Uploaded October 2025 | Updated September 2026, 1 week ago
The 8-cylinder is a racing motorcycle presented by the Italian motorcycle manufacturer Moto Guzzi to compete in the 500 Class of the MotoGP. He took part in the 1956 and 1957 world championship. Carcano created a new engine for the new GP Guzzi: it was a 90º V-shaped 8-cylinder 4-stroke engine, with two overhead camshafts per bank and two valves per cylinder, with a unit displacement of 62.3 cm³ for a total of 498.5 cm³ (bore 44 mm, stroke 41 mm). This engine was water-cooled, had distributor ignition and dry sump lubrication. The great modernity of the project, characterized by very innovative technical solutions, however had to deal with materials that were not as advanced, causing numerous reliability problems, furthermore the high power of the engine put the frame, a double cradle made of tubes, into crisis. The engine was quite delicate, in races the bike often scored the best lap but just as often it was forced to retire due to mechanical failures due to excessive stress on the materials, which is why the separable connecting rods and the monolithic shaft no longer appear in the final version, replaced by monolithic connecting rods mounted on a decomposable crankshaft made by the German Hirth, and the valves controlled by the so-called "cups" instead of the threaded plates above the return springs. To all this must be added the inadequacy of the tires of the time for the dynamic qualities of the motorcycle. The engine in the initial version delivered 68 HP at 12,000 rpm. During the 1955 world championship he took part in both tests and qualifying sessions, but without taking part in any races. He made his racing debut on 2 April 1956 at the Coppa d'Oro Shell in Imola, driven by Ken Kavanagh. The 8-cylinder also broke many records, for example the 10 km from a standing start broken in 1957 in Terracina by the British Bill Lomas and the km and mile from a standing start achieved at Brescia-Montichiari airport by Dickie Dale whose 8 cylinder had the characteristic that on the usual bell-shaped fairing there were no lateral "vents" to allow the passage of air to the radiator, given the shortness of the journey. 1957 was its last year of racing as Moto Guzzi signed, together with other Italian manufacturers, the so-called abstention pact, which clipped the wings of any further development (including a 350 cm³ version). A model of the 8-cylinder is currently on display in the museum of the house in Mandello del Lario with the engine next to it which still amazes visitors and anyone who understands anything about motorbikes, just look at the incredible interweaving of the 8 20" Dell'Orto carburettors mm (from 21 mm in the definitive version) built specifically for this motorcycle, with synchronization levers to have a more homogeneous carburetion. In 1997 a patron from Lecco decided to finance a project to build some copies of the 8-cylinder in every way, including materials. The proposal was accepted by a small company from Mandell (Venini Tullio) which, with the contribution of Todero and some former Guzzi employees, built these examples. One was displayed during the international motorcycle rally inside the Moto Guzzi factory in 1997 itself. Another example, driven by Todero himself, was used for the historic race on the Mandello street circuit, also during the motorbike rally.
The 8-cylinder is a racing motorcycle presented by the Italian motorcycle manufacturer Moto Guzzi to compete in the 500 Class of the MotoGP. He took part in the 1956 and 1957 world championship. Carcano created a new engine for the new GP Guzzi: it was a 90º V-shaped 8-cylinder 4-stroke engine, with two overhead camshafts per bank and two valves per cylinder, with a unit displacement of 62.3 cm³ for a total of 498.5 cm³ (bore 44 mm, stroke 41 mm). This engine was water-cooled, had distributor ignition and dry sump lubrication. The great modernity of the project, characterized by very innovative technical solutions, however had to deal with materials that were not as advanced, causing numerous reliability problems, furthermore the high power of the engine put the frame, a double cradle made of tubes, into crisis. The engine was quite delicate, in races the bike often scored the best lap but just as often it was forced to retire due to mechanical failures due to excessive stress on the materials, which is why the separable connecting rods and the monolithic shaft no longer appear in the final version, replaced by monolithic connecting rods mounted on a decomposable crankshaft made by the German Hirth, and the valves controlled by the so-called "cups" instead of the threaded plates above the return springs. To all this must be added the inadequacy of the tires of the time for the dynamic qualities of the motorcycle. The engine in the initial version delivered 68 HP at 12,000 rpm. During the 1955 world championship he took part in both tests and qualifying sessions, but without taking part in any races. He made his racing debut on 2 April 1956 at the Coppa d'Oro Shell in Imola, driven by Ken Kavanagh. The 8-cylinder also broke many records, for example the 10 km from a standing start broken in 1957 in Terracina by the British Bill Lomas and the km and mile from a standing start achieved at Brescia-Montichiari airport by Dickie Dale whose 8 cylinder had the characteristic that on the usual bell-shaped fairing there were no lateral "vents" to allow the passage of air to the radiator, given the shortness of the journey. 1957 was its last year of racing as Moto Guzzi signed, together with other Italian manufacturers, the so-called abstention pact, which clipped the wings of any further development (including a 350 cm³ version). A model of the 8-cylinder is currently on display in the museum of the house in Mandello del Lario with the engine next to it which still amazes visitors and anyone who understands anything about motorbikes, just look at the incredible interweaving of the 8 20" Dell'Orto carburettors mm (from 21 mm in the definitive version) built specifically for this motorcycle, with synchronization levers to have a more homogeneous carburetion. In 1997 a patron from Lecco decided to finance a project to build some copies of the 8-cylinder in every way, including materials. The proposal was accepted by a small company from Mandell (Venini Tullio) which, with the contribution of Todero and some former Guzzi employees, built these examples. One was displayed during the international motorcycle rally inside the Moto Guzzi factory in 1997 itself. Another example, driven by Todero himself, was used for the historic race on the Mandello street circuit, also during the motorbike rally.
