The Honda VTEC system allows you to change the height of the valves and the angle of their overlap, depending on the speed of the wheel shaft. It increases engine power at high speed and reduces the fuel consumption at low speed.
There are slightly different systems for gas distribution phase changes of 2.0 and 2.4 litre Honda Cord 7. The K20A engine uses a more economical system to adjust the height of the lift only. On the more powerful K24A engines, it is possible to change the rise and intake and exhaust valves.