There was very little the Italian manufacturers could do to fight the German teams in the highest class of Grand Prix racing in the second half of the 1930s. The seemingly endless funds made available by the German government proved to be too much. Realizing that the race was long lost, they turned to the 'Voiturette' class, which was intended mainly for privateers. To reduce costs, there was a displacement limit of 1.5 litres, but the involvement of the Italian teams quickly saw the most advanced cars being entered.
With the 6CM, Maserati was one of the top runners in 1936 and 1937. The strongest competition came from the British ERAs, until Enzo Ferrari's workshop started work on an all new racer for Alfa Romeo. At its debut in 1938, the Alfa Romeo 158 or 'Alfetta' was the most advanced Grand Prix racer ever constructed, with a hugely powerful supercharged eight cylinder engine. Maserati's engineers quickly started work on a replacement for the 6CM, which was left utterly obsolete by the new Alfa.
The 6CM's six cylinder engine was completely discarded and replaced by a state of the art 'four'. The double overhead camshafts operated four valves per cylinder; not a new setup, but one rarely used successfully in the past. To take the most advantage of the multiple valves, each exhaust valve had a separate pipe on the manifold.A 1930s racer was not complete without a Supercharger, so the 4CL was fitted with a Roots-type. Power was quoted around 220 bhp at an incredible 8000 rpm. Its body and chassis followed that of the 6CM.
Production of Maserati's new Voiturette started early in 1939 and in total around 25 cars were constructed up until 1946/7. Unfortunately the advanced racer was pitched against one of the greatest Grand Prix cars ever; the Alfetta. Mercedes-Benz also hastily constructed a 1.5 litre version of their 'Silver Arrows'. The German's interest in Voiturette racing was the direct result of Italian Grand Prix organizers focusing on Voiturette racers rather than the bigger Grand Prix cars. The most important of these was the Tripoli Grand Prix.
Throughout 1939 victories were scored by the Maseratis in minor races in Italy. A highlight in the small racer's career was Villoresi's pole position in the 1939 Tripoli Grand Prix. In 1948 the 4CLT/48 was introduced, which featured an all new tubular chassis and a more powerful twin-supercharged version of the 16 valve four cylinder engine.
Pictured is a 4CL originally campaigned by the 'Scuderia Milano'. It was assembled by the factory in 1946 from parts built in 1939. It is pictured here at a number of events during the 2004 Monterey Historics weekend, where it was displayed by Symbolic Motors, who currently have it for sale.