MITSUBISHI LANCER EVOLUTION X 2008 Service Manual

A/C COMPRESSOR
HEATER, AIR CONDITIONING AND VENTILATION55-9
A/C COMPRESSORM2551001100268
HIGH EFFICIENCY COMPRESSOR WITH
INTEGRATED OIL SEPARATOR
High efficiency compressor with integrated oil sepa-
rator has been adopted to enhance fuel economy by
reducing the A/C operating rate.
MAGNETIC CLUTCH WITH THERMAL
FUSE
At the compressor lock, the thermal fuse integrated
in the magnet clutch is blown due to the frictional
heat against the compressor in order to reduce risk
of the drive belt breakage. The thermal fuse, together
with the coil, is coated with resin to enhance resis
-
tance to corrosion.
2-STEP PROFILE COMPRESSOR
The centre area of the scroll in the compressor pro-
vides 2-step profile, and thickness of area "B" shown
in the figure has been increased to enhance
strength. With this feature, thickness of area "A"
shown where lesser load is applied is reduced, thus
compressor performance is enhanced by compress
-
ing refrigerant even in central area, comparing to the
previous model.
CONDENSERM2551001400140
The condenser has been integrated with the radiator (cooling
module) to optimise ventilation and reduce weight.
AC507301
aa bbAA
BB
AC
Section a - aSection b - b Front viewFront view <2-step profile
compressor>
AC608768
Condenser
AB
Radiator

DUCT
HEATER, AIR CONDITIONING AND VENTILATION55-10
DUCTM2551001300358
The rear heater duct has been introduced, and the
air distribution ratio to front and rear seats has been
optimised in order to enhance the air heating perfor
-
mance for the rear seats, and to prevent the circula-
tion of cooled air back to the front seats. with rear duct>
AC608058
To front door window
(Side defroster)
Side ventilator
Center ventilatorTo windshield (Defroster)
To front door window
(Side defroster)
To passenger seat footwell
To driver seat footwell
To rear seat footwell
(Vehicle with rear duct)
To rear seat footwell
(Vehicle with rear duct)
Side ventilator
AB

VENTILATION SYSTEM
HEATER, AIR CONDITIONING AND VENTILATION55-11
VENTILATION SYSTEMM2551002000554
Fresh air is sucked from the front deck and
exhausted through the air outlet behind the rear
bumper. Optimizing areas of the outside air induction
hole and the air outlet enhances ventilated air
amount, reducing noise.
AC608060Rear ventilator ductAB

NOTES

11A-1
GROUP 11A
ENGINE
MECHANICAL
CONTENTS
GENERAL DESCRIPTION. . . . . . . . .11A-2BASE ENGINE . . . . . . . . . . . . . . . . . .11A-3

GENERAL DESCRIPTION
ENGINE MECHANICAL11A-2
GENERAL DESCRIPTIONM2112000101162
This model is equipped with a newly developed 4B11
engine. It is a 4-cylinder, double overhead camshaft
(DOHC) engine with a 2.0-L cylinder displacement.
This engine has adopted the following features:
•MIVEC (MITSUBISHI INNOVATIVE VALVE TIM-
ING ELECTRONIC CONTROL SYSTEM) for
both the intake and exhaust valves
•Cylinder block made of an aluminum alloy
•Valve train with direct-acting valve tappets
•Silent timing chain
MAIN SPECIFICATIONS
DescriptionsSpecifications
Engine type4B11
Bore × stroke mm (in)86 (3.4) × 86 (3.4)
Total displacement cm3 (cu in)1,998 (121.9)
Combustion chamberPent-roof type
Number of cylinders4
Valve mechanismTy p eDOHC
Intake valve8
Exhaust valve8
Compression ratio10.0
Va l v e t i m i n gIntake valveOpens (BTDC)3° − 28°
0° − 25°
Closes (ABDC)45° − 20°
48° − 23°
Exhaust valveOpens (BBDC)41° − 21°
44° − 24°
Closes (ATDC)3° − 23°
0° − 20°
Maximum output kW/r/min (HP/r/min)107/6,000 (143/6,000)
113/6,000 (152/6,000)
Maximum torque N⋅m/r/min (lbs-ft/r/min)194/4,250 (143/4,250)
198/4,250 (146/4,250)
Fuel injection system typeElectronic control MPI
Ignition system typeElectronic spark-advance control type (4-coil
type)
Generator typeAlternating current system (with built-in IC
regulator)
Starter motor typeReduction drive type

BASE ENGINE
ENGINE MECHANICAL11A-3
BASE ENGINEM2112001001050
CYLINDER HEAD
A cylinder head made of an aluminum alloy, which is
lightweight and offers a high level of cooling effi
-
ciency, has been adopted. A pentroof combustion
chamber with a center spark plug has been adopted.
It has a small valve compound angle to realize a
compact chamber.
Cross-flow type intake and exhaust ports have been
adopted. Two intake ports and two exhaust ports are
provided independently on the right and left sides.
Five camshaft bearings are provided at the intake
and exhaust sides, respectively. The No. 4 bearing
sustains the thrust load of the camshaft. Only the No.
1 bearing uses a bearing cap that integrates both the
intake and exhaust sides.
VA LV E S E AT S
Sintered alloy valve seats have been adopted.The oversized (0.3 mm) service parts are available.
VA LV E G U I D E S
Valve guides that are common to both the intake and
exhaust have been adopted.The oversized (0.25 mm) service parts are available.
AK502483
Valve guide
AD
Exhaust side
Intake side

BASE ENGINE
ENGINE MECHANICAL11A-4
CYLINDER HEAD GASKET
A dual-layer, metal type cylinder head gasket that
excels in heat resistance and sealing performance
has been adopted.
CYLINDER HEAD COVER
A Plastic cylinder head cover has been adopted.
AK604543
Oil hole
Water hole
Water hole
AB
AK502485

BASE ENGINE
ENGINE MECHANICAL11A-5
CYLINDER BLOCK
A cylinder block made of an aluminum alloy has
been adopted for weight reduction.
5 bearings are used for the crankshaft journals and
the No. 3 bearing sustains the thrust load of the
crankshaft.
The water jacket is the full Siamese type.
An oil jet is used in front of the cylinder block to sup-
ply engine oil to the timing chain.
AK502486
Oil jetCylinder blockBearing cap
AE
Ladderframe
ITEMSPECIFICATIONS
Distance between top and
crankshaft center mm (in)230.1 (9.06)
Bore mm (in)86 (3.4)
Bore pitch mm (in)96 (3.8)
Stroke mm (in)86 (3.4)

BASE ENGINE
ENGINE MECHANICAL11A-6
PISTONS
The pistons are made of a special aluminum alloy.
Their weight has been reduced by lowering their
overall height and increasing the depression at each
end of the piston pin.
The piston pin hole center is offset 0.8 mm (0.031 in)
towards the thrust side of the piston center.
The skirt portion along the perimeter of the piston is
finished with streaks that excel in oil retention and
seizure resistance.
PISTON PINS
The piston pins are the semi-floating type. Each pin
is press-fit and secured in the small end of the con
-
necting rod, while it floats in the piston.
20
A
AK603610
Front mark
Piston offset
AB
ITEMSPECIFICATIONS
Basic diameter mm (in)86 (3.4)
Pin hole diameter mm (in)21 (0.8)
Overall height mm (in)50.5 (1.99)
AK502996AE
D
hd1d2
ITEMSPECIFICATIONS
Outer diameter (D) mm
(in)21 (0.8)
Inner diameter (d1) mm
(in)12 (0.5)
Inner diameter (d2) mm
(in)10.5 (0.41)
Overall length (h) mm (in)58 (2.3)