Cylinder Head Components

CYLINDER HEAD COMPONENTS

CYLINDER HEAD COMPONENTS (PART 1):

CYLINDER HEAD COMPONENTS (PART 2):

Cylinder Heads
The cylinder heads are unique to each cylinder bank. Deep-seated bolts, to reduce distortion, secure the cylinder heads to the cylinder block. Two hollow dowels align each cylinder head with the cylinder block.

The 14 mm spark plugs, one per cylinder, locate in recesses down the center line of each cylinder head.

The engine-lifting eyes are bolted to the cylinder heads; two on the rear (one per head) and one at the front.

Camshaft Covers

Camshaft Covers:

The camshaft covers are manufactured from thermo-plastic. The RH camshaft cover incorporates an outlet for the part load engine breather. The LH camshaft cover incorporates an outlet for the full load engine breather and the engine oil filler cap. Identical oil separators are incorporated below the breather outlet in each cover.

Silicon rubber in-groove gaskets seal the joints between the camshaft covers and the cylinder heads. Together with spacers and seals on the camshaft cover fasteners, they also isolate the covers from direct contact with the cylinder heads, to reduce noise.

Cylinder Head Gasket
The multi-layered steel cylinder head gasket has cylinder specific water flow cross-sections for uniform coolant flow.

Camshafts
The camshafts are manufactured in chilled cast iron. Five aluminum alloy caps retain each camshaft. Location numbers, 0 to 4 for the intake camshaft and 5 to 9 for the exhaust camshaft, are marked on the outer faces of the caps.

Camshafts:

Sensor Ring

Sensor Ring (Part 1):

Sensor Ring (Part 2):

Timing rings for each camshaft position sensor are located at the rear of both intake camshafts. A flat, machined near the front of each camshaft, enables the camshafts to be locked during the valve timing procedure.

Camshaft Position Sensor

Camshaft Position Sensor:

The camshaft position sensors are installed in each cylinder head at the rear of the intake camshaft. It is a variable reluctance sensor that provides an input to the ECM regarding the position of the camshaft.

Inlet and Exhaust Valves
Each cylinder head incorporates dual overhead camshafts operating four valves per cylinder via solid shimless aluminum alloy valve lifters.

The lightweight valve gear provides good economy and noise levels. Valve head diameters are 31mm (1.220 inch) for the exhaust and 35 mm (1.378 inch) for the intake. All valves have 5 mm (0.197 inch) diameter stems supported in sintered metal seats and guide inserts. Collets, valve collars and spring seats locate single valve springs on both intake and exhaust valves. Valve stem seals are integrated into the spring seats.

CAUTION: Due to slight variations in length, the valves are not interchangeable between marques (Land Rover, Jaguar and Aston Martin).

Fuel Injectors

Fuel Injectors:

Eight, top fed, twelve-hole, fuel injectors are installed in the fuel rails. The injectors are electromagnetic solenoid valves controlled by the ECM. Two O-rings seal each injector to manifold interface. The fuel jets from the injectors are directed onto the back of the intake valves.