Alfa Romeo P3 – The Milestone: Star of the track

In the early Thirties, Alfa Romeo dominated Grand Prix racing with the brilliant Tipo B. It won at its first outing and evolved over the years to 330 HP, with a top speed of 275 km/h. It is quite rightly viewed as one of the milestones in Alfa Romeo’s racing history.

At the end of 1931 Vittorio Jano was commissioned to create the Tipo B racing car (subsequently rechristened the P3), the natural evolution of the Tipo A, in which drivers of the stature of Nuvolari and Campari had already won major victories. The project proved demanding from the engineering point of view, but spawned an unbeatable car.

The Tipo A had two parallel in-line engines coupled to two gearboxes, a solution that was powerful but particularly complex and time-consuming to set up. In contrast, the younger sister had just one straight 8 engine consisting of two blocks with aluminium alloy fixed heads, each with its own overhead camshaft; a gear train mounted between the two blocks drove them both. The “twin 4 cylinder” unit was fed by two carburettors and supercharged by two Roots coaxial volumetric compressors, operated by the same central gear train. The engine had a displacement of 2654 cc and produced a maximum power of 215 horsepower at 5600 rpm.

The transmission – especially the differential assembly and drive shafts – had a very distinctive layout. The longitudinal front engine was paired with dry multi-plate clutch and four-speed gearbox. The two drive shafts in a “V” arrangement led out of the differential, installed right next to the gearbox, and drove the rear wheels through bevel gear pairs. Jano’s solution enabled the driver’s seat to be placed inside the V between the two drive shafts, lowering the car’s centre of gravity.

The car made its winning debut at Monza, in the 1932 Italian Grand Prix: Nuvolari dominated the race, starting a long series of victories which were to make the P3 one of the most successful Alfa Romeos of all time.

The 1932 edition of the Italian Grand Prix was run on the original Monza Circuit, which included the road track and the high-speed loop, for a total of 10 kilometres per lap. In the five-hour race, lasting 83 laps, Tazio Nuvolari dominated the proceedings, even lapping Fagioli’s new 16-cylinder Maserati V5, which came in second. It was the start of a long series of wins – in 1932 Nuvolari also won the International Motorsport Championship – which inspired Alfa Romeo to continue with the constant development of its single-seater racer.

In 1934 the engine was enlarged to 2905 cc with 255 horsepower. During the next season, the car’s management was handed over to Scuderia Ferrari, which modified the suspension and the braking system, which was now hydraulic: the displacement was boosted further to 3165 cc and the engine produced 265 horsepower. The final evolution first appeared at the French Grand Prix in 1935: 3822 cc generating 330 horsepower.

The 1935 German Grand Prix has quite rightly gone down in motorsport history thanks to Nuvolari’s amazing win, perhaps the most impressive of his entire career, as he achieved victory on the Nürburgring, beating off fierce competition from Mercedes and Auto Union on their home turf.

In those years, as well as the handful of races valid for the European Drivers’ Championship, a large number of other Grand Prix events – just as important and prestigious – were held more or less all over Europe. One of these was the only edition of the Montreux Grand Prix, in Switzerland, which was held on 3 June 1934 and won by Count Carlo Felice Tossi at the wheel of the Scuderia Ferrari Alfa Romeo P3.

ENGINE: inline-8, anterior longitudinal, double block, 2 alluminium head, 2 OHC, 2 carbs and 2 Roots compressor, 2654 cm³
POWER: 215 HP @ 5.600 rpm
SPEED: 232 km/h
WEIGHT: 700 kg
DESIGN: Alfa Romeo
TYPE OF BODY: Grand Prix
*Special thanks to FCA/Stellantis Heritage

User Login

Reset password or Register


    Contact us

      Be part of Enzari

      Sign up to our newsletter and receive your free copy of the “A brief history of Italian cars”