Valves
D
Remove all carbon from valves.
D
Inspect each valve for wear, burn or distortion at its face and
stem end, as necessary, replace it.
D
Measure thickness of valve head. If measured thickness ex-
ceeds limit, replace valve.
1. Valve head thickness
2. 45
_
D
Inspect valve stem end face for pitting and wear. If pitting or wear
is found there, valve stem end may be resurfaced, but not so
much as to grind off its chamfer. When it is worn so much that
its chamfer is gone, replace valve.
D
Seating contact width:
Create contact pattern on each valve in the usual manner, i.e.,
by giving uniform coat of marking compound to valve seat and
by rotatingly tapping seat with valve head. Valve lapper (tool
used in valve lapping) must be used.
Pattern produced on seating face of valve must be a continuous
ring without any break, and the width “a” of pattern must be within
specified range.
ENGINE MECHANICAL (F8D ENGINE)
6A1-35
Valve head thickness
Standard
Limit
IN
0.8 – 1.2 mm
0.6 mm (0.024 in.)
EX
(0.03 – 0.047 in.)
0.7 mm (0.027 in.)
Standard seating width revealed
In
1.80 – 2.20 mm
(0.0709 – 0.0866 in.)
g
by contact pattern on valve face
Ex
1.65 – 2.05 mm
(0.0650 – 0.0807 in.)
Содержание 800
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Страница 644: ...Prepared by Overseas Service Department 1st Ed October 1999 Printing 646 ...