Title: CASE Model 420 Gasoline Crawler Dozer Service Repair Manual Instant Download
1Model 420 Gasoline Crawler Service Manual
9-70121
epr ted
2RAWER
Property of NAME COMPANY REGISTERED NO.
Published by The Industrial Service
Department CASE CORPORATION Rocine, Wisconsin
FORM NO. P-70121
October 1959
3(No Transcript)
4https//www.ebooklibonline.com Hello dear
friend! Thank you very much for reading. Enter
the link into your browser. The full manual is
available for immediate download. https//www.ebo
oklibonline.com
5FOREWORD It is the policy of the J.I. Gase Go .
to build machines with long and useful life
expectency . The reputation of this company and
its products are depe nde nt upon the dil iqe nt
a nd conscientious maintenance give n the se
products by the fie Id service people . Thousands
of satisfied users have proven the de sign
and quality of the J.I. Case products . In the
final ana lys is it will be the field service
personne 1 that will write the f inal chapter to
the succe ss story . The J.I. Gase Go.
recognizes the importance of the thor- oughly
trained technician . No longer is the mechanic
con- sidered as a "grease monkey" or the nece s
sary evil " . To help the service man gain his
rightful place as a Profe s s ional , the
company ha s inaugurated a Mobile Training
Program " . This program has bee n highly succe
ssful and very fruitful . The J.I. Gase Go . now
is planning even greater and more far reaching
programs to futher this ende avor . Service
Repre sentative s for the J, I. Ga se Go . and
its Dealers Serviceme n are located all over the
world , and they repre sent the finest in Service
Personne1. This Service Manual has been written
as a reference guide , and is dedicated to
those that service , maintain a nd teach the J.
I. Ga se Indus trial Equipme nt .
iii
6THE J.
I. GASE MO BILE TRAINING PROGRAM
The Mobile Training Unit is another service made
ava ila b1e to the Gase Dealers . Each dealer
should be s ure to take ad- vantage of the
training program offered by these Mobile units .
Watch for it whe n it come s to your territory ,
and be sure to attend .
iV
7(No Transcript)
8(No Transcript)
9GENERAL SP EGIFICATIO NS GROUP I SECTION A -
MODEL 420 SPECIFICATIO NS CAPAGITIES (U. S. )
10 Gallons
Fuel Tank ........................
Cooling ... c ....... t . t ....... t ... . 12
Quarts
Transmi s sion-Differential .................. 7
l/2
Quarts
Flnal Drive (each) ..................... . 2-
l/2 Pints Crankcase ........... ............ 5-
l/2 Quarts with filter.......... 6 Quarts Air
Gleaner ............................
lPint Hydrauli c System ........................6
Gallons TRACTOR Engine, base Gasoline
................... 148 Ou. In. Gross Engine
Flywheel HP ...................... 42 Drawbar HP
................ .......... 30 Electrical
System .................... .... 12 Volts Cooling
Fan Diameter (Suction and Pusher) ..
.......... 16 Inches Radiator ..... ........ ...
.... Tube and Fin Construction Pre s suri zed
with 4 lb. Gap
Clutch .......... .....
Heavy-Duty, Dry- ape Single Di sc Foot Operated
Transmi sslon .................. Spur Gear,
Manual Shift No. Speed Forward ...................
..... 3 No. Speed Reverse .......................
. 1 Battery ............... ... .. 12 Volt
Positive Grounding Number ........................
.... 1 Papa city .... ...... .. . .. .. ....
.. 50 Amp . Hr. Generator Make ............ ....
Auto - Lite and Delco Remy Papa city . . . . .
. . . . . . . . . . . . . .. . . . . 2
0 Ampere s DIMENSION S AND WEIGHTS Length,
Overall Without Drawbar ................. 101
In. Height ............... .
..... 56 In. Gauge ............... ..
. ... - - - . 48 In. Wldth, Overall
........................ 60 l/2 In. Ground
Clearance Without Drawbar ............... 14-1/4
In. Ground Clearance Under Drawbar ...............
. 1l1/I4-n. Drawbar Height .......................
... 12 In. Drawbar Movement, Lateral
.................. 1l9/I2-n.
10Track Shoe Width, Standard.....................
11 In. Track Shoe Wldth, Maximum..................
.. 20 In. Number of Track Links Per
Side..................... 31 Length of Track on
Ground..................... 57 In. SprocketTeeth .
.............. .......... 23 Ground Area
Gonta ct .................... l,25 4 Sq .
In. Height of Grouses .......................
1-1/2In. Track Pin Diameter .........
................1-In. Track Bushing
Diameter..................... 1-1/2 In. Track
Bolt Diameter ....................... 3/8
In. Track Rollers , No. Per Side
...................... 4 Track Roller Diameter
(Flange) .................. 7-1/2
In. SupportRollers, No. Per Side............
. . ..... l Weight (Standard Basic)
Shipping ................ 4,850 Lbs. Track Roller
Diameter (Hub) . . . . . . . . . . . . . . .. . .
6- l/4 In. ENGINE Ga se Ga soline , 148 Cu . In.
Number of Cylinders............. - -
Bore...............
3-3/8In.
Stroke .....................
4-1/8 In. 1-3-4-2 7 l to l
FiringOrder..............
Gompression Ratio ..............
Valve Tappet Glearance ................... 014
In. Governed RPM (Full Load)...........
......... (No Load) ....... ..
(Gold) 1850 . 2 000 . 500
Idle SpeedRPM ........... ..........
PERFORMANG E DATA
- Gear RaUo
- 13.20 to 1
- 8.34 to l
- 5 . 08 to l
- 1 1. 42 to 1
Speed s
Forward
F, irst , , . , Se co, nd.
........ . . ............ . .
- 74 . .
- 7 S
- 4. 52
- 2 . 0 1 . .
Third .............. ...
Reverse . . . . . . . . . . . . . . . . .. . .
Drawbar Pull (In pounds)
5815 3863 2203
Fir st o o o
Second ..........................
Third ., .......................
SECTION B - 420 LOAD ER SPECIFICATIONS
Bucket Gapa city ...... . . . . . . . . . . . . .
. . . . Digging Depth Below Ground 3Angle
Grading Angle ...... Bucket Rollba ct at Ground
Level ...
5/8 Gu . Yd. 10-1/2 In . to 130 2 6
I- 2
11Dump Clearance ........................ 102
In. Dump Reach at Maximum Lift ..................
27-7Z8 In. At 7 Foot Dump .....................
34-7/8 In. Lifting time From Ground Level to Max.
Lift ........... 61/2 -See. Dumping
Time ....................... 1l/-See.4 Lowering
Time .......................... 6 See. Wldth of
Bucket .... , , . , .. , ............ 62-5/8
In. Tractor Width ........................
61/20In. - Overall Height .......................
6l3/In2- Overall Length .........................
146 In. Weight Wlth Counterweight ........... ,,
.., , . 40 Lbs. Lift Capacity Fully
Raised.................... 2600 Lbs.
. ,
Dump Cylinder Size ............, , . , , , . , .
12-1/4"
Lift Cylinder Size ................... 3-1/2 " x
27-1/4" Pump Capacity at Rated RPM .........,. ...
, , 18 Gal./M1n. Wldth of Loader Bucket
.................... 62-5/8 In SECTION C LOADER
BACKHO E SPECIFICATIONS BACKHO E OPERATING DATE
Reach Prom Axle . . .
. ............. 2 18 In. Reach I-tom
Pivot ... .................... 194 Inc Max.
Digging Depth ....................... 144
In. Max. Dump Reach ........................118
In Glearance , Full Llft, Bucket Tucked
................ 126 In, Glearance , Full Lift,
Bucket Extended ................180 In.
186 In. .... 1800
Height Overall , I'-ull Lift, Bucket
Extended Swing Arc, Uninterupted . .............
... .
Stabilizer Spread, Ground Level ........., .. ,
, .
. 72 In, 10
Vertical Cut on Max. Grade of ...........,.
.., , ,
BUCKET OPERATING DATA Bucket Capaci,ty . , . .
, . . . .............3/4 Cu.Yd. Rated Gapacity,
Full Li,ft, , , , . . . . . . . . . . . . .
. 2600 Lbs. Rollback at Ground Level ..... . . .
. . . . . . . . . . . . . . 26
Dump Angle , Full Lift ..... Gradlng Angle
..........
AAAAAAAAAy43
Lifting Time , Ground Level to Max. Height
........... 6- 1/2 Sec. Dumping Time
........................ 1-1/4Sec.
Lowering Time ......................... .
6 Sec.
DIMENSION S AND WEIGHT Width of Loader Bucket
.................... 62-5/8 In. Width of Tractor
........................ 6l0/In2- Width, Overall
, Travel Position .................. 73 In.
I- 3
12Height, Overall , Travel Position
.........., , ., , , ., 12 1 In.
Length, Overall , Travel Position
...............,
204-1 2 In.
Ground Glearance ..................., , ,
10 In.
Weight (approx.) - ................
16173 Lb,s,
HYDRAULIG SYSTEM Backhoe Cy1inders ,
Doub1e-acttng Chrome-Plated Rods Boom , (1)
3-1/2 "x3S" , 1- 3/4" Rod After S/N 3 00 9833,
4"x35 ,1-3/4" Rod. Crowd .....
............ (4l" x)26- l/8 ", 2 "
Rod. Bucket .............. (1) 3- l/2 " x 27- l/4
", 1-3/4 " Rod. Sw ............... (2) 2- 1/2 " x
16- l/2 , 1- l/4 Rod. Stabilisers ...............
.. (2) 3 " x 9 , 1- l/2 Rod. Loader Cylinder s,
Double-Acting Chrome-Plated Rods Lift ..
. ......... (2) 3- 1 2 x 27- 1 4 ", 1-3
4 "Rod. Bucket ................ (2) 2- l/3 " x 13
", 1- l/4 "Rod. Pump Gapaclty at 2000 RPM ......
....... 19 Gal/Mln. Hydraulic Gapaclty, With
Filter ...... ...... 24 Quarts. SEGTION D - DO
ZER SPEci7cATIONS TILT- CROWN DO ZER Moldboard
Width ......................... 76 In. Moldboard
Height ..., .., , , . , .. ........... 25 In.
Lift Above Ground ........................ Drop
Below Ground .......................
22 Ing 10 In.
Hydraulic Lift Cylinders ................ 2-1/2"
x 19-1/8" Hydraulic Tllt Cylinders ......... .. ..
2-1/2" x 4-3/4" Pump Gapaciy At 2000 RPM ...
, , , .......... 15 Gal/M1n. Moldboard Gown
Adjustment .................... 11 In. Moldboard
Pitch Adjustment ..................... i0O Weight
............................ 6025 Lbs. ANGLE DO
ZER
..... , , ., .. .
Moldboard Width
92 In.
Moldboard Length ........., .. , , . , , , ,
. , , , , , 25 In. Left Above Ground .............
......... 2l3/In4- . Drop Below
Ground ...................... 10-3/4 In.
Hydraulic Lift Cylinders ......, .. , . , , , , .
2- l/2 " x 19-1/8" Hydraulic Angle Gylinders
.......,.. , , . , , . , 3- l/3 " x 9-5/8 "
Pump Gapaclty At 2000 RPM ... ............. iGsal/
Min.
Moldboard Angle Adjustment ..........., , , ..,
.., , 250
HO
Moldboard Grown Adjustment ........... , . ,
., ,, ,
127 In.
., ., . , ..
Overall Length (Blade Straight) .............
Weight ............... ,, .. , ... ,
6350 Lbs.
1-4
13SECTION E - TORQUE SPECIFICATION S When a nut
is tightened on a bolt or a stud, a clamping
action i s set up between the nut and the
component parts. Actually as a nut is
tightened, the bolt or stud is stretched
or elonqated slightly . This stretching action
of the bolt or stud maintain s the clamping
force on the compon- ent parts being held
together. Your torque wrench wlll regi s- ter In
"foot - poundsbf torque tightness. Be sure to
use the
recommended torque tightness
Figure 1 - Torque Wrench
shown in this Service Manual , for each specific
assembly procedure . Unle ss otherwi se stated in
the applicable section in thls manual, bolts are
to be tightened as follows BOLT TORQUE G HART
NC (National Gourse) Thread
NF (National Fine) Thread
Size Torque (Ft. Lbs.)
Size Torque (Ft, Lbs.)
1/4-28 NF .., ., . , .
10- 12 19-24 45-50 70-80 100- 110
1/4-20 NC ......... 9- 11
5/16- 18 NG ........17-2 l
5,16-24 NF .......
3/8-I6NC. . . . . . . . 35-40 7/16-14 NC . . . .
. . . 60-65 1/2-13 NG ....... 90-100 9/16-12
NC ...... 120-130 5/8-11 NG....... 180-190 3/4-10
NC ....... 310-320 7/8-9 NC ....... 535-545
3/8-24 NF ........
7/16-20 NF .......
1/2-20 N F .......
9/16-18 NF . . . . . . . 140-150
. . ., . . . 220-230
5/8-18 NF
3/4-16 NF . . . . . . . 380-390
7/8-14 NF. . . . . . . 620-630
890-940 1300-1350 1750-1850 2350-2450 3000-3100
1-8 NC . . . . . . . . 755-765
1-14 NF ........
1-1/8-12 NF..... 1-1/4-12 NF.....
1-1/8-7 NC. . . . . . 1-1/4-7 NC. . . .
. 1-3/8-6NC . . . . . 1-1/2-6 NC. . . . .
1070-1130 1470-1530 ig 0-1980 2450-2550
,
1-3/8-12 NF . , .
1-1/2-12 NF.....
i - s
14- In order to properly control thl s stretch and
not build up excessive pre rsure (whtch can snap
a bolt In two) the torque wrench should be used .
How ever, In or- der to obtain falrly accurate
torque wrench tlghtnes s , several factors must
be un- derstood. I'-allure to consider the
following conditgionis ll prevent an accurate
torque wrench reading - Be sure to lubricate the threads of the bolt
before the nut 1s Installed. - Use the exact type of washer, under the nut, as
Indicated.
3.
Be sure to pull the torque wrench handle with a
steady even pull, exerted at right angles to the
wrench handle, when the dial 1s being read. (DO
NOT USE AN EXTENSION ON THE HANDLE A S IT WILL
CAUSE THE DIAL READING TO BE INACCURATE. )
1-6
15(No Transcript)
16GROUP II THE GASOLINE ENGINE SECTION A
GYLINDER HEAD ASSEMBLY ... ........... Inspection
and Repair of Rocker Arm As sembly ..........
Stripping and Removing Head Assembly ...........
.
PAGE I-I1
I-2I I-3I I-4I
Checking Gompression ..., ................
Removing and Inspecting Valves ................
I-5I Valve Springs ........................
I-I10 Installing Gylinder Head . , ...............
. I-I12 Valve Rotor, s . . , ..,
.. , ... ........... I-I14 SEGTION B TIMING
GEAR GOVER ....... .. ...... I-I14
Removing Timing Gear C, over ................
I-I14 I-I15 I-I16 II - 16 I-I17
Removing Governor Lever and Arm As sembly
..........
, , .......... - - ... - - - - - - ..
Removing Flyweight Governor , .. In stalling
Flyweight Governor - - Replacing Timing Gear
Co-ve-r -
...... - - - ....
SEGTIO N G LUBRIGATING SYSTEM ...
. . . . . . . . . . .
. 11-18
Oil Pump ........,..
. . . . . . . . . . . . . . . . . . . . . . .
. . . II- 19 . . . 11-22 . . . . . II- 23
In stalling Filter Ba se . .. . . Changing Filter
Element .... .
SECMON D- GAMSHAFT. . . . .
- . . . . . . . . . . . . .
. 11-24
Removing Cam shaft Gear .... ... ... ...
... 11-24
Removing Cam shaft .... , . ...........
... II-24
Istnall ing Bushing s ......
II - 25 11-26 II- 26
Istnalling Cam shaft .... ............... Isnflitn
g aGam shaft Gear ... . . . . . . . . . . . .
. SEGTION E - GRANK SHA FT
II- 27
Removing Grank shaft Inspecting Grank shaft
Installing Grant shaft In stafling Grank shaft
Rear on Seal and Retainer
II - 28 II - 29 II - 29 II- 30
SECTION F - CRANKSHAFT BEARINGS . . . . . . . . .
. . . . . . . . II- 32 Removing Liners
.......................I3I3 -
Inspection ... ........-..
Undersize Liners .......................11-34
17Out-of-Round .........................I-3I5 Ins
talking Main Bearing Liners and Gaps
..............II - 35 Tightening Main Bearing
Gap ..................II - 37 Connecting Rod
Bearings ....................II - 37 Inspecting
Bearings ......................II - 39 SECTION G
- PIS'TO N AND RO D ASSEM BLY ............ ...
I-I40
Removing .... ................. . Inspecting
Pistons ................. . Installing Rings .
................. . Installing Piston Replacement
Piston Rings ...... . Installing Piston Pin
Bushing ............ .
. . . . .11-40 . . . . .II-40 . . . . .II-
41 . . . . .11-42 . . . . .11-45
Installing Piston Pin ................ . . . . .
.II- 46 SECTIO N H - PIS70 N SLEEVES
.................. . .11-46
Removing Sleeves . . . . . . . . .
. . . . . . . . . . . . .II- 46
Installing Sleeves . . . . . . . . . . . . . . .
. . . . . . . .II-46 SE GZIO N I - WAZER PUMP AND
COOLING SYSTEM ...... ... II
47 RemovingWaterPump, ..... ................11-48
Disas sembly Water Pump ....................I-4I8
Inspection of Pump .......................I-4I9 A
ssembling Water Pump.....................II-50 Gle
aning Gooling System ....................11-50 Ra
diator . . . . . . . . . . . . . . . . . . . . . .
. . . . .II-61 Pressure Radiator
Gap .....................II- 51 Fan BeltAdjustment
......................II-52 Replacing
Thermostat. . . . . . . . . . . . . . . . . . . .
. .II-52
ZestingZhermostat.. , , , . Radiator Anti-Free ze
, .. , .
...... . - - - - .......... - . -
- -
II-53 II - 53
SEGTIO N J - GENERAL SPE CIFIGAZIO NS .........
.....II - S 4 SECTIO N K SERVICE
HINTS .............. ......II 59
Engine Will Not Star,t, , , , . , , , . Engine
Backfires,...,.. .. , ..............II-
............II59
61
Engine Misfires ...............
Ignition System, . , .. , , , , , ..............11
-67
Engine Lacks Po,we,r .. , , .. ,
.............11-68 ......, .. ...II-63
Engine Overheats ..., .. , .. , ,
Excessive FuelGonsumption...................II70
Excessive Oil Consumption ...................II-
71 LowOilPressure. . . . . . . . . . . . . . . . .
. . . . . . .11-71 OilLeakage. . . . .
. . . . . . . . . . . . . . . . . . . . .11-73
18THE GASO LINE ENGINE GROUP II SEGTIO N A
GYLINDER HEAD ASSEM BLY
GENERAL Gylinder head is of the va1ve in head
construction , containing the valve opera- ting
mechanism , intake and exhaust ports and
combustion chamber . Four pas sages extending
through the head are provided for cooling purpose
s . Individual rocker arms on the rocker shaft
are secured by three mounting brack- ets . The
rocker arms are operated by push rods and cam
followers from the cam shaft. Figure 1.
O il is supplied by a drilled oil pas sage
leading from the center main bearing through the
block and head to the roe her shaft and rocker
arms .
NUT
' 4 STUO X 4 " STUD
"X 2 SGREW (3) LOCK WASh4 E R 13') P LU G (2)
BUOY tNG ( )
The complete roe her arm shaft as sembly
SPRING (4) ROCKER ARM
BRACKET
can be removed from the cylinder head by
removing the three capscrews , and removing ,y
ROCkER SHAF T (2) RETAIN
the nuts from the studs reie as ing the
rocker shaft brackets . Figure 2 .
BUSH ING
EP BRAGKET sosrT REToi N ER
vALVE SPRINGS
To prevent separation of parts when the
complete rocker arm as sembly i s removed or ins
talled , a simple holder can be use d . This tool
can ea sily be fashioned f r o m a piece of
flat s teeI. Figure 3.
PUSH R OO (8)
Figure 1 - Va lve Action
ROCKEFt AftU
ROCKER ARt SMAFT aPAcKEXo
FR0Wt/4 Z/FLAT AS
Figure 2 - Re moving Rocker Arm
Figure 3 - Us ing Rocker Arm Holder
19INSPEGTION AND REPAIR OF ROGKER ARM ASSEM BLY
1.
Inspect each of the rocker arm shaft bushings
for scores , scratches , or exces sive wear
making sure the oil holes are properly
aligned a n d not plugged . G upping at the end
of the levers that contact the valve stem should
be observed and discarded or reground where
it is excessive . Guppinq makes it difficult
to secure and maintain proper adjustment of the
valve . Figure 4 .
0I L H OLE IN BUSH I NG ON TOP
REAM BUSH I NG TO 7 5 .752 5
Figure 4 - Gupped Rocker Arm Figure 5 - Bush ing
Oi1 Hole Check adjusting screw for cracks ,
chipping , or excessive wear. Replace where
necessary.
2.
3. Examine rocker arm bushings for evidence of
cracking , pitting , or excess ive wear . A
further check for proper s iz ing of bushings to
the shaft can be made by placing a rocker arm on
the rocker shaft in the exact pos ition it will
ride when as sembled on the cylinder head. 'the
arm must be free on the shaft and free from any
sidewise motion or wobble . If any is noted ,
replace bushing .
4.
When installing new bushings in the rocker arms ,
make certain the oilhole in the bushing is in the
top pos ition as shown in Figure 5 . A/ter
replacing bushing , ream to . 7525 inches .
NOTE New replacement rocker arms are supplied
complete with bushings installed .
5 .
Examine the rocker shaft for wear and
replace if there are indications of shoulders
on the shaft.
6. Proper as sembly of rocker arms with
relation to the oil hole in the shaft is shown
in Figure 6. Improper lubrlcation will re
suit if the drilled hole is reversed . 11-2
20LEFT NAND RIGHTISO
R R ROCxER ARjg
OU HOt.E iN
SNAfT TOARD
YALvE StOE
Figure 6 - O il Hole In Shaft Figure 7 - Right
And Left Rocker Arm When reas sembling rocker
arms on shaft, make certain the right and
left rocker arms are assembled in their
respective pos itions . See Figure 7.
7.
8.
When replacing the rocker arm a ssembly, the
capscrews and stud nuts are tightened to 20 ft.
1bs . with a torque wrench .
STRIPPING AND REMOVING HEAD ASSEM BLY In order to
perform further servicing of cylinder head as
sembly It must be re- moved from the engine as
follows 1. Disconnect throttle rod at governor
arm .
2.
Remove carburetor and manifold as a unit. Unle ss
servicing of one of these as semblies is required
, no futher disa ssembly is nece s sary. Figure
8.
3 .
Remove water outlet elbow with hose and
thermostat as a unit. Figure 9.
IITAME VALVE fiETAtfiER
12
UPPER HOSE
WATEP OUTLfT
Flgure 8 - Removing Manifold As sembly
Figure 9 - Water Outlet Elbow
II-3
214.
Loosen the cylinder head stud nuts as shown in
Figure 10 .
5.
Map edges of head with a lead or rawhide
mallet and lift from engine as shown in Figure
11. Do not attempt to pry head from the block as
damage to the machined surfaces will re sult.
Figure 10 - Us ing Wrench Exte ns ion
Figure 11 - Removing Gylinder Head
6.
Remove cylinder head gasket and note impres s
ion made by cylinder sleeve s . Whe n s 1 e e v
e s a r e in proper pos ition and cylinder head
stud nuts are proper ly tightened, a sharp impre
s s ion will be made on the gas ket as shown in
I'-igure 12 .
Figure 12 - Head Ga s ket Gondition
GLEANING GYLI NDE R HEAD
1.
Remove dirt and carbon from the cylinder head
by scraping and brushing . Blow out cooling pas
sages with an air hose .
- CHE GKI NG GO MP RESS IO N
- O ne of the sources of lack of power is poor
compress ion in one or more of the cylinders . An
engine with poor compre s s ion is inefficient
and should not be kept in service . If compres s
ion is poor , it is because of compres sion
leaks past the valve s or rings . - Remove wires from spark plugs and remove plugs
from cylinder head. - Move throttle and choke valve to full open
position. - Install compress ion gauge into front spark
plug port. Crank engine four revolutions and
read gauge . Repeat this operation on the
three remaining cylinders . Figure 13.
II-4
224.
Compression pressure depends on starting s p e e
d , engine tempera- ture , and compre s sion
ratio. If the readings indicated on the compres-
sion qauge fall within the pres sure r a n g e
listed on the eompres s ton pre ssure chart and
do not vary more than 5 lbs . be t w e e n
cyllnders , eompres sion pres sure can be con-
sidered norma 1.
REMOVE SPARK PMJGS
MPRESSION
COMPRESSION PRESSURE GHART 14 8 Gu .
In. Engine Gasoline 140-15 0 lbs .
Figure 13 - Zes ting G ompre s s ion
5.
If pressure in any cylinder is weak , pour
approximately one tablespoon of oil into spark
plug hole while piston is down . Wait a few
minute s for oi1 to run down over piston rings to
prevent oi1 from getting on valve and repeat te
st. The oi1 s ea 1s the rings so a low reading on
first test , which remains low on a second te st
, indicate s leafy valves . A high reading on
second test , in- dicate s lea ky rings . An
extrem ly low compre s sion reading on two
adjacent cylinders indicate s a leaking or blown
cylinder head gas ket. A gas ket which has blown
out between cylinders will cause erratic
explos ions . Replace with a new gas ke t.
6.
A higher than normal reading may indicate
exces sive carbon depos its on walls of
combustion chamber. Remove head and clean .
REMOVING AND INSPECTING VALVES
1.
Place cylinder head on its side . Use a valve
sprinq compressor t o o 1 to compre ss each
spring until the valve stem retainer locks can
be removed. Figure 14. Remove valve stem
retainers and springs .
2.
3.
Remove va1ve through reverse side of cylinder
head .
4.
Glean valves thoroughly. Do not use e m e r y p a
p e r or a stlff wire brush which will damage va
lve s .A bras s wire bru sh is recommended .
5.
Note that the intake valves have a rubber g a s k
e t r e t a i n e r which preve nts oil from
being sucked into the combustion chamber on the
in- ta ke stro be of the piston . Figure 16.
Figure 14 - Removing Valve
236.
- Valves must be replaced if any of the f o 11o w i
n g conditions exist - Stem bent.
- Stem worn or scored.
- Stem nicked.
- Retainer groove worn.
- Zip damaged or worn.
- Face margin not maintained .
RETAINER
GASKET RETAINER ROTOCAP
VALVE SPR I NG
F I LL ET
STEIO
RETAI NE R GRoOVE
UG H EA
Figure 15 - Valve Nomenclature
INTAKE VALVE
Valve Guides
EXHAUST VALVE
Before reconditioning valves seats , the valve
guides should be inspected for exces sive wear
which will result in im- properly seated valves .
EXHAUST Figure 16 - Valve Assembly
NTAKE
Thoroughly clean the valve guides and check for
wear by inserting the valve into
- the valve guide . Too much clearance not
- only prevents the valve from seating properly but
also allows oil to enter the com- bustion
chamber increasing oi1 consumption and caus
ing heavy carbon depos its and warped valves .
Exces sive clearance in exhaust valve guides also
causes poor heat transfer , misalignme nt, and
poor seating resulting In early seat and
valve warp . Figure 17. - If it is found that the valve guides need
replacing , press out from the bottom. - Glean carbon deposit from valve guide rece sse s
. - Pres s valve guide s into the head from the top
. Figure 18 .
4.
When ins talllng new guides , pres s into
place so that guide extends 31/32 inch above
counterbored surface of cylinder head as shown
in Figure 18.
II- 6
24UST
INTAlfE
VALVE GUIDE CONDITION VALVE SEAT INSERTS L P. AND
HIGH ALTITUDE HEAD.
3432 REAM AFTER ASSEMBLY
GUIC lN GOOD SHAPE
VALVE UNSEATED
DUE TO BAO GUIOE
VALVE GUIDE
gELL MOUTHED GUIDE
Figure 17 - Valve Guide Gondition Figure 18 - In
sta fling Valve Guide
5 .
After as sembly , ream guides to . 34 22 - .
3432 inches . Figure 19.
6. Glean out valve guides us inq a valve guide
cleaning tool . Both guides are reamed to the
same dimensions as difference in clearance is
obtained in valve stem diameters . Exhaust
valves require greater clearance and therefore
have a small stem . When installing valves , coat
valve stems and guides with a thin film of light
oil.
NOTE
Every new valve guide must be reamed to proper
dimens ions before valves are installed .
- Gheck valve seat for evidence of pitting or
burning. - Check width of contact area on ex- haust valve .
- Check width of contact area on in- take valve .
Too wide a seat will collect carbon and a narrow
seat will tend to reduce heat dis sipa- tion
of the valve head .
Figure 19 - Valve Guide Reamer 11-7
254. Gheck concentricity of valve seat with dial
indicator . 00 2 i s maximum allowed
runout. Figure 20 . When it becomes ne ces sary
to re -condition valve seats , modern power
grinding tools should be used . Ma ke certain
the proper grade and size wheel is
used. NOZE Gasoline engine head does not have
exhaust seat inserts . When valve rotators are
used it is de s ira ble to have face to face
contact be- twee n the valve seat in the head and
the face of the valve . Zhe seats in the 148
cubic inch engine using valve rotators are
ground to 4 6 while on engines not equipped with
rotators , the valve seat is ground to 450 , It
is advantageous to have one-degree interfere nce
angle between the seat and the valve face in
order to re- move face depths its from the valve
where rotators are not ins talled . NOTE Where
e quipme nt is not available for grinding valve
seats to 4 6 , it is permis s ible to grind
both valve face and valve seat to 45 which
will give a face to face contact.
A POO R VALVE GRINDIN U JOB GANNOT BE IMPROVE D
BY VALVE LAPPING
- Valve Face Runout
- Ghe ck defaced valve with a V- block type of
gauge . Figure 21. - Runout must not exceed . 00 2.
Figure 20 - Valve Seat Run Out
INTAKE
EXHAUST
148 Cu. In. Engine
Gas oline Engine
Gasoline Engine
Angle of Seat
46
30
Width of Seat
.078 - .064
. 078 - . 0 66
Angle of Valve Face
44
30
Diameter
. 3390 - . 3382
.3414 - .3406
II - 8
26AT
EXHAUST INTERFERENCE ANGLE
EXHAUST FAGE-TO-FACE CONTACT
F1qure 22 - Valve Seat Angle
DO NOT GRIND MARGIN TO LESS THAN I/2 OF ORIGINAL
WIDTH
OtSCAAO vALVE OF RUNOUT iS MORE THAN ,0O2"
VALVE FACE MARGIN
- Figure 23 - Valve Face Margin
- Valve Face Margin
- Valve face margin of less than one-half the
original margin of a new valve should be r e p l
a c e d. Knife edges are conducive to edge
roll- over, valve burning ,and pre-ignition due
to heat localiz ing on valve edge . - Figure 21 - Ghecking Valve Face Run Out
- Maintain rea sona ble margin . Figure 23.
- Face intake valve to 30 .
3. Face all exhaust valves on 14 8 cu . in.
engine to 4 4 .
GONTACT AREA
TOO WIDE
PftUSSIAN BLUE
064" TO 078
OF VALVE
PRUSSIAN BLUE
CONTACT AREA
VALVE AND INSERT AFTER GRINDING SEAT MUST OE
NARROWED AND CENTERED IN FACE
ON VALVE
Figure 24 - Seat Gontact Width
Figure 25 - Sea t D ontact Width
27Suggest If the above button click is invalid.
Please download this document first, and then
click the above link to download the complete
manual. Thank you so much for reading
28SEAT AND FACE POSITION
RIGHT
WRONG
Figure 26 - Seat And Face Position 4. Remove
only enough material to re- move b u r n e d or p
i t t e d p o r t i o n of face .
tF fiUchQJT OR6 THAN .00Z
5 . Gheck valve stem for straightnes s . If
runout is more than- 00 2, discard valve . Figure
2 7.
6. Using a micrometer , check the dia- meter of
the valve steori n e a r t h e valve head and
compare the reading taken near tip end of valve .
If dif-
ference valve.
is more than . 002 dis card Figure 28.
Figure 2 7 - Checking Valve Stem Run Out
Figure 28 - Checking Valve Stem Diameter VALVE
SPRINGS Inspect intake and exhaust valve springs
for proper length and tens ion .
II - 10
29https//www.ebooklibonline.com Hello dear
friend! Thank you very much for reading. Enter
the link into your browser. The full manual is
available for immediate download. https//www.ebo
oklibonline.com