A password will be e-mailed to you.

Bisiluro: Fanciful Aerodynamics from OSI

“It’s not exactly a beautiful car, is it?” said the woman to the left of me in the train. She’s my better half and was looking over my shoulder as I was selecting the pictures for the article. “Well, no I suppose it isn’t…” I answered, slightly fluttered by her even bothering to have an opinion about today’s car. “…but it’s interesting and certainly amusing.” And largely that really sums up the design of the car. But with these charming old cars, that’s often an attribute in itself.

There’s a reasonable chance that you might not have heard of Officine Stampaggi Industrial or their acronym: OSI. It’s of course Italian and translates into something along the lines Industrial Pressing Company. So in other words, pressing steel into body panels on a very large scale. Up through the sixties, OSI became one of the leading body fabricating companies in Italy after being founded by the former Ghia president Luigi Segre. Like most other carrozzeria of the era, OSI also fabricated prototypes and special one-offs for the big manufacturers such as Innocenti, Ford and Alfa Romeo.

OSI built the rather radical Scarabeo for Alfa Romeo to display at various International car exhibitions.

In 1967, OSI finalised a very unusual and interesting construction: the Bisiluro – which means Silver Fox in Italian. The car was intended to compete in the 24 hour race at Le Mans, but first they presented the innovative design at the annual motor show in Torino. The whole design was decidedly focused around the latest knowledge and technology on aerodynamics and largely resembled the wing of a jet fighter, but with wheels on.

The engine was borrowed from a Renault Alpine and was a small, rev-happy 1-litre 4-cylinder. They installed the engine within the left pontoon to counteract the weight of the driver who was sat in the right pontoon. This created a nicely balanced weight distribution despite the somewhat odd construction, and the compact and slippery race car was capable of reaching a topspeed of 248 km/h or 154 mph. In 1967, that was nothing short of phenomenal and it certainly proved beyond a shadow of a doubt that they were onto something with their Bisiluro.

The major part of its aerodynamic qualities came from using three large and individual spoilers. Effectively, besides creating downforce, the three spoilers connected the two pontoons. The front and rear spoilers were adjustable too, so they could be set to provide any specific amount of downforce depending on the circuit which was being raced at.

Sadly, just like so many other intriguing ideas, the visions never materialised into reality. OSI soon shut doors with a dismal economy as the stream of contracts from the major manufacturers dried out. Short of a few test runs with the Bisiluro, nothing more came from the project. Which is a real shame of course, as it would have been interesting to see what the lightweight construction and innovative aerodynamics of the Silver Fox were capable of at Le Mans and other race circuits in the late sixties…


One Response

  1. Tony Wawryk

    This piece sent me scurrying back up to the loft to dig out my old Top Trumps cards again, as I was sure I’d seen this intriguing car before, many years ago, and lo and behold, there it was! I always thought it resembled a catamaran on wheels. A shame it never got to show what it might have been capable of. I couldn’t find out it’s current whereabouts but I have seen photos of it at the 2013 Goodwood Festival of Speed, so presumably it’s in a private collection somewhere.
    Incidentally, “bisiluro” is in fact Italian for “twin torpedo” and it seems there have been a couple of other cars built on a similar twin hull principle.


Leave a Reply to Tony Wawryk Cancel Reply

Your email address will not be published.

Skip to toolbar