Cylinder Head Oil Supply

Oil is routed from the cylinder block through a front and rear duct to the cylinder head. The duct at the front edge supplies 2 circuits in the cylinder head with oil:

1. Circuit for the hydraulic tappets, vacuum pump and cam chain lubrication 

A longitudinal duct on the intake side supplies the following components with oil:

• The hydraulic tappets
• The vacuum pump
• The nozzle for cam chain lubrication

2. Circuit for the intake camshaft's front bearing, the CPS valves and the tappets with CPS function 

A duct supplies the intake camshaft's front bearing and both the CPS valves.

The front CPS valve controls the oil flow to the tappets for cylinders 1, 2 and 4 and the rear CPS valve controls the oil flow to the tappets for cylinders 3, 5 and 6.

When the CPS valve solenoids are activated, the valves open (i.e. shift from low to high valve lifting height) and the tappets are supplied with oil under pressure.

The longitudinal duct that supplies the rear CPS valve is equipped with a bleed hole. This is to ensure that no air reaches the CPS valves or the tappets.

Courtesy of JAGUAR CARS, INC.

The duct is also equipped with 2 calibrated passages to each tappet circuit (i.e. the circuits after the CPS valves). A continuous flow through the circuit ensures the necessary stable pressure differences required for a stable transfer between the small and large tappet (or vice versa).

A filter is located in each passage.

The duct at the rear edge supplies the following components/functions with oil:

• The camshaft chain's hydraulic tensioner
• The VCT valve and the VCT unit for the intake camshaft
• The camshaft bearings for the intake camshaft (6, i.e. all except the front)
• The camshaft bearings for the exhaust camshaft (all 7)