Alfa Romeo 6C 2500 S Castagna

The Alfa Romeo 6C 2500 S Castagna, chassis number 916.203, is a one-off coupé constructed by Carrozzeria Castagna of Milan on the Alfa Romeo 6C 2500 Sport chassis shortly after the end of the Second World War. Completed circa 1947, the vehicle represents a singular example of post-war Italian coachbuilding executed on one of Alfa Romeo’s most advanced pre-Giulietta platforms. The underlying chassis belongs to the 6C 2500 Sport variant, introduced in 1939 and resumed in limited numbers after 1945. It employed a 2,443 cc inline six-cylinder engine with dual overhead camshafts and hemispherical combustion chambers. In standard single-carburetor form, output reached approximately 95 horsepower, though higher-performance configurations with triple carburetors were capable of exceeding 110 horsepower. Power was transmitted to the rear wheels via a four-speed manual gearbox. Suspension was fully independent, with double wishbones and coil springs at the front and trailing arms with coil springs at the rear. Four-wheel hydraulic drum brakes were standard equipment. The bodywork was constructed by Castagna in aluminum and steel over a traditional wooden frame. The coupé configuration featured a long, tapered roofline terminating in a fastback tail, with integrated rear wheel fairings and minimal external ornamentation. The design reflected the restrained aerodynamic tendencies of the immediate post-war period, with emphasis placed on clean surfaces and proportion rather than decorative detailing. Only one example of this model is known to have been built. Chassis 916.203 was exhibited by Castagna at the Rome Motor Show in the late 1940s and was likely intended as a show car to demonstrate the firm’s post-war capabilities. No additional units or direct derivatives are recorded. The car’s early ownership remains unclear, though it has been preserved in private hands and occasionally appears in historic motoring circles.