four wheel drive BMW 645Ci COUPE 2004 E63 N62B44 Engine Workshop Manual

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N62 Engine
Eccentric Shafts
The eccentric shafts (one per cylinder head) are driven by the
Valvetronic motors and are supported by four caged needle
bearing assemblies for a smooth rotation.
To assist in maintaining the set positions and counter the
valve train torque, a torque compensation spring is mounted
on the end of the shaft for tension.
Magnets are fitted in the (removable) magnetic wheel at the
end of the eccentric shaft. Together with the position sensor,
the Valvetronic Control Module determines the exact shaft
position. The eccentric shaft sensor is mounted through the
cylinder head cover (one per cylinder head) at the back.
The magnetic wheel is secured to the shaft by a bolt and is
indexed by a tab (arrow) to prevent incorrect installation.
Intermediate Lever and Roller Finger
The intermediate lever is positioned further (minimum valve
opening) or closer (maximum valve opening) to the camshaft
by the the progressive “lobe” on the eccentric shaft as it is
rotated. This offers a variable ratio effect for valve actuation.
The roller finger is used to actuate the intake valve.
The intermediate levers and roller fingers are matched (by
classification) to ensure uniform valve lift.
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42-02-3643-02-32
43-02-38
43-02-33