A.L.F.A. 40/60 HP Aerodinamica Castagna

A body that changed the question

The 40/60 HP Aerodinamica is memorable because its body makes airflow the central design subject. The Castagna commission, also known as the Siluro Ricotti, surrounds a pre-war Alfa chassis with an elongated, rounded enclosure. The museum identifies one example produced and an aluminum droplet body. The Alfa Romeo museum specification provides the technical record.

Its collector significance lies in the relationship between a conventional mechanical foundation and an unconventional body. A one-off design should be evaluated at that specific body-and-chassis level. It does not turn the broader 40/60 HP family into a one-off model.

The commission and its design logic

Alfa Romeo’s anniversary account explains that Ricotti wanted additional passenger accommodation and sheltered luggage space while retaining useful performance. Castagna’s approach brought those practical requirements into a streamlined envelope. The commission history connects the shape with its brief.

The result is useful to study as a packaging exercise as well as a visual experiment. A body that encloses passengers and luggage has to manage access, sightlines and space. Its aerodynamic purpose must work alongside those constraints. The unusual exterior therefore tells only part of the design story.

Museum specifications

The museum records a 6082 cc four-cylinder engine, 70 hp at 2200 rpm, rear-wheel drive and four forward speeds. It gives a wheelbase of 3200 mm, a weight of 1250 kg and a maximum speed of 139 km/h. These are the museum’s documented specifications for this entry.

A maximum-speed number expresses the historical performance claim; it supplies no measured drag coefficient. The importance of streamlining can be discussed without reverse-engineering a precise aerodynamic efficiency from one speed figure. Body shape, frontal area, cooling openings and running conditions all affect that relationship.

One commission, several provenance questions

The one-example museum tally belongs to the Aerodinamica. It is separate from the number of ordinary 40/60 HP chassis and from the competition derivative. It also should not be read as a verified count of surviving original bodies.

For an artifact displayed today, original construction, later body alterations and any reconstruction work deserve separate documentation. This profile covers the historical commission and the museum specification; it does not assign an unverified chassis number or claim an uninterrupted original-body history. The original commission and a later representation must remain clearly distinguished in any future image caption.

Why it belongs in a design collection

The strongest way to present the Aerodinamica is through its design brief. It invites the reader to consider how a coachbuilder might solve a new problem using an existing chassis. That makes it a valuable companion to the open Corsa and the purpose-built Grand Prix project.

A collector or curator should prioritize drawings, commission records, period photographs and a documented restoration file. Together, those materials explain how the body was made and which historical state is represented. A striking silhouette is the starting point for research, rather than its conclusion.

Frequently asked questions

What is the Siluro Ricotti?

It is the Castagna-bodied 40/60 HP Aerodinamica commission.

How many were produced?

The Alfa Romeo museum records one example for the Aerodinamica entry.

What maximum speed is documented?

The museum quotes 139 km/h.

Does one produced prove one original survivor?

A production count does not establish the survival or originality of a body displayed later.

Related vehicle profiles

• 40/60 HP Corsa
• 1914 Grand Prix

Primary references

1. Museo Alfa Romeo: Aerodinamica specifications
2. Alfa Romeo: 40/60 HP anniversary

Photo and credit

Museum reconstruction of the Castagna-bodied 40/60 HP Aerodinamica in Arese. Source: www.traumautoarchiv.de. Photo: traumautoarchiv.de / Wikimedia Commons · CC BY-SA 2.0 · Source: www.traumautoarchiv.de. Resized and JPEG-compressed for web display; no content retouching. Website layouts may crop the image.