
'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL
D
straight
in the hole, then tap the dowel lightly
with
a hammer until it
bottoms.
d.
When installing bearing eaps, be sure to tighten
the
bolts
evenly in each cap to
pull
it into place
without bending the
dowels
or distorting the
bearing
cap.
e. Other parts of the block which require inspec tion
and
possible
repair,
but which are directly
related
to other
engine
components (such as tappets, pistons, camshaft, valves, crankshaft, and
oil
pump) are covered later in this section.
D-35.
Cylinder
Bores
The
cylinder bores may be reconditioned by honing
or
reboring. Use oil-soaked rags to protect
crank
shaft
journals
and other
engine
parts from abrasive
dust during all reconditioning operations.
Both
honing and reboring of the cylinders must be
done
carefully to fit the pistons and to obtain
specified clearances. If reboring of the cylinder bores is not required but the walls are glazed, use
a
finishing
hone
to remove the glaze. Reboring the cylinders must not be attempted unless ade
quate facilities and experienced service technicians
are
available. The amount of material to be removed is determined from the original diameter
of the cylinder bores (3.125" to 3.127") [79,375 a
79,426
mm.] plus the amount of oversize in diameter
of the oversize pistons to be fitted. Pistons are
available
in the following oversizes.
.010"
[0,254
mm.] .030" [0,762 mm.] .020" [0,508 mm.] .040" [1,016 mm.}
The
largest cylinder bore
will
determine the over
size to which all cylinders must be rebored, since the size and weight of all pistons must be uniform
to maintain proper
engine
balance. The maximum rebore should not exceed .040" [1,016 mm.] from
standard.
Measure
the cylinder diameters by making mea
surements both parallel to and at right angles to
crankshaft
over entire piston travel and at
bottom
of cylinder. Proceed as follows:
a.
If bores are scored; if out-of-round
exceeds
.005
"
[0,127 mm.]; if diameters differ more than .005";
or
if taper
exceeds
.005
"
on diameter, it is generally
recommended that cylinders be reconditioned by
reboring
and honing to the next oversize using new
pistons of the proper size.
Note:
If reboring is performed, allow .0015"
[0,0381
mm.] for final honing.
All
cylinder bore diameters must be within .002
"
[0,0508
mm.] after reconditioning.
b.
If bore measurements are within the above
limits,
but indicate hollows or waviness, cylinders should be honed with 250 grit
stone
hone. Pump
hone
up and down in cylinder while it is rotating
to produce a satin-finish, diamond cross-hatched
pattern
approximately 30° with horizontal. Hone
only enough to correct waviness.
c. If cylinder bore correction is unnecessary, break the glaze on cylinder walls with a 250 grit
stone
hone
or with a suitable deglazing tool. Operate the
hone
or deglazer to obtain diamond cross-hatched
pattern
previously mentioned.
d.
Regardless of type of correction on cylinder
walls,
wash out bores thoroughly afterwards and
apply
a light coat of
engine
oil. If cylinders have
been rebored or honed heavily, measure cylinder
diameters again to assure proper selection of piston
size.
D-36.
Pistons, Rings, and Connecting Rods
Pistons are each fitted with three rings, two com pression rings and one oil control
ring.
The pistons have an extra
groove
above the top ring which acts as a heat dam or insulating
groove
to protect
against sealing of the top ring in the ring
groove
with
hard
carbon. The piston pin is secured by the lock screw.
The
pistons and connecting rods were removed from
the
engine
as assemblies. If cylinders were rebored,
new oversized pistons and rings
will
have to be in
stalled.
Disassemble the pistons and rods. Remove the
two compression rings, the oil control
ring,
and the oil control ring expander from each piston. Do not remove the
bolts
from the lower end of the
connecting rods unless the
bolts
are damaged.
Clamp
each connecting rod and piston assembly
in
a padded bench vise and remove the piston pin
lock
screw and lockwasher. Press the piston pin
out of the piston and connecting rod.
Clean
all
carbon,
gum, and lacquer
deposits
from both the
inner
and outer surfaces of each piston, connecting
rod,
and piston pin. Use a ring
groove
cleaner or a
broken
ring filed to a sharp square
edge
to clean
the carbon from the piston ring
grooves
and the
insulator
groove. Use care not to scrape metal from
the sides of the
grooves
or make
burrs
on ring
groove
surfaces. Run a length of wire through the
oil
spray
hole
near the lower end of the connecting
rod
to clear the
hole
of hardened oil
deposits
or
foreign matter.
Carefully
inspect the pistons and
replace
any that are broken or cracked. Replace
pistons if any of the ring lands are chipped, broken,
or
rounded on the
edges;
or if the piston is scored,
scratched,
or burned so seriously that the imperfec
tions cannot be removed with a hand honing
stone
or
crocus cloth.
Replace
the pistons as follows:
a.
After cylinder bores have been carefully checked for out-of-round and taper (Par. D-35), check fit
of each piston to cylinder bore with block and
pistons clean and dry and at approximately 70
°F.
[21°C]
by using Piston Fitting Gauge And Scale
Tool
No. C-690 as shown in Fig. D-7. Use a .003"
[0,0762
mm.] thickness
gauge
%" [19 mm.] wide.
The
piston is fitted upside down in the block to
facilitate the operation. The
gauge
must extend the
full
length of the piston on the thrust side
(opposite
side from slot in piston
skirt).
Scale should register
5
to 10 pounds [2,3 a 4,5 kg.]
pull
to remove the
thickness
gauge
from
between
cylinder
wall
and piston. Excessive
pull
indicates need for a slightly
smaller
piston or additional honing of cylinder. In sufficient
pull
indicates need for fitting a larger piston. 47

D
HURRICANE
F4
ENGINE
10444
FIG.
D-14—PISTON
RING INSTALLATION D-37.
Piston Ring Application Chart
Cylinder
Bora
Ovtrsiie
Correct
Ring
Size
Ring
Gap
Fitting
End
Gap
Std.
te .009'
[•0,228
mm.]
Std.
None
.007' to
.045'
[0,1778 a
1.1430
mm.]
.010*
to .019'
[0,254
a
0,4826
mm.)
-.020'
File
fit .007'
to
.017'
[0,1778 a 0,4318 mm.]
.020'
to
.024'
[0,508 a
0,6096
mm.] -.020'
None
.007' to .029*
[0,1778 a
0,7366
mm.]
.025'
to
.029'
[0,635 a
0,7366
mm.] -.030'
File
fit
.007'
to .017*
.030' to .034*
[0,762 a
0,8636
mm.] -.030'
None
.007'to
.029'
.038'to
.039'
[0,8890
a
0,9908
mm.] -.040*
File
fit
.007'
to .017'
.040' [1,016 mm.]
-.040*
None
.007'
to .017'
D-38.
Crankshaft
The
crankshaft is machined from a heat-treated
carbon
steel forging and is carefully balanced both
dynamically
and statically. The crankshaft is
supported by three replaceable main bearings. The
front main bearing is flanged to take the end
thrust
of the crankshaft. A flanged section on the
rear
of the crankshaft acts as an oil slinger. While the crankshaft is out of the engine, handle it care
fully
to prevent damage to the connecting rod
crankpins
and the main bearing journals. Refer
to
Fig.
D-l5.
D-39.
Crankshaft Inspection
and
Repair
Clean
out the drilled oil passages in the crankshaft
journals
with a small rifle brush making sure to get rid of all sludge or gum deposits. Blow out the passages with compressed air after cleaning.
Clean
the crankshaft thoroughly with a suitable
cleaning solvent. Inspect the crankshaft for
cracks,
alignment, and condition of the crankpins and the
main
bearing journals. Use magnafuix equipment,
if
available, to check for cracks or structural flaws.
Cracks,
misalignment, and scored or worn journals
and
crankpins necessitate crankshaft repair or replacement.
Check
crankshaft counterweights to be sure they
are
not
loose.
D-40.
Checking Crankshaft Alignment
To
check alignment, mount the crankshaft in the
cylinder
block with the front and
rear
bearings in
place but with the intermediate bearing removed.
With
a dial indicator mounted on the crankcase
and
the indicator button resting on the intermediate bearing
journal,
slowly rotate the
crank
shaft and
note
the reading on the indicator
dial.
Install
the intermediate bearing and remove first
the front and then the
rear
bearings to repeat the operation with the dial indicator, checking the
front and
rear
bearing journals. The maximum allowable run-out is .002"
[0,0508
mm.].
D-41.
Checking Main Bearing Journals
An
ordinary 3" [7,62 cm.] micrometer may be used.
The
standard
journal
diameter is
2.334"
to 2.333" 50

D
HURRICANE
F4
ENGINE d.
Remove the intake valve adjusting screw lock-
nuts from each of the rocker arm valve lash ad
justing
screws. Remove the screws from the rocker
arms.
D-76.
Inspection and
Repair
Run
a round wire brush through the bore of the
rocker
arm shaft and clean out the drilled oil holes.
Clean
out the oil
holes
in the rocker arm shaft
brackets,
and the oil
holes
and
grooves
in the bores
of the rocker arm.
Inspect
the diameter of the shaft at the rocker arm
bearing
areas. Replace the shaft if there are scores
or
abrasion marks along the length of the shaft.
Check
the shaft for alignment by rolling it across
a
smooth level surface. If the shaft
will
not
roll
freely, or if it rolls with a bumping motion, the
shaft is out of alignment and must be replaced.
Inspect
the threads of the adjusting screw
hole
in
the rocker arms and if necessary clean with a
proper
size tap. Replace the adjusting screw lock-
nut or the adjusting screw if either part is damaged
or
deformed.
Inspect
the threads in the tapped
hole
in the top
of the rocker arm shaft brackets and if necessary
clean
with a proper size tap. Replace the bracket
if
either side is worn or scored.
D-77.
Reassembly
a.
Install
two rocker arm shaft plugs, one in each
end of the shaft. Slide two
rocker
arm
shaft brackets
onto
the center of the shaft. Align the tapped
holes
in
the brackets with the drilled
holes
in the top of
the shaft and install the rocker arm shaft lock
screws,
making sure the points of the screws enter
the drilled
holes
in the shaft.
b.
Screw the intake valve adjusting screws into
the rocker arms and install the locknuts.
c.
The rocker arms are paired; that is, two of the
arms
are angled to the right and two are angled to
the left. One of each type is used on each end of
the rocker arm shaft. Slide a rocker arm with the
adjusting
screw end of the rocker arm angling
away
from the bracket
onto
the shaft so that the
adjusting
screw is on the same side of the shaft
as the mounting
hole
in the bracket.
d.
Temporarily
secure the end bracket in place by
installing
a rocker arm cover stud in the tapped
opening in the top of the support.
e. Assemble the parts on the
opposite
end of the
rocker
arm shaft repeating
steps
c and d above.
D-78. ENGINE REASSEMBLY
The
engine
reassembly procedure in the following
paragraphs
is given in the sequence to be followed
when the
engine
is being completely overhauled.
Individual
inspection,
repair,
and fitting operations
previously covered in detail are made throughout
the reassembly procedure. The reassembly pro
cedure
does
not cover accessories. If a new cylinder
block
fitted with pistons is used, many of the
operations
will
not be required.
Mount
the cylinder block in an
engine
repair stand.
If
an
engine
stand is not available, perform the fol
lowing reassembly operation in a manner designed to protect personnel against an accident and the
engine
and its parts against damage.
Note:
During
engine
reassembly, use Perfect Seal
Aerosol
Spray
Sealer
Part
No.
994757
on all
engine
gaskets to ensure against vacuum, oil, gasoline and
water
leaks. Apply to head gaskets, valve covers,
water
pumps, oil pan gaskets, radiator and heater
hose
connections, felt gaskets, gasoline and oil line
connections, stud bolts,
spark
plug threads, and
grease retainer washers. Refer to manufacturer's in
structions on container for proper application pro
cedure.
D-79.
Install
Oil
Gallery
Plug
Coat
plug threads with a suitable sealing compound
and
install the plugs in the front and
rear
ends of
the oil gallery in the cylinder block and the
rear
end of the cylinder head. Torque the plugs 20 to 25 lb-ft. [2,8 a 3,4 kg-m.].
There
is also a pipe plug
(}/g,f
[3,2 mm.] slotted, headless) in the opening in the main oil gallery inside the cylinder block at No. 2 cylinder and another pipe plug
(}/g
"
square-head) in the opening
in
the oil passage directly below the oil pump intake
passage. If
these
two pipe plugs were removed,
make
certain they are reinstalled in the locations
described above or the counterweight of the
crankshaft
might strike the projecting head of the
square-head
plug.
D-80.
Install
Tappets
Turn
the block upside down. Beginning at the
rear
end of the cylinder block, install the intake
and
exhaust valve tappets in the tappet bores in the cylinder block in the following order: one
exhaust, two intake, two exhaust, two intake, and
finally
one exhaust valve tappet.
Check
the tappet to bore fit of each tappet as it
is installed in the block. If the stem-to-block
clearance
tolerance of .0005" to .002" [0,0127 a
0,051 mm.] is
exceeded
install a new tappet fitting
within
this tolerance or ream the bore to accomo date the next oversize tappet which is available
in
.004" oversize.
D-81.
Install
Camshaft and
Thrust
Plate
Lubricate
all camshaft bearings and cam surfaces generously with clean, light
engine
oil.
Carefully,
so not to damage or score the camshaft front bear
ing,
install the camshaft, locating it properly in the bearings. Do not allow the
rear
end of the camshaft to strike sharply against the expansion plug
installed
in the
rear
end of the bore.
Install
the camshaft thrust plate. Slide the thrust
plate spacer
onto
the end of the camshaft with the
beveled inner
edge
of the spacer facing the cam
shaft. If the same camshaft is being reinstalled,
install
any shims previously removed. These shims
are
placed
between
the camshaft shoulder and the
spacer.
Torque the thrust plate attaching
bolts
20
to 26 lb-ft. [2,8 a 3,6 kg-m.].
End
play of the camshaft is determined by running
clearance
between
the
rear
face of the camshaft
gear and the thrust plate. The standard clearance 62

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL
D
Lubricate
the connecting rod bearing surfaces
generously with
engine
oil and install the bearing
cap with the numbered side matched to the num
bered side of the connecting rod. Torque the nuts
evenly 35 to 45 lb-ft. [4,8 a 6,2 kg-m.]. The con
necting rod cap nuts are locked with stamped nuts.
Used
stamped nuts should be discarded and re
placed with new
ones.
These locking stamped nuts
should be installed with the flat face toward the
connecting rod nut.
Turn
the locking nut finger
tight and then 34
turn
more with a wrench. Refer
to Par. D-36 for detailed information on fitting pistons and rings in the cylinder bores.
D-96.
Install
Crankshaft
Pulley
Align
the keyway in the pulley with the woodruff key installed in the crankshaft. Drive the pulley
onto
the crankshaft and secure it in place with
the crankshaft pulley nut. Insert a block of wood
between
one of the counterweights on the
crank
shaft and the side of the cylinder block to prevent the crankshaft from turning, then tighten the nut.
D-97.
Install
Oil Pan
Before installing the oil pan, make a final internal
inspection particularly making certain that the
inside of the cylinder block is clean. Apply a thin
coat of gasket paste on the oil pan. Place the new
oil
pan gasket in position. Set the oil pan in posi
tion on the cylinder block and install the oil pan.
Torque
the attaching
bolts
12 to 15 lb-ft. [1,7 a 2,1
kg-m.].
Install
the oil pan
drain
plug and gasket
and
tighten the plug securely.
D-98.
Install
Cylinder
Head
Make
certain that the entire top of the cylinder
block
assembly, the lower surface of the cylinder
head,
and the cylinder head gasket are clean. Blow
all
dirt
or carbon out of the blind tapped bolt
holes
in
the cylinder block before the cylinder head and gasket are installed. Using aerosol spray sealer
Part
No. 994757, spray a thincoat on both surfaces
of the head gasket, position the new cylinder head gasket with the crimped
edges
of the gasket metal down (See Fig. D-31).
This
gasket position allows a
positive seal along the narrow surfaces of the
cylin
der
head
between
the combustion chambers and
eliminates the possibility of burning combustion
10102
FIG.
D-41—CYLINDER
HEAD
BOLT
TIGHTENING
SEQUENCE
gases
reaching
an
asbestos
portion of the cylinder
head gasket.
Install
the cylinder head bolts. Tighten
the
bolts
with a torque wrench to 60 to 70 lb-ft. 8,3 a 9,7
kg-m.]
in the sequence shown in
Fig.
D-41.
Do not overlook installing the cylinder head bolt
in
the intake
manifold
directly under the
car
buretor
opening.
D-99.
Install
Rocker Arm Assembly
a.
Insert
ball
ends of the intake valve push rods through the cylinder head and cylinder block and
seat them in the cupped head of the intake valve
tappets.
b.
Install
the
rocker-arm
assembly on the 'four
rocker-arm-mounting
studs. Align the rocker arms
so that the
ball
ends of the intake valve tappet
adjusting
screws fit into the cup ends of the push
rods.
c.
Install
the four rocker-arm-attaching nuts.
Thread
each nut down evenly in sequence, one
turn
at a time, until the torque is 30 to 36 lb-ft. [4,1 a 5,0 kg-m.].
d.
Cement a new gasket on the rocker arm cover.
Install
the cover placing an oil seal then a flat
washer
and nut on each cover stud. Cement a new gasket on the exhaust valve cover.
Install
the cover and crankcase ventilation fittings using a
new gasket back of the vent cover and new copper
ring
gaskets under the attaching screw heads.
Torque
the valve tappet cover nuts 7 to 10 lb-ft. [1,0 a 1,4 kg-m.].
D-100.
Install
Distributor and
Spark
Plugs
To
correctly install the distributor, it
will
be neces
sary
to place No. 1 piston in the firing position.
To
locate the firing position of No. 1 piston, first
turn
the
engine
until No. 1 piston is moving up on
the compression stroke as indicated by compression
pressure
being forced through the
spark
plug open
ing.
Turn
the
engine
slowly until the 5° before top
center
mark
on the timing gear cover is in align
ment with the
mark
on the crankshaft pulley. Oil
the distributor housing where it bears on the
cylin
der
block and install the distributor. Mount the
rotor
on distributor shaft and
turn
the shaft until
the rotor points towards No. 1
spark
plug terminal
tower position (when cap is installed, about 5
o'clock) with the contact points just breaking.
Move the rotor back and forth slightly until the
driving
lug on the end of the shaft enters the slot cut in the oil pump gear and slide the distributor
assembly down into place. Rotate the distributor body until the contact points are just breaking.
Install
the hold down screw.
Connect
the core
primary
wire to the distributor.
Clean
and adjust the
spark
plugs, setting the elec
trode
gaps
at .030" [0,762 mm.].
Install
the plugs
to prevent any foreign matter entering the com
bustion chambers during the remaining operations.
Torque
the
spark
plugs 25 to 30 lb-ft. [3,5 a 4,6
kg-m.].
Install
spark
plug cables, placing them in the dis
tributor
cap terminal towers starting with No. 1
and
installing in a counter clockwise direction of
the firing order sequence (1-3-4-2). 67

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL
D D-l 13. HURRICANE
F4
ENGINE SPECIFICATIONS
MODEL:
ENGLISH
ENGINE:
Type
Number of Cylinders
Bore
Stroke
Piston Displacement...........
Bore
Spacing (center to center): 1 and 2, 3 and 4
2 and 3
Firing
Order Compression Ratio Compression Pressure... .
Number of Mounting Points:
Front
Rear
Horsepower (SAE)
Horsepower (Max Brake) Maximum Torque @
2000
rpm.
PISTONS:
Material
Description
Length
,.
Diameter (near
bottom
of
skirt).
Weight.
Clearance
Limits:
Piston-To-Cylindcr
Bore
Ring
Groove Depth:
No. 1 and 2 Ring No. 3 Ring
Ring
Groove Width:
No. 1 Ring No. 2 Ring
No. 3 Ring
Piston Pin Hole Bore
Cylinder
Bore — Standard.....
—
max. out of round
F-Head
4
W
134.2 cu. in.
3.437"
4.938"
1-3-4-2
6.7:1
120 to 130 psi.
2
1
15.63
@
4000
rpm. 114 lb-ft. 75
-
max. taper..
-
max. rebore.
PISTON RINGS:
Function:
No. 1 and 2 No. 3. .
Material:
No. 1. .
No. 2 and 3
Width;
No. 1 and 2
No. 3. . . .
Gap
(Std. to .009 Cyl. Bore).
Thickness:
No. 1 and No. 2 Rings....
No. 3 Ring
Side Clearance in Groove:
No. 1 Ring No. 2 Ring
No. 3 Ring
PISTON
PINS:
Material
Length
Diameter
Type
Clearance
in Piston
(selective
fit).
Aluminum
Alloy
Gam
Ground, T-slot, Tin Plated
3.1225*
to
3.1245*
13.5 oz.
Selective Feeler Fit
.1593" to .1655"
.1693" to .1755"
.0955" to .0965" .095" to .096"
1875" to .1885" .760" to .770"
3.125"
to
3.127"
.005" .005" .040"
Compression
Oil
Cast
Iron,
Chrome-plated Face
Cast
Iron
.007" to .017"
.134" to .144" .115" to .125"
.002" to .004"
.0015" to .0035" .001" to .0025"
SAE
1016 Steel
2.781"
.8119"
Locked
in Rod
.0001"
to .0003"
METRIC
7,937
cm.
11,112
cm. 2199 cm*
8,729
cm.
12,542
cm.
8,4 a 9,2 kg-cm2
15,77 kg-m.
9,525
cm.
7,9311
a
7,9362
cm.
382,7
gr.
4,046
a
4,203
mm.
4,300
a
4,457
mm.
2,4257
a
2,4511
mm. 2,413 a
2,438
mm.
4,7625
a
4,7879
mm.
19,304
a
19,558
mm.
7,9375
a
7,9425
cm.
0,1270
mm.
0,1270
mm.
1,0160
mm.
2,38 mm.
4,76 mm.
0,178 a
0,432
mm.
3,403
a
3,657
mm. 2,821 a 3,175 mm.
0,051 a 0,102 mm.
0,038
a
0,088
mm.
0,025
a
0,063
mm.
70,637
mm.
20,6223
mm.
0,0025
a
0,0076
mm. 71

D
HURRICANE
F4
ENGINE
D-l
13
HURRICHNE
F4
ENGINE
SPECIFICATIONS
(Continued)
MODEL:
CONNECTING
RODS:
Material.
Weight
Length
(center to
center)......
Bearing:
Type.
Material
Length
Over
All
Clearance
Limits.
..........
Undersize
Bearings
Available
End
Play
Installation
Bore:
Upper
Lower
CRANKSHAFT:
Material....................
End
Thrust
End
Play
Main
Bearings:
Type.
Material
Clearance
Undersize
Bearings
Available
Journal
Diameter
Bearing
Length:
Front.
No.
2. . .
No.
3
Out
of
round
and out of taper
limits
Direction
of
Cylinder
Offset..........
Amount
of
Cylinder
Offset
Crankpin
Journal
Diameter
Flywheel
Run Out
(max.)
ENGLISH
CAMSHAFT:
Bearings:
Material..........
Number
Clearance.
Journal
Diameter:
Front Front
Intermediate.
Rear
Intermediate..
Rear
Bearing
Diameter:
Front Front
Intermediate.
Rear
Intermediate..
Rear
End
Play
Drive:
Type.............
Crankshaft
Gear.
. .
Camshaft
Gear
VALVE
SYSTEM:
Valve
Rotators
Tappets:
Clearance
—
Cold:
Intake
Exhaust
Clearance
for
Timing
(intake).
SAE
1141
Forged
Steel
32 oz.
9.187"
Removable
Steel-backed
Babbitt
1.089" to 1.099"
.001"
to .0019"
.001" .002"
.010"
.012" .020" .030"
.004"
to .010"
From
Above
.8115"
to .8125"
2.0432"
to 2.0440"
SAE
1040
Forged
Steel
Front
Bearing
.004*
to .006*
Removable
Steel-backed
Babbitt
.0003"
to .0029*
.001"
.002" .010"
.012" .020"
.030"
2.333"
to 2.334"
1.64"
1.72"
1.66"
.001"
Right
.125"
1.9375" to
1,9383
.005"
Steel-backed
Babbitt
(Front
only) 4
.001"
to .0025"
2.1860" to 2.1855"
2.1225"
to 2.1215"
2.0600" to 2.0590" 1.6230" to 1.6225"
2.1870" to 2.1890"
2.125"
to 2.126"
2.0625"
to 2.0635"
1.625" to 1.626"
.004*
to .007"
Helical
Gear
Cast
Iron
Pressed
Fiber-Steel
Hub
On
Exhaust
Valve
.018*
.016* .026"
METRIC
907
gr.
23,33 cm.
2,766 a 2,791 cm.
0,025 a 0,0483 mm.
0,025 mm. 0,051 mm.
0,254
mm.
0,305 mm. 0,508 mm.
0,762 mm.
0,102 a
0,254
mm.
20,612 a 20,637 mm. 5,1897 a 5,1917 cm.
0,102 a 0,152 mm,
0,0076 a 0,0736 mm. 0,025 mm.
0,051 mm.
0,254
mm.
0,305 mm.
0,508 mm.
0,762 mm.
5,9261
a 5,9286 cm.
4,16 cm.
4,36 cm.
4,21 cm.
0,025 mm.
3,175 mm.
4,9213 a 4,9233 cm. 0,127 mm.
0,025 a
0,063
mm.
5,5524 a
5,5511
cm.
5,3911
a 5,3886 cm.
5,2324 a 5,2298 cm.
4,1224 a
4,1211
cm.
5,5549 a 5,5600 cm.
5,3975 a 5,4000 cm. 5,2387 a 5,2412 cm.
4,1275 a 4,1300 cm. 0,101 a 0,178 mm.
0,461 mm. 0,406 mm.
0,660
mm. 72

Dl
DAUNTLESS
V-6
ENGINE
DM.
GENERAL
This
section describes service and repair of the
Dauntless V-6 engine. The
engine
code
number shown in
Fig.
A-4 is provided to identify the Daunt
less
V6-225 engine. The meaning of the coded letters and numbers that are stamped on the right front face of the crankcase, just below the rocker
arm
cover,
between
exhaust manifold ports, is given
below.
Letter
to
Designate
Market
M
—
Military
E
—
Export
D
— Domestic
Letter
to
Designate
Year
Built
N
— 1967
P
— 1968
R
— 1969
S
— 1970
T
— 1971
Letter
to Designate
Engine
and Compression
Ratio
H—V6-225
9.0 to 1
C.R.
(2 Bbl.
Carb.)
Y—V6-225
9.0 to 1
C.R.
Marine
(Low
Profile)
(2
Bbl.Carb.)
Z—V6-225
9.0 to 1
C.R.
Marine
(High
Profile)
(2 Bbl.
Carb.)
K—V6-225
7.6 to 1
C.R.
(2 Bbl.
Carb.)
L—V6-225
7.4 to 1
C.R.
(2 Bbl.
Carb.)
Market
Domestic
—
Year
"1967"
Engine
J
Day
Plus Chg. If
Any-
Service Engine "S"
Short
Block
"R" -Oversize Bores "B"
Undersize Crank
&
"A"
Rod
Bearings
The
identifying letter or letters follow the
engine
letters are decoded as follows:
A—.010"
Undersize
Main
and Connecting Rod
Bearings
B—.010"
Oversize Pistons
AB—Combination
of A and B
S—Service
Engine
R—Short
Block
All
disassembly and assembly procedures are pre sented in logical order, assuming a complete
engine
overhaul
with
engine
removed from the vehicle.
However,
many of
these
procedures can also be
performed as on-vehicle services if vehicle or
engine
components are removed to gain access to parts
involved.
Note:
Some
engines
are equipped with an exhaust
emission control system. Service information on
the components of this system is given in sec tion F2.
Dl-2.
ENGINE
DESCRIPTION
The
Dauntless V-6
engine
has a displacement of
225 cubic inches. It has a compression ratio of
9.0 to 1, which permits use of regular-grade
gaso
line.
See
Figs.
Dl-1 and Dl-2.
The
cylinder block is made of cast
iron.
Two banks
of cylinders (three cylinders per bank) are cast at a
90-degree
angle. The lower part of the cylinder-
block
extends
below the centerline of the
crank
shaft, forming a continuous flat surface with the
rear
crankshaft main bearing cap and the timing
chain
cover.
This
design allows installation of an
oil
pan with a
one-piece
gasket. The cylinders in
the left bank (as viewed from the driver's seat) are
numbered
1-3-5,
from front to
rear.
The cylinders
in
the right bank are numbered
2-4-6,
from front
to
rear.
The
crankshaft is supported in the cylinder block
by four steel-backed full-precision bearings, all of
which
have an identical diameter.
Crankshaft
main bearings are numbered 1 to 4, front to
rear.
The
thrust
bearing is flanged to maintain crankshaft position and to compensate against crankshaft end
thrust
The No. 2 bearing is the thrust bearing.
The
crankshaft is counterbalanced by weights,
which
are cast integral with the
crank
cheeks. The
weights
are shaped to a contour which
gives
mini
mum
clearance with cylinder barrels and piston
skirts
to conserve space.
Connecting
rods have I-beam sections with
bosses
on each side. Metal is removed, as required, to secure correct weight and balance. The lower end
of each connecting rod has a steel-backed preci
sion bearing. The piston pin is a press fit into the upper end. The outer ends of the piston pin
are
a slide fit in the piston
bosses.
The
full-skirted, aluminum alloy pistons are cam ground and tin plated. Two compression rings and
one oil control ring are installed above the piston
pin.
The cast iron compression rings in the two
upper
grooves
of the piston have a
groove
or bevel cut around the inner
edge
on one side. The
top compression ring is installed with this
groove
or
bevel up. The lower compression ring is installed
with
bevel down. The oil
ring,
in the lower groove,
consists of two thin steel
rails
separated by a
spacer.
It is backed by a hump-type spring-steel
expander.
V-6
engine
cylinder heads are made of cast
iron.
Their
valve
guides
are cast integrally. Right and left cylinder heads are identical and interchange
able. In service, however, it is
good
practice to
install
the cylinder heads on the side from which
they were removed.
The
valves are in line in each head, at an angle
10°
above the centerline of the cylinder bores.
Each
valve has a spring strong enough to ensure
positive valve seating throughout the operating speed range of the engine. The valve rocker arm
mechanism is protected by a
sheet
metal cover.
This
cover is seated on a raised surface of the
cylinder
head. It is gasketed to prevent oil leaks.
The
rocker arms for each bank of cylinders are mounted on a tubular steel shaft, supported on
the cylinder head by brackets. The rocker arms
are
made of aluminum. They have inserts at the
push
rod socket and the valve stem contact face.
The
camshaft is located above the crankshaft be
tween the two cylinder banks; it is supported in
four steel-backed babbitt-metal bearings. The cam shaft is driven at one-half crankshaft speed by
sprockets and a single outside-guide type chain.
Hydraulic
valve lifters and
one-piece
push rods operate overhead rocker arms and valves of both
banks
of cylinders from a single camshaft.
This
system requires no lash adjustment during assem
bly
or in service.
In
addition to its normal function of a cam follower,
each hydraulic valve lifter also serves as an auto- 76

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL
Dl
12710
FIG.
D1
-3—HYDRAULIC VALVE
LIFTER
ASSEMBLY, CROSS-SECTIONAL VIEW
1—
Snap
Ring
6—Ball Retainer
2— Rod
Seat
7—Plunger Spring
3—
Oil
Inlets
8—Lifter
Body
4—
Plunger
9—Bronzed
Cap
5— Feed
Hole
sages
in the block and cylinder head.
The
water cooled system is pressurized to provide efficient
engine
cooling. It consists of a centrifugal-
type water pump, mounted on the timing chain cover, and is driven by the
engine
fan pulley. The
pump provides coolant flow equally to both
cylin
der banks under control of a thermostat. Coolant
flow is around the cylinders and through the
cylinder
head to dispel the heat of combustion in
the engine.
Dl-3.
Engine Mounts
The
engine-transmission unit is mounted to the chassis at three points by rubber pads. The two
front mounts are bolted to the
engine
cylinder
block and the frame members. These mounts sup port most of the
engine
weight, and absorb
vibra
tion which would otherwise be caused by changes
in
engine
output torque. The single
rear
mount is
placed
between
the transmission and the trans mission support. It supports part of the engine'
and
transmission weight, and locates the
rear
of
the
engine
with respect to the centerline of the
vehicle.
Dl-4. ENGINE REMOVAL
To
remove the
engine
from the vehicle follow the
procedurers listed below:
a.
Remove hood. b. Disconnect battery cables from battery and
engine. c. Remove air cleaner.
d.
Drain
coolant from radiator and engine.
e.
Drain
engine
oil.
f. Disconnect alternator wiring harness from con nector at regulator.
cj.
Disconnect the fuel evaporative purge line con nected to the
P.C.V.
valve.
h.
Disconnect upper and lower radiator
hoses
from
the engine.
i.
Remove right and left radiator support
bars,
j.
Remove radiator from the vehicle.
k.
Disconnect
engine
wiring harnesses from con
nectors located on
engine
firewall.
I.
On
engines
equipped with exhaust emission con
trol,
remove the air pump, air distribution manifold,
and
anti-backfire (gulp) valve. See Section F2 for
procedure.
m.
Disconnect battery cable and wiring from en
gine
starter assembly.
n.
Remove
engine
starter assembly from engine,
o.
Disconnect
engine
fuel
hoses
from fuel lines at
right
frame
rail,
p. Plug fuel lines.
q.
Disconnect choke cable from carburetor and cable support bracket mounted on engine,
r.
Disconnect exhaust pipes from right and left
engine
manifolds.
s. Place
jack
under transmission and support trans
mission weight.
f. Remove
bolts
securing
engine
to front motor mounts.
u.
Attach suitable sling to
engine
lifting
eyes
and,
using hoist, support
engine
weight.
v. Remove
bolts
securing
engine
to flywheel housing.
w. Raise
engine
slightly and slide
engine
forward
to remove transmission main shaft from clutch plate spline.
Note:
Engine and transmission must be raised
slightly to release the main shaft from the clutch
plate while sliding the
engine
forward.
x. When
engine
is free of transmission shaft raise
engine
and remove from vehicle,
y. Place
engine
on suitable blocking or
engine
stand and remove sling from engine.
Dl-5.
ENGINE DISASSEMBLY
Engine
disassembly is presented in the sequence to be followed when the
engine
is to be completely
overhauled after removal from the vehicle. Some of the operations of the procedure are also applicable separately with the
engine
in the vehicle,
provided that wherever necessary the part of the
engine
to be worked on is first made accessible by removal of
engine
accessories or other parts.
When
the disassembly operations are performed
with
the
engine
out of the vehicle, it is assumed,
in
this procedure, that all of the accessories have
been removed
prior
to starting the disassembly and
the oil has been drained.