1929 Alfa Romeo 6C

This 1929 Alfa Romeo 6C 1750 is one of approximately 120 third-series Super Sports built during a single production year and is said to have been delivered new in supercharged form to the UK as a rolling chassis before being clothed in drophead-coupe coachwork by James Young. Chassis 0312896 was reportedly sold to its first owner in September 1929 in the UK, where it was later rebodied in the style of a Zagato Spider circa the early 1990s. The car was purchased in 1996 by a Japanese collector who subsequently commissioned a three-year refurbishment by Phil Reilly & Co. in California that included an overhaul of the DOHC inline-six to a displacement of 1,767cc with updated internal components. Following the conclusion of the project in 2000, the car completed the 2001 Mille Miglia and contested a variety of other events before the owner’s passing. It was purchased by the selling dealer in October 2023 and imported to the US. Finished in red over black leather, the car features a Roots-type supercharger, a single SU carburetor, a constant-mesh four-speed manual transmission, mechanically actuated four-wheel drum brakes, black-painted 18” wire wheels, dual rear-mounted spares, a Bosch central driving light, an electric cooling fan, and an electric fuel pump. This 6C 1750 SS is now offered in San Diego, California, with invoices and photos from the late-1990s refurbishment and a clean Mississippi title. The 6C platform was developed by Vittorio Jano based on the championship-winning P2 Grand Prix car designed by Jano upon his 1923 arrival as Alfa Romeo’s chief engineer. The 6C 1500 debuted at the 1925 Milan Motor Show before entering production in 1927 and soon became available in twin-cam Sport and Super Sport variants. The second-series 1500 was succeeded in 1929 by the third-series 1750, which was also offered in single- or twin-cam configurations, the latter of which included the competition-oriented Super Sport in either con compressore (supercharged) or naturally aspirated form. Examples of the 6C 1750 SS were responsible for victories in the Mille Miglia, 24 Hours of Spa Francorchamps, and several Grand Prix contests. This example’s initial James Young coachwork is said to have been replaced with its current Zagato-style spider layout in the early 1990s. The body was repainted in red during the refurbishment performed between the late 1990s and 2000, and closeups of the finish, trim, and lenses are provided in the photo gallery below. Design features include low-cut doors, an adjustable windshield that hosts dual Desmo side mirrors, headlight stone guards, a Bosch central driving light, turn signals, and a soft top that folds into the rear bodywork beneath a matching boot. The 18” wire wheels were refurbished and finished in black during the late-1990s project and are secured by bright two-eared knock-offs. Michelin tires measuring 4.75/5.25 are mounted at each corner as well as on a pair of matching spares secured within the rear bodywork. The selling dealer notes that the tires are approximately 15 years old and should be replaced. Stopping is handled by rod-actuated body-color finned drum brakes at each corner. The right-hand-drive cockpit was re-trimmed during the refurbishment and features black leather over a two-place bench with matching upholstery over the door panels and upper dash. Features include a central gated shifter with reverse lockout, branded pedals, ribbed aluminum floor paneling, door pockets, a dash-mounted rearview mirror, and a fire extinguisher mounted in the passenger footwell. An electrical cutoff switch has been added forward of the driver’s seat. The four-spoke steering wheel sits ahead of a body-color dash hosting Jaeger instrumentation including a 180-km/h speedometer, a 6,300-rpm tachometer, an eight-day clock, and gauges monitoring fuel level and oil pressure. The five-digit odometer shows 18k kilometers (~11k miles), approximately 22 of which have been added under current ownership. A Barnacle coolant temperature gauge is situated under the dash. The Vittorio Jano-designed inline-six features a detachable cast-iron cylinder head with hemispherical combustion chambers, dual overhead camshafts, and a Roots-type supercharger that breathes through a single SU sidedraft carburetor. An engine overhaul during the late-1990s refurbishment included overboring the cylinders for a displacement increase to 1,767cc as well as the resurfacing of the block, regrinding and nitriding of the crankshaft, and reconditioning of the cylinder head. Replacement components included Venolia forged pistons with full-floating wrist pins, Deves piston rings, Carrillo connecting rods, Megacycle camshafts, and Jim Stokes-supplied valves and springs. The supercharger, carburetor, oil pump, and water pump were also rebuilt during the project, and an electric fuel pump was added along with an electric cooling fan. Fluid and filter changes were performed in preparation for the sale. Power is sent to the rear wheels via a constant-mesh four-speed manual transmission, and the clutch was replaced during the 1990s refurbishment. Suspension incorporates semi-elliptical leaf springs and friction shock absorbers at each corner. Number 0312896 is shown stamped on the upper crankcase above as well as on the crankcase tag, matching the chassis and engine numbers shown stamped on the chassis tag in the gallery below. Also shown in the gallery is number 2893 stamped on one of the hood hinges. Photos and invoices from the late-1990s refurbishment are included in the sale, as are various other documents from previous ownership and brochures from the 2001 Mille Miglia.