Isuzu AA-6HK1T, Workshop Manual

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ENGINE MECHANICAL 6A–53
Valve Spring
Valve Spring Free Height
Use a vernier caliper to measure the valve spring free
height.
If the measured value is less than the specified limit, the
valve spring must be replaced.
Spring Free Height
Intake
Standard: 65.9 mm (2.59 in)
Limit: 64.6 mm (2.54 in)
Exhaust
Standard: 68.1 mm (2.68 in)
Limit: 66.7 mm (2.63 in)
Valve Spring Squareness
Use a surface plate and a square to measure the valve
spring squareness.
If the measured value exceeds the specified limit, the
valve spring must be replaced.
Spring Squareness
Intake
Standard: 2.9 mm (0.114 in)
Limit: 3.4 mm (0.134 in)
Exhaust
Standard: 3.0 mm (0.118 in)
Limit: 3.4 mm (0.134 in)
Valve Spring Tension
Use a spring tester to measure the valve spring tension.
If the measured value is less than the specified limit, the
valve spring must be replaced.
Spring Tension/Compression Height
Intake
Standard: 384 N (35.5 kg/78 lb) / 46 mm
Exhaust
Standard: 383 N (39.0 kg/86 lb) / 46 mm