1.2.2 Exhaust Valves
DETROIT DIESEL 53
Fig. 11 - Relationship Between Exhaust Valve,
Insert and Cylinder Head (Two Valve Head)
produces a finer, more accurate finish since only one
Fig. 9 - Refacing Exhaust Valve
point of the grinding wheel is in contact with the valve
seat at any time. A micrometer feed permits feeding
valve at the valve head must not be less than 1/32 " in
the grinding wheel into the work .001 " at a time.
thickness and must still be within the specifications
shown in Figs. 11 and 12 after refacing.
Before either a new or used valve is installed, examine
the valve seat in the cylinder head for proper valve
seating. The angle of the valve seat insert must be
exactly the same as the angle of the valve face to
provide proper seating of the valve. The proper angle
for the seating face of both the valve and valve seat
insert is 30o.
When a new valve seat insert is installed or an old
insert refaced, the work must be done with a grinding
wheel (Fig. 10).
The eccentric grinding method for reconditioning
valve seat inserts is recommended. This method
To grind the valve seat inserts for a four valve
cylinder head, use the following tools:
1. Grinder J 8165-1
2. Dial Gage J 8165-2
3. Pilot J 7792-1
4. Grinding Wheel (15 o) J 7792-2
5. Grinding Wheel (30 o) J 7792-3
6. Grinding Wheel (60 o) J 7792-4
Grind the valve seat inserts as follows:
o
1. First apply the 30
grinding wheel on the valve seat
insert.
o
2. Use the 60
grinding wheel to open the throat of
the insert.
3. Then grind the top surface with a 15 o wheel to
Fig. 10 - Grinding Valve Seat Insert
narrow the width of the seat from 3/64 " to 5/64 "
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