Mitsubishi Lancer Evolution 8 MR. Manual - part 2

1-1

ENGINE (4G6) – GENERAL

SECTION 1

ENGINE (4G6)

CONTENTS

General ....................................................1-1

1. Major Specifications ....................................1-1
2. Engine Performance Curve.........................1-2

Base Engine (6 M/T) ...............................1-2

1. Cylinder head gasket...................................1-2
2. Pistons ..........................................................1-3
3. Piston rings (2nd) ........................................1-3

4. Oil rings ........................................................1-4
5. Counterbalance shaft  .................................1-4
6. Camshaft.......................................................1-5

Intake / Exhaust System (6 M/T)............1-6

1. Exhaust system ...........................................1-6

Control system (6 M/T)...........................1-8

1. Supercharging pressure control ..............1-10

General

The 4G63-T/C engine fitted in the Lancer Evolution VIII MR is basically the same as the 4G63-T/C engine used in the Lancer
Evolution VIII.

The basic structure is the same in both the 6M/T (6-speed) and 5M/T (5-speed) versions, but the following improvements have
been made to the 6M/T version, in order to achieve higher performance.

• Adoption of 5-ply cylinder head gasket
• Addition of V-shaped groove in piston , and modified shape in cooling channel
• Reduced oil consumption by increasing tension in piston rings and reducing end-to-end gap
• Extra durability and reduced oil consumption by using new treatment on outer surface of oil ring side rail, and altering

thickness

• Lighter counterbalance shaft
• Increased output at high engine speeds by modifying intake cams

Major Specifications

Item 

6 M/T

5M/T

Total Displacement cc

1997

Combustion chamber

Pentroof type

Bore x stroke  (mm)

85.0 x 88.0

Compression ratio

8.8

Camshaft arrangement

DOHC-4 valve

Fuel

Premium unleaded

Max. output (kW/rpm)

206/6500

Max. torque (Nm/rpm)

400/3500

392/3500

Fuel system

Electronic controlled multipoint fuel injection

Ignition system

Electronic controlled two-coil

Lash adjuster

Equipped

ENGINE (4G6) – GENERAL, BASE ENGINE (6 M/T)

1-2

2. Engine performance curve (6 M/T)

Base Engine (6 M/T)

1. Cylinder head gasket 

A 5-ply metal gasket has been introduced, in order to improve sealing properties. 

Shaft output (kW)

Shaft torque (N•m)

Engine r.p.m.

 

ENGINE (4G6) – BASE ENGINE (6 M/T)

1-3

2. Pistons

•

Addition of V-shaped groove.
A V-shaped 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 channel

V-shaped
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.

Item

Evolution VIII MR

Evolution VIII

Tension

10.5 N

7.0 N

End to end gap

0.30 – 0.45 mm

0.35 – 0.50 mm

End to end gap

ENGINE (4G6) – BASE ENGINE (6 M/T)

1-4

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