Nissan Titan. Manual — part 320
EM-84
< REMOVAL AND INSTALLATION >
CYLINDER HEAD
VALVE GUIDE REPLACEMENT
When the valve guide is removed, replace it with an oversized (0.2 mm, 0.008 in) valve guide.
1. To remove the valve guide, heat the cylinder head to 110
° to
130
°C (230° to 266°F) by soaking it in heated oil.
2. Remove the valve guide using suitable tool.
WARNING:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
3. Ream the cylinder head valve guide hole using suitable tool.
4. Heat the cylinder head to 110
° to 130°C (230° to 266°F) by
soaking it in heated oil.
SEM008A
SEM931C
Valve guide hole diameter:
Standard
Intake and exhaust : 9.975 - 9.996 mm (0.3927 -
0.3935 in)
Oversize (service)
Intake and exhaust : 10.175 - 10.196 mm (0.4006
- 0.4014 in)
SEM932C
SEM008A
CYLINDER HEAD
EM-85
< REMOVAL AND INSTALLATION >
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5. Press the valve guide from the camshaft side to the dimensions
as shown.
WARNING:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
6. Ream the cylinder head valve guide using suitable tool.
VALVE SEAT CONTACT
• After confirming that the dimensions of the valve guides and valves
are within specifications, perform this procedure.
• Apply prussian blue (or white lead) onto the contacting surface of
the valve seat to check the condition of the valve contact on the
surface.
• Check if the contact area band is continuous all around the circum-
ference.
• If not, grind to adjust the valve fit and check again. If the contacting
surface still has NG conditions even after the re-check, replace the
valve seat.
VALVE SEAT REPLACEMENT
When the valve seat is removed, replace it with oversized (0.5 mm, 0.020 in) valve seat.
1. Bore out the old seat until it collapses. Boring should not continue beyond the bottom face of the seat
recess in the cylinder head. Set the machine depth stop to ensure this.
2. Ream the cylinder head recess diameter for service valve seat.
• Be sure to ream in circles concentric to the valve guide center.
• This will enable valve seat to fit correctly.
KBIA2530E
Valve guide inside diameter:
Intake and exhaust : 6.000 - 6.018 mm (0.2362
- 0.2369 in)
SEM932C
SBIA0322E
Oversize [0.5 mm (0.020 in)] (Service):
Intake
: 38.500 - 38.516 mm (1.5157 - 1.5164 in)
Exhaust
: 32.700 - 32.716 mm (1.2874 - 1.2880 in)
SEM795A
EM-86
< REMOVAL AND INSTALLATION >
CYLINDER HEAD
3. Heat the cylinder head to 110
° to 130°C (230° to 266°F) by
soaking it in heated oil.
4. Cool the valve seats well with dry ice. Force fit the valve seat into the cylinder head.
WARNING:
• Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.
• Avoid directly touching cold valve seats.
5. Finish the seat to the specified dimensions using suitable tool.
CAUTION:
When using valve seat cutter, firmly grip the cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on the cutter or cutting many different times may
result in stage valve seat.
6. Grind to obtain the dimensions indicated as shown.
• Using compound, grind to adjust valve fitting.
7. Check again for normal contact.
VALVE SPRING SQUARENESS
SEM008A
SEM934C
KBIA2531E
KBIA2544E
CYLINDER HEAD
EM-87
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• Set try square along the side of valve spring and rotate the spring.
Measure the maximum clearance between the top face of spring
and try square.
• If measurement is not within specifications, replace the valve
spring.
VALVE SPRING DIMENSIONS AND VALVE SPRING PRESSURE LOAD
• Check the valve spring pressure at the specified spring height.
• If measurement is not within specifications, replace the valve spring.
Limit
: Less than 2.2 mm (0.087 in)
PBIC0080E
Standard:
Intake and exhaust
Free height:
50.58 mm (1.9913 in)
Installation height:
37.0 mm (1.457 in)
Installation pressure:
165.8 - 187.0 N (16.9 -
19.1 kg, 37- 42 lb)
Height during valve open: 28.2 mm (1.110 in)
Load with valve open:
314.8 - 355.0 N (32.1 -
36.2 kg, 71 - 80 lb)
SEM113
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