Mitsubishi 4G6 series

4G6 ENGINE (E-W) -
Cylinder Head and Valves
11A-9-9
VALVE SEAT REPLACEMENT PROCEDURE
(1) Cut the valve seat to be replaced 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.
Valve seat ring hole diameter
Item Standard value mm
SOHC Intake 0.30 O.S. 34.30 - 34.33
0.60 O.S. 34.60 - 34.63
Exhaust 0.30 O.S. 31.80 - 31.83
0.60 O.S. 32.60 - 32.63
GDI Intake 0.30 O.S. 35.30 - 35.33
0.60 O.S. 35.60 - 35.63
Exhaust 0.30 O.S. 33.30 - 33.33
0.60 O.S. 33.60 - 33.63
(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.
See “VALVE SEAT RECONDITIONING PROCEDURE”.
AddedPWEE9616-A
E
Aug. 1998Mitsubishi Motors Corporation
0.5 - 1 mm
0.5 - 1 mm
1EN0275
Height of
seat ring
Oversize I.D.