VVT systems
Current developments in internal combustion engines demand better control of the air entering the cylinder in order to maintain efficiency, torque and power under the engine’s operating demands. Control systems have been designed that instantly adapt cylinder filling, keeping operating efficiency at its maximum and allowing the engine to adapt fully to any operating condition.
VVT systems consist mainly of sprockets with internal hydraulic chambers (hydraulic units or sprockets), control solenoid valves and oil filters exclusive to the system.
VVT systems adapt cylinder-filling efficiency instantly under any engine operating condition, and because of their wide operating variability they demand very high quality in the sprockets or hydraulic units and in the control valves.
CIC VVT sprockets/hydraulic units and control valves are made of premium steels with IT7-grade tolerances, which allows a very fast response to the control signals from the electronic control module and very low inertia, giving maximum precision under variable signals.
CIC offers a wide variety of sprockets/hydraulic units and control valves that strictly meet the original standards demanded by modern engine manufacturers. Internal seals made of Viton, with high temperature and corrosion resistance, guarantee a long service life with no leaks while maintaining pressure in the pressure chambers.
Requirements for correct installation of CIC VVT components:
- Before removing VVT system components—since their operation depends on the condition of the engine lubrication system—first check engine oil pressure and then the pump outlet oil flow.
- Check for fault codes. If any exist, follow the troubleshooting procedure.
- Follow the component removal instructions in the service manual, especially those regarding control-module procedures.
- Clean all oil feed passages to the VVT system completely.
- If the system has a dedicated oil filter, it must be cleaned completely.
- Follow the service manual instructions during assembly.
- Use only the tightening torques specified by the engine manufacturer to secure all system components.
- Replace the engine oil and the main filter.
- Hydraulically pre-charge all hydraulic sprockets and solenoid valves before and after installation.
- It is essential to follow the system reset and reprogramming procedure (in the control module) before and after starting the engine.