2008 MITSUBISHI LANCER EVOLUTION X engine

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)

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