TM 5-3805-260-24
CYLINDER HEAD AND VALVE COMPONENTS
The following procedure may be used to knurl
valve guide bores using the United Tool Process:
1. Clean and buff head, guides, and . Check valve stem
diameter. The intake stem diameter is . 3725 + .
0005 in. (9. 462 + 0. 013 mm) and the minimum
size worn is . 3710 in. (9. 423 mm). The tapered
stem exhaust ale has a stem diame ter of . 3715 + .
0005 in. (9. 436 +- 0. 013 mm) at the keeper end
of the stem, and . 3705 + . 0005 in. (9. 411 + 0.
013 mm) at the head end of the stem. The
minimum size worn is . 3690 in. (9. 373 mm).
2. Place head on the FT806 Cylinder Head Bench or
8S6691 Cylinder Head Stand with spring end of
value guides toward you.
NOTE: Use FT967 Adapter Plates to mount head on
FT806 Cylinder Head Bench.
3. Select the drill jig that corresponds in size to the valke
guide. Use the 3/16 in. drill and stop in a slow
speed drill. Drill an offset hole in guide 1/8 in. to
3/16 in. (3. 2 to 4. 8 mm) deep (hole to be drilled
on exhaust manifold side of guide).
4. Using the proper size knurling tool and wheel, insert
tool into guide and place wheel edge in offset notch.
Place one drop of lubricant in each offset notch
before knurling, and one drop on wheel after
installing wheel in knurling tool. Use straight hex
blade pronvided to match knurling tool and adapter
in speed reducer. Hold outer sheel of reducer from
turning and start drill. Follow, the rotating tool with
slight pressure through the guide.
CAUTION
Use the mechanical speed reducer for all knurling
and reaming as excessive speed and torque
destroys tools. If possible, use a drill with a no load
speed of 600 rpm.
5. After knurling all guides, and before reaming, try
valves in each end of guides. They should not fit
nto guides. If valves will go in either end of guides,
the guides must be knurled again using the next
size wheel. Ream the guides with a . 374 in.
reamer before knurling. Repeat knurling and
reaming process until valves will not fit into guides.
6. Ream valve guide bores to . 3745 + . 0005 in. (9.
512 + 0. 013 mm). To ream valve guide bore use
a . 374 in. reamer. The reamer will ream the bore
. 0005 to . 0008 in. (0. 013 to 0. 020 mm) over
the size marked on the reamer.
7. After reaming, clean guides thoroughly before
checking valguide bore size.
8. Before installing, clean salve guide bores with the
IP5571 Brush and a strong detergent. Stroke each
bore several times with the brush rotating to remove
all dirt and loose chips.
After the guides are knurled, the valves land
valve seats must be ground to provide proper sealing.
For valve grinding specifications, see VALVE
GRINDING SPECIFICATIONS CHART.
VALVE GRINDING SPECIFICATIONS
Item
Exhaust
Intake
Seat Angle
45 1/2° + ½°
30 1/2° + ½°
Seat Width
(Maximum)
105 in.
2. 67 mm
. 120 in.
3. 05 mm
Seat Outside
Diameter (new)
1. 735 + . 005 in.
(44 07 + 0. 13
mm)
2. 045 + . 005
in.
(52. 23 + 0. 13
mm)
Seat Outside
Diameter(Maximum)
1. 760 in.
(44. 70 mm)
2. 065 in.
(52. 45 mm)
Angle to Grind
Insert to Reduce
Seat
Maximum Diameter
15°
Heads with
inserts installed
15°
Depth of Bore to
Reduce Seat
Maximum Diameter
-
Heads without
inserts . 170 in.
(4. 32 mm)
Valve Face angle
45°+ 1/4°
30°+¼|
Valve Lip
Thickness (new)
. 063 In.
. 091 in.
(2. 31 mm)
Valve Lip
Thickness
(Minimum)
. 044 in.
(1. 12 mm)
. 070 in.
(1. 78 mm)
Valve Head
Diameter
1. 804 + . 005 in.
(45. 82 + 0. 13
mm)
2. 094. 005 in.
53. 19 + 0. 13
mm)
Maximum Distance
Valve Head to
Cylinder
Head Face
(Closed Valve)
. 085 in.
(2. 16 mm)
.
068 in.
(1. 73 mm)
Minimum Distance
Valve Head to
Cylinder Head Face
(Closed Valve)
. 050 in.
(1. 27 mm)
. 036 in.
(0. 91 mm)
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