Suzuki 2000 Grand Vitara SQ625 Service Manual page 469

6A4-50 ENGINE MECHANICAL (J20 ENGINE)
IN
D Seating contact width:
D Valve seat repair:
1. Valve seat cutter
EX
Create contact pattern on each valve in the usual manner, i.e. by
giving uniform coat of marking compound to valve seat and by ro-
tatingly 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 of pattern must be within
specified range.
Standard seating width
revealed by contact pattern
revealed by contact attern
on valve face
A valve seat not producing a uniform contact with its valve or
showing width of seating contact that is out of specified range
must be repaired by regrinding or by cutting and regrinding and
finished by lapping.
1) EXHAUST VALVE SEAT: Use valve seat cutters to make two
cuts as illustrated in figure. Two cutters must be used: the first
for making 15_ angle, and the second for making 45_ angle.
The second cut must be made to produce desired seat width.
Seat width for valve seat:
1.1 – 1.3 mm (0.0433 – 0.0512 in.)
2) INTAKE VALVE SEAT: Use valve seat cutters to make three
cuts as illustrated in figure. Three cutters must be used: the 1st
for making 15_ angle, the 2nd for making 60_ angle, and 3rd
for making 45_ angle. The 3rd cut (45_) must be made to pro-
duce desired seat width.
Seat width for intake valve seat:
1.1 – 1.3 mm (0.0433 – 0.0512 in.)
3) VALVE LAPPING: Lap valve on seat in two steps, first with
coarse size lapping compound applied to face and the second
with fine-size compound, each time using valve lapper accord-
ing to usual lapping method.
In
1.1 – 1.3 mm
(0.0433 – 0.0512 in.)
Ex