By 1955, the battle for endurance racing supremacy had become a three-way arms race between Ferrari, Mercedes-Benz, and Jaguar. Mercedes had won Le Mans in 1952 with the W194. Jaguar had taken it back in 1953 with the C-Type, and again in 1954 with the D-Type was waiting in the wings. Ferrari had answered with the 375 Plus, winning the 1954 24 Hours of Le Mans. But the 1955 season demanded something new. Both Mercedes and Jaguar were running straight-six engines — reliable, powerful, proven. Enzo Ferrari, who had built his legend on the V12, made an extraordinary decision: he commissioned engineer Aurelio Lampredi to design a straight-six.

Lampredi took the four-cylinder engine from the 750 Monza and added two cylinders. The result was the Tipo 121 — a 4,412 cc twin-overhead-cam unit with twin-spark ignition and three Weber 50 DCOA/3 carburettors, producing 330 brake horsepower at 5,800 rpm. It was mounted in a Tipo 509 chassis clothed in Scaglietti bodywork — a body so well proportioned that it has been called one of the most aggressive shapes of its era. The aerodynamic fin behind the driver echoed the Jaguar D-Type. The nose, low and purposeful, was designed to cut through air at speeds no other Ferrari had reached.

Only four Ferrari 121 LMs were built. For the 1955 24 Hours of Le Mans, Scuderia Ferrari entered three of them. Eugenio Castellotti and Paolo Marzotto drove car number four. Phil Hill and Umberto Maglioli took number three. Maurice Trintignant and Harry Schell were in number five. In practice, Castellotti set the fastest time of any driver and recorded 291 km/h on the Mulsanne Straight — faster than the Jaguar D-Type, faster than the Mercedes-Benz 300 SLR. The Ferrari 121 LM was the quickest car at Le Mans that year.

The race told a different story. Castellotti’s engine failed after five hours and 52 laps. Hill and Maglioli retired with overheating and clutch problems after 76 laps. Trintignant and Schell lasted the longest — ten hours and 107 laps — before their clutch gave out. All three factory Ferrari 121 LMs were out before midnight. The 1955 Le Mans was won by Jaguar, but the race is remembered above all for the catastrophic accident involving Pierre Levegh’s Mercedes-Benz, which remains the deadliest incident in motorsport history.

After Le Mans, new regulations imposed a 2.5-litre capacity limit. The Tipo 121 engine became obsolete overnight. Ferrari returned to the V6 Dino engine and never built another inline-six. All four Ferrari 121 LM chassis survive today in private collections. Chassis 0546 LM — driven by Taruffi at the 1955 Mille Miglia and by Trintignant at Le Mans — sold at RM Sotheby’s in Monterey in 2017 for $5.72 million after a five-year restoration by Ferrari Classiche to its exact 1955 Le Mans specification.

This photograph captures the nose of the Ferrari 121 LM at close range — the Scaglietti bodywork, the blue centre stripe that marks this car as a product of international endurance racing, the sculptural form of a machine that was faster than anything else on the straight and too fragile to last the night.