Pic. 2.228. Camshaft phase regulator: 1 - phase regulator
To improve the filling of the cylinders with the working mixture in all modes, the K4M and F4R engines are equipped with a phase regulator of the intake camshaft (pic. 2.228).
The displacement of the closing moment of the intake valves optimizes the filling of the cylinders depending on the speed of the crankshaft. The result is increased torque at medium loads and power at high engine speeds.
Under these conditions, the later closing of the intake valves ensures the supply of an additional portion of the fuel mixture due to the high speed of its movement.
On the contrary, at a low rotational speed, the inertia of the charge is small. Early closing of the exhaust valves avoids poor filling of the cylinders and loss of torque due to the displacement of part of the fresh charge of the mixture.
The higher the crankshaft speed, the later the intake valves should close.