Range Rover (LM) V8-4398cc 4.4L (M62) (2003)
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Each camshaft has REVERSE threaded bores in their centres for the attachment of the timing chain sprockets on the exhaust cams and the VCC
transmissions for each intake camshaft as shown.
Camshaft Position Impulse Wheels:
the camshaft position impulse wheels provide camshaft position status to the engine control module via the camshaft position sensors. the asymmetrical
placement of the sensor wheel pulse plates provides the engine control module with cylinder specific position ID in conjunction with crankshaft position
V8 VCC Control
As the engine camshafts are rotated by the primary and secondary timing chains, the ME7.2 control module activates the VCC solenoids via a PWM
(pulse width modulated) ground signal based on a program map. the program is influenced by engine speed, load, and engine temperature.
In its inactive or default position, the valves direct 100% engine oil pressure tow to achieve maximum retard VCC positioning.
As the Pulse Width Modulation (PWM) increases on the control signal the valve progressively opens the advance oil port and proportionately closes the
retarded oil port.
Oil pressure pushes the piston toward the advance position. Simultaneously the oil pressure on the retarded side (rear) of the piston is decreased and
directed to the vent port in the solenoid valve and drains into the cylinder head.
At maximum PWM control, 100% oil flow is directed to the front surface of the piston pushing it rearward to maximum advance.
