Abstract
In the beginning of the article it will be presented a short introduction about the necessity of designing and developing newer solutions of VVT (Variable Valve Timing) systems in order to satisfy the actual needs which consist in fuel consumption, exhaust gases emissions and internal combustion engine performances. Further, a comparison between the main VVT systems will be presented so that we could make an idea over cost-performance ratio. After the introduction, the influences that VVT system involve on specific parameters of internal combustion engine: load control, load composition control, in-cylinder gas motion control. Therefore the conclusions will be presented.
Keywords: Variable Valve Timing systems, internal combustion engine, volumetric efficiency, engine load, emissions.