Valve Seat; Valve Spring - Doosan DP158LCF Operation & Maintenance Manual

Valve Seat

1. Visual inspection: Inspect the damage and wear of
valve seat and if necessary replace.
2. Valve seat thickness and angle: Assemble the valves
at the cylinder head and using the measuring instru-
ment from the lower face, measure the projection
amount of valve. If the measured value is more than
the use limit, replace the valve seat.
Item
Valve seat thickness
(at cylinder head sur-
face)
10
0 20
90
80
70
50
60
Item
In. Valve
Valve seat angle
Ex. Valve
Standard Limit
0.65 ~ 0.95mm 2.5mm
30
40
DV2213120A
Limit
30°
45°
45
DV2213121A
10. Cylinder block/head
3. The disassembly of valve seat cam be pulled out by
means of a special tool with the arc welding done at
two points of valve seat rotating tool or valve seat.
Cylinder head
4. Regarding the valve seat assembling, shrink the valve
seat by putting it in the dry ices for about 1 hour or
so, and then press it into the cylinder head by means
of a special tool.
5. After coating the grinding powder paste on valve head
contacting face of valve seat, and after executing a
sufficient lapping operation with the rotating and
grinding motion of valve, wipe off the grinding agent
thoroughly.

Valve Spring

1. Visual inspection: Check if the exterior of the valve
spring is damaged with the naked eye. Replace it with
a new one if required.
2. Fee length of valve spring: Measure the free length
of the valve spring with the vernier clipers. If the
reading is larger than the specified valve, replace the
valve spring.
Item
Fee length of valve spring
175
Valve sheet
Weld bead
DV2213122A_E
Limit
Inside 65.5mm
Outside 64mm