L322 Range Rover System Description and Operation
ENGINE - V8
DESCRIPTION AND OPERATION 12-2-13
The cylinder heads for each bank are different lengths due to the offset of the cylinder rows (cylinder bank 1–4 is
shorter).
NOTE: The cylinder head gasket part numbers are different for the two cylinder banks.
The cylinder head is machineable to a limit of 0.3 mm. A repair cylinder head gasket is available and is identified by
a small hole beside the 4th and 8th cylinder apertures.
Camshafts
Two solid cast iron camshafts are used for each cylinder head. The cams run in five machined bearing surfaces with
numbered caps for identification.
The camshafts are also marked for identification and incorporate hexagonal machined blocks for timing the cams
during installation.
For installation and servicing, the camshafts are held in position with locking pins. These pins are inserted into the
front camshaft bearing caps on both cylinder heads.
Valves
The intake and exhaust valves are arranged in a “V” pattern. The valves use single, conical, coil bound shaped valve
springs and Hydraulic Valve Adjustment (HVA) tappets and each comprises the following components:
l
Valve x 1 (inlet or exhaust)
l
Valve stem seal x 1
l
Valve spring x 1
l
Valve spring seat x 1
l
Valve spring cap x 1
l
Valve collets x 2
l
Tappet x 1.
Hydraulic Valve Adjustment Tappets
Bucket type hydraulic tappets are used for adjusting the valve clearance. The buckets are self-breathing with a carbon
nitride finished cam contact surface.
Primary drive
Primary drive is provided by a single roller chain from the crankshaft to the two rubber coated cam gears. The train is
guided by a centrally positioned V-shaped aluminium deflector rail, a straight rail on cylinder bank 5 to 8 and a curved
tensioner rail on cylinder bank 1 to 4.
Timing chain adjustment is carried out with a hydraulic tensioner mounted on the upper case for cylinders 1 to 4
Secondary Drive
Secondary drive is from the intake camshaft to the exhaust camshaft by a single roller chain. Chain tension is
maintained by a hydraulic, spring assisted tensioner that incorporates an oil spray jet.
The oil supply for the chain tensioner also supplies the VCC hydraulic units through a pressure control valve.