Valve Clearance: Adjustment
- Perform adjustment depending on selected head thickness of valve lifter.
- The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differences caused by temperature. Use the specifications for hot engine condition to adjust.
- Remove camshaft. Refer to "REMOVAL AND INSTALLATION ".
- Remove the valve lifters at the locations that are outside the standard.
- Measure the center thickness of the removed valve lifters with a micrometer.
- Use the equation below to calculate valve lifter thickness for replacement.
- Valve lifter thickness calculation.
t = t1 + (C1 - C2)
t = Thickness of replacement valve lifter.
t1 = Thickness of removed valve lifter.
C1 = Measured valve clearance.
C2 = Standard valve clearance.
- Thickness of a new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder).
Stamp mark 696 indicates a thickness of 6.96 mm (0.2740 in)
Available thickness of valve lifter: 26 sizes with a range of 6.96 to 7.46 mm (0.2740 to 0.2937 in), in steps of 0.02 mm (0.0008 in), when assembled at the factory.
- Valve lifter thickness calculation.
- Install the selected valve lifter.
- Install camshaft.
- Manually turn crankshaft pulley a few turns.
- Check that valve clearances for cold engine are within specifications, by referring to the specified values.
- After completing the repair, check valve clearances again with the specifications for warmed engine. Use a feeler gauge to measure the clearance between the valve and camshaft. Make sure the values are within specifications.
Valve clearance standard:
Cold Intake : 0.24 - 0.32 mm (0.009 - 0.013 in)
Exhaust : 0.26 - 0.34 mm (0.010 - 0.013 in)
Hot* Intake : 0.304 - 0.416 mm (0.012 - 0.016 in)
Exhaust : 0.308 - 0.432 mm (0.012 - 0.017 in)
*: Reference data at approximately 80°C (176°F)