Iconic metal – the Moto Guzzi 500 V8

1957 MOTO GUZZI 500 V8

This 1957 marvel, known as the ‘Otto Cilindri’ or just plain ‘Otto’ to its friends, packaged a watercooled V8 motor with dual over head camshafts behind a dustbin fairing. Expensive, complex and just downright beautiful, come look under the skin of this amazing race machine designed by Giulio Carcano.

Racing motorcycles don’t come more legendary than Moto Guzzi’s fabulous V8!

Above: Output was 75hp at a remarkable 12,500rpm.together with a weight of only 135kg and a minimal frontal area (only 30mm wider than Guzzi’s 350 single) the combination produced a top speed of 178mph at the Belgian GP in 1957 and 187mph at the MIRA test track in France.

Left: Right… only five more to find…

Below: A 350cc version was constructed but never raced.

THE V8 DESIGN WAS LOGICALLY ARRIVED AT BY ENGINEER GIULIO CARCANO AS A MEASURE TO LEAPFROG THE FOURCYLINDER MV AND GILERA COMPETITION WITHOUT INCURRING THE WIDTH OF A STRAIGHT-SIX. THE CRANKSHAFT IS ONLY 13.5 INCHES LONG!

ENGINE SPECIFICATION EVOLVED CONSIDERABLY OVER THE THREE YEARS THE BIKE WAS DEVELOPED. BY 1957 A MULTI-PIECE CRANKSHAFT HAD REPLACED THE EARLIER ONE-PIECE UNIT. THE CON-RODS WERE LENGTHENED AND NEW CAMSHAFT PROFILES USED. DESPITE ONLY WINNING THREE RACES IN THREE YEARS AND SUFFERING FROM MANY MECHANICAL RETIREMENTS, NOT TO MENTION RIDERS THAT WEREN’T KEEN TO BRAVE ITS HANDLING WOES, THE V8 DEFINITELY TOPS THE LIST OF LEGENDARY GRAND PRIX EXOTICA AND HAS ITS OWN UNIQUE BEAUTY.

Words and photographs: Phil Aynsley

Left: Four sets of points reside under each circular end-cap positioned at the left-hand end of the intake camshafts. Baggsie not setting them up! Below: The eight magnesium 20mm Dell’orto carburettors were cast and machined by Guzzi. Each is fitted with its own float bowl after the original design’s dual float bowls proved problematic. Right: Despite a solid looking front-end, the bike’s handling left a lot to be desired.the rearward weight bias due to the engine position was most likely the main reason for this.

The only change from original specification is the adoption of a pressurised cooling system – better suited to the parading duties the bike now undertakes. The tank is clearly visible next to the right-hand front suspension.

Five or six V8s were built during the 1955-1958 period together with enough parts for many more – which is how this bike came to be. It was built up from a majority of original parts quite a few years ago, so differs from the several more recent replicas that have been constructed.