Isuzu NHR 4J Series, Workshop Manual

Page: 38 / 406

00 – 34 SERVICE INFORMATION
SERVICE STANDARD
Engine Mechanical
mm (in)
Service standard Service limit
Parts Items
4JG2
4JB1 / 4JB1T /
4JB1TC
4JG2
4JB1 / 4JB1T /
4JB1TC
Remarks
Cylinder head deck, and
exhaust manifold mating
surface for flatness
0.05 (0.002) or less 0.2 (0.0079)
Cylinder head height 92.0 (3.622) 91.55 (3.6043)
Cylinder
Head
Cylinder Head Lower Face
Warpage.
Manifold Warpage.
Hot plug sinking
Hot plug exert pressure
0.05 (0.002)or less
0.05 (0.002) or less
-
4,500 – 5,500 kg
(9922.5 - 12127.5 lbs)
0.20 (0.008)
0.20 (0.008)
0.02 (0.0008)
-
Cannot be
Reground
Valve
Spring Free height
Squareness
Spring tension N (kg/lb)
48.0 (1.891)
-
296 (30.2/66.4)
47.10 (1.856)
1.7 (0.067)
257.9 (26.3/57.9) At installed
height
38.9 (1.531)
7.946 - 7.961
(0.3128 - 0.3134)
7.921 - 7.936
(0.3118 - 0.3124)
0.039 - 0.069
(0.0015 - 0.0027)
0.064 - 0.096
(0.0025 - 0.0038)
13.0 (0.512)
1.1 (0.0433)
7.880 (0.3102)
7.850 (0.3090)
0.200 (0.0079)
0.250 (0.0098)
-
1.6 (0.0630)
1.41 (0.0556)
1.39 (0.0547)
1.79 (0.0705)
1.83 (0.0720)
1.1 (0.0433)
1.1 (0.0433)
1.5 (0.06)
1.5 (0.06)
Valve
and
Valve
Guide Diameter Valve Stem
IN
EX
Valve and valve guide
clearance
IN
EX
Valve guide upper end
height (Measured from the
Cylinder head upper face)
Valve guide margin
Valve thickness IN
EX
Valve seat contact surface
angle
Valve seat contact width
IN
EX
45°
1.7 (0.0669)
2.0 (0.0787)
2.2 (0.0866)
2.5 (0.0984)