Alfa Romeo 6C 2300B Cabriolet Castagna

The Alfa Romeo 6C 2300B Cabriolet bodied by Carrozzeria Castagna and bearing chassis number 813.830 was constructed in 1937 on the short-wheelbase variant of the second-generation 6C 2300 platform. It was presented at the 1937 Salone dell’Automobile di Milano on the stand of Castagna, an established Milanese coachbuilder with a long-standing association with the marque. The 6C 2300B was introduced in 1935 as an evolution of the earlier 6C 2300, itself first launched in 1934. The revised “B” series featured independent front suspension by double wishbones and coil springs, and independent rear suspension by swing axles and torsion bars. Chassis 813.830 was equipped with the standard production engine: a 2,309 cc inline six-cylinder with dual overhead camshafts and hemispherical combustion chambers. Power was transmitted through a four-speed manual gearbox to the rear axle. In its standard touring configuration, the engine produced approximately 76 CV at 4,400 rpm. Braking was by hydraulically actuated drums on all four wheels. The body, constructed by Castagna, followed the open cabriolet type with two doors and a folding canvas roof. The design was characterized by long, integrated fenders, a slightly raked grille, and enclosed rear wheel spats. The cabin was arranged for two or four occupants, depending on configuration, and finished with Castagna’s typical attention to materials and fittings. Panels were formed in aluminium and steel over a traditional wooden substructure. The exterior reflected emerging aerodynamic sensibilities while retaining the formal elegance associated with Italian coachbuilding of the period. Only one example of this configuration is recorded. No additional chassis bearing similar bodywork has been identified in surviving documentation or period press. Chassis 813.830 is therefore considered a unique example. The car was intended as a showpiece rather than a production model and was used by Castagna to demonstrate its stylistic language applied to a technically modern chassis.