Known as the Type 860, the design dates back to 1965. First seen as a 350cc racer, the idea came about after a Czech government minister noticed the European GP teams had far more exotic machinery than the CZ factory outfit. Although competitive with all but the might MV fours, CZ used dated single cylinder designs with roots planted firmly in post war machinery.
A complex V4 design was penned by CZ designer Frantisek Pudil and presented to the government, eventually the project given the go ahead but with a very limited budget. Due to the severe lack of suitable components and manpower, only Pudil and his assistant was allowed the time to work on the project, the final machine wasn’t ready until the day before the Czech GP in 1969. Lack of development time showed in engine problems during the first practice and the team was forced to run the outdated machinery in the race to save face.
More serious and rigorous testing was completed during the winter of 69/70 and the following season saw the screaming 350cc V-four competitive, although reliability issues remained throughout that year. For 1971, the engine grew in size to 418cc and a new frame using the engine as a stressed member was designed. For the first time many western components found their place on to CZ machines, Italian Ceriani forks and brakes were fitted and Dunlop tyres used too, greatly helping the handling and performance. A factor holding back the development of the exotic machine was the lack of testing facilities, most of the test riding was completed on public roads around the factory with the practise sessions of GP meetings being the only times the CZs took to a race track for real.
The original 350 design used an 8-speed gearbox, but this was soon replaced by a 6-speed unit enabling it to comply with the new FIM regulations of the period. The Achilles heel of the design was its overall weight, the lack of funding, and exotic materials, in the eastern block, meant the 500cc type 860 tipped the scales some 37kgs more than the class leading MV Agusta, the Italian machine also produced around 90bhp, so was more powerful too.
The machine was never up to beating the MV but was the very best of the rest usually in the hands of chief CZ factory racer Bohumil Stasa, his best result in GP being in 1972 on the 350 V4 when he finished 2nd behind Jarno Saarinens Yamaha at Brno. For 1973 much work was completed making the 350 more competitive, it was thought that the class leading MV350 had been neglected in favour of their premier class machinery thus giving the CZ some hope of playing catch up, a disc brake and an all new Bosch electronic ignition was fitted, but it was too little too late; CZ had been instructed to concentrate on their off road racers and leave the road racing to Jawa. Stasa requested that he retain the machinery to develop and compete with them privately, but this was denied. All of the factory V4s were ordered to be destroyed, but as is so often the case with such instructions, the parts were simply hidden away and to date several engines and one complete machine (seen here and owned by a UK collector) survive intact.
Had the Czech factory been properly funded, then it is likely that MV Agusta would not have had it quite so easy during the late 60s and early 70s. If CZ had beaten the mighty MV at their own game, them who knows where the marque would have ended up, but this wasn’t to be and within months the screaming four strokes had to make way for the new world order as Suzuki and Yamaha arrived with their watercooled strokers.
CZ type 860 500cc V4 Specifications
- Engine – Air cooled 90deg V four DOHC
- Capacity – 418cc
- Bore/stroke – 55 x 44mm
- Power – 72bhp @ 13600rpm
- Torque – 27ft-lb @ 10000rpm
- Carburation – 28mm Dell’Ortos
- Transmission – 6-Speed dry clutch chain final drive
- Frame – Steel Tube
- Suspension – 36mm Ceriani telescopic forks, CZ rear shocks
- Brakes – 230mm 4-leading shoe drum, 200mm Oldani drum
- Wheels – 3.00 x 18 3.25 x 18
- Weight – 142kgs
- Top speed – 162mph
- Wheelbase – 1400mm
- Fuel capacity – 20lts
CZ500 V4 Type 860 Gallery
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