Alfa Romeo P2

The Jano Grand Prix chapter

The Alfa Romeo P2 marks a decisive engineering chapter. Vittorio Jano’s design placed a supercharged straight-eight at the center of a dedicated Grand Prix car. The museum dates assembly of the first example to June 2, 1924, followed by testing and the Cremona debut. The museum’s development history documents that sequence.

The collector interest lies in the combination of a tiny original production run and a major competition role. It is a model-level profile: claims about which chassis won a particular event require a separate provenance file.

Six original cars

The museum’s collection specification records six P2s produced. The number is kept as the P2 model total. It does not count a separate batch for the 1925 championship season, and it does not establish a current survivor tally. The museum specification sheet supplies the production figure.

This is particularly important for the inventory, which has a second entry focused on the 1925 works championship cars. That entry is a historical subset or configuration focus, not six additional cars. The two records should never be added to suggest a twelve-car production run.

Supercharging and specification stages

The museum lists a 1987 cc straight-eight with gear-driven twin overhead camshafts and a supercharger. Its collection specification gives 155 hp at 5500 rpm, four forward speeds, rear-wheel drive, 750 kg and 225 km/h. The narrative history separately describes an early 140 hp output.

Alfa Romeo’s engine retrospective identifies the increase from 140 to 155 CV late in 1925. That explains why a model profile can encounter two valid period values. The display sheet’s figure should retain its context; it must not silently become the output of every car at the June 1924 debut.

The championship and later development

The P2 brought Alfa Romeo the first World Championship for Grand Prix cars in 1925. The museum explains the subsequent regulation change to a 1.5-liter limit and the later return of revised P2s to prominent competition in 1930.

The production identity and the development history should be read together. A later mechanical update does not necessarily represent another newly manufactured chassis. When discussing rare competition cars, trace physical identity across the modifications rather than counting each new specification as a new vehicle.

Authentication of an original P2

The strongest file would connect stamped identifiers with factory documentation, dated competition records, ownership transfers and restoration work. A racing car’s body, engine and ancillary systems may change during its working life. The file should describe those changes individually.

For a displayed or running example, establish which historical specification is represented and the evidence for that choice. Neither a six-car total nor a famous race livery can authenticate a particular chassis. A clear provenance narrative turns a celebrated model into an intelligible individual artifact.

Frequently asked questions

How many Alfa Romeo P2s were produced?

The Alfa Romeo museum lists six original cars for the P2 model.

What engine did the P2 use?

A supercharged 1987 cc straight-eight with twin overhead camshafts.

Why do 140 and 155 appear as output figures?

The manufacturer describes an early 140 hp stage and a later increase to 155 CV late in 1925.

Was the 1925 title a Formula 1 title?

It was the World Championship for Grand Prix cars, preceding the Formula 1 World Championship inaugurated in 1950.

Related vehicle profiles

• 1925 P2 championship focus
• 1914 Grand Prix

Primary references

1. Museo Alfa Romeo: P2 specifications
2. Museo Alfa Romeo: P2 development history
3. Alfa Romeo: historical engine development

Photo and credit

Alfa Romeo P2 photographed at Goodwood in 2009; surviving display configuration. Photo: Brian Snelson / Wikimedia Commons · CC BY 2.0. Resized and JPEG-compressed for web display; no content retouching. Website layouts may crop the image.