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Giotto Bizzarrini’s “Macchinetta”

Based on the Topolino, the early work of the great Tuscan designer anticipated many of the cornerstones of his vision, starting from the concept that a car must be designed to serve aerodynamics, and not vice versa

Drawings courtesy of Massimo Grandi

Massimo Grandi Drawing - Giotto Bizzarrini Fiat Topolino

The little car – AKA the “Macchinetta”, as it was called – came about as a study/prototype, and is still the only example existing today. It was assembled between 1952 and 1953 by Giotto Bizzarrini while he was finishing his mechanical engineering degree at Pisa University, but contrary to what we have frequently read, it wasn’t the subject of his thesis. His thesis was on the theoretical and practical study of the engine of the Nimbus 750 motorcycle, a 4-cylinder, air-cooled model, examining possible modifications to obtain greater performance and how to adapt the chassis of the Fiat 500 to install the engine.

Massimo Grandi Drawing - Giotto Bizzarrini Engine Nimbus 750 4 cylinders

During his thesis, Bizzarrini envisaged the possibility of using the Nimbus 750 engine for his Topolino, but as we will see he gave up on this idea. This was a car that in 1948 was adapted as a "Sports Type Barchetta" by the previous owner Amedeo Menegon; Bizzarrini bought it in 1952 and rebuilt it with the mechanic Oreste Pasqualetti from Pisa, who assembled the new aluminium bodywork designed by Giotto himself.

The engine used was a 1952 500 B (No. 347591) which originally had a cast iron head (while the 500 C had an aluminium head): this was a 569 cm3 straight 4-cylinder with 16.5 HP. To increase the power, Bizzarrini replaced the head with one developed by Siata (Società Italiana Applicazioni Tecniche Auto Aviatorie) in Turin: with 2 Dell'Orto carburettors, it had a pneumatic injection system that cut in when the rpm and intake manifold depression were low, thus giving the “Macchinetta” a variable power of between 25 and 30 HP and a maximum speed of 145-155 km/h.

Compared to the original position, the engine/gearbox unit was moved closer to the passenger compartment to improve the balancing of the weights of the car and use a shorter drive shaft, which would allow the front bonnet profile to be lowered.

Massimo Grandi Drawing - Giotto Bizzarrini Fiat Topolino and Macchinetta's transmission scheme

The radiator was then moved in front of and no longer behind the engine, allowing the engine to be moved closer to the bulkhead: this was the same arrangement we find in Bizzarrini’s elaboration of the Ferrari 250 Boano to set up the 1961 GTO prototype, the so-called “Papera”, and again in the Ferrari 250 Breadvan adapted from a Ferrari 250 SWB previously owned by the driver Olivier Gendebien.

Massimo Grandi Drawing - Giotto Bizzarrini Ferrari 250 GT Boano Transmission
Massimo Grandi Drawing - Giotto Bizzarrini Ferrari 250 GT Papera and Breadvan Transmission

It is from these solutions based on purely aerodynamic choices that we have to interpret all the works of Giotto Bizzarrini the designer: this goes for his Topolino as well as all his subsequent car production. The idea was always the same: the aerodynamics had to guide the design, and therefore the shape of the car, not vice versa.

My passion for aerodynamics,” he said, referring precisely to the Macchinetta, “comes from my time at university in Pisa, where I had built an aerodynamic little car based on a FIAT Topolino chassis, which reached 150 km/h. It was there that I first heard of Kamm’s theories on the K-tail.

Massimo Grandi Drawing - Giotto Bizzarrini and Macchinetta from an original drawing

Giotto always based his passion for aerodynamics more on experiment than on theory. Certainly, as he states himself, he learned the theories of Kamm, Koenig and Jaray, with his 1921 patent, but from the Macchinetta onwards he applied principles that also remained unchanged in the “Papera”, the Breadvan and his Bizzarrini 5300 road version: a low front, the engine as central as possible (obviously we’re talking about front-engine cars) and a high K-tail.

He said, “In the late Fifties, sports cars were still based on aerodynamics that were 40 years old, which tried to give the bodywork a winged profile, a winged profile on 4 wheels. The result was high, solid rounded fronts, hosting a front engine and low, tapered tails. I was convinced that we had to do the exact opposite: a low, tapered front to reduce the drag and prevent it from lifting up, a high K-tail to reduce the wake turbulence, improving the drag even more, as Prof. Kamm demonstrated. The cars of the time would have run better in reverse!!!”

Of course, he was referring to the famous “thick wing” line that was very common from the late 1930s to the 1950s, as we can see in this example of a Fiat Stanguellini.

Fiat Stanguellini Berlinetta Sport MM 1940

In Bizzarrini’s very first work, in any case, we can see his special attention to Kamm’s experiments. If for instance we look at the K2 prototype designed by Kamm and built by Wendler on a 1938 Mercedes 170 V chassis, certain similarities can be found, even though Bizzarrini’s design is a modern interpretation of this. The rear end design, for example, with the rear window divided into three parts, even seems to anticipate that of the 1958 twin-shaft Fiat-Abarth 750 Monza Zagato.

Kamm Merceds 170 inspiring Giotto Bizzarrini's design
Massimo Grandi Drawing - Comparison of the Giotto Bizzarrini's design of the Macchinetta

A similar solution had however already been seen in the 1939 Alfa Romeo 2900 8C Touring Superleggera.

Alfa Romeo 2900 8C Touring Superleggera inspiring Giotto Bizzarrini's design

The rounded, egg-shaped tail is of course reminiscent of the 1951 Ferrari 166 MM/212 Berlinetta “Uovo”, designed by Franco Reggiani for Carrozzeria Fontana on specific instruction of Count Giannino Marzotto.

Massimo Grandi Drawing - Comparison of the Giotto Bizzarrini's design of the Topolino and the Ferrari Uovo

And if we look more generally at the “Topolino”- based sports berlinettas, such as the 1949 Patriarca 750 Sport Faina or the 1948 Fiat 500 Berlinetta Maestri, we can immediately see how Bizzarrini’s shapes are far more different, already looking to a new season of Italian design.

Massimo Grandi Drawing - Comparison of the Giotto Bizzarrini's design. Patriarca 750 Berlinetta and  Fiat 500 Maestri Berlinetta

The only berlinettas that, only in design terms, can be likened to that of Bizzarrini are the 1951 Giannini 750 berlinetta, clearly inspired by the Ferrari 166 berlinetta “Panoramica” Zagato, and the Topolino 500 Panoramica, again by Zagato.

Massimo Grandi Drawing - Comparison Fiat Gianning 750, Ferrari 155 and Fiat MM Topolino

Certainly, the Macchinetta was a work of his youth, and cannot be compared to his later works, but it remains a small masterpiece of design and genius. Indeed, when Enzo Ferrari welcomed Bizzarrini to Maranello in 1956, seeing his Topolino, he exclaimed: "When you have built this car and driven it over the Abetone Pass and down to Modena, you can come and work at Ferrari.”

Massimo Grandi Drawing - Comparison of the Giotto Bizzarrini's design of the Macchinetta


Massimo Grandi, architect and designer, previously director of the Car Design laboratory at the Design Campus of the Department of Architecture at the University of Florence. Member of the ASI Culture Commission. Among his published works: “La forma della memoria: il progetto della Ferrari Alaspessa”, “Car design workshop”, “Dreaming American Cars”, “Ferrari 550 Alaspessa: dall’idea al progetto”, “Quando le disegnava il vento”, “Il paradigma Scaglione”, “La più veloce: breve storia dei record mondiali di velocità su strada” (with others).


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