Winterthur Gas X40-B, Maintenance Manual

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Maintenance
2751 − 3/A1
Winterthur Gas & Diesel Ltd.
4/ 4
5. Checking the valve seat
After grinding it is necessary to check
whether the new or re-ground valve
makes correct contact with the valve seat.
For this the spindle head seat face is
spread with a thin coating of blueing
paste, then inserted vertically into the
valve guide bush.
Note: The angle difference is chosen
such that in the hot operating
condition the valves makes contact
by 50 − 100% from the outer edge
(Fig. 6). The blueing check should
show that the cold valve makes
contact only from inside around the
whole circumference. The angle
difference can be checked at gap
’S’ on the outer edge with a feeler
gauge (Fig. 7).
1) The blueing on the valve seat must be
checked by tapping the valve head three
or four times with a hammer on a
wooden block! (Fig. 5).
Do not rotate the valve spindle on the
valve seat face, as this risks seizure of the
seating.
Valve Seat − Replace / Grind
2016
HA RC
50 − 100%
003.455/00
003.457/00
016.773/08
30
_
+ 2’
0
S = 0.005 ... 0.02 mm
Fig. 5
Fig. 6
Fig. 7