CMC Alfa-Romeo P3, 1933, Clear Finish

The Alfa-Romeo Tipo B was a single-seater Grand Prix racing car built and raced by Alfa-Romeo between 1932 and 1936. Designed by Vittorio Jano, the car was based on the Alfa-Romeo 8C models. The P3 was Alfa-Romeo’s second single-seater after the Tipo-A monoposto of 1931. It took over some components of the earlier very successful Alfa-Romeo P2, which led to the unofficial name “P3” in the press and among motorsport enthusiasts. Thanks to the numerous victories achieved by Tazio Nuvolari and Achille Varzi, among others, it is considered one of the best competition cars ever built.

The chassis with longitudinal spars and cross members made of pressed steel C-sections, derived from that of the Tipo A, was adapted to the regulations and modified to accommodate the new engine. This version of the engine had a larger displacement of 2654 cm³ (bore × stroke: 65 × 100 mm) than the turbocharged in-line eight-cylinder engine of the 8C 2300 “Monza”. It was advanced for its time, with a light alloy cylinder block and head split into two halves, each with four cylinders. Jano divided the block to reduce the torsional vibrations of the crankshaft and camshafts by placing all the power take-offs in the centre of the crankshaft: the drive for the camshafts, on the side the drive for the supercharger fans and opposite on the exhaust side the drive for the pumps for oil and cooling water. The crankcase was in one piece. The engine had dry sump lubrication, two Roots compressors and two Weber carburettors, magneto ignition and water cooling. It produced 215 hp at 5600 rpm.
The four-speed gearbox and the multi-plate clutch were blocked to the engine.
The wheels were suspended front and rear on rigid axles with semi-elliptic leaf springs and friction shock absorbers, rear springs and shock absorbers were double. The drum brakes were mechanically operated. A novelty of the type B P3 was the placement of the differential directly behind the manual gearbox. From there, the power was transmitted to the rear wheels via bevel gear pairs with two diagonally arranged shafts. The differential being further forward reduced the unsprung masses and the load on the rear axle. This was to reduce the tendency to oversteer and the driver’s seat could be mounted directly on the floor panel in the sense of a low centre of gravity between these shafts.
This 700 kg single-seater with its simple, streamlined bodywork reached 225 km/h.

Tazio Nuvolari won the very first race of the Tipo B/P3 on 5 June 1932 at the 10th Italian Grand Prix in Monza. The season continued with six more victories for Alfa-Romeo, including the most important Grands Prix of the time, namely those of France and Germany (at the Nürburgring). The second driver was the German Rudolf Caracciola. Thanks to these successes, Alfa-Romeo won the International Automobile Championship with Nuvolari, which in that year was based on the Grands Prix of Italy, France and Germany.

In 1933, the factory team “Alfa-Romeo” was closed due to Alfa-Romeo’s financial problems. Direct participation in competitions was consequently suspended. All of Alfa-Romeo’s racing material was handed over to Scuderia Ferrari in Modena, which had prepared and fielded the racing cars since 1929. That year, the Tipo B did not take part in the first 25 competitions and did not compete again until August. It won six of the remaining eleven races, including the Italian and Spanish Grands Prix.