After limited success with the supercharged 1.5-litre Ferrari 125 F1 in the first season of Formula One competition, Enzo Ferrari decided to pursue the naturally aspirated 4.5-litre class permitted under the prevailing formula regulations. He brought in engineer Aurelio Lampredi to replace Gioacchino Colombo as technical director, tasking him with developing an entirely new large-displacement V12 engine through a stepped series of progressively larger displacements.
Lampredi's first step was the experimental 275 S sports prototype, fitted with a 3.3-litre V12 and raced at the 1950 Mille Miglia. The engine then appeared in Grand Prix form as the 275 F1, which debuted at the Belgian Grand Prix on June 18, 1950. Alberto Ascari drove the 275 F1 to fifth place in Belgium, establishing the viability of the naturally aspirated approach.
The 340 F1 replaced the 275 F1 at the Grand Prix of Nations in Geneva on July 30, 1950. Its name reflected the new engine displacement: a 4.1-litre (4,101.66 cc) version of Lampredi's V12, bored out from the 3.3-litre unit. The engine produced 335 hp, a significant step up from its predecessor.
Alongside the larger engine, the 340 F1 received a new de Dion tube rear suspension arrangement derived from the Formula 2 Ferrari 166 F2, replacing the earlier live axle. The wheelbase was extended to 2,420 mm to accommodate the layout changes, though other external dimensions were retained from the 275 F1.
Alberto Ascari drove the 340 F1 at Geneva and demonstrated that the car had the pace to run with the front-running Alfa Romeo 158 of Juan Manuel Fangio — a significant benchmark, as the Alfa Romeos had been untouchable for much of the season. However, Ascari was forced to retire from the race with engine trouble, preventing the car from proving its competitive potential in a race result.
Although the 340 F1 only contested one championship race and failed to finish, it represented a critical proof of concept within Ferrari's development ladder. Ferrari's own engineers recognized it as a capable machine but understood it was not yet the final answer — that came with the 4.5-litre Ferrari 375 F1, which debuted at Monza on September 3, 1950, with two cars entered.
The 375 F1 carried the development directly forward from the 340 F1's chassis and suspension architecture, fitting the full 4,493 cc V12. Through continuous refinement in 1951, the 375 F1 finally ended Alfa Romeo's dominance of Formula One when José Froilán González won the British Grand Prix at Silverstone on July 14, 1951 — Ferrari's first World Championship race victory. Alberto Ascari then won at the Nürburgring and Monza to secure Ferrari's position as the sport's preeminent constructor.
The 340 F1 thus occupies a precise but important place in Ferrari's history: the transitional design that confirmed the larger-engine strategy before the 375 F1 delivered on its promise.