TM 5-3810-294-34
Table 1-4. Repair and Replacement Standards (Continued)
Manufacturing Dimensions
Maximum allowable
and tolerances inches
wear or clearance
Component
From
To
maximum
PISTON PINS:
Length
.......................................................
3.795
3.797
Diameter
.......................................................
1.1089
1.1090
Pin fit (room temperature 70F)
Recommended clearance in rod ...................
0.0005
0.0007
Recommended clearance in piston:
Tight end................................................
0.0001L
0.0002T
Loose end ..............................................
0.0001L
0.0005L
FEELER GAUGE RIBBON CHECKING:
Width - inch .......................................................
1/2
1/2
Thickness - inch .....................................................
0.003
0 003
Tension on scales (pounds} ...................................
6
18
Desired tension (pounds) .......................................
11
13
PISTON RINGS:
Compression rings
Number used on each piston .........................
2
Size
.......................................................
3/32
3/32
Oil rings:
Number used on each piston .........................
1
Size
.......................................................
3/16
Ring diameter.................................................
4-3/8
4
Ring gap:
Compression ..................................................
0.025
0.035
U-Flex-No gap at ring joint (Gap
built between ring segments})
Fit in groove:
Top
.......................................................
0.0040
0.0055
Second .......................................................
0.0020
0.0035
Third
............................................0.0015
0.0035
INTAKE VALVES:
Stem diameter .......................................................
0.435
0.435
Valve to rocker arm clearance (hot) .......................
0.024
0.026
Stem clearance in guide.........................................
0.0015
0.0040
Width of valve seat .................................................
5/64
7/64
Note Valve face angle is 4 degrees
EXHAUST VALVES:
Stem diameter ....................................................... 0.4365
0.4375
Valve to rocker arm clearance (hot) ....................... 0.024
0.026
Stem clearance in guide......................................... 0.0020
0.0045
Width of valve seat .................................................
1/8
3/32
Slo-roto valve cap to stem clearance ..................... 0.001
0.005
Note Valve face angle is 45 degrees
VALVE GUIDES:
Distance above head..............................................
1-1/16
Inside diameter .......................................................
0.438
0.499
VALVE LIFTERS:
Clearance in block..................................................
0.0010
0.0035
VALVES SPRINGS:
Free length:
Inner (new) .....................................................
2-11/32
2-9/32
Outer (new) ....................................................
2-9/16
2-1/2
Length - valve open:
Inner (new) .....................................................
1-1/2
Outer (new) ....................................................
1-45/64
1-5/8
Pounds pressure-valve open:
Inner
.......................................................
88
88
Outer
.......................................................
133
141
1-7
