Rover K Series 1.8 VVC Instructions de fonctionnement
Workbook
Engine K Series 1.8 VVC
Rover Group are constantly seeking ways to improve the specification and design of its
vehicles and alterations take place continually.
Whilst every effort is made to produce up-to-date literature, this training workbook should
not be regarded as an infallible guide to current specification, nor does it constitute an
offer for the fitment of any particular system or component.
All rights reserved. no part of this Training Workbook may be reproduced without
prior permission of -
TECHNICAL ACADEMY
GAYDON TEST CENTRE
BANBURY ROAD
LIGHTHORNE
WARWICK
CV35 0RG
This Training Workbook is designed to support the Service Product Training courses and
is issued as part of the training programme.
It may be used to compliment other literature available but the Repair Operations Manual
should always be consulted prior to servicing or repair work.
© ROVER GROUP LIMITED - Nov 1997
ENGINE K SERIES 1.8 VVC
Technical Academy
01-34-RG-W-Ver:1 Page 1 of 28
Variable Valve Control - VVC
Introduction
The 1.8 litre 16 valve ‘K’ Series engine with Variable Valve control, (VVC), is available in
the MG-F and the New Rover 200 series.
The 1.8 litre VVC engine also employs the MEMs 2J Engine Management System
The engine shares the key design features of the four cylinder ‘K’ Series engine, with the
ultra light, 'sandwich' construction of low pressure aluminium sand castings, held together
by high tensile through bolts for strength and low distortion.
The VVC engine also includes lightweight hydraulic tappets and lightweight pistons, giving
smoother running, particularly at higher engine speeds. The engine also includes 'damp
cylinder liners', first introduced to ‘K’ Series engines in 1995.
The main emphasis in this workbook is the overhaul procedure of the VVC cylinder head
with the aid of special tools.
To begin with, the following text will explain the operating principles of the VVC
mechanism.
Figure 1
ENGINE K SERIES 1.8 VVC
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Variable Valve Control
Engine tuning is usually a compromise between low speed drive-
ability and high speed power, and an increase in one is normally
accompanied by a reduction in the other The main reason for this
'trade off is a phenomenon called 'Inertial Ram Effect'.
The VVC overcomes these basic restraints by employing a
continuously variable camshaft profile; opening the intake valve for
longer periods at high engine speeds and shorter periods for more
sedate conditions to enhance bottom end torque and idle stability.
How VVC Works
The inlet camshaft, (and there are four of them), still receives drive
from the crankshaft in the normal manner; restricted to the overall
ratio of one camshaft revolution to every two from the crankshaft.
Working within this basic restraint, Rover engineers were able to
squeeze around 20% more power over the standard engine by
varying the speed of the camshaft within each revolution; slowing it
down whilst the valve is open to give a longer duration and speeding
it up to give a 'snap' open and close condition.
A = Distance covered in first half of rotation
B = Distance covered in second half of rotation
The principle of operation is extremely simple; driving through an eccentric mechanism
gives the necessary variation in velocity throughout the camshaft revolution.
Changes in the position of the eccentric in relation to the camshaft lobe, either speeds up,
or slows down the valve's opening sequence. Having the position of the eccentric
controlled through a hydraulic rack and pinion enables the MEMS 2J ECM to control
exactly the open period of each pair of intake valves.
Rotation of the Camshaft Drive
The inlet valve cam drive is turned at half crankshaft speed by a toothed drive belt.
Rotation of the Drive Ring
Because the drive ring centre is offset from the camshaft centre, the drive ring rotates
eccentrically and speeds up and slows down during its turn.
Rotation of the Cam Lobe
The slot on the drive ring engages the crank on the cam lobe and the eccentric rotation
becomes even more pronounced.
The basic principle is relatively easy to explain around one cylinder and one intake valve.
Figure 2
ENGINE K SERIES 1.8 VVC
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Designing a working system for a 4 cylinder 16 valve engine was somewhat more
complex! Accepting that all four pairs of camshaft lobes are positioned differently to cope
with their unique role in the four stroke cycle, then each pair must be controlled with a
degree of independence.
To achieve this, two VVC mechanisms are positioned either end of the cylinder head, each
controlling an inlet camshaft assembly; each of these assemblies drives two semi-
independent camshafts, one for each pair of valves, making four inlet camshafts in all.
As there is no direct drive between the two inlet camshaft assemblies, an additional drive
belt is used, transmitting drive from the back of the exhaust camshaft to the rear inlet cam
assembly.
A control shaft is used to transmit drive to both VVC mechanisms, this is in turn controlled
by a hydraulic rack driven by the Hydraulic Control Unit (HCU), the position of which is
monitored and controlled by the MEMS 2J ECM through two solenoid valves and a
camshaft period sensor. The main ECM inputs for VVC are engine speed and load.
Figure 3
1. Camshaft drive 5. Piston
2. Control sleeve 6. HCU solenoids
3. Drive ring 7. Control shaft
4. Independent shaft
ENGINE K SERIES 1.8 VVC
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VVC Technical Specifications
Type ‘K’ 1.8 VVC
Bore 80.0mm
Stroke 89.3mm
Capacity 1796cc
Compression ratio 10.5:1
Maximum power 147 PS @ 7000 rev/min.
Maximum torque 174 Nm @ 4500 rev/min.
Maximum rev/min 7300 rev/min.
The following graph shows the power and torque comparison between the 1.8 litre 16
valve engine and the 1.8 litre 16 valve VVC engine.
Figure 4
A. Power (PS)
B. Engine speed (rpm)
C. Torque (Nm)
ENGINE K SERIES 1.8 VVC
Technical Academy
01-34-RG-W-Ver:1 Page 5 of 28
The following illustration shows the engine compartment components
for the 1.8 VVC MG-F.
Figure 5
1. Fuel filter 14. Manifold absolute pressure sensor
2. Resonator 15. Throttle cable
3. Fuel pump 16. Oil temperature sensor
4. Air filter 17. Ignition coil
5. Throttle position sensor 18. Fuel rail
6. Engine coolant temperature sensor 19. Idle air control valve
7. Intake air temperature sensor 20. Crankshaft position sensor
8. Camshaft position sensor 21. Throttle body
9. Oxygen sensor 22. Evaporative emission canister, purge valve
10. Injector (4 off) 23. Evaporative emission canister
11. Hydraulic control solenoids 24. Engine management relay module
12. Hydraulic control unit 25. Engine control module
13. Fuel pressure regulator 26. Inertia fuel shut-off switch
ENGINE K SERIES 1.8 VVC
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The MEMS-2J, VVC Engine Control Module, (ECM), monitors all normal functions as with
other engines, but with the ‘variable valve control’, the ECM controls the inlet valve
opening and closing periods.
•The ECM measures the cam period via the camshaft sensor, and also controls the
VVC mechanism with two solenoids: one which increases the period and one which
reduces the period.
•The ECM also implements tune select which means that each ECM may contain
engine calibrations for one or more vehicles. In order to prevent an ECM being fitted to
a vehicle with the wrong calibration selected, when first supplied, the ECM has no
calibration selected therefore the engine will not run. When fitted to a vehicle, the ECM
calibration for that particular vehicle must be selected using ‘Test Book’ diagnostic
equipment in addition to programming the ECM security code.
This Training workbook relates to the Service repairs and adjustments the VVC cylinder
head.
Overhaul procedures and adjustments for the cylinder block, using the correct special tools
is the same for all 4 cylinder ‘K’ series engines.
Camshaft Timing Belt
NOTE: It is important that the camshaft drive belt adjustment is carried out when the
engine is ‘COLD’.
The front camshaft timing belt adjustment and replacement on the 1.8 VVC engine is
similar to any of the other 4 cylinder ‘K’ Series engines using the same special tool, 18G
1570 to lock the camshaft gears, and 18G 1742 to lock the crankshaft/flywheel from
turning, the latter fitted in the starter motor aperture.
NOTE: The front and rear camshaft drive belts are renewed at 60,000 miles (96,000km.)
The front timing belt is unique to the 1.8 VVC engine, and timing belts for standard ‘K’
engines must not be fitted. There are no routine adjustments recommended for the front
or rear camshaft drive belts.
•The timing belt is tensioned by special equipment at manufacture, eliminating the use
of a tensioner spring.
•A new timing belt for Service is supplied with the tensioner spring and pillar bolt.
•Inspection of the front and rear timing belts is by removing the top belt cover, (front),
and rear cover for the rear belt.
Check the timing belts for uneven wear, splitting or oil/water contamination.
If any of these faults are apparent, identify the cause of the fault and rectify,
then fit a new timing belt.
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New Timing Belt (front)
NOTE: When fitting a new timing belt, fit the spring pillar bolt and tensioner spring
supplied with the new belt. After tensioning the timing belt, remove the spring and
pillar bolt.
IMPORTANT: The tensioner spring without the rubber sleeve is unique to the VVC engine,
and has a higher spring loading. The tensioner spring, (with the rubber sleeve), is a
common fitment to all other four cylinder ‘K’ Series engines and must not be used on the
VVC engine.
Figure 6
Camshaft Drive Belt (Remove)
•With the upper timing belt cover removed, rotate crankshaft clockwise to align the
timing marks on the camshaft gears, and locate 18G 1570 between the gears.
•Always mark direction of rotation, (DOR), on the drive belt if it is to be reused.
•Release ½ turn, Allen bolt and tensioner backplate bolt, then move the tensioner down
to the fully off position, and retighten back plate bolt to 10Nm.
•Ease the timing belt from the gears using finger pressure only.
•Prevent the crankshaft from turning using 18G 1742, and undo and remove the
crankshaft pulley bolt, then remove lower timing belt cover.
Remove the timing belt from the engine.
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Camshaft Drive Belt (Refit)
•Ensure camshaft and crankshaft gears are clean and dry.
•Correctly align the timing marks on camshaft gears then fit 18G 1570 to retain the
camshaft gears in there correct position.
•Ensure that the timing mark is correctly aligned on the crankshaft gear.
•Position drive belt onto crankshaft gear then over camshaft gears, keeping the belt taut
from the crankshaft gear and between camshaft gears .
•Use finger pressure and ease drive belt over tensioner pulley and water pump gear,
making sure that the drive belt is central over all gears.
•Fit the lower belt cover noting correct alignment of rubber dust seal, and tighten cover
bolts to 5Nm.
•Fit crankshaft pulley, tightening the pulley bolt to 205Nm.
•Ensure that the tensioner Allen bolt and backplate bolt are loosened by ½ turn.
•Fit pillar bolt and tensioner spring.
•Remove 18G 1570 from camshaft gears.
•Rotate crankshaft 2 complete turns and realign the timing marks.
•Tighten tensioner backplate bolt to 10Nm, and Allen bolt to 45Nm.
•Remove tensioner spring and pillar bolt.
•Fit top drive belt cover.
Camshaft Rear Timing Belt
There is no adjustment procedure for the rear timing belt on the VVC engine.
If the belt has to be removed for any reason, then the following procedure should be
carried out.
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