Isuzu 4ja1 User Manual

6A – 62 ENGINE MECHANICAL
Manifold Fitting Face Warpage
Use a straight edge and a feeler gauge to measure the
manifold cylinder head fitting face warpage.
Regrind the manifold cylinder head fitting surfaces if the
measured values are greater than the specified limit but less
than the maximum grinding allowance.
If the measured values exceed the maximum grinding
allowance, the cylinder head must be replaced.
Manifold Fitting Face Warpage
mm (in)
Standard Limit
Maximum Grinding
Allowance
0.05
(0.002) or less
0.20
(0.008)
0.40
(0.016)
Exhaust Manifold Warpage
Use a straight edge and a feeler gauge to measure the
manifold cylinder head fitting face warpage.
If the measured values exceed the specified limit, the manifold
must be replaced.
Exhaust Manifold Warpage mm (in)
Standard Limit
0.05 (0.002) or less 0.20 (0.008)
Valve Stem and Valve Guide Clearance
Measuring Method-I
1. With the valve stem inserted in the valve guide, set the dial
indicator needle to "0".
2. Move the valve head from side to side.
Read the dial indicator.
Note the highest dial indication.
If the measured values exceed the specified limit, the valve
and the valve guide must be replaced as a set.
Valve Stem Clearance mm (in)
Standard Limit
Intake Valve
0.039 - 0.071
(0.0015 - 0.0028)
0.200
(0.008)
Exhaust Valve
0.064 - 0.096
(0.0025 - 0.0038)
0.250
(0.0098)
027RY00001
027RY00002
011RY00022

Isuzu 4ja1 Specifications

General

Brand	Isuzu
Model	4ja1
Category	Engine
Language	English