Cylinder Head Components: Camshafts

Each cylinder head is fitted with two camshafts; inlet and exhaust. The lobes on the camshafts act on the valve tappets to open and close the valves.

The camshafts run on machined bearing journals in the cylinder heads and camshaft caps. The camshaft caps are marked with 'IN' and 'EX' to denote inlet and exhaust. The caps at the front of the engine are marked 'AB'. Before removal, each camshaft cap must be marked with its position to ensure correct re-assembly. Each camshaft cap is secured with two bolts.

Each camshaft is fitted with a VCT actuator assembly. Each actuator contains a sprocket which drives the camshaft via a timing chain driven from the crankshaft. The VCT actuator assembly can change the timing of the camshaft, increasing engine efficiency and performance.