When Moto Guzzi led the world

“The Guzzi V8 was fast and sounded wonderful, with a 12,000rpm wail”

Ducati may be Italy’s most hallowed motorcycle brand but the Bologna manufacturer is a Giovanni come-lately compared to more venerable Italian marques like Benelli, Gilera and Moto Guzzi. While Ducati marks its 75th anniversary as a motorcycle manufacturer this year, Moto Guzzi celebrates its centenary.

These days Guzzi is a European Harley- Davidson, selling big, lusty air-cooled V-twins that hark back to simpler times. But from the 1930s to the 1950s the company led the world with some fabulous feats of engineering, most famously its V8 500cc grand prix bike.

The idea of Moto Guzzi was conceived on a First World War airfield by Corpo Aeronautico Militare pilot Carlo Guzzi and mechanic Giorgio Parodi. Guzzi would be chief engineer, while Parodi and brother Angelo – sons of Genoese shipowners – would bankroll the venture.

Based in Mandello del Lario on the shores of Lake Como, the company went racing within months of its first motorcycles rolling off the production line in the spring of 1921. That autumn Moto Guzzi took its first victory, conquering the Targa Florio in Sicily.

Carlo Guzzi was full of ideas and produced a series of masterful designs that established Moto Guzzi as a major force. His trademark was the horizontal single-cylinder engine with oversquare cylinder dimensions, four-valve head, bevel-driven overhead camshaft, integral gearbox and dry-sump lubrication.

His next creation was the Bicilindrica 500cc V-twin, with a second cylinder grafted onto the crankcase at 120 degrees to the first. The longitudinal vee was the perfect racing engine –a comfortable fit within the chassis, no wider than a single and producing more performance with smoother running. Half a century later Ducati saved itself from bankruptcy by adopting similar V-twin engines.

In 1935 Isle of Man genius Stanley Woods rode the Bicilindrica to Guzzi’s first Senior TT victory. The 500 had a sprung rear end (with friction dampers adjustable from the saddle), which ended the dominance of Norton’s rigid rear-end machines.

After the war Moto Guzzi entered its golden age. Engineer Giulio Cesare Carcano refined the horizontal singles to win nine 350cc riders and constructors world titles during the 1950s. Guzzi had a wind tunnel at its factory, allowing it to lead the aerodynamics race with all-enveloping bodywork, nicknamed dustbins.

Inevitably, Moto Guzzi wanted success in the premier 500cc class, dominated by Gilera’s transverse-mounted four-cylinder engine, so they commissioned Carlo Gianini to create a Guzzi four. Gianini had been part of Gilera’s design team, so this time he built a longitudinal four. This machine was technically advanced, with shaft drive, linked brakes and an early type of fuel injection. But its unusual engine configuration and considerable wheelbase caused problems.

Carcano’s response to the failure of the four was an eight-cylinder 500. The Japanese are credited with the miniaturisation of cylinder sizes, but Carcano’s V8 500 preceded Honda’s six-cylinder 250 by a decade.

“The engine went from sketchbook to dyno room in just six months”

It was an audacious endeavour. Carcano knew he must not negate the engine’s horsepower with excessive size and weight. In fact the bike weighed 135kg, less than the rival Gilera and MV Agusta fours.

Carcano’s water-cooled 90-degree DOHC V8 was a miracle, always trying to balance out the often mutually exclusive benefits of size, performance and reliability. The numbers were tiny: a bore/stroke of 41/44mm, 23mm inlet valves, 21mm exhaust valves, 6mm valve lift, 20mm carburettors and 10mm sparkplugs.

Cacano chose a 90-degree vee angle for its perfect primary balance. And each crank web was a complete disc, spreading inertia along the full length of the crankshaft, thereby avoiding the torsional stresses of mounting a flywheel at one end of the shaft.

Carcano worked feverishly, taking the engine from sketchbook to dyno room in just six months. The project was kept top secret, with the idea of ambushing Gilera and MV Agusta at the French GP at Reims in May 1955.

From this point on bad luck haunted the V8. Guzzi’s fastest riders got hurt, the bike was hampered by niggling problems and despite Carcano’s brilliance the engine was unreliable: his thinking was ahead of 1950s metallurgy.

The Guzzi V8 was fast and sounded wonderful, with a 12,000rpm wail through its eight exhaust pipes. Second time out, at the 1956 Dutch TT, Bill Lomas took pole, but a missed gear ended his weekend. Three weeks later Lomas took pole at the German GP and enjoyed a battle for victory with Geoff Duke, Gilera’s world champion. Lomas would’ve won the race but for a split water

“The Guzzi V8 was fast and sounded wonderful, with a 12,000rpm wail”


During preparations for the Monza GP Lomas completed a full race-distance test at record-breaking pace, then crashed in the race that preceded 500cc event.

During the winter Carcano worked hard to debug the V8, at the same time increasing peak power to 79bhp, ten more than the fours. However, luck continued to avoid the project. In July 1957 Australian Keith Campbell dominated the Belgian GP, clocking 178mph on the Masta straight, 20mph faster than the fours, only for a battery lead to break.

Further refinements were planned for 1958, but in February Moto Guzzi, with Gilera and Mondial, quit racing because of a sales slump. Only Count Domenico Agusta, subsidised by his helicopter business, continued.

Mat Oxley has covered motorcycle racing for many years – and also has the distinction of being an Isle of Man TT winner
Follow Mat on Twitter @matoxley