Ferrari 121 LM Scaglietti Spyder

The 121 LM at a glance

Why Ferrari built a six-cylinder Le Mans car

In the early 1950s Ferrari's engineer Aurelio Lampredi developed a line of large in-line engines alongside the V12s. His four-cylinder units powered the Ferrari 750 Monza, and adding two cylinders produced a family of straight-sixes.

The first step was the 118 LM of early 1955, itself an evolution of the 376 S. For Le Mans Ferrari wanted more power to fight the Jaguar D-Type, so the engine was enlarged to 4.4 litres and renamed Tipo 121. One car was converted before the Mille Miglia in April 1955 and the rest after it; the factory then built or rebuilt four cars to the new specification. It was the final capacity step for Ferrari's racing sixes before the company moved on to the Dino V6.

Engine, chassis and Scaglietti body

The Tipo 121 engine measured 102 mm bore by 90 mm stroke, which gives 4,412 cc, or about 735 cc per cylinder. It used twin overhead camshafts, two valves and two spark plugs per cylinder, dry-sump lubrication, a compression ratio of 8.5:1 and three Weber 50DCOA/3 carburettors. Ferrari's own figure was 330 PS (243 kW); auction catalogues quote up to 360 bhp (265 kW), well above the D-Type's output.

The chassis followed Ferrari practice of the time. A tubular steel frame (Tipo 509, shared with the 376 S) carried unequal-length wishbones and coil springs at the front and a De Dion axle with a transverse leaf spring at the rear. Brakes were drums all round, and power went to the rear wheels through a 5-speed manual gearbox. The wheelbase was 2,400 mm and the fuel tank held 150 litres, enough for long stints at Le Mans.

Scaglietti in Modena built the bodies: low, smooth spyders with a single wrap-around screen for the driver, a headrest fairing behind the cockpit, side vents behind the front wheels and wire wheels. At the front it had a pair of main headlamps, two extra lamps beside the grille and a medium-sized bonnet scoop, and the fuel tank sat in the tail.

By our calculation the 121 LM had about 3.5 kg per kW at its 330 PS rating (850 kg ÷ 243 kW), or about 3.2 kg per kW if the higher figure is taken. You can check similar numbers for modern cars with our power-to-weight calculator, or set two classics side by side with the comparison tool.

The 1955 Le Mans 24 Hours

Le Mans was the reason the car existed, and it was a race of extremes for Ferrari. In practice Eugenio Castellotti set the fastest lap, 4 minutes 14 seconds, and a 121 LM was timed at 291.2 km/h over the flying kilometre on the Mulsanne Straight; the fastest Jaguar D-Type managed 281.9 km/h.

The race went badly. Three 121 LMs started:

The 1955 race is remembered above all for the disaster in which a Mercedes-Benz crashed into the crowd. For Ferrari it showed that the big six was fast but not durable enough for 24 hours.

Other races in 1955

The 121 LM had a short European career. At the Mille Miglia in April 1955 both Castellotti and Paolo Marzotto retired; Marzotto's car, chassis 0546LM, lost a tyre at around 280 km/h on the first stage. After Le Mans the results improved: Maglioli won the Aosta–Gran San Bernardo hill climb outright, and Castellotti finished third in the sports car Swedish Grand Prix.

New engine capacity limits for 1956 left the 4.4-litre cars without a place in European endurance racing, and all four were sold to American customers.

American racing and the Pebble Beach crash

In the United States the 121 LMs found the success they lacked in Europe. Between 1955 and 1963 they were driven by Jim Kimberly, Carroll Shelby, Phil Hill, Ray Cherryholmes, John Kilborn and Ernie McAfee; McAfee, Shelby and Cherryholmes won the most races with them.

The story of chassis 0546LM shows both sides. The oil executive William Doheny bought it and entered it for Ernie McAfee, and the pair dominated California amateur racing. In April 1956, at the Del Monte Trophy race at Pebble Beach, McAfee missed a downshift on lap 33 and hit a pine tree; he was killed. The accident ended racing on the Pebble Beach roads. Doheny rebuilt the car over the next two years, and his family kept it for about two decades. Three 121 LMs were entered in the 1957 Cuban Grand Prix, where two retired and one never arrived.

The four cars and their value today

Ferrari's chassis numbers for the series include 0484LM, 0532LM, 0546LM and 0558LM. Two of them, 0484LM and 0546LM, began as 118 LMs and were converted by the factory, and all four survived their racing lives.

The best-documented sale is 0546LM, offered by RM Sotheby's at Monterey on 18 August 2017. It had returned to racing at the Monterey Historics from 1974 and was shown at the Pebble Beach Concours in 1975 and 1976. The estimate was 6.5–7.5 million US dollars, and the car sold for 5.72 million US dollars including premium, about 4.9 million euros at the exchange rate of the time. Analysts linked the lower result to the 118-to-121 conversion and the car's thin works racing record. The old version of this page quoted an "estimated" price of about 4.2 million dollars without a date or source; that figure has been removed.

How the 121 LM compares

The six-cylinder car was the most powerful of Lampredi's in-line engines, but its weight and heat made it hard on clutches and brakes. Ferrari's racing V12s, seen in the 375 MM, returned as the main line from 1956.