VVT: it is a variable valve timing;
CVVT: continuous variable valve timing;
CVVT is the abbreviation of English Continue Variable Valve Timing. The translation into Chinese is a continuous variable valve timing mechanism. It is one of the many variable valve timing technologies that have been gradually applied to modern cars in recent years. For example, BMW is called Vanos, TOYOTA is called VVT-i, Honda is called VTEC, but whatever it is called, their aim is to match the best valve overlap angle (valve timing) for different engine working conditions, but the method is different.
Single VVT-i is unilaterally variable valve control. When the engine is turning, there is a problem in the field. The rotary area is only controlled unilaterally. There may be a phenomenon of dislocation in the rotary area. So a very important problem at this time is to balance the suction and exhaust to make the engine turn. The suction and exhaust balance can be achieved in any case.
Double VVT-i refers to the control of intake and exhaust systems respectively. In rapid acceleration, the control of the intake VVT-i will advance the intake time and increase the valve lift, and the control of the exhaust VVT-i will delay the exhaust time. This effect is like a smaller turbocharger, which can effectively improve engine power. At the same time, because of the increase of intake volume, the combustion of gasoline is more complete and the goal of low emission is achieved.