Chrysler 300M, Dodge Interpid. Manual — part 248

sure piston is at TDC in each cylinder of the
valve spring that is being removed.

(13) Remove spark plug adapter tool.

INSPECTION

When valves have been removed for inspection,

reconditioning or replacement, valve springs should
be tested (Fig. 50). As an example; the compression
length of the spring to be tested is 38.00 mm (1.496
in.). Turn table of Tool C-647 until surface is in line
with the 38.00 mm (1.496 inches.) mark on the
threaded stud and the zero mark on the front. Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give
the spring load at test length. Fractional measure-
ments are indicated on the table for finer adjust-
ments. Refer to Engine Specifications to obtain
specified height and allowable tensions (Refer to 9 -
ENGINE - SPECIFICATIONS). Replace springs that
do not meet specifications.

INSTALLATION

INSTALLATION - CYLINDER HEAD OFF

(1) Install valves if removed.
(2) Install valve stem seal/spring seat assembly

over valve guides on all valve stems (Fig. 52). Ensure
that the garter spring is intact around the top of the
rubber seal.

(3) Place valve spring (color-coded end facing up)

and valve retainer into position.

(4) Compress valve spring with valve spring com-

pressor. Install locks and release tool. If valves
and/or

seats

are

reground,

measure

the

installed height of springs (B) (Fig. 51), make
sure measurements are taken from top of

spring seat to the bottom surface of spring
retainer. If height is greater than 38.75 mm (1.5256
in.), install a 0.762 mm (0.030 in.) spacer in head
counterbore under the valve spring seat to bring
spring height back within specification.

Fig. 50 Testing Valve Spring

1 - SPECIAL TOOL C-647

Fig. 51 Checking Valve Tip Height and Valve Spring

Installed Height

1 - SPRING RETAINER
2 - GARTER SPRING
3 - VALVE SPRING SEAT TOP
4 - CYLINDER HEAD SURFACE

Fig. 52 Valve, Spring, and Valve Seal

1 - VALVE
2 - VALVE RETAINING LOCKS
3 - VALVE SPRING RETAINER
4 - VALVE SPRING
5 - VALVE SEAL AND VALVE SPRING SEAT ASSEMBLY

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ENGINE

9 - 39

VALVE SPRINGS (Continued)

INSTALLATION - CYLINDER HEAD ON

(1) Compress valve spring using Special Tool MD

998772A with Adaptor 6527 only enough to install
retainer and locks.

(2) After installing locks, release tension on valve

spring and verify proper installation.

(3) Remove Special Tool MD 998772A.
(4) Install rocker arm and shaft assembly. (Refer

to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - INSTALLATION)

(5) Install cylinder head covers. (Refer to 9 -

ENGINE/CYLINDER

HEAD/CYLINDER

HEAD

COVER(S) - INSTALLATION)

(6) Install spark plugs. (Refer to 8 - ELECTRICAL/

IGNITION CONTROL/SPARK PLUG - INSTALLA-
TION)

(7) Install upper intake manifold. (Refer to 9 -

ENGINE/MANIFOLDS/INTAKE

MANIFOLD

-

INSTALLATION)

(8) Connect negative cable.

ENGINE BLOCK

DESCRIPTION

The cylinder block (Fig. 53) is made of heat treated

aluminum with cast-in-place iron liners. The block is
a closed deck design with the right bank forward. To
provide high rigidity and improved NVH, the block
has cast-in contours and ribs, along with powdered
metal 6 bolt main caps (4 vertical, 2 horizontal), with
a die cast aluminum structural beam windage tray
mounted to the main caps.

STANDARD PROCEDURE - CYLINDER BORE
HONING

(1) Used carefully, the cylinder bore resizing hone,

recommended tool C-823 or equivalent, equipped with
220 grit stones, is the best tool for this honing proce-
dure. In addition to deglazing, it will reduce taper and
out-of-round as well as removing light scuffing, scoring
or scratches. Usually a few strokes will clean up a bore
and maintain the required limits.

Fig. 53 ENGINE BLOCK AND CRANKSHAFT

1 - MAIN CAP BOLT - VERTICAL

5 - CYLINDER BLOCK

2 - MAIN CAP

6 - MAIN CAP BOLT - HORIZONTAL

3 - MAIN BEARING - LOWER

7 - CRANKSHAFT THRUST WASHER

4 - MAIN BEARING - UPPER

8 - CRANKSHAFT

9 - 40

ENGINE

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VALVE SPRINGS (Continued)

(2) Deglazing of the cylinder walls may be done

using a cylinder surfacing hone, recommended tool
C-3501 or equivalent, equipped with 280 grit stones,
if the cylinder bore is straight and round. 20–60
strokes depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Use a light
honing oil. Do not use engine or transmission oil,
mineral spirits or kerosene. Inspect cylinder walls
after each 20 strokes.

(3) Honing should be done by moving the hone up

and down fast enough to get a cross-hatch pattern.
When hone marks intersect at 40-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 54).

(4)

A controlled

hone

motor

speed

between

200–300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 40–60
degree angle. Faster up and down strokes increase
the cross-hatch angle.

(5) After honing, it is necessary that the block be

cleaned again to remove all traces of abrasive.

CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.

CLEANING

Clean cylinder block thoroughly using a suitable

cleaning solvent.

INSPECTION

ENGINE BLOCK

(1) Clean cylinder block thoroughly and check all

core hole plugs for evidence of leaking.

(2) If new core plugs are to be installed, (Refer to 9

- ENGINE - STANDARD PROCEDURE - ENGINE
CORE AND OIL GALLERY PLUGS).

(3) Examine block and cylinder bores for cracks or

fractures.

(4) Check block deck surfaces for flatness. Deck

surface must be within service limit of 0.1 mm (0.004
in.).

CYLINDER BORE

NOTE: The cylinder bores should be measured at
normal room temperature, 21°C (70°F).

The cylinder walls should be checked for out-of-

round and taper with Tool C119 or equivalent (Fig.
55) (Refer to 9 - ENGINE - SPECIFICATIONS). If
the cylinder walls are badly scuffed or scored, the
cylinder block should be replaced, and new pistons
and rings fitted.

Measure the cylinder bore at three levels in direc-

tions A and B (Fig. 55). Top measurement should be
10 mm (3/8 in.) down and bottom measurement
should be 10 mm (3/8 in.) up from bottom of bore.
(Refer to 9 - ENGINE - SPECIFICATIONS).

Fig. 54 Cylinder Bore Cross-Hatch Pattern

1 - CROSS-HATCH PATTERN
2 - 40°–60°

Fig. 55 Checking Cylinder Bore Size

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ENGINE

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ENGINE BLOCK (Continued)

CONNECTING ROD BEARINGS

STANDARD PROCEDURE - CONNECTING RODS
AND BEARINGS

CONNECTING ROD BEARINGS

The bearing caps are not interchangeable and

should be marked at removal to insure correct
assembly.

The bearing shells must be installed with the

tangs inserted into the machined grooves in the rods
and caps. Install cap with the tangs on the same side
as the rod.

Fit all rods on one bank until complete.
Limits of taper or out-of-round on any crankshaft

journals should be held to 0.015 mm (0.0006 in.).
Bearings are available in standard, 0.025 mm (0.001
in.), and 0.254 mm (0.010 in.) undersizes. Install the
bearings in pairs. Do not use a new bearing
half with an old bearing half. Do not file the
rods or bearing caps.

(1) For measuring main bearing clearance and con-

necting rod bearing clearance use plastigage (Fig.
56). For more information on using plastigage (Refer
to 9 - ENGINE - STANDARD PROCEDURE). Refer
to Engine Specifications for bearing clearance specifi-
cations (Refer to 9 - ENGINE - SPECIFICATIONS).

NOTE: The rod bearing bolts should be examined
before reuse. If the threads are necked down the
bolts must be replaced (Fig. 57).

CONNECTING ROD BOLTS

(1) Examine connecting rod bolts for stretching.

Stretching can be checked by holding a scale or
straight edge against the threads. If all the threads
do not contact the scale the bolt must be replaced.

(2) Before installing the nuts the threads should

be oiled with engine oil.

(3) Install nuts on each bolt finger tight. Then

alternately torque each nut to assemble the cap prop-
erly.

(4) Tighten the connecting rod cap nuts to specifi-

cations. (Refer to 9 - ENGINE - SPECIFICATIONS)

CONNECTING ROD SIDE CLEARANCE

(1) Mount a dial indicator to a stationary point on

engine. Locate probe perpendicular to and resting
against the connecting rod cap being checked. Move
connecting rod all the way to rear of its travel. Zero
the dial indicator. Move connecting rod forward to
limit of travel and read the dial indicator (Fig. 58).
Compare measurement to specification listed in
engine specifications (Refer to 9 - ENGINE - SPECI-
FICATIONS). Repeat procedure for each connecting
rod. Turn crankshaft for connecting rod accessibility.

CRANKSHAFT

DESCRIPTION

The crankshaft (Fig. 53) is constructed of a forged

micro alloy steel. A six throw, nine counterweight
crankshaft is supported by four select fit main bear-
ings with number two serving as the thrust washer
location. The six separate connecting rod throws are
an even-firing design which reduces torque fluctua-
tions while a torsional vibration damper is used to
control torsion caused vibration of the crankshaft.
Rubber lipped seals are used at front and rear. The
front seal is retained in the oil pump case and the
rear seal is retained in a block-mounted housing.

Fig. 56 CHECKING CONNECTING ROD BEARING

Fig. 57 CHECK FOR STRETCHED BOLTS

1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT

9 - 42

ENGINE

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