Mitsubishi Colt Ralliart. Manual — part 609

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <4G1>

11D-36

8. Give another 90

° turn in the tightening direction to

each bolt, making sure that the paint mark on the
bolt head and that on the cylinder head are on the
same line.

INSPECTION

M1113007000873

CYLINDER HEAD

1. Before cleaning the cylinder head, check it for

traces of water and gas leakage and for cracks
and any other damage.

2. Thoroughly remove oils, scale, sealants, carbon

and other contamination. Clean the oil passages,
then check using compressed air that they are not
blocked.

AK202724

3. Check the cylinder head gasket surface for warp

using a straightedge and thickness gauge.
If the surface is warped beyond the limit, grind the
surface for rectification.

CAUTION

The thickness of the metal that can be removed
by grinding from both the cylinder head and the
mating cylinder block is limited to 0.2 mm in
total.

Gasket surface warp

Standard value: 0.03 mm or less
Limit: 0.2 mm
Grinding limit: 0.2 mm

Cylinder head height (standard value for new

part):

131.9

− 132.1 mm

VALVES

1. Check the valve face for correct contact with the

seat. Reface the valve if the contact is partial or
one sided.

AK300593AB

Margin

Contact
(Should be at
centre of face)

2. Measure the margin.

Replace the valve if its margin is smaller than the
limit.

Standard values:

Intake 1.0 mm
Exhaust 1.5 mm

Limits:

Intake 0.5 mm
Exhaust 1.0 mm

AK304590AB

Total length

3. Measure the total length of the valve.

Replace the valve if the length is less than the
limit.

Standard values:

Intake 106.35 mm
Exhaust 106.85 mm

Limits:

Intake 105.85 mm
Exhaust 106.35 mm

Main

Index

Group

TOC

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <4G1>

11D-37

VALVE SPRINGS

AK300594

Out of square

Free height

AB

1. Measure the free height of the spring.

Replace the spring if its height is smaller than the
limit.

Standard value: 54.8 mm
Limit:53.8 mm

2. Measure the squareness of the spring.

Replace the spring if it is out of square beyond the
limit.

Standard value: 2

° or less

Limit: 4

°

VALVE GUIDE

AK300168

Guide inside diameter

Stem diameter

Valve
guide

AE

Measure the valve guide inside diameter and valve
stem diameter to calculate the clearance between
the valve guide and valve stem.
If the limit is exceeded, replace the valve guide or
valve, or both.

Standard values:

Intake 0.02

− 0.05 mm

Exhaust 0.03

− 0.06 mm

Limits:

Intake 0.10 mm
Exhaust 0.15 mm

VALVE SEATS

AK300596

Valve stem
projection

Spring
seating
surface

AB

Valve stem
end

With the valve installed in position and its face
pressed against the valve seat, measure the valve
stem projection (distance between the valve stem
end and spring seating surface). If the measurement
exceeds the limit, replace the valve seat.

Standard values:

Intake 48.8 mm
Exhaust 48.7 mm

Limits:

Intake 49.3 mm
Exhaust 49.2 mm

VALVE SEAT RECONDITIONING

1. Before reconditioning the valve seat, check the

clearance between the valve guide and valve
stem and, if necessary, replace the valve guide.

AK201838AC

65˚

65˚

0.9 – 1.3 mm

0.9 – 1.3 mm

20˚

15˚

43.5˚ to 44˚

Intake valve stem seal

Exhaust valve stem seal

2. Resurface the valve seat to the indicated width

and angles.

3. After resurfacing, lap the valve and valve seat

using lapping compound.

Main

Index

Group

TOC

CYLINDER HEAD AND VALVES

ENGINE OVERHAUL <4G1>

11D-38

VALVE SEAT REPLACEMENT

AK300597

0.5 – 1 mm

0.5 – 1 mm

Cut

AB

1. Cut inside of the valve seat to be replaced until its

wall becomes thin enough for removal, then
remove the valve seat.

AK300598

Valve seat
height

Oversize hole diameter

AB

2. Rebore the valve seat hole in the cylinder head to

a diameter matched to the diameter of the
selected oversize valve seat.

Intake valve seat hole diameters:

0.3 oversize 31.30

− 31.33 mm

0.6 oversize 31.60

− 31.63 mm

Exhaust valve seat hole diameters:

0.3 oversize 27.80

− 27.82 mm

0.6 oversize 28.10

− 28.12 mm

3. Before fitting the valve seat, cool it in liquid

nitrogen to prevent damage to its hole in the
cylinder head due to interference.

4. Resurface the valve seat. See the VALVE SEAT

RECONDITIONING section.

VALVE GUIDE REPLACEMENT

1. Force out the valve guide toward the cylinder

block using a press.

CAUTION

Do not use a replacement valve guide of the
same size as the removed one.
2. Machine the valve guide hole in the cylinder head

to the size matched to the selected oversize valve
guide.

Valve guide hole diameters

0.05 oversize: 10.55

− 10.57mm

0.25 oversize: 10.75

− 10.77 mm

0.50 oversize: 11.00

− 11.02 mm

AK201837AC

Projection

3. Press-fit the valve guide until it remains protruded

above the cylinder head by the amount indicated
in the illustration.

Standard value: 22.7

− 23.3 mm

NOTE: Press the valve guide from above the cyl-
inder head.
NOTE: The valve guides for the intake valves are
different in length from those for the exhaust
valves (48 mm for intake valves; 55 mm for
exhaust valves)

4. After installing the valve guide, insert a new valve

in it to check for smooth movement.

Main

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TOC

OIL PAN AND OIL PUMP

ENGINE OVERHAUL <4G1>

11D-39

OIL PAN AND OIL PUMP

REMOVAL AND INSTALLATION

M1113008101241

AK401832AD

Apply engine oil to
all moving parts
before installation.

10

18

19

12

14

16

13

9

7

20

4

5

8

23 ± 4 N·m

39 ± 5 N·m

7.0 ± 1.0 N·m

10 ± 2 N·m

11

6

17

10 ± 2 N·m

14 ± 1 N·m

19 ± 3 N·m

44 ± 5 N·m

10 ± 2 N·m

15

3

2

1

27 ± 2 N·m

AK401832

Removal steps

>>

F

<< 1. Oil filter

2. Oil cooler bolt
3. Oil cooler

>>

E

<< 4. Oil pressure switch

>>

D

<< 5. Drain plug

6. Drain plug gasket
7. Transmission stay

<<

A

>> >>

C

<< 8. Oil pan

9. Oil screen
10. Oil screen gasket
11. Baffle plate

12. Relief plug
13. Relief spring
14. Relief plunger

>>

B

<< 15. Front oil seal

>>

A

<< 16. Oil pump case

17. O-ring
18. Oil pump cover
19. Oil pump outer rotor
20. Oil pump inner rotor

Removal steps (Continued)

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TOC