Engine Components: Valvetrain: Notes
The following graphic shows the design of the cylinder head on the N55 engine with Valvetronic III and direct fuel injection.
NOTE:
Notice the hollow, lightweight design of the camshafts (7) and the blow-by passages leading into the intake ports (15).
INDEX EXPLANATION CHART
| Index | Explanation |
|---|---|
| 1 | VANOS unit, intake camshaft |
| 2 | VANOS unit, exhaust camshaft |
| 3 | Injector well |
| 4 | Spark plug well |
| 5 | Camshaft housing |
| 6 | Valvetronic servomotor |
| 7 | Inlet camshaft |
| 8 | Torsion spring |
| 9 | Gate |
| 10 | Eccentric shaft |
| 11 | Intermediate lever |
| 12 | Roller lever tappet |
| 13 | Valve head |
| 14 | Oil spray nozzle |
| 15 | Passages for introducing blow-by gas into the intake ports |