The cylinder head (17,18) has a number of bearings (43) for mounting of an inlet camshaft (23,27) and an exhaust camshaft (21,25). The exhaust camshaft has a drive pinion (46) whereas the inlet camshaft has a driven gearwheel (47). The inlet camshaft has a mechanism for altering the valve timing (53). The shaft journal which is located next to the driven gearwheel has a diameter which is larger than the others in order to improve the rigidity of the inlet camshaft.
