Mitsubishi 4G1 Service Manual page 201

0.5 - 1 mm (.020- ,039 in.)
Installation
Removal
Press
Press
a
Push rod
Valve
guide
VALVE SEAT RECONDITIONING PROCEDURE
between the valve guide and valve and, if necessary,
replace the valve guide.
(2) Using the special tool or seat grinder, correct to obtain the
specified seat width and angle.
(3) After correction, valve and valve seat should be lapped with
a lapping compound.
VALVE SEAT REPLACEMENT PROCEDURE
wall thickness. Then, remove the valve seat.
1 EN027~
(2) Rebore the valve seat hole in the cylinder head to a selected
oversize valve seat diameter.
Seat ring hole diameter: See "Service Specifications"
on page IIC-10.
(3) Before fitting ttie 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.
1 EN02
See "VALVE SEAT RECONDITIONING PROCEDURE".
VALVE GUIDE REPLACEMENT PROCEDURE
(1) Using the special tool and a press, remove the valve guide
toward cylinder head gasket surface.
a
(2) Rebore valve guide hole to the new oversize valve guide
outside diameter.
-01 Valve guide hole diameter: See "Service Specifica-
tions" on page IIC-10.
Valve
guide
NOTE
Do not install a valve guide of the same size again.
(3) Using the special tool, press-fit the valve guide, working
from the cylinder head top surface.
(4) After installing valve guides, insert new valves in them to
check for sliding condition.
(5) When valve guides have been replaced, check for valve
contact
TSB Revision
and correct valve seats as necessary.