2C 1957 A completely different techniques were used with the 350 cc two-cylinder, especially with regard to the frame. This machine had a trellis frame that consisted of triangular constructions of thin tubes, and where the engine was a structural part. The cylinders leaned sharply forward and the machine used the old-fashioned Earles front fork again, probably because using the same thin tubes it was lighter than a telescopic fork. By applying two external flywheels, the engine block could be made compact and strong. The engine also had a dry-sump system and delivered around 47 hp at 12,000 rpm. MV Agusta 350 6C 1968 In 1968 they wanted to continue developing the six-cylinder engine, but the FIM ruled that from now on the 350 and 500 cc racers should not have more than four cylinders. A prototype was built, this time with four valves per cylinder, but that could not be used in the world championship. Sometimes the drivers did practice on it: in 1971 both Giacomo Agostini and Angelo Bergamonti did that in the spring race in Modena. Technical data MV Agusta prototypes References Bibliography 350 racers Grand Prix motorcycles Motorcycles introduced in 1954