Valve Clearance: Adjustments
ADJUSTMENT1. Measure the valve clearance.
2. Remove camshaft.
3. Remove valve lifters at the locations that are out of the standard.
4. Measure the center thickness of removed valve lifters with a micrometer.
5. Use the equation below to calculate valve lifter thickness for replacement.
Valve lifter thickness calculation: t = t1 + (C1 - C2)
t = Valve lifter thickness to be replaced
t1 = Removed valve lifter thickness
C1 = Measured valve clearance
C2 = Standard valve clearance:
Intake: 0.30 mm (0.012 in)*
Exhaust: 0.33 mm (0.013 in)*
*: Approximately 20°C (68°F)
^ Thickness of new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder).
Stamp mark 788U or 788R indicates 7.88 mm (0.3102 in) in thickness.
NOTE: Two types of stamp marks are used for parallel setting and for manufacturer identification.
^ Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory).
CAUTION: Install identification letter at the end, "U" and "R", at each of proper positions. (Be careful of misinstallation between intake and exhaust)
6. Install selected valve lifter.
7. Install camshaft.
8. Manually turn crankshaft pulley a few turns.
9. Make sure that the valve clearances for cold engine are within the specifications by referring to the specified values.
10. Install all removal parts in the reverse order of removal.
11. Warm up the engine, and check for unusual noise and vibration.