24h Le Mans
24 HOURS CENTENARY – PERPETUAL INNOVATION ⎮ A fundamental symbol of power and sportiness on both the road and the track, the 12-cylinder V has carved an exceptional place for itself at the race thanks namely to its pioneer, Ferrari, who won with the engine for the first time in 1949.
Car manufacturers have always focused on engine architecture to improve car performance, beginning in the 1920s when the effort was centred between 4-cylinder and 6-cylinders.
Though a 4-cylinder engine triumphed in 1923 and 1924 thanks to Chenard & Walker then Bentley, a 6-cylinder took the reins in 1925 and 1926 thanks to Lorraine-Dietrich. Bentley's 4-cylinder reclaimed the advantage in 1927, but that year also saw the first inline 8-cylinder engine at the race (SCAP), finishing second in 1928 (Stutz). Alfa Romeo gave an inline 8-cylinder its first win in 1931, a performance repeated in 1932, 1933 and 1934. The first 8-cylinder V powered a Derby in 1935, then the first 12-cylinder V equipped a Delahaye in 1938, without any success (retirements). Lagonda V12s did however finish third and fourth in 1939.
But why so much interest in engine architecture? Power is the most crucial element of winning, that's why.
So, the first engines at Le Mans had 4 cylinders, but by increasing the displacement to 3.5 litres to avoid having oversized pistons, the move to 6 cylinders proved interesting. The more the number of cylinders is multiplied, the lower the unit displacement. This makes it possible to limit the stroke and the bore, and therefore to reduce the inertia of the engine, allowing it to rev more easily at higher rotational speeds and generally provide more power for the same displacement. The number of cylinders can be increased to 8 or even 12, there was even a 16-cylinder in Formula 1 at one time.
Inline or V? The choice of this architecture fixes the length of the engine. It's simple for a 4-cylinder, but when it comes to a 6, 8 or 12, the length can be limited by dividing it into two banks of 3, 4 or 6 cylinders. The goal is to limit the length of the crankshaft to reduce vibration and the number of bearings to minimise friction which absorbs power. Also, a shorter engine is easier to install in a car. In the era of front engines, lengthening of the bonnet was avoided thanks to installation in a rear central position (extending the wheelbase would have resulted in too many repercussions). As a result, a V12 engine does not become more cumbersome than an inline 6-cylinder and a V6 is shorter than an inline 4-cylinder.
In 1949, after the post-war hiatus, a young constructor named Ferrari arrived at Le Mans with a V12 engine (only a 2-litre) and won. The legacy of the Italian marque and its favourite engine architecture had begun, and another victory was secured in 1954 with a V12 (4954 cm3).
The regulations greatly limited engine displacement in 1956, and the Ferraris of that year ran with a 4-cylinder 2.5-litre before returning to the V12 (3800 cm3) from 1957.
In 1958, the Italian manufacturer's V12 (returned to 3 litres, again due to a change in the regulations) secured a convincing win. This type of engine powered all of the Scuderia's prototypes, with a few exceptions such as the Dino V6, and the unforgettable GTOs in the GT class.
After Aston Martin's surprise victory in 1959, Ferrari claimed the top step on the podium a staggering six times between 1960 and 1965. The capacity of the V12 increased, from 3 litres in 1960 and 1961, to 4 litres in 1962, to return to 3 litres in 1963, but with the engine installed centrally at the rear for the first time. After that, the intensity of the duel with Ford forced Ferrari gradually to increase the capacity of its V12 to fight the American marque's 5-litre then 7-litre V8s, going from 3.3 litres in 1964 to 4 litres in 1965 (though a 3.3-litre won that year). Ford triumphed in 1966 and 1967 with its 7-litre V8, Ferrari having nevertheless pushed its V12 to 4 and even 4.4 litres.
During that period, Maserati also attempted a V12, without ever mastering its reliability, and subsequently returned to a V8.
In the wake of the Scuderia's official withdrawal from competition in 1968, only a few private 275 LMs or GTBs released the roar of a Ferrari V12 at the 24 Hours. However, another V12 with an unmistakable sound appeared on the scene to the thrill of spectators: the 3-litre Matra!
In 1969, a Porsche flat V12 faced off against Matra. With a 4.5-litre capacity and air cooling, the engine powered the 917 whose top speed made quite an impression to say the least. The German V12 won the very next year and followed that up with a second consecutive win in 1971, beating the V12s in the Ferrari 512 Ss then 512 Ms. In its heyday in 1970, 22 cars with 12-cylinder engines (flat or V) figured on the starting grid, then 19 in 1971.
At the beginning of the 3-litre era, the Matra V12 strung together wins and in 1973 navigated a major battle with the new Ferrari flat-12 engine. There were still as many as 17 12-cylinder cars on the starting grid that year (but only seven prototypes), then only 10 in 1974.
V12 engines fell out of favour, despite being very efficient and delivering more power than V8s: 12 pistons rubbing against the walls of 12 cylinders, and very high rotational speeds, generated more consumption. In 1975, the first year fuel efficiency became a priority, only two Ferrari Daytonas remained in the GT class. After 1976, no 12-cylinder prototypes were fielded in the 24 Hours, the grid boasting only turbocharged V6s or naturally aspirated V8s. Only a few Ferrari GTs, including the unforgettable 512 BB, kept the V12 flame going until 1984.
Other than the Porsche 917 "modernised" in 1981, it would take until the advent of the Group C class to see another 12-cylinder at the race again. Jaguar won with a huge 7-litre V12 in 1988 and 1990. But the car fell victim to FIA regulations that imposed 3.5-litre V10s common to Formula 1 and endurance racing in 1992 and 1993.
Relaxation of the regulations between 1994 and 2000 allowed the V12 to regain its luster, this time thanks to BMW. The engine first won in a McLaren F1 in 1995, then again in 1999 in a factory prototype.
The creation of the LMP1 class and BMW's official withdrawal from competition again eliminated V12s after a last appearance in a private car in 2000. Only a few Ferrari V12s (always them) remained in GT, such as the 550 Maranello and 575 GTC until 2005.
Fortunately, the transition to TDI (turbo diesel) revived the cylinder race. To pull more power from a diesel, you need large, high-capacity engines. Audi installed a V12 (5500 cm3) in its R10 with two turbochargers and Peugeot came with a 908 HDi FAP powered by a twin-turbo V12 (5500 cm3). And so the V12 engine was able to add four new wins to its track record (three for Audi and one for Peugeot). However, Audi then began to downsize, transitioning to a V10 then to a V6 between 2009 and 2011.
The arrival of hybridisation led to the reduction in engine size in 2012. The goals of saving fuel, weight and space in the car required small internal combustion engines to be coupled with electric motors, so the V12 was once again sidelined. Similarly in GT, Ferrari opted for a V8 in the 458 Italia. After 2011, no roar of a V12 has echoed around the circuit at the 24 Hours of Le Mans.
PHOTOS (Copyright - ACO/Archives): LE MANS (SARTHE, FRANCE), CIRCUIT DES 24 HEURES, 1939-2009 24 HOURS OF LE MANS. From top to bottom: the #9 Peugeot 908 HDi FAP became in 2009 the last V12 prototype to win the race; this Lagonda V12 (#5) finished third in 1939 thanks to Charles Brackenbury/Arthur Dobson; in 1949, Luigi Chinetti (centre, wearing a striped tie) gave the V12 its first win with the Ferrari 166 MM (#22); two six-cylinder banks visible on the rear bonnet of this Matra (#33) driven by Jean Guichet/Nino Vaccarella, fifth in 1969; the same year, the #12 917 was powered by the first 12-cylinder engine in Porsche's history; in 1988, Jaguar's naturally aspirated 7-litre V12 (#2) ended the domination of Porsche's turbocharged flat-six; originally designed for the McLaren F1 road car, the BMW V12 made its mark in a factory prototype driven by Yannick Dalmas/Pierluigi Martini/Joachim Winkelhock (#15) in 1999; in 2008, the turbo diesel V12 in the #2 Audi R10 TDI scored its third and final consecutive victory.
