 82.7 km/h 2000cc 70 102 73.4 km/h 1500cc 63 93 66.9 km/h 1100cc 52 85 61.1 km/h
The Track Once again, an effort was made to apply a temporary mixture of gravel, dirt and tar to the road surface in spring-time. A third layer was put down on the long Hunaudières straight from Le Mans city to Mulsanne (more commonly known as the Mulsanne Straight).
For the spectators, further efforts were made to provide entertainment through the event. As well as the cafés and jazz-band, a new dance-hall, a boxing ring and a chapel were built. The first campsite area was also designated for people to stay on-site overnight.
Entries There were 30 finishers from the 1923 eligible for entry in the race, but only 21 were taken up. Six of the eleven manufacturers did not return, however another six French manufacturers stepped in to fill their places, leaving Bentley as the only foreign entry. Sunbeam had put in an entry, but withdrew it later to focus on the French Grand Prix racing.
Category Entries Classes Very large engines 5 over 3-litre Large-sized engines 7 2 to 3-litre Medium-sized engines 13 1.5 to 2-litre Small-sized engines 16 up to 1.5-litre Total entrants 41
After a winning debut in the 1923 race, Chenard-Walcker returned with a big team of six cars. The biggest car in the field was a 4-litre, rated at 22CV and built by effectively putting two 2-litre engines end to end. It delivered about 125 bhp giving a claimed 170 kp/h (105 mph) top speed. It was given to the previous year's winners René Léonard and André Lagache. A 3-litre 15CV, similar to the successful 1923 models was raced by the two Bachmann brothers, Raoul and Fernand. For the Triennial Cup, the team entered its smaller cars: a pair of the Type TT 12CV 2-litres as well as one of the two new Type Y 1.5-litre cars present.Spurring 2011, p.101-3
After being initially sceptical the previous year, W. O. Bentley was now a firm convert, and offered to provide John Duff full factory support for a return to Le Mans. Learning from the previous year, his new Bentley 3 Litre now had four-wheel brakes, and wire mesh put over the headlights and matting wrapped the fuel tank – both measures put in to reduce potential damage from flying stones. The durable Rapson tyres were employed again on the Rudge-Whitworth wheels. Duff also advised changes to make mechanical fixes quicker during the race and recommended some team members be stationed at Mulsanne corner with a telephone so he could signal if he was going to be pitting at the end of the lap. He also did extensive practise putting up and taking down the hood.Spurring 2011, p.94-6
A new range of the La Lorraine-Dietrich B3-6 3.5-litre cars were unveiled at the end of 1923, including a Sport version deliberately built for racing. Now with a 4-speed gearbox, the new engine put out 115 bhp, getting the car up to 145 kp/h (90 mph). Three cars were entered, two running on Michelin tyres and the other on Englebert.
Bignan doubled its team this year to four cars with their distinctive triple headlights. The new 3-litre engine was powerful, putting out 124 bhp and the 2-litre cars were new models, without the expensive “Desmo-chromique”engine. The team had already done well, winning the first post-war Monte Carlo Rally and setting 24-hour endurance records on the new Montlhéry circuit.Spurring 2011, p.109
Ariès was a new entrant this year and arrived with four cars. It was founded in 1903 by former Panhard et Levassor engineer Baron Charles Petiet and had competed in the early inter-city races. Two shortened GP versions of the standard Type S were prepared, one with a 3.2-litre and the other with a 3-litre engine. There were also two 1100cc cars entered: an older CC2 and a new CC4 4-seater. Getting back into post-war racing in 1924 Petiet assembled a team of well-known drivers. Fernand Gabriel was leading the ill-fated 1903 Paris-Madrid race when it was stopped. Arthur Duray had set land speed records before the war and finished second in the 1914 Indianapolis 500 behind René Thomas. Robert Laly had been Thomas’ riding mechanic in the same race.Spurring 2011, p.105-7
Rolland-Pilain again had four cars entered. The latest C23 version had a 2-litre engine capable of 50 bhp and 120 kp/h (75 mph). For the race the company entered lengthened four-seat tourer versions.Spurring 2011, p.110-1 Brasier returned with another pair of its 2.1-litre TB4 model with its 4-speed gearbox.Spurring 2011, p.103 Charles Montier also returned with his modified Ford special, now fitted with 4-wheel brakes. Again Montier drove it himself with his brother-in-law Albert Ouriou.Spurring 2011, p.110
Oméga-Six was another new entrant this year. A venture founded in 1922 by Gabriel Daubech, who had made his money in timber. He wanted to get into the mid-range car market with a new option – a high-end 6-cylinder. The cars had a torpédo bodystyle, 4-speed gearbox with a 2-litre engine produced 50 bhp capable of 120 kp/h (75 mph).Spurring 2011, p.114 Louis Chenard (unrelated to Chenard-Walcker) had a small self-named Parisian car-factory. He ran one of his torpedo-style Type E tourers having a 1.2-litre Chapuis-Dornier engine, with his brother Émile.Spurring 2011, p.118 Likewise Georges and René Pol, who made taxis and delivery vans, wanted to venture into the sports car field. So they built a simple 1.7-litre car, named the GRP, and entered it into the race.
Georges Irat arrived with a “Compétition Spéciale” version of the 4A. With a higher-revving 2-litre engine that put out 60 bhp getting it up to 135 kp/h (85 mph).Spurring 2011, p.112 This year Corre La Licorne had three of its new model, the Type V16, now with a 10CV 1.5-litre SCAP engine. The “boat-tail” chassis had a 4-speed gearbox and 4-wheel brakes.Spurring 2011, p.115-7 New entry Alba also used the 1.5-litre SCAP engine, and also had its patented servo-less four-wheel braking also used by the Citroën Type C.Spurring 2011, p.117
SARA had three of its ATS 2-seater model, one entered in the Triennial Cup and the other two in the Biennial Cup.Spurring 2011, p.112 This year Amilcar brought two cars – the same privately owned CV that had done well the previous year, and a new Type C Grans Sport. Its 1074cc engine produced 33 bhp and was driven by works drivers André Morel and Marius Mestivier.Spurring 2011, p.104 Majola had been racing cycle-cars after the war, but arrived at Le Mans with a bigger 1.1-litre 7CV 4-seater tourer.Spurring 2011, p.115
Practice Once again, with no official practice session, several teams arrived earlier in the week before the scrutineering on Friday to do some practice laps. However, Maurice Rost crashed his Georges Irat and it could not be repaired in time to take the start.
Race Start The ACO were vindicated for changing the event date, with hot, dry weather over race-week. This carried on into the weekend and dust would prove to be the issue this year. Rudge-Whitworth representative Émile Coquille was the official starter this year. Last away was Charles Montier whose Ford Special proved temperamental to start.Clarke 1998, p.15: Motor Jun17 1924 At the end of the first lap, it was the 3-litre Bignans of de Marne and Ledure with Lagache's big 4-litre Chenard-Walcker between them setting the pace.
Straight away, de Marne easily beat Clement's lap record from the previous year by 15 seconds. Then after five laps, the convertibles had to come in to do their compulsory raising of the hood. Lagache almost missed his pit signal, having to brake heavily and reverse 100 metres to his pit spot. Duff's practicing paid off as he only took 40 seconds to put his up. But fastest of all were Montier and Lucien Erb, in his SARA, who only took 27 seconds.