The paper presents an algorithm to set the parameters of the dynamics of the classic mechanism the main of internal combustion. It shows the distribution of the forces (on the main mechanism of the engine) on engines with internal combustion. Dynamic, the gears can be distributed in the same way as forces. Practically, in the dynamic regimes, the velocities have the same synchronization as forces. The method shall be applied separately for two distinct situations: When the engine is working on a compressor and in the system of the motor. For the two individual cases, two independent formulae are obtained for the dynamic cinematic forces (gearbox). The calculations shall be made for an engine with a single cylinder. The change of speed in the dynamics feels like a variation of the angular speed of the engine. It is more difficult to be taken into account (theoretically) effect on engine with several cylinders.