Frelander 2. Manual - part 156

The intake camshaft is equipped with 3 lobes for each valve. One centrally located with a small lifting height of 3.6 mm, and 2
outer lobes with greater (same) lifting heights of 10.0 mm.

At small lifting heights, only the centrally located lobe works on the valve, which occurs via the inner tappet. The outer lobes work
on the outer tappet that follows the movement of the lobes. The return spring is compressed and ensures that the tappet is
always in contact with the camshaft. When the centrally located tappet and the outer tappet are not joined, the outer tappet
moves without affecting the valve. Thus the lifting height is small. At high lifting height, the inner tappet and the outer tappet are
joined via the 2 lock pins.

The position of the lock pins is controlled hydraulically by 2 electro-hydraulic CPS solenoid valves. These valves are located in the
camshaft housing.

Item

Part Number

Description

CPS solenoid valve - cylinders 3, 5 and 6

CPS solenoid valve - cylinders 1, 2 and 4

One solenoid controls the valves for cylinders 1, 2 and 4 whilst the other controls the valves for cylinders 3, 5 and 6. The solenoids
therefore control 6 valves each (when the engine has 2 intake valves and 2 exhaust valves per cylinder).

The position of the solenoids valves, on or off, are controlled by the ECM
For additional information, refer to:

Electronic Engine Controls

(303-14A Electronic Engine Controls - I6 3.2L Petrol, Description and

Operation).
.

The inner tappet works like a hydraulic tappet, which compensates for any wear. The valve clearance is therefore '0'.

The exhaust camshaft is conventional and has a lifting height of 10.0 mm. The tappets are mechanical (i.e. have valve clearance).

Camshaft Data

Intake

Opening angle, 3.6, mm lifting height:

- Crankshaft degrees - 152°
- Crankshaft degrees - 76°

Opening angle, 10.0 mm lifting height:

- Crankshaft degrees - 240°
- Crankshaft degrees - 120°

Exhaust

Opening angle, 10.0 mm lifting height:

- Crankshaft degrees - 240°
- Crankshaft degrees - 120°

The intake camshaft has a VCT unit.

Lifting height

Opens

Closes

Intake 3.6 mm

32 BTDC to 28 ATDC

120 ATDC to 180 ATDC (or 60 BBDC to 0 BBDC)

Intake 10.0 mm

37 BTDC to 23 ATDC

203 ATDC to 263 ATDC (or 23 ABDC to 83 ABDC)

Exhaust, 10.0 mm

228 BTDC (or 48 BBDC)

12 ATDC

BTDC = Before Top Dead Centre
ABDC = After Bottom Dead Centre
BBDC = Before Bottom Dead Centre
ATDC = After Top Dead Centre

Camshaft Position in Relation to Load and RPM

Item

Part Number

Description

Range for lifting height 3.6 mm

Range for lifting height 10.0 mm

Small lifting height, 'early' camshaft

Small lifting height, 'late' camshaft

Large lifting height, 'early' camshaft

Large lifting height, 'late' camshaft

By closing the intake valves early at low load and low engine speed, reduced fuel consumption is achieved.

Item

Part Number

Description

CPS solenoid valve (x 2)

Oil circuit, tappet CPS function

Calibrated passage (choke)

To bearing, exhaust camshaft

Tensioner, camshaft chain

Nozzle, camshaft chain lubrication

Oil circuit, hydraulic adjusting valve clearance

Vacuum pump

VCT unit

Oil inlet, rear

Return

To bearing, intake camshaft

To front bearing, intake camshaft

Return

Oil inlet, front

Bleeding

The oil inlet, located on the front edge of the cylinder, supplies oil to the following:

The hydraulic tappets
The vacuum pump
The nozzle for cam chain lubrication
The intake camshaft's front bearing
The electro-hydraulic CPS solenoid valves, front and rear
The tappets with CPS function

There is a bleed valve (16) in the duct for the rear electro-hydraulic solenoid valves.

The duct is also equipped with 2 calibrated passages (3) to each tappet circuit (2) (i.e. the circuits after the CPS solenoid valves).
A continuous flow through the circuit ensures the necessary stable pressure differences that are necessary for a stable transfer
between the small and large tappet (or vice versa).

• NOTE: In the event of a small lifting height, the tappet circuit, in principle, has no pressure when the CPS valves are open, which
produces a return flow to the oil pan.

A filter is located in each passage.

The oil inlet, located on the rear edge of the cylinder, supplies oil to the following:

The camshaft chain's hydraulic tensioner
The intake camshaft VCT unit
The intake camshaft's bearings
The exhaust camshaft's bearings

To switch from low lift to high lift and vice versa as smoothly as possible, the transfer is only permitted when certain conditions
are completed. These are:

That the oil temperature is above +40°C (104°F). Calculated internally in the ECM, from, amongst other things, the coolant
temperature
Occasionally the volumetric efficiency is the same for low and high lift, which means that the air requirement is within a
range where it can be managed initially by VCT control. This is to achieve as soft a transfer as possible.
It is possible to adjust ignition timing to prevent torque peaks during CPS control

For additional information, refer to:

Electronic Engine Controls

(303-14A Electronic Engine Controls - I6 3.2L Petrol, Description and

Operation).

Variable Camshaft Timing Solenoid and Camshaft Position Sensors

Item

Part Number

Description

CMP Sensor - exhaust camshaft

VCT solenoid

CMP Sensor - intake camshaft

The profile, or position and shape of the camshaft lobes are optimized for a certain engine rpm, but this normally limits low-end
torque or high-end power. At high engine speeds, an engine requires large amounts of air. However, the intake valves may close
before all the air has been given a chance to flow in. On the other hand, if the camshaft keeps the valves open for longer periods
of time, problems start to occur at the lower engine speeds. This will cause unburnt fuel to exit the engine since the valves are
still open.

To overcome this, VCT changes the valve timing by either advancing or retarding the camshafts to allow for optimum engine
performance, reduced emissions, and increased fuel efficiency. This is achieved via an electronically controlled hydraulic solenoid
valve located in the camshaft housing at the rear of the engine, behind the rear CPS solenoid. The ECM transmits a signal to the
solenoid, which directs engine oil into the VCT unit. A valve spool in the VCT unit regulates the flow of oil.
For additional information, refer to:

Electronic Engine Controls

(303-14A Electronic Engine Controls - I6 3.2L Petrol, Description and

Operation).
.

There are 2 CMP sensors located in the camshaft housing. The CMP sensors monitor the position of the camshafts to establish
ignition timing order, fuel injection triggering and for accurate VCT camshaft advance-retard timing feedback.

The CMP sensor is a Hall-effect sensor, which switches a battery fed supply on and off. The supply is switched when the teeth of
the reluctor pass by the tip of the sensor. The 4 teeth are of differing shapes, so the ECM can determine the exact position of the
camshaft at any time.
For additional information, refer to:

Electronic Engine Controls

(303-14A Electronic Engine Controls - I6 3.2L Petrol, Description and

Operation).

Spark Plugs

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