If an uneven distribution is determined, the engine can be repaired by installing roller cam followers of different classes.
The repair is to be carried in accordance with the instructions in the repair manual from the TIS. The use the different classes of roller cam followers is described in the following.
Roller cam followers from four classes are available for repair.
Each class means a change in the valve lift of approx. 0.01 mm.
As with four possible classes there is a maximum difference of 3 classes, the classification alone can balance a difference of 0.03 mm. This corresponds to 10% in the case of a valve lift of 0.3 mm.
The roller cam followers are marked by laser with the classes 1, 2, 3 or 4.
Ex works, it is usually the case that roller cam followers of only one class are fitted in each engine.
The lower the class, the smaller the valve lift.
|
Class 1-2 fitted |
Class 3-4 fitted |
Air volume too low |
Fit class 4 on the defective cylinder |
Fit class 1 on the undamaged cylinders |
Air volume too high |
Fit class 4 on the undamaged cylinders |
Fit class 1 on the defective cylinder |