Chevrolet 70 1969 Series, Shop Manual

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E N G IN E 6-35
E N G IN E SPEC IFIC A TIO N S (CONT.)
C A M S H A F T AND BEARINGS (V-6 ENGINES)
Camshaft Brg. I.D. (in Place)
No. 1 (Front)....................................... 2.0583”-2.0593"
No. 2 ................................................... 2.0269''-2.0279"
No. 3 ................................................... 1.9957"-1.9967”
No. 4 ................................................... 1.8432”-1.8442”
Camshaft Journal Diameter
No. 1 (Front)....................................... 2.0573”-2.0563"
No. 2 ................................................... 2.0259''-2.0249"
No. 3 ............................. ..................... 1.9947”-1.9937"
No. 4 ................................................... 1.8422”-1.8412”
Permissible Runout at Intermediate Journals
with Camshaft Supported at E n d s................. 0.0015”
Camshaft Bearing to Journal Clearance. . 0.001"-0.003"
Camshaft End P l a y ............................. 0.0045”-0.0085"
Camshaft Thrust Plate Thickness . . . . 0.187"-0.185”
Camshaft Drive
401M & 4 7 8 M ............................................ Gear Train
TIMING GEARS
Backlash (Between Mating Gears). .
Gear Runout (After Installation)
Crankshaft G e a r ...........................
Camshaft G e a r .............................
Idler G e a r ....................................
Idler Gear End Play (401M & 478M)
Idler Gear Bushing I.D. (In Place) .
Idler Gear Shaft O .D ........................
Idler Gear Bushing to Shaft Clearance
C O N NECTIN G RODS AN D BEARINGS
0.002”-0.004”
.
0
.
0 0 2
'
1.4005”-
1.3990”-
.
0
.
001
" -
0
.
0 0 2
"
0 . 0 0 2 ”
0
.
0 0 2
"
’-0.005"
1.4015"
1.3995”
0.0025"
I.D. at Large Bore with Cap Bolts
Tightened......................................... 3.0160”-3.0165"
I.D. of Bore at Upper End ................. 1.3125"-1.3135"
Piston Pin Bushing I.D. Installed . . . . 1.2401”-1.2405”
Piston Pin to Bushing Oil
Clearance......................................... 0.0001"-0.0006”
Std. Connecting Rod Brg. Half Vertical Thickness
(at right Angle to Split Line)............ 0.1011"-0.1014"
Vertical Oil Clearance Between Rod Bearing
and Crankpin.....................................0.0010"-0.0031”
Connecting Rod Brg. Material
401M, 4 7 8 M ........................................................M500
Rod End Play on Crankpin................... 0.006” -0.011”
Connecting Rod Alignment
Pin Hole Axis Must be Parallel in All Planes with
Axis of Large Bore w ithin...................... 0.002” in 7”
PISTON AND PISTON PIN
Standard Piston Diameter at Top of Skirt
(Measured at Right Angle to Piston Pin):
Standard Piston Selective Sizes (Production)
Size No. 401M Engine
1 4.8705"-4.8708"
2 4.8708”-4.8711"
3 4.8711"-4.8714"
4 4.8714"-4.8717"
5 4.8717"-4.8720"
6 4.8720”-4.8723"
7 4.8740"-4.8743"
478M Engine
1 5.1199"-5.1202"
2 5.1202”-5.1205”
3 5,1205”-5.1208”
4 5.1208”-5.1211”
5 5.1211"-5.1214"
6 5.1214"-5.1217"
7 5.1234”-5.1237"
Note: Piston sizes listed are dimensions when taken
with pistons at Temperature of 70° to 7 5 °F.
Service Pistons
Standard Sizes Available Use in Cylinders Marked
1 ....................................................................... 1 or 2
3 ....................................................................... 3 or 4
5 ....................................................................... 5 or 6
7 ................................................................................. 7
See applicable tabulation of standard piston sizes which
are same for production and for service.
Finished Pistons available in
following O versizes...............0.005” , 0.020” , and 0.040”
Piston Skirt to Cylinder Bore Clearance (At right angle
to axis of pin)
4 0 1 M ................................................... 0.0033”-0.0039”
4 7 8 M .................................................... 0.0039”-0.0045”
Note: Fit Oversize Pistons with Skirt Clearance of
0.0030” to 0.0040” on all engines, the larger clearance
desired for the larger diameter bores.
Piston Pin Hole Standard I.D. (in Piston)
Red Color C o d e .................................. 1.2403” -1.2404”
Green Color C o d e ................................ 1.2402”-1.2403"
Piston Pin Clearance in Piston Boss . . . 0.0003”-0.0005"
Piston Pin O.D . (Red Color C ode).......... 1.2398”-1.2400”
O ve rsizes..........................................0.001” and 0.002"
Standard Piston Pin Available in Red Color Code Only
for Service Fit Standard and Oversize Pins as follows:
Clearance in Piston............................. 0.0003"-0.0005"
Clearance in Rod Bushing.................... 0.0001”-0.0006”
Piston Ring Groove Width
Compression Ring Grooves
Top Groove ..................................... 0.0965”-0.0975”
2nd Compression Ring Groove . . . . 0.0960”-0.0970"
3rd Compression Ring Groove . . . . 0.0955"-0.0965"
Oil (Bottom) Ring Groove................. 0.1885”-0.1895”
Piston Ring Clearance in Groove
Top G roo ve.......................................... 0.0030” -0.0055”
2nd Compression Ring
4 0 1 M ................................................. 0.0030"-0.0045”
478M .............................................. 0.0025”-0.0040”
3rd Compression Ring........................ 0.0025"-0.0040"
Oil (Bottom) Ring
4 0 1 M ................................................. 0.0010"-0.0030"
4 7 8 M ................................................. 0.0020"-0.0035"
Piston Ring Gap
Top Ring
4 0 1 M ................................................... 0.024"-0.034"
4 7 8 M ................................................... 0.026”-0.036"
2nd Ring
4 0 1 M ................................................... 0.015”-0.025"
4 7 8 M ................................................... 0.017”-0.027”
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH O P M A N U A L