THE LEGENDARY GUZZI V8
The Ultimate Racer?
Ask anyone interested in motorcycle history to nominate the most exotic and most desirable Grand Prix racer ever built, and the Moto Guzzi 500 V8 will certainly be very close to the top of their list of choices. It is a prime example of two-wheeled engineering and, although it effectively only raced for two years in 1956-57 and never won a World Championship Grand Prix, there is an aura about this almost-mythical motorcycle that’s entirely in keeping with its improbable specification, and incredible allure.
Conceived in the mid-1950s, the 500cc V8 revved safely to 16,000 rpm and was speed-trapped at 286 kmh/178mph during the 1957 Belgian Grand Prix at Spa-Francorchamps in its final race. It produced 79bhp at 12,500rpm in its ultimate guise thanks to its eight cylinders, sixteen valves, eight carburettors and four camshafts, and is truly the stuff of legend. Especially as it was created in a small workshop in the Moto Guzzi factory on the shores of Lake Como by a team of just twelve men, including the three design engineers who conceived it.
The Guzzi V8 was the product of the fertile mind of the firm’s chief engineer, Giulio Cesare Carcano – the same man who developed its ultra-lightweight 250/350 singles from the original pre-war design by Carlo Guzzi himself and maintained their world-beating capabilities well into the nineteen-fifties. In that period, they scooped eight World titles in nine years, including three in the 250cc class and five successive 350cc crowns against its four-cylinder rivals from Gilera and MV Agusta.
Carcano’s comparable 500cc single, however, was unable to consistently keep up with the four-cylinder competition so the long-lived 120º V-twin Bicilindrica – which won GP races 17 years apart – was employed as a stopgap measure before it was finally pensioned off early in 1953.\
A four-cylinder shaft drive with an in-line car-type engine was tried in the 1953 and ’54 seasons but won only two minor races before the project was abandoned. That left the problem of what was to replace it. Carcano right away rejected the idea of a transverse ‘across the frame’ four, since this would mean that Moto Guzzi – renowned for its avant-garde engineering – would be regarded as just following in the tyre tracks of its Gilera and MV rivals.
A V8, however, would be a radical step but in many ways also a logical one. It had the potential to be no wider than the Gilera four then dominating 500GP racing but with the added advantage that it could rev much higher than the long-stroke Gilera’s 10,500 rpm ceiling in its pursuit of more power higher up the rev scale. Plus a 90º cylinder angle would deliver the desired primary balance for smooth power delivery.
So, in July 1954, Carcano instructed his development engineers Enrico Cantoni and Umberto Todero to draw up a concept design and at a meeting that September Moto Guzzi’s owner Enrico Parodi gave Carcano the green light to develop such a bike. It was Cantoni who was tasked with drawing up the engine and his initial design was ready on November 15, 1955. By the following March, the engine was running on the dyno at the Mandello del Lario factory by the shores of Lake Como. Carcano & Co. had amazingly created a running machine in the space of just five months, with the prototype already delivering a promising 62bhp at 11,500 rpm. It was ready for Guzzi’s Australian works rider Ken Kavanagh to ride it slowly up and down the road outside the Guzzi factory on April 14th 1955, much to the excitement of the on-looking crowd of Moto Guzzi management and employees.
Kavanagh, however, was never truly happy with the handling of the V8 so his English team-mate Bill Lomas took over the bike’s development for the 1956 season. And, after a test at Monza with modified steering geometry aimed at curing the high-speed instability, he seemingly had the problem sorted out.
In the German GP at Solitude on July 22nd Lomas displayed the V8’s true potential for the first time and, in front of the massive 160,000 crowd, he engaged in a titanic battle for victory with Gilera’s three-time World champion, Geoff Duke.
The pair repeatedly exchanged the lead in a 25-minute struggle, which ended when both were forced to retire. The Guzzi’s problem was an essentially minor one – just a split water hose. Encouragingly, Lomas had set a new lap record at 153.50kmh/95.38mph and that race was without doubt the highlight of the V8’s 1956 season.
After changes to the engine, including a redesigned crankshaft, the bike underwent extensive winter testing, during which Bill Lomas rode it for 1,600km of destruction tests on the banked speedbowl at Montlhéry in France and the road circuit at Oulton Park in England – both of which it survived intact. The revised 500cc V8 reappeared at the end of February 1957. Further proof of its speed came on a straight 10km stretch of the Appian Way outside Rome where Lomas broke several FIM World Records for the 500, 750 and 1,000cc classes!
The V8 then made its racetrack debut on March 19th in the first round of the 1957 Italian championship at Siracusa in Sicily. There, it finally obtained its first race win in the hands of Giuseppe Colnago, defeating the Gileras of Libero Liberati and Gilberto Milani to win convincingly and setting a new lap record at 154.19kmh/95.81mph in the process. Colnago’s teammate, Alano Montanari, had earlier led the race on another V8, before retiring with handling problems.
Five weeks later, Dicky Dale made it back-to-back victories with a truly dominant win in the Coppa d’Oro (Gold Cup) at Imola on April 22nd. Unquestionably that was the V8’s finest hour, as Dale scythed through the field after a slow start to defeat the hordes of Gilera and MV fours.
During the rest of the season, a string of injuries sidelined the Moto Guzzi team riders and this prevented the V8 from displaying its full potential, although Dickie Dale did get a respectable fourth place in the Isle of Man TT despite the bike running on only six of its eight cylinders for the last fifty miles or more.
Notwithstanding the problems in 1957, the V8 seemed set fair for success in 1958 and overtures were even made to try and poach John Surtees from MV Agusta. But then there came a bombshell that rocked the world of motorcycling. The huge success of the FIAT 500 minicar decimated motorcycle sales in Italy and all manufacturers were struggling to survive. As a result of this, at the end of the 1957 season, they all agreed to cease the expensive business of running their race teams. And so the world never did get to see the legendary Moto Guzzi V8 fulfil its true potential.
Words: Bruce Cox
Information and Images provided by The Motorcycle Files
Recommended Reading (Available exclusively via Amazon)
MOTO GUZZI GRAND PRIX CLASSICS
Author: Alan Cathcart
(Part of the Great Racing Motorcycles series published by The Motorcycle Files)
THE MOTO GUZZI 500cc Vee-Eight Grand Prix Racer
(An e-book by Alan Cathcart published by The Motorcycle Files)
