Cylinder Head Assembly: Description and Operation

The DOHC (LL0) cylinder head is aluminum and is cast using the lost foam process. The camshafts are held in the cylinder head with bearing caps and driven by a chain off the front crankshaft sprocket. The chain is hydraulic tensioned and has a ratchet mechanism to keep the chain tight. Motion from the camshaft is transmitted to the 16 valves by direct acting hydraulic lifters. The valve guides are pressed in to the cylinder head and serviceable. Guides, seats and valves are used to service the cylinder head in the event of valve stem or seat wear. Standard size valve seals, seats and valves are released for service. Standard size and 0.025 mm (0.010 inch) oversize outer diameter valve guides are released for service.