1932 Alfa Romeo 6C 1750

The Alfa Romeo 6C 1750 was light and nimble with excellent road-holding characteristics and plenty of reliable power. Its all-alloy straight-six was designed by Vittorio Jano and in its ultimate configuration, used twin overhead camshafts, hemispherical combustion chambers, and a roots-type supercharger. It was built in three series between 1930 and 1933, and in both Gran Sport and Testa Fissa forms, the 6C 1750s won nearly every major sports car race of its era, including the 24 Hours of Spa, Monza Grand Prix, Brooklands Double Twelve, and the Mille Miglia.

The Alfa Romeo 6C, with the '6C' in reference to its six-cylinder engine, was produced from 1927 through 1954 beginning with the 6C 1500 of 1927 to 1929. It was introduced at the Milan Motor Show in 1925 and began series production in 1927. The engine's displacement measured 1,487 cc (thus, the 1500 portion of its name) and the early examples were bodied by James Young and Carrozzeria Touring. The 6C Sport model arrived in 1928 and its dual-overhead-camshaft engine earned many race victories, including the 1928 Mille Miglia. Of the approximately 3,000 examples of the 6C 1500 produced, around 200 had the DOHC version of the engine and ten with superchargers (known as Super Sport).

The 6C 1750 arrived in 1929 with a 1,752cc engine with the base version using a single overhead camshaft while the Super Sport and Grand Sport used a double overhead camshaft. A supercharger was available, and most examples were sold as rolling chassis with coachwork provided by Zagato, Castagna and Touring Superleggera. Sport touring or spider bodies were popular, and perhaps as few as three were given coachwork by Carrosserie Figoni and another three by James Young. Wheelbase sizes varied, with the Turismo version measuring 122-inches, the Sport and G.T. being 115-inches, the GT Compressor at 124.4 inches, and the Super Sport and Gran Sport measuring a short 108.1-inches. The suspension was independent at the front with torsion bars and unequal-length wishbones, while the rear employed a live axle suspended on trailing links and a one-piece torsion bar. The gearbox was a four-speed manual unit and four-wheel mechanical drum brakes provided the stopping power. The mechanical braking system used large drums actuated by a transmission system. The pressed steel frame was perfectly balanced and rigid due to its reinforced axles. The leaf springs were mounted outside the car body instead of beneath the side members, and the lower center of gravity greatly improved its performance. Its balance was further perfected by placing its fuel tank further back, positioning the weight above the rear wheels which aided in axle balance.

When the supercharger was installed, it endowed the water-cooled 6-cylinder engine with greater horsepower and torque. In Gran Sport configuration, the engine developed approximately 85 horsepower and gave the nimble vehicle a top speed of around 90 miles per hour. With and without a volumetric compressor, output from the 6C 1750 engine ranged from 46 horsepower of the Turismo version to the 102 hp of the Gran Sport 'Fixed Head.' The latter was a special version built in limited quantities with its cylinder head and crankcase cast in a single block to eliminate the seals. Weighing a mere 840kg, these versions had a top speed of 105.6 mph.

During the 1929 season, the 6C won every major racing event in which it was entered, including the Grand Prix of Spain, Tunis, Monza, Belgium, Ulster TT, Brooklands Double Twelve, and the Mille Miglia. The car was victorious at the 1930 Mille Miglia and the Spa 24 Hours. Tazio Nuvolari drove one to an overall victory at the IV Coppa delle Mille Miglia. Giuseppe Campari repeated this feat in 1931 with his.

During its production lifespan, Alfa Romeo produced 2,635 examples of the 6C 1750, including 369 examples of the Super Sport and Grand Sport.

by Daniel Vaughan | Sep 2021