2004 MITSUBISHI LANCER EVOLUTION VIII Workshop Manual

ENGINE (4G6) – BASE ENGINE (6 M/T)13
2. Pistons
• Addition of Vshaped groove.
A Vshaped groove has been formed in the second land, with a view to reducing oil consumption.
•Modification of cooling channel.
The shape of the cooling channel, which recycles the oil, has been modified in order to improve recycling efficiency.
Modified shape of
cooling channelVshaped
groove added
3. Piston Rings (2nd)
To increase the tension in the piston rings, they have been changed
to ductile cast iron, from the standard cast iron used previously.
The end to end gap in the rings was also reduced.
These modifications are designed to reduce oil consumption.
ItemEvolution VIII MREvolution VIII
Tension10.5 N7.0 N
End to end gap0.30 – 0.45 mm0.35 – 0.50 mm
End to end gap

ENGINE (4G6) – BASE ENGINE (6 M/T)14
4. Oil Rings
The outer circumference of the side rail has been treated with chrome nitride. The thickness of the side rail has also been
reduced from 1.7 mm to 1.63 mm, with a view to increasing durability and reducing oil consumption.
(Evolution VII MR) (Evolution VIII)
Chrome nitride
5. Counterbalance shaft
The shape of the shaft was changed in order to reduce weight.
Counterbalance shaft (right)
Counterbalance shaft (left)Thickness
reduced
Thickness
reduced

ENGINE (4G6) – BASE ENGINE (6 M/T)15
6. Camshaft
Output at high engine speeds has been improved by altering the cam profile of the intake camshaft, and optimizing the valve
timing.
Evolution VIII MREvolution VIII
Cam height mm35.9635.79
Evolution VIII MR Evolution VIII
T.D.C (top dead centre) T.D.C (top dead centre)
Intake valve open
Intake valve
closedExhaust
valve closed
Exhaust
valve openIntake valve open
Intake valve
closedExhaust
valve closed
Exhaust
valve open
B.D.C (Bottom dead centre) B.D.C (Bottom dead centre)

ENGINE (4G6) – INTAKE / EXHAUST SYSTEM (6 M/T)16
Intake / Exhaust System (6 M/T)
1. Exhaust system
11 Turbocharger
A largenozzle 10.5T turbo has been adopted in order to improve mid to highrange torque. Optimum control of the
supercharging pressure has ensured good torque and response at medium engine speeds.The positions of the turbine housing and the wastegate holes have also been changed to achieve smoother outflow and
increase lowspeed torque. Along with these modifications, the wastegate valve has been changed from an oval to a circular
valve.
(Evolution VIII MR) (Evolution VIII)
Turbine housingTurbine housing
Wastegate holes Wastegate holes
Oval valve Circular valve

ENGINE (4G6) – INT
AKE / EXHAUST SYSTEM (6 M/T)17
12 Exhaust silencer
A tailpipe with builtin soundabsorbing material has been adopted, in order to increase the silencing effect.
Structural diagram
Main exhaust
silencer
Tailpipe
(with builtin soundabsorbing material)Crosssection
A–A
Sound
absorbing
material

ENGINE (4G6) – GENERAL, BASE ENGINE (6 M/T)18
Control system (6M/T)
The following changes have been made, based on the control system in the 4G63DOHCT/C engine fitted in the current
Lancer Evolution VIII.
* Addition of wastegate solenoid valve (1 valve –> 2 valves)
System Block Diagram
Air flow sensor (AFS)
Air temperature sensor
Atmospheric pressure sensor
Water temperature sensor
Throttle position sensor (TPS)
A/C switch
A/C load signal
Cam position sensor
Crank angle sensor
Alternator FR terminal
Vehicle speed sensor
Power steering fluid pressure
switch
Knock sensor
Intercooler water spray (auto)
Intercooler water spray (manual)
O
2sensor
Ignition switch –IG
Ignition switch –STPower supplyEngine ECU
Fuel injection control
Idle speed control (ISC)
Ignition timing control
Engine control relay control
Fuel pump relay control
A/C relay control
Fan motor control (radiator)
Fan relay control (A/C
condenser)
Alternator control
Air flow sensor filter reset
control
Fuel pressure control
Supercharging pressure
control
Secondary air controlIntercooler water spay control
Engine warning light control
O
2sensor heater control
Purge control
Diagnosis output
RAM data transmissionNo. 1 indicator
No. 2 indicator
No. 3 indicatorNo. 4 indicator
ISC servo (stepper motor)
Ignition coil A (No.1 – No.4)
Ignition coil B (No.2 – No.3)
Engine control relay
Fuel pump relay 2
Fuel pump relay 3
A/C relay
Fan controller (radiator fan)
Fan motor relay (HI, LOW)
(A/C condenser)
Alternator G terminal
Air flow sensor
Fuel pressure control valve
No. 1 wastegate solenoid valve
No. 2 wastegate solenoid valve
Secondary air control solenoid
valve
Intercooler water spray relay
Intercooler water spray lamp
Tachometer
Engine warning lights O
2sensor heater
Purge control solenoid valve
Diagnosis output terminal
Diagnosis output terminal (for
MUTII)

ENGINE (4G6) – GENERAL, BASE ENGINE (6 M/T)19
1. O2 sensor2. Air flow sensor3. Air intake sensor4. Throttle position
sensor
5. Cam position sensor6. Crack angle sensor7. Atmospheric pressure
sensor
8. Water temperature
sensor
9. Knock sensor•Power supply
• Ignition switch IG
•Ignition switch ST
•Vehicle speed sensor
• A/C switch
1. Injector2. ISC servo (stepper
motor)
3. Fuel pressure control
solenoid valve
4. No.1 wastegate solenoid
valve
5. No.2 wastegate solenoid
valve
6. Purge control solenoid
valve
7. Secondary air control
solenoid valve•Engine control relay
•Fuel pump relay 2, 3
•A/C relay
•Ignition coil
• Fan controller
Engine ECU
6. Purge control
solenoid valveCanister
7. Secondary air
control solenoid valveFrom fuel tank
Secondary
air valveBypass
valve
1. O2sensor
3. Fuel pressure
control solenoid valve
4. Throttle
position
sensor
7. Atmospheric pressure
sensor
3. Air intake
sensor2. Air flow sensor
4. No.1
wastegate
solenoid valve
5. No.2 wastegate
solenoid valve
Only operates on 6M/TWastegate actuatorFuel pressure
regulator
1. Injector5.Cam position sensor8.Water temperature sensor
9.Knock sensor
Crack angle sensor
Catalytic converter Air
intakeCheck
valve
2. ISC servo
Vacuum
tank
From fuel
pump To fuel
tank
Control system diagram

ENGINE (4G6) – CONTROL SYSTEM (6 M/T)110
1. Supercharging pressure control
The maximum torque has been increased, compared to the 4G63DOHCT/C engine in the current Lancer Evolution VIII, by
installing an additional wastegate solenoid valve (increased from 1 to 2 valves).
By adding a parallel No.2 wastegate solenoid valve to the previous system, provides extra relief capacity for the pressure
applied to the wastegate actuator thus increasing the range of supercharging pressure..
The engine ECU raises the supercharging pressure even further, thus raising the maximum torque, by driving the No.2
wastegate solenoid valve when the engine approaches maximum torque.
The No.1 wastegate solenoid valve is essentially controlled in the same way as previously.
Air flow
sensor
Knock
sensor
Engine
ECUBatterySecondary air
control solenoidvalve
Secondary
air valve
Ignition
switch
Air
intakeBypass valveVacuum tank
Intercooler
Turbocharger
Wastegate
actu
ator No. 1
wastegate
solenoid
valve
No. 2 wastegate
solenoid valve Crank angle
sensor