Mitsubishi Montero (1991+). Manual - part 110

         Install head bolts. Head bolts should be tightened in proper

steps and sequence to specification. See Fig. 1. Install remaining

components. Tighten all bolts to specification. Adjust valves if

required. See VALVE ADJUSTMENT in this article.

NOTE:    Some manufacturers require that head bolts be retightened

         after specified amount of operation. This must be done to

         prevent head gasket failure.

         VALVE ADJUSTMENT

         Engine specifications will indicate valve train clearance and

temperature at which adjustment is to be made on most models. In most

cases, adjustment will be made with a cold engine. In some cases, both

a cold and a hot clearance will be given for maintenance convenience.

         On some models, adjustment is not required. Rocker arms are

tightened to specification and valve lash is automatically set. On

some models with push rod actuated valve train, adjustment is made at

push rod end of rocker arm while other models do not require

adjustment.

         Clearance will be checked between tip of rocker arm and tip

of valve stem in proper sequence using a feeler gauge. Adjustment is

made by rotating adjusting screw until proper clearance is obtained.

Lock nut is then tightened. Engine will be rotated to obtain all valve

adjustments to manufacturer’s specifications.

         Some models require hydraulic lifter to be bled down and

clearance measured. Different length push rods can be used to obtain

proper clearance. Clearance will be checked between tip of rocker arm

and tip of valve stem in proper sequence using a feeler gauge.

         On overhead cam engines designed without rocker arms actuate

valves directly on a cam follower. A hardened, removable disc is

installed between the cam lobe and lifter. Clearance will be checked

between cam heel and adjusting disc in proper sequence using a feeler

gauge. Engine will be rotated to obtain all valve adjustments.

         On overhead cam engines designed with rocker arms, adjustment

is made at push rod end of rocker arm. Ensure that the valve to be

adjusted is riding on the heel of the cam on all engines. Clearance

will be checked between tip of rocker arm and tip of valve stem in

proper sequence using a feeler gauge. Adjustment is made by rotating

adjusting screw until proper clearance is obtained. Lock nut is then

tightened. Engine will be rotated to obtain all valve adjustments to

manufacturer’s specifications.

         CYLINDER HEAD OVERHAUL

         * PLEASE READ THIS FIRST *

NOTE:    Always refer to appropriate engine overhaul article in the

         ENGINES section for complete overhaul procedures and

         specifications for the vehicle being repaired.

         DISASSEMBLY

         Mark valves for location. Using valve spring compressor,

compress valve springs. Remove valve locks. Carefully release spring

compressor. Remove retainer or rotator, valve spring, spring seat and

valve. See Fig. 2.

Fig. 2:  Exploded View of Intake & Exhaust Valve Assemblies - Typical

This Graphic For General Information Only

         CLEANING & INSPECTION

         Clean cylinder head and valve components using approved

cleaning methods. Inspect cylinder head for cracks, damage or warped

gasket surface. Place straightedge across gasket surface. Determine

clearance at center of straightedge. Measure across both diagonals,

longitudinal centerline and across the head at several points. See

Fig. 3.

Fig. 3:  Checking Cylinder Head for Warpage - Typical

This Graphic For General Information Only

         On cast cylinder heads, if warpage exceeds .003" (.08 mm)

in a 6" span, or .006" (.15 mm) over total length, cylinder head must

be resurfaced. On most aluminum cylinder heads, if warpage exceeds .

002" (.05 mm) in any area, cylinder head must be resurfaced. Warpage

specification may vary with manufacturer.

         Cylinder head thickness should be measured to determine

amount of material which can be removed before replacement is

required. Cylinder head thickness must not be less than manufacturer’s

specifications.

         If cylinder head required resurfacing, it may not align

properly with intake manifold. On "V" type engines, misalignment is

corrected by machining intake manifold surface that contacts cylinder

head. Cylinder head may be machined on surface that contacts intake

manifold.

         Using oil stone, remove burrs or scratches from all sealing

surfaces.

         VALVE SPRINGS

         Inspect valve springs for corroded or pitted valve spring

surfaces which may lead to breakage. Polished spring ends caused by

a rotating spring, indicates that spring surge has occurred. Replace

springs showing evidence of these conditions.

         Inspect valve springs for squareness using a 90 degree

straightedge. See Fig. 4. Replace valve spring if out-of-square

exceeds manufacturer’s specification.

Fig. 4:  Checking Valve Spring Squareness - Typical

This Graphic For General Information Only

         Using vernier caliper, measure free length of all valve

springs. Replace springs if not within specification. Using valve

spring tester, test valve spring pressure at installed and compressed

heights. See Fig. 5.

         Usually compressed height is installed height minus valve

lift. Replace valve spring if not within specification. It is

recommended to replace all valve springs when overhauling cylinder

head.

Fig. 5:  Checking Valve Spring Pressure - Typical

This Graphic For General Information Only

         VALVE GUIDE

         Measuring Valve Guide Clearance

         Check valve stem-to-guide clearance. Ensure valve stem

diameter is within specifications. Install valve in valve guide.

Install dial indicator assembly on cylinder head with tip resting

against valve stem just above valve guide. See  Fig. 6.