Mitsubishi 4G1 series, Руководство по обслуживанию

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ENGINE Cylinder Head and Valve SOHC
height
I
mm
in.)
1 mm
in.)
1
1
Removal
Installation
Press
Press
Valve
guide
(4) Check the valve seat
The valve seat can be determined by measuring the
valve spring’s installed height. (If the valve seat is
great, the valve seat’s installed height also is great.)
If the valve spring’s installed height exceeds the service
limit, replace the insert with an oversize part as described
below.
Installed height of spring (both intake and exhaust)
Standard value: 40.4 mm (1.591 in.)
Limit: 41.4 mm
in.)
VALVE SEAT REPLACEMENT PROCEDURE
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.
Intake valve seat hole diameter
0.30 O.S.: 44.30 44.33 mm (1.7441 1.7453 in.)
0.60 O.S.: 44.66 44.63 mm (1.7559 1.7571 in.)
Exhaust valve seat hole diameter
0.30 O.S.: 38.30 38.33 mm in.)
0.60 O.S.: 38.60 38.63 mm (1.5197 1.5209 in.)
(3) Before fitting the valve seat, either heat the cylinder head
up to approximately or cool the valve seat in
liquid nitrogen, to prevent the cylinder head bore from
galling.
Using a valve seat cutter, correct the valve seat to the
specified width and angle.
See “VALVE SEAT RECONDITIONING
VALVE GUIDE REPLACEMENT PROCEDURE
Remove the snap ring from the exhaust valve; guide.
(2) Using the push rod and a press, remove the valve guide
toward the cylinder head gasket surface.
(3) Rebore the valve guide hole to the new oversize valve guide
outside diameter.
Valve guide hole diameter
0.05 O.S.: 13.05 13.07 mm in.)
0.25 13.25 13.27 mm
in.)
0.50 O.S.: 13.50 13.52 mm in.)
TSB Revision