Variable valve timing or VVT gears are an increasingly common component in the latest generation of engines. Their function is to bring about early opening and/or delayed closure of the intake and exhaust valves. They are present in belt-driven engines, but particularly in chain-driven engines.

Before this innovative timing technology was introduced, the timing gear was fitted directly to the camshaft to form a single part. Rotation of the camshaft or camshafts was driven exclusively by rotary movement from the driveshaft. In other words, in a conventional timing system, the intake and exhaust valves always opened at the same point during the combustion cycle, unless technical problems caused premature chain or belt failure.

The engineering of timing systems with VVT gears introduced the possibility of advancing or delaying valve opening to benefit engine performance. The effect of this performance enhancement is mainly evident in emission reduction, improved engine torque and fuel saving. Modulating valve timing allows torque and power to be available at different times.

More and more engines are being fitted with this technology and more manufacturers will do so in the future. In the very near future, VVT gears for camshafts will become an essential part of car timing systems as manufacturers strive to maximise performance while reducing overall engine size. With its state-of-the-art technology, Lyra Bearing is able to provide a wide range of VVT gears for chain and belt timing systems, ensuring a quality level comparable to that of the original equipment.