M-80 | USSR, 1945
M-80 was the first racing motorcycle of own design produced in 1946 at the Gorky Motorcycle Plant (GMZ). It had a 746-cc engine with compression ratio of 9.5 and 40 h.p. rating at 6000 rpm. The weight of the motorcycle was 192 kg, the maximum speed was 170 km/h.
It is possible to speculate whether the design of the motorcycle engine was entirely created on the GMZ or the creator of the M-80, Naum Gudkin, used some of the stored M-75 engines (the development of which was carried out at the same time). Perhaps the second version is most likely, since the centralization of the motorized survey in the USSR allowed to transfer parts and entire structures from one enterprise to another.
The M-80 had the same running gear as the М-72, and it was only slightly modified and made more light-weight. The motor remained much in common with the M-72 engine, with the only difference that the cylinders and upper-valve heads repeated the design of the BMW R75.
Kaynak: Motorworld by V. Sheyanov