Mitsubishi Galant (2004+). Manual - part 604

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL <3.8L ENGINE>

11D-33

>>C<< RETAINER LOCK INSTALLATION
Using special tool MD998735 or MD998772, compress the
valve spring and insert the retainer lock into position.
NOTE: The valve spring, if excessively compressed, causes
the bottom end of retainer to damage the stem seal.

>>D<< CYLINDER HEAD BOLT INSTALLATION

CAUTION

Attach the head bolt washer in the direction shown in the
figure.
1. Tighten the bolts in the illustrated sequence two or three

steps.

Tightening torque: 108

± 5 N⋅m (80 ± 4 ft-lb)

2. Back off the bolts once and tighten them again to the

specified torque in step1.

AK100166

MD998735

AKX00617

MD998772

AKX01452AB

FRONT

MD998051

HEAD
BOLT
WASHER

RIGHT
BANK

LEFT
BANK

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL <3.8L ENGINE>

11D-34

INSPECTION

M1113007000464

CYLINDER HEAD
1. Check the cylinder head gasket surface for flatness by using

a straightedge in the directions of A through G shown in the
illustration.

Standard value: 0.03 mm (0.0012 inch)
Limit: 0.2 mm (0.007 inch)

2. If the service limit is exceeded, correct to meet the

specification.

Grinding limit: *0.2 mm (0.007 inch)

3. *If the service limit is exceeded, correct to meet the

specification.

Cylinder head height (specification when new):

120 mm (4.7 inches)

VALVE
1. Check the valve face for correct contact. If incorrect, reface

using a valve refacer. The valve should make a uniform
contact with the seat at the center of the valve face.

2. If the margin exceeds the service minimum limit, replace the

valve.

Standard value:

<Intake> 1.0 mm (0.04 inch)
<Exhaust> 1.2 mm (0.05 inch)

Minimum limit:

<Intake> 0.5 mm (0.02 inch)
<Exhaust> 0.7 mm (0.03 inch)

3. Measure the valve's total length. If the measurement is less

than specified, replace the valve.

Standard value:

<Intake> 110.30 mm (4.343 inches)
<Exhaust> 112.11 mm (4.414 inches)

Minimum limit:

<Intake> 109.80 mm (4.323 inches)
<Exhaust> 111.61 mm (4.394 inches)

VALVE SPRINGS
1. Measure the free height of the spring and, if it is smaller than

the minimum limit, replace the spring.

Standard value: 51.0 mm (2.01 inches)
Minimum limit: 50.0 mm (1.97 inches)

2. Measure the squareness of the spring and, if the limit is

exceeded, replace the spring.

Standard value: 2

° or less

Limit: 4

AKX00733

AKX00619

MARGIN

VALVE SEAT
CONTACT

AKX00624

AKX00607

2˚

FREE
HEIGHT

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL <3.8L ENGINE>

11D-35

VALVE GUIDES
Measure the clearance between the valve guide and valve
stem. If the limit is exceeded, replace the valve guide, valve, or
both.

Standard value:

<Intake> 0.02

− 0.05 mm (0.0008 − 0.0019 inch)

<Exhaust> 0.04

− 0.06 mm (0.0016 − 0.0023 inch)

Limit:

<Intake> 0.10 mm (0.003 inch)
<Exhaust> 0.15 mm (0.005 inch)

VALVE SEAT
Assemble the valve, then measure the valve stem projection
between the end of the valve stem and the spring seating sur-
face. If the measurement exceeds the specified limit, replace
the valve seat.

Standard value:

<Intake> 48.30 mm (1.902 inches)
<Exhaust> 51.71 mm (2.036 inches)

Limit:

<Intake> 48.80 mm (1.921 inches)
<Exhaust> 52.21 mm (2.056 inches)

VALVE SEAT RECONDITIONING PROCEDURE

CAUTION

Before correcting the valve seat, check the clearance
between the valve guide and valve and, if necessary,
replace the valve guide.
1. Using the special tool or a seat grinder, correct to obtain the

specified seat width and angle.

2. After correcting the valve seat, lap the valve and valve seat

using lapping compound. Then, check the valve stem
projection.

AKX00714

VALVE
GUIDE

STEM OUTSIDE
DIAMETER

GUIDE INSIDE DIAMETER

AKX00695

SPRING SEATING
SURFACE

VALVE STEM END

VALVE STEM
PROJECTION

AK101830AB

0.9 – 1.3 mm
(0.04 – 0.05 in)

65˚

15˚

25˚

43.5˚ – 44˚

0.9 – 1.3 mm
(0.04 – 0.05 in)

CYLINDER HEAD AND VALVES

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ENGINE OVERHAUL <3.8L ENGINE>

11D-36

VALVE SEAT REPLACEMENT PROCEDURE

CAUTION

Before replacing the valve seat, check the valve guide and,
if necessary, replace the valve guide.
1. Cut the valve seat from the inside to thin the wall thickness.

Then, remove the valve seat.

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

oversize valve seat diameter.

Seat ring hole diameter:

Intake valve

0.3 oversize 37.80

− 37.83 mm (1.4882 − 1.4894

inches)
0.6 oversize 38.10

− 38.13 mm (1.5000 − 1.5012

inches)

Exhaust valve

0.3 oversize 34.80

− 34.83 mm (1.3701 − 1.3713

inches)
0.6 oversize 35.10

− 35.13 mm (1.3819 − 1.3831

inches)

3. Before fitting the valve seat, either heat the cylinder head up

to approximately 250

°C (482°F) or cool the valve seat in

liquid nitrogen, to prevent the cylinder head bore from
galling.

4. Using a valve seat cutter, correct the valve seat to the

specified width and angle. Using a valve seat cutter, correct
the valve seat to the specified width and angle. See "VALVE
SEAT RECONDITIONING PROCEDURE" on the previous
page.

VALVE GUIDE REPLACEMENT PROCEDURE
1. Remove the snap ring from the exhaust valve guide.
2. Using a press, remove the valve guide toward the cylinder

head gasket surface.

CAUTION

Do not install a valve guide of the same size again.
3. Re-bore the valve guide hole of the cylinder head so that it

fits the press-fitted oversize valve guide.

Valve guide hole diameter:

0.05 oversize 11.05

− 11.07 mm (0.4350 − 0.4358 inch)

0.25 oversize 11.25

− 11.27 mm (0.4429 − 0.4437 inch)

0.50 oversize 11.50

− 11.52 mm (0.4528 − 0.4535 inch)

4. Install the new snap ring into the groove of exhaust valve

guide.

AKX00610

0.5 – 1 mm
(0.020 – 0.039 in)

0.5 – 1 mm (0.020 – 0.039 in)

CUT
AWAY

AKX00611

HEIGHT OF
SEAT RING

OVERSIZE DIAMETER

AKX00712

REMOVAL

INSTALLATION

PRESS

PUSH ROD

VALVE
GUIDE

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