Mitsubishi Eclipse. Manual — part 881

CYLINDER HEAD AND VALVES

TSB Revision

ENGINE OVERHAUL <3.0L>

11D-33

>>D<< CYLINDER HEAD BOLT INSTALLATION
1. Insert the cylinder head bolt with a washer attached into the

bolt hole in the cylinder head. The washer must be set with
the "rounded shoulder" side upward.

2. Tighten the cylinder head bolts to the specified torque in the

sequence shown.

Tightening torque: 108

± 5 N⋅m (80 ± 4 ft-lb)

3. Loosen all bolts fully.
4. Retighten the cylinder head bolts to the specified torque in

the sequence shown.

Tightening torque: 108

± 5 N⋅m (80 ± 4 ft-lb)

INSPECTION

M1113007000044

.

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

a straightedge and feeler gauge 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 it exceeds the limit, correct to meet the specification.

Grinding limit: *0.2 mm (0.007 inch)
*Includes combined with cylinder block grinding.

Cylinder head height (specification when new):

120 mm (4.7 inches)

.

AKX00657

CYLINDER HEAD BOLT

ROUNDED
SHOULDER

WASHER

CYLINDER
HEAD

AB

AKX00673

MD998051

TIMING BELT SIDE

AB

AKX00733

CYLINDER HEAD AND VALVES

TSB Revision

ENGINE OVERHAUL <3.0L>

11D-34

VALVE
1. Check the valve seat contact. The valve seat contact should

be uniform at the center of the valve face. If incorrect, reface
using a valve refacer.

2. If the margin is below the 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 the limit, replace the valve.

Standard value:

<Intake> 112.30 mm (4.421 inches)
<Exhaust> 114.11 mm (4.493 inches)

Minimum limit:

<Intake> 111.80 mm (4.402 inches)
<Exhaust> 113.61 mm (4.473 inches)

.

VALVE SPRINGS
1. Measure the free height of the springs. If it is less than the

limit, replace.

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

2. Measure the squareness of the springs. If it exceeds the

limit, replace.

Standard value: 2 degree angle or less
Limit: 4 degree angle

.

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

Standard value:

<Intake> 0.02

− 0.05 mm (0.0008 − 0.0019 inch)

<Exhaust> 0.04

− 0.07 mm (0.0016 − 0.0027 inch)

Limit:

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

.

AKX00619

MARGIN

VALVE SEAT
CONTACT

AB

AKX00624

AKX00607

2˚

FREE
HEIGHT

AB

AKX00714

VALVE
GUIDE

STEM OUTSIDE
DIAMETER

GUIDE INSIDE DIAMETER

AB

CYLINDER HEAD AND VALVES

TSB Revision

ENGINE OVERHAUL <3.0L>

11D-35

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: 49.30 mm (1.941 inches)
Limit: 49.80 mm (1.960 inches)

VALVE SEAT RECONDITIONING PROCEDURE

1. Before correcting the valve seat, check for the clearance

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

2. Using the special tool or a seat grinder, correct to obtain the

specified seat width and angle.

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

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

VALVE SEAT REPLACEMENT PROCEDURE

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.

Intake seat ring hole diameter:

0.3 oversize

34.30

− 34.33 mm (1.3504 − 1.3516 inches)

0.6 oversize

34.60

− 34.63 mm (1.3622 − 1.3634 inches)

Exhaust valve seat ring hole diameter:

0.3 oversize

31.80

− 31.83 mm (1.2520 − 1.2531 inches)

0.6 oversize

32.10

− 32.13 mm (1.2638 − 1.2650 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.

AKX00695

SPRING SEATING
SURFACE

VALVE STEM END

VALVE STEM
PROJECTION

AB

AKX00717

0.9 – 1.3 mm
(0.04 – 0.05 in)

65˚

45˚

30˚

AB

AKX00610

0.5 – 1 mm
(0.020 – 0.039 in)

0.5 – 1 mm (0.020 – 0.039 in)

CUT
AWAY

AB

AKX00611

HEIGHT OF
SEAT RING

OVERSIZE DIAMETER

AB

CYLINDER HEAD AND VALVES

TSB Revision

ENGINE OVERHAUL <3.0L>

11D-36

4. 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

block.

CAUTION

Do not install a valve guide of the same size again.
3. Rebore 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 − 0.4457 inch)

0.50 oversize 11.50

− 11.52 mm (0.4528 − 0.4535 inch)

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

guide.
NOTE: The inlet valve guide has no snap ring groove.

5. Press-fit the valve guide until it protrudes 14.0 mm (0.55

inch) from the cylinder head top surface as shown in the
illustration.
NOTE: When press-fitting the valve guide, work from the
cylinder head top surface.
NOTE: After installing the valve guides, insert new valves in
them to check for smooth operation.

AKX00712

REMOVAL

INSTALLATION

PRESS

PRESS

PUSH ROD

VALVE
GUIDE

VALVE
GUIDE

AB

AKX00727

14 mm
(0.55 in)

AB