length NISSAN PATROL 1998 Y61 / 5.G Engine Mechanical Workshop Manual

3. Remove engine gussets and oil pan bolts.
+Remove bolts/nuts in numerical order shown in ®gure, alternat-
ing left and right ones toward the center.
4. Remove oil pump assembly.
Installation
Always install with new oil seal.
1. Install oil pump assembly.
Location Bolt length mm (in)
V120 (0.79)
V235 (1.38)
V345 (1.77)
V455 (2.17)
2. Install oil pan. Tighten bolts in the order shown in the ®gure.
+Always replace oil pan gaskets with new ones when reas-
sembling.
+Install oil pan gasket after cleaning the contacting surface.
+Oil pan bolts/nuts:
Bolt
:8-12Nzm (0.8 - 1.2 kg-m, 69 - 104 in-lb)
Nut
:10-14Nzm (1.0 - 1.4 kg-m, 87 - 122 in-lb)
3. Install engine gusset and oil pan guard.
SEM739B
SEM432C
SEM794F
SEM739BA
OIL PAN
Removal (Cont'd)
EM-15

7. Measure distance from cylinder head surface to intake and
exhaust valves. If speci®ed distance is exceeded, replace
valve(s) or valve seat(s).
Speci®ed distance: mm (in)
Standard
þ0.069 to 0.269 (þ0.0027 to 0.0106)
VALVE DIMENSIONS
1. Check dimensions in each valve. For dimensions, refer to SDS.
2. Correct or replace any valve that is out of tolerance.
3. Valve face or valve stem end surface should be refaced by
using a valve grinder.
When valve head has been worn down to 0.5 mm (0.020 in) in
margin thickness, replace the valve.
Grinding allowance for valve stem tip is 0.2 mm (0.008 in) or
less.
VALVE SPRING SQUARENESS
Check valve spring for squareness using a steel square and sur-
face plate.
If spring is out-of-square ``S'' more than speci®ed limit, replace with
new one.
Out-of-square:
Outer
Less than 1.9 mm (0.075 in)
Inner
Less than 1.6 mm (0.063 in)
VALVE SPRING PRESSURE LOAD
Measure the free length and the tension of each spring. If the
measured value exceeds the speci®ed limit, replace spring. Refer
to SDS.
SEM787F
EM030
E M 111
SEM333
EM113
CYLINDER HEAD
Inspection (Cont'd)
EM-35

VALVE LIFTER
1. Check contact and sliding surfaces for wear or scratches.
2. Check diameter of a valve lifter.
Outer diameter:
34.960 - 34.975 mm (1.3764 - 1.3770 in)
3. Check valve lifter guide bore.
Bore diameter:
34.998 - 35.018 mm (1.3779 - 1.3787 in)
Standard clearance:
0.023 - 0.058 mm (0.0009 - 0.0023 in)
If valve lifters are noisy, check valve lifter.
(1) Depress plunger forcibly with your ®nger.
If it moves about 1 mm (0.04 in), it indicates air is inside valve lifter.
(2) Reinstall valve lifter.
(3) Bleed air by running engine at 2,400 rpm under no-load for
about 20 minutes.
CAUTION:
When camshaft is removed to install, remove or inspect
hydraulic valve lifters, do not start engine for at least 30 min-
utes after reinstalling camshaft. (Wait until hydraulic valve lift-
ers have reached their set lengths.) Before starting engine,
rotate crankshaft by hand to ensure pistons do not interfere
with valves.
(4) Next check to ensure all air is bled. [Refer to step (1) above.]
(5) If there is still air, replace valve lifter.
SEM723B
SEM724B
SEM725B
CYLINDER HEAD
Inspection (Cont'd)
EM-36

2. Measure outer diameter of piston pin ``Dp''.
Standard diameter ``Dp'':
26.994 - 27.000 mm (1.0628 - 1.0630 in)
3. Calculate piston pin clearance.
dp þ Dp = þ0.004 to 0 mm (þ0.0002 to 0 in)
If it exceeds the above value, replace piston assembly with pin.
PISTON RING SIDE CLEARANCE
Side clearance:
Top ring
0.060 - 0.093 mm (0.0024 - 0.0037 in)
2nd ring
0.040 - 0.073 mm (0.0016 - 0.0029 in)
Max. limit of side clearance:
0.1 mm (0.004 in)
If out of speci®cation, replace piston ring. If clearance exceeds
maximum limit with new ring, replace piston.
PISTON RING END GAP
End gap:
Top ring
0.20 - 0.28 mm (0.0079 - 0.0110 in)
2nd ring
0.20 - 0.46 mm (0.0079 - 0.0181 in)
Oil ring
0.30 - 0.56 mm (0.0118 - 0.0220 in)
Max. limit of ring gap:
0.4 mm (0.016 in)
If out of speci®cation, replace piston ring. If gap still exceeds maxi-
mum limit with new ring, rebore cylinder and use oversized piston
and piston rings. Refer to SDS, EM-62.
+When replacing the piston, check cylinder block surface
for scratches or seizure. If scratches or seizure are found,
hone or replace the cylinder block.
CONNECTING ROD BEND AND TORSION
Bend:
Limit 0.025 mm (0.0010 in)
per 100 mm (3.94 in) length
Torsion:
Limit 0.025 mm (0.0010 in)
per 100 mm (3.94 in) length
If it exceeds the limit, replace connecting rod assembly.
SEM024AA
SEM822B
SEM038F
CYLINDER BLOCK
Inspection (Cont'd)
EM-48

VA LV E
Unit: mm (in)
SEM188A
Valve head diameter ``D''
Intake 39.0 - 39.3 (1.535 - 1.547)
Exhaust 32.0 - 32.3 (1.260 - 1.272)
Valve length ``L''
Intake101.53 - 101.97
(3.9972 - 4.0146)
Exhaust101.38 - 101.82
(3.9913 - 4.0087)
Valve stem diameter ``d''
Intake 6.965 - 6.980 (0.2742 - 0.2748)
Exhaust 6.945 - 6.960 (0.2734 - 0.2740)
Valve seat angle ``a''
Intake
45É15¢- 45É45¢
Exhaust
Valve margin ``T''
Intake 1.35 - 1.65 (0.0531 - 0.0650)
Exhaust 1.65 - 1.95 (0.0650 - 0.0768)
Valve margin ``T'' limit More than 0.5 (0.020)
Valve stem end surface
grinding limitLess than 0.2 (0.008)
Valve lifter
Unit: mm (in)
Valve lifter diameter34.960 - 34.975
(1.3764 - 1.3770)
Lifter guide hole diameter34.998 - 35.018
(1.3779 - 1.3787)
Clearance between lifter and lifter guide hole0.023 - 0.058
(0.0009 - 0.0023)
Valve guide
Unit: mm (in)
SEM796F
Standard Service
Valve guide
Outer
diameterIntake11.023 - 11.034
(0.4340 - 0.4344)11.233 - 11.234
(0.4422 - 0.4423)
Exhaust11.023 - 11.034
(0.4340 - 0.4344)11.233 - 11.234
(0.4422 - 0.4423)
Valve guide
Inner diam-
eter (Fin-
ished size)Intake 7.000 - 7.018 (0.2756 - 0.2763)
Exhaust 7.000 - 7.018 (0.2756 - 0.2763)
Cylinder head
valve guide
hole diameterIntake10.975 - 10.996
(0.4321 - 0.4329)11.185 - 11.196
(0.4404 - 0.4408)
Exhaust10.975 - 10.996
(0.4321 - 0.4329)11.185 - 11.196
(0.4404 - 0.4408)
Interference ®t of valve
guide0.027 - 0.059 (0.0011 - 0.0023)
Standard Limit
Stem to guide
clearanceIntake0.020 - 0.050
(0.0008 - 0.0020)0.1 (0.004)
Exhaust0.040 - 0.070
(0.0016 - 0.0028)0.1 (0.004)
Valve de¯ection limit 0.2 (0.008)
Projection length ``L'' 10.2 - 10.4 (0.402 - 0.409)
SERVICE DATA AND SPECIFICATIONS (SDS)
Inspection and Adjustment (Cont'd)
EM-58