Mitsubishi Galant. Manual - part 71
CYLINDER HEAD AND VALVES
TSB Revision
ENGINE OVERHAUL <3.0L>
11D-33
VALVE SEAT
Assemble the valve, then measure the valve stem projection
between the end of the valve stem and the spring seating
surface. If the measurement exceeds the specified limit,
replace the valve seat.
Standard value: 49.30 mm (1.941 inches)
Limit: 49.80 mm (1.960 inches)
VALVE SEAT RECONDITIONING PROCEDURE
1. Before correcting the valve seat, check for the clearance
between the valve guide and valve and, if necessary,
replace the valve guide.
2. Using the special tool or a seat grinder, correct to obtain the
specified seat width and angle.
3. After correcting the valve seat, lap the valve and valve seat
using lapping compound. Then, check the valve stem
projection.
VALVE SEAT REPLACEMENT PROCEDURE
1. Cut the valve seat from the inside to thin the wall thickness.
Then, remove the valve seat.
2. Rebore the valve seat hole in the cylinder head to a selected
oversize valve seat diameter.
Seat ring hole diameter:
Intake valve
0.3 OS 34.30
−−−−
34.33 mm (1.3504
−−−−
1.3516 inches)
0.6 OS 34.60
−−−−
34.63 mm (1.3622
−−−−
1.3634 inches)
Exhaust valve
0.3 OS 31.80
−−−−
31.83 mm (1.2520
−−−−
1.2531 inches)
0.6 OS 32.10
−−−−
32.13 mm (1.2638
−−−−
1.2650 inches)
3. Before fitting the valve seat, either heat the cylinder head up
to approximately 250
°
C (482
°
F) or cool the valve seat in
liquid nitrogen, to prevent the cylinder head bore from
galling.
4. Using a valve seat cutter, correct the valve seat to the
specified width and angle.
AKX00695
SPRING SEATING
SURFACE
VALVE STEM END
VALVE STEM
PROJECTION
AB
AKX00717
0.9 - 1.3 mm
(0.04 - 0.05 in)
65˚
45˚
30˚
AB
AKX00610
0.5 - 1 mm
(0.020 - 0.039 in)
0.5 - 1 mm (0.020 - 0.039 in)
CUT
AWAY
AB
AKX00611
HEIGHT OF
SEAT RING
OVERSIZE ID
AB