ENGINE
Hydraulic tappets
During normal operation, engine oil pressure,
present in the upper chamber, passes through the
non-return ball valve and into the lower chamber.
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Clip
Pushrod seat
Inner sleeve
Upper chamber
Non-return ball valve
Spring
When the cam begins to lift the outer sleeve, the
resistance of the valve spring, felt through the push
rod and seat, causes the tappet inner sleeve to
move downwards inside the outer sleeve. This
downward movement of the inner sleeve closes the
ball valve and increases the pressure in the lower
chamber sufficiently to ensure that the push rod
opens the valve fully.
Outer sleeve
Lower chamber
The purpose of the hydraulic tappet is to provide
maintenance free and quiet operation of valves. It
achieves this by utilising engine oil pressure to
eliminate the mechanical clearance between the
rockers and the valve stems.
As the tappet moves off the peak of the cam, the ball
valve opens to equalise the pressure in both
chambers which ensures the valve closes when the
tappet is on the back of the cam.
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DESCRIPTION AND OPERATION
| Categories | Land Rover, Land Rover Defender, Range Rover |
|---|---|
| Tags | Land Rover |
| Model Year | 1999 |
| Download File |
|
| Product Name | Range Rover 4.0 & 4.6 Litre, Defender V8i |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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