[Liquid_Fire]

Curiosamente o VTEC nasceu no R&D de motociclos e não nos automoveis, Teve inicio no desenvolvimento da gama de competição dos anos 70 quando a honda começou a tentar implementar os pistões ovais, e culminou no desenvolvimento da Famosa NR 750, antes de passar para o meio automóvel.

Palavras do engenheiro Makoto Hirano, responsável na honda nessa altura, por desenvolvimento de engenharia e produto:


“The idea of the oval piston came from the need to reduce piston friction in the
four-cylinder engine… we had to make more cylinders in the four-stroke-cycle
engine and an extremely short piston stroke. So we built a ‘one-cylinder’ which
is equal to two cylinders. Which means, to build an eight-cylinder in order to
fit the four-cylinder rules limit on the race,” says Hirano. “There were no
suppliers who could collaborate with us to make oval piston rings. They said,
‘Oval piston rings won’t go mainstream. Furthermore, we have no special
equipment.’ But we strongly requested them many times.
Incidentally, the VTEC (variable valve timing and lift electronic control) was
invented during that period. During development of the oval piston, we tried to
have the eight valves to four valves. We studied about losing the engine’s
‘startability’ to improve the combustion and to increase the horsepower in the
middle-to-low rpm area. A test engineer found this by coincidence and this
innovation led to the idea of the engine of the CBR400. If Honda had given up
the oval piston development, there wouldn’t have been any Honda VTEC,”