POWR
Power unit
5-27
60C5D11
3. Measure the valve stem diameter
b
.
Replace if out of specification.
4. Measure the valve stem runout. Replace
if out of specification.
Checking the valve guides
NOTE:
• Use the valve guide clearance calculation
method or the valve runout measurement
method to check the valve guides.
• Before checking the valve guide make sure
that the valve stem diameter is within spec-
ification.
1. Measure the valve guide inside diameter
a
.
2. Calculate the valve stem-to-valve guide
clearance as follows. Replace the valve
guide if out of specification.
Valve margin thickness
a
:
Intake:
0.8–1.2 mm (0.031–0.047 in)
Exhaust:
1.0–1.4 mm (0.039–0.055 in)
Valve stem diameter
b
:
Intake:
5.97–5.99 mm
(0.2350–0.2358 in)
Exhaust:
5.96–5.97 mm
(0.2347–0.2350 in)
Valve stem runout:
Intake: 0.01 mm (0.0004 in)
Exhaust: 0.01 mm (0.0004 in)
Valve guide inside diameter limit
a
:
6.01–6.02 mm (0.2367–0.2370 in)
Valve stem-to-valve guide clearance
= valve guide inside diameter – valve
stem diameter:
Intake:
0.02–0.05 mm
(0.0008–0.0019 in)
Exhaust:
0.04–0.06 mm
(0.0016–0.0023 in)
S60C5450