Saying that the Moto Guzzi's v-twin engine and the Fiat 500 are two Italian motoring icons recognized worldwide is perhaps stating the obvious. But what if I told you that, in the early 1960s, a weird crossover between the two nearly happened?
Buckle up, as you're about to learn about the secret story of the Moto Guzzi engine designed for the Fiat 500.
Boom and Bust
Our story begins sometime in the late 1950s. Italy was going through a period of explosive economic growth, during which more and more people each year could afford to buy Fiat's new small cars, the 600 and the 500.
But, although the country as a whole was doing very well for itself, the same couldn't be said about the Italian motorcycle industry, which had to all but reinvent itself.
Up to that point, Moto Guzzi and the rest of the Italian motorbike industry's "bread and butter" had been small-displacement 'bikes bought by those who could not afford an automobile: a market that, following the average Italian's increased living standards, was quickly drying up.
Working for the future
Moto Guzzi's technical department, headed by the engineer Giulio Cesare Carcano, got busy exploring new products and ventures for the company's future, one of which was a 90° v-twin designed in 1958 and meant to be tested on a Fiat 500 owned by engineer Carcano himself.
The idea was to somehow lure Fiat into offering a special, sporty version of the 500 equipped with engines supplied by Moto Guzzi.
Designed to mount straight onto the Fiat's standard flywheel and gearbox, the initial version of the 500cc Guzzi v-twin had a single chain-driven central camshaft and roof-type combustion chambers with parallel valves. Cooling air was provided by an axial fan on the crankshaft and a sheet metal cowling that directed the flow onto the cylinders and heads.
Following a successful trial period using Carcano's Fiat 500, the project picked up momentum around 1960, when the engine was redesigned with hemispherical combustion chambers, and its displacement was increased to 550cc first, then 600cc in 1961.
Fitted with a 34 mm double-choke Weber carburetor, the Moto Guzzi engine produced 27HP at a heady 6000Rpm: it may not sound like much, but it was a substantial increase over the regular Fiat 500D engine, rated at 17HP at 4400 Rpm.
High hopes
At this point, Moto Guzzi's project had caught the eye of the motoring press, with the company openly discussing the idea of supplying between 10 to 40 engines a day to Fiat for a mooted high-performance derivative of the 500 capable of over 135 Km/h.
By 1963, a new and improved version of Guzzi's v-twin was running at the factory's bench, producing up to 32HP at 6000Rpm and performing so well once fitted to a Fiat 500D to convince Moto Guzzi's patron Enrico Parodi to finally get in touch with Fiat's boffins.
Thanks, but no thanks
Fiat tested the prototype for three months, after which it was returned to Moto Guzzi with a positive note about the car's performance, but...
...nothing else.
With Karl Abarth already covering the market for go-faster Fiat derivatives with great success, it's fair to assume that Fiat's management had zero interest in dealing with Moto Guzzi, whose engine project was then consigned to the dustbin of history.