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JA
REMOVAL AND INSTALLATION (Continued)
(2) Inspect the remaining margin after the valves
are refaced (Fig. 47). Intake valves with less than
0.95 mm (1/32 inch.) margin and Exhaust valves
with less than 1.05 mm (3/64 inch) margin should be
discarded.
Fig. 47 Intake and Exhaust Valve Refacing
(3) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained. For valve specifications see Valve Specifica-
tion Chart.
VALVE SPECIFICATION CHART
Face Angle
Intake and
45 - 45 1/2°
Exhaust:
Head Diameter
Intake:
33.12 - 33.37 mm (1.303 - 1.313 in.)
Exhaust:
28.57 - 28.83 mm (1.124 - 1.135 in.)
Length (Overall)
Intake:
114.69 - 115.19 mm (4.515 - 4.535 in.)
Exhaust:
116.94 - 117.44 mm (4.603 - 4.623 in.)
Stem Diameter
Intake:
5.934 - 5.952 mm (0.2337 - 0.2344 in.)
Exhaust:
5.906 - 5.924 mm (0.2326 - 0.2333 in.)
Valve Margin
Intake:
1.15 - 1.48 mm (0.0452 - 0.0582 in.)
Exhaust:
1.475 - 1.805 mm (0.0580 - 0.0710 in.)
(4) Measure the concentricity of valve seat and
valve guide using a valve seat runout dial indicator.
Total runout should not exceed. 0.051 mm (0.002
inch.) (total indicator reading).
(5) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLY with Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of the valve face, lower valve seat
with a 15 degrees stone. If the blue is transferred to
the bottom edge of valve face raise valve seat with a
65 degrees stone.
• Intake valve seat diameter is 33 mm (1.299 in.)
• Exhaust valve seat diameter is 28 mm (1.102
in.)
(6) Valve seats which are worn or burned can be
reworked, provided that correct angle and seat width
are maintained. The intake valve seat must be ser-
viced when the valve seat width is 2.0 mm (0.079 in.)
or greater. The exhaust valve seat must be serviced
when the valve seat width is 2.5 mm (0.098 in.) or
greater. Otherwise the cylinder head must be
replaced.
(7) When seat is properly positioned the width of
intake and exhaust seats should be 0.75 to 1.25 mm
(0.030 to 0.049 in.) (Fig. 48).
Fig. 48 Valve Seat Refacing
(8) Check valve tip to spring seat dimensions A
after grinding the valve seats or faces. Grind valve
tip to 43.51 - 44.57 mm (1.71 - 1.75 in.) for exhaust
valve and 45.01 - 46.07 mm (1.77 - 1.81 in.) for
intake valve over spring seat when installed in the
head (Fig. 49). The valve tip chamfer may need to be
reground to prevent seal damage when the valve is
installed.
CLEANING
Clean all valve guides, valves and valve spring
assemblies thoroughly with suitable cleaning solution
before reassembling.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and
insert in cylinder head.
2.0L SOHC ENGINE
9 - 35
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