Valve spring and lifters

Model(s)

xjcdadmin Mon, 05/17/2010 - 12:06

1. Checking the valve springs

a. This engine uses two springs of different sizes to prevent valve float or surging. The valve spring specifications show the basic value characteristics.

b. Even though the spring is constructed of durable spring steel, it gradually loses some of it's tension. This is evidenced by a gradual shortening of free length. Use a vernier caliper to measure spring free length. If the free length of any spring has decreased more than 2 mm (0.080 in) from its specification replace it.

c. Another symptom of a fatigued spring is insufficient spring pressure when compressed. This can be checked using a valve spring compression rate gauge. Test each spring individually. Place it in the gauge and compress the spring first to the specified compressed length with the valve closed (all spring specifications can be found in the previous section, Valve Spring), then to the length with the valve open. Note the poundage indicated on the scale at each setting. Use this procedure with the outer springs, then the inner springs.

NOTE:
All valve springs must be installed with larger pitch upward as shown.

Valve Spring Specifications
	OUTER	INNER
Free length	37.2 mm 0.465 in)	35.5 mm (1.398 in)
Installed length (valve closed)	32.0 mm (1.260 in)	30.5 mm (1.201 in)
Installed pressure	18.5 kg (40.8 lb)	9.3 kg (20.5 lb)
Allowable tilt from vertical	2.6°	4-

2. Valve lifter

a. Check each valve lifter for scratches or other damage. If the lifter is damaged in any way, the cylinder head surface in which it rides is probably also damaged. If the damage is severe, it may be necessary to replace both the lifter and the cylinder head.

NOTE:
For proper valve lifter-to-head clearance, always install lifters on their original valves.