Mitsubishi 4G1 Service Manual page 498

Press
Push rod
Valve
guide
SOHC - 6VALVE
SOHC - IGVALVE -
(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 llF-14.
(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".
VALVE GUIDE REPLACEMENT PROCEDURE
Press
(1) Using the special tool and a press, remove the valve guide
toward cylinder head gasket surface.
(2) Rebore valve guide hole to the new oversize valve guide
outside diameter.
Valve guide hole diameter: See "Service Specifica-
tions" on page llF-14.
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 and correct valve seats as necessary.
INSTALLATION SERVICE POINTS
(2) The special tool must be used to install the valve stem seal.
Improper installation could result in oil leaking past the valve
guide.
Caution
Do not reuse the valve stem seal.
Revision
TSB
Cylinder Head and Valves
VALVE STEM SEAL INSTALLATION