1990 MITSUBISHI ECLIPSE engine

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ENGINE
I
Piston Rings
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9-2ENGINE- General Information
GENERAL INFORMATION
MAJOR
SPEClFlCATiONS
Row- -
Items
Number and arrangement of cylinderCylinder bore x stroke
mm (in.)
Total displacementcc (cu.in.1Compression ratio
Combustion chamber
Valve mechanismNumber of valve
Intake
Exhaust
Valve timing
IntakeOpen/CloseExhaust Open/Close
Lubrication
Oil pump
Fuel system
SuperchargerCooling system
Water pump
Alternator
Starter motor
Ignition system
Exhaust gas recirculation systemCatalytic converter
Crankcase ventilation system
Evaporative emission control system
Non-Turbo engineTurbo engine4 in-line, longitudinal
4 in-line, longitudinal
85 x
88 (3.346 x 3.465)85 x 88 (3.346 x 3.465)1997 (121.9)
1997 (121.7)
9.07.8
Pentroof typePentroof type
Double overhead camshaftDouble overhead camshaft
(DOHC)(DOHC)
88
88
26 “BTDU46”ABDC21”BTDC/Sl”ABDC56BBDUS”ATDC55”BBDUS”ATDC
Pressure feed-full flow filtrationPressure feed-full flow filtration
Gear typeGear type
Electronic control multipoint
fuelElectronic control multipoint fuel
injectioninjection
Turbo typeLiquid cooled-forced circulationLiquid cooled-forced circulation
-Impeller typeImpeller type
AC generator with a built-involtage regulatorAC generator with a built-in
voltage regulator
Planetary gear reduction drivePlanetary gear reduction drivetype
Two-coil type, electronic controlTwo-coil type, electronic control
ignitionignition
Conventional type: For FederalConventional type: For Federal
and Canadaand Canada
Electronical control type:Electronical control type:
For CaliforniaFor CaliforniaMonolithic type,
under-floorMonolithic type, under-floor
installationinstallation
Closed typeClosed type
Charcoal canister typeCharcoal canister type
I

q7 --_-.-ENGINE
- General Information9-3TECHNICAL FEATURES
HIGH PERFORMANCE AND . . .._..............1. The DOHC 16-valve engine ensures excellent intake and exhaust
FUEL ECONOMYefficiency.
2. The rocker arm is of the roller-type-cam-follower design which Iminimizes friction loss.
3. The combustion chamber is of the pentroof type with a squish
area that offers outstanding combustion efficiency.
4. The multipoint fuel injection system is electronically
controlled.5. The intake manifold is the inertia supercharging type which
improves intake efficiency and the dual-type exhaust manifold
offers good exhaust efficiency.
6. The two-coil type electronic control ignition system ensures
good ignition performance.
LOW VIBRATION AND. . . . . . ..I.................1. The hydraulic lash adjuster, together with the roller rocker arm,
LOW NOISEcontributes to reduced operating noise of the valve mechanism.
2. A cogged type belt is used to drive the camshaft.
3. The auto tensioner maintains the optimum timing belt tension.
4. The torsional damper reduces twisting vibration in the crankshaft’
to a minimum.
5. The silent shaft system reduces engine vibration and rolling
’moment to a minimum
SERVICEABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1. The self-diagnosis system makes troubleshooting easier.
2. The lash adjuster eliminates the need for valve clearance
adjustment.3. The auto tensioner eliminates the need for timing belt
tension adjustment.
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ENGINE- General information9-5
6EN0362Lb.. - -. __
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9-6ENGINE -General Information
6EN0363.-- -- -.. _-44

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ENGINE- Base Engine9-7I
BASE ENGINE
Valve seat
Squish area
Spark plug hole
Exhaust portintake port
Piston O.D.
6EN0076Camshaft lubricatingValve guide
6ENO246Camshaft lubricating
oil passage
6ENO247
(1) The combustion chamber is of the pentroof(2) The spark plugs are located at the center of the
type. The two intake and two exhaust ports arecombustion chambers.
in a crossflow arrangement. There is a
squish(3) The camshaft bearings are placed at six loca-area provided in the combustion chamber,tions on the intake side, and six on the exhaust
which promotes turbulence, further mixing ofside (see next page illustration). The thrust load
the air-fuel mixture, and more efficient
combus-of each camshaft is transmitted to the No. 1
tion.
bearing.
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9-8ENGINE - Base Engine
0
Ri
Bearing cap No.
No. 6R: Exhaust side
cyL: intake stdeNo. 5\-
CLNo.4 bd
P
j
CamshaftQsproc:kets -
sideintake sideno. 16EN0077ROCKER COVER
Rocker cover
From airintake
hose
erection that the spark
plug cable is installed.
6EN0378Breather plate
Rocker cover
To intakemanifoldPositive crankcase
ventilation valve
Viewed from bottom
of rocker cover
l Blow-by gas
C$ Fresh air6EN0384Installed inside the rocker cover is the breather plate. Theblowby gas passes through the space between the breather
plate and rocker cover and is drawn through the positive-
crankcase-ventilation valve to the intake manifold. As a result,
-fresh air is drawn to the engine cylinders.

CYLINDER BLOCKENGINE
- Base Engine9-9
Engine oil tocylinder
headCoolant inlet
ASilent
front
Engine oil main gallery
Silent shaft bearing,
rear
\shaft bearing,
A taw
Silenishaft bearing.
rearengine only)
6EN0246
(1) There is an oil jet provided for each cylinder just under the
main gallery of the cylinder block. When the pressure of oil
from the main gallery exceeds 200
kPa (2 kg/cm’, 28 psi),
the oil pushes open the check valve, spurting over the
inside of the piston, thus cooling it. (Turbo engines only)
(2) The water jacket is the Siamese type.