engine MITSUBISHI LANCER EVOLUTION X 2008 User Guide

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)

BASE ENGINE
ENGINE MECHANICAL11A-7
PISTON RINGS
The piston rings consist of No. 1 and No. 2 rings and
an oil ring.
AK604544
Oil ring
SpacerRailMaker mark
AB
Oil ring Piston ring No. 1Piston ring No. 1
Piston ring No. 2Piston ring No. 2
ItemPiston ring No. 1Piston ring No. 2Oil ring
ShapeInside bevel, BarrelTaper undercut3-piece, Barrel
Surface treatment (cylinder
contact surface)Chrome platingParkerizingHard plated Parkerizing
Supplier mark1T2TNone

BASE ENGINE
ENGINE MECHANICAL11A-8
CONNECTING RODS
The connecting rods are made of highly rigid, forged
carbon steel. The cross section of the rod portion is
shaped like the letter H.
A fracture-split process has been adopted for split-
ting the big end of the connecting rod.
The fracture split connecting rod has the high inser-
tion force between the rod and the cap as well as the
high installation location accuracy.
The oil holes that feed oil from the main journals of
the crankshaft to the crankshaft pins lubricate the
bearings at the big ends of the connecting rods.
CONNECTING ROD BEARINGS
The upper and lower connecting rod bearings are the
same. Each connecting rod bearing is provided with
a backing plate. Its bearing portion is made of an alu
-
minum alloy and its backing plate is made of ordinary
sheet steel.
The width of the connecting rod bearing has been
made as narrow as possible in proportion to the
bearing cap in order to reduce friction loss.
24
AK502491
D
L d
AD
20
ItemSpecifications
Small end hole diameter
(d) mm (in)21 (0.87)
Big end hole diameter (D)
mm (in)51 (2.01)
Center-to-center distance
(L) mm (in)149.25 (5.876)
AK502492AD A
H
Identification
color
ItemSpecifications
Width (H) mm (in)17 (0.7)
Thickness (A) mm (in)1.5 (0.06)

BASE ENGINE
ENGINE MECHANICAL11A-9
CRANKSHAFT
A forged crankshaft has been adopted.
It has 5 main bearings and 8 balance weights.
The crankshaft pins are located at equal 180° inter-
vals.
The oil holes feed engine oil from the journals to the
pins.
A crankshaft sprocket and an oil pump drive shaft are
press-fit to the front of the crankshaft.
CRANKSHAFT BEARINGS, THRUST BEARINGS
The upper crankshaft bearings have oil grooves and
the lower crankshaft bearings do not.
Each crankshaft bearing is provided with a backing
plate. Its bearing portion is made of an aluminum
alloy and its backing plate is made of ordinary sheet
steel. A thrust bearing, which sustains the load in the
thrust direction, is provided at each end of the No. 3
bearing.
AK502493AD
Balance weight
Balance weightBalance weightOil hole
Oil hole
ItemSpecifications
Pin outer diameter mm
(in)48 (1.9)
Journal outer diameter
mm (in)52 (2.0)
AK602940AC
Groove
Front
Thrust bearing
Upper bearingLower bearing
Oil groove
Oil hole
Identification
colorIdentification
color
ItemSpecifications
Crankshaft bearingWidth mm
(in)18 (0.71)
Thickness
mm (in)2.0 (0.08)
Crankshaft thrust
bearingThickness
mm (in)2.0 (0.08)

BASE ENGINE
ENGINE MECHANICAL11A-10
CRANKSHAFT PULLEY
The pulley is made of cast iron.
The pulley portion has grooves for the V-ribbed belt
(with 6 crests).
The flange portion of the pulley has a timing mark
notch for checking the ignition timing.
A torsion damper has been adopted to reduce the
torsional vibration of the crankshaft, as well as to
dramatically reduce noise and vibration in the
high-speed range.
DRIVE PLATE
The drive plate is made of sheet metal.The drive plate is mounted with 7 bolts.
AK604551Timing markRubberAB
AK502496
Ring gear Drive plate
AD

BASE ENGINE
ENGINE MECHANICAL11A-11
FLYWHEEL
A cast iron ring gear is a shrink fit in the iron casting
of the flywheel.
The flywheel is mounted with 7 bolts.
TIMING CHAIN TRAIN
The two camshafts are driven by the timing chain via
the camshaft sprockets.
The timing chain is a silent, endless type, consisting
of 180 links. It is installed around the V.V.T. sprockets
and the crankshaft sprocket.
Three (orange) mark link plates are installed on the
timing chain to locate the sprockets.
AK603618AB
Ring gear
AK502497
Timing mark
link plate (orange)Timing mark
Timing mark
link plate (orange)
Intake V.V.T. sprocket
Chain guide
Crankshaft spocket
Cranshaft spocket
timing mark
Timing mark
link plate (orange) Exhaust V.V.T. sprocket
Tensioner lever
Timing chain
tensioner
AD
ItemNumber of teeth
V.V.T. sprockets54
Crankshaft sprocket27

BASE ENGINE
ENGINE MECHANICAL11A-12
TIMING CHAIN TENSIONER
The tensioner maintains the tension of the timing
chain. It contains a piston with a built-in spring.
With the tensioner installed, its piston directly pushes
on the tension lever in order to automatically adjust
the tension of the timing chain.
VA LV E T R A I N
The valve train is the 4-valve, double overhead cam-
shaft (DOHC) type in which the camshafts are
located above the valves.
Two intake and exhaust valves for each cylinder are
arranged in a V shape.
A valve tappet is interposed between the camshaft
and each valve, which allows the valve to open and
close.
AK502997
SpringPiston
AE
Rack and
washer
assembly
AK502499
Exhaust
camshaftIntake
camshaft
Valve tappet
Intake valve
Exhaust valve
AD

BASE ENGINE
ENGINE MECHANICAL11A-13
VA LV E S
The valves are made of heat-resistant steel and are
nitrided on their entire surface.
VALVE STEM SEALS
The valve stem seals are integrated with the valve
spring seats.
The valve stem seal portion excels in sealing perfor-
mance and is equipped with a spring to prevent oil
from descending.
VA LV E S P R I N G S
To prevent the engine from surging at high speeds,
unequal-pitch springs are used.
AK502500
LL Dd dD
AD
Intake Exhaust
ItemIntake valveExhaust valve
Head diameter
(D) mm (in)35 (1.4)29 (1.1)
Stem diameter
(d) mm (in)5.5 (0.22)5.5 (0.22)
Overall length (L)
mm (in)113.180
(4.4559)105.887
(4.1688)
AK502501
Spring
AD
AK502502
h
AD
ItemSpecifications
Free height (h) mm (in)47.44 (1.867)
Total number of windings8.67

BASE ENGINE
ENGINE MECHANICAL11A-14
VALVE TAPPETS
To adjust the valve lift, 47 sizes of valve tappets are
available in 0.015 mm (0.0006 in) increments, from
3.000 mm (0.1181 inch) to 3.690 mm (0.1453 in).
MIVEC (MITSUBISHI INNOVATIVE VALVE TIMING ELECTRONIC CONTROL SYSTEM)
The MIVEC consists of the parts shown in the illus-
tration.
This system continuously varies and optimally con-
trols the opening and closing timing of the individual
intake and exhaust valves, in order to improve torque
and power output in all speed ranges.
AK502503
Identification
markThickness
AD
AK503014
Exhaust V.V.T. sprocket
Section A-ASection B-B
Engine oil control
valve filter
Intake V.V.T. sprocket
Cylinder head
Cylinder blockB
B
Engine oil
control valve
Cylinder head
Cylinder block A
A
AE
Engine oil
control valve