Abstract
In this paper is presented a variable valve timing system with the hydraulical action proposed by the authors. It is described its construction, its operating and there are show some experimental research results of the variable valve timing system obtained on the different working conditions. The paper indicates some results of the physico-mathematical model of the assumption of the variable valve timing spark ignition engine operating and the load check by the inlet valve.Also, are presented the experimental research results of the variable valve timing engine working on the loads different.