TM 5-3825-226-24
CYLINDER HEAD AND VALVE COMPONENTS
SP5170 KNURLING GROUP
1. 5P5178 Lubricant. 2. 5P5187 Tap Wrench. 3.
5P5177 Speed Reducer(7to 1). 4. 5P517B Brush. 5.
5P5175 Knurl ing Arbor. 6. 5P5171 Reamer (.371
in.). 7. 5P5172 Reamer (.372 In.). 8. 5P5173
Reamer (.373 in.). 9. 5P5174 Reamer (.374 in.).
1. Clean and buff head, guides and valves. Check
valve stem diameter. The intake valve stem
diameter is .3725 ± .0005 in. (9.462 ± 0.013 mm)
and the minimum size worn is .3710 (9.423 mm).
The tapered stem exhaust valve has a stem
diameter 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 rocker arm side
toward you.
NOTE
Use FT967 Adapter Plates to mount
head on FT806 Cylinder Head Bench.
3. Dip the 5P5176 Brush (4) into the 5P5178 Lubricant
(1) and run the brush through the guide.
NOTE
The 5P5178 Lubricant is specially
formulated for knurling cast iron
guides and will prolong arbor life. If
not available, use only Black Sulfur
cutting oil or parafin base oil.
4. Dip the 5P5175 Knurling Arbor (5) into the 5P5178
Lubricant just prior to knurling. Use the 5P5177
Speed Reducer (3) and a 1/4 inch electric drill (1200
to 1600 rpm recommended) to drive the arbor. Hold
the speed reducer and drill firmly during knurling. Do
not push or guide arbor during knurling.
KNURLING GUIDE
3. 5P5177 Speed Reducer. 5. 5P5175 Knurling
Arbor.
5. Select the reamer that is closest to the size of the
valve stem that is to be used and ream the guide
using the speed reducer and 1/4 inch electric drill.
Push firmly to ream.
REAMING GUIDE
NOTE: It is not necessary to use
lubricant for reaming.
6. Clean the valve guides with brush and solvent.
7. Install the valve. It is permissible to use a maximum
force of 6 lbs. (27 N) with no oil to install the valve.
Should valve not fit, use next size larger reamer and
ream as in Step 5.
8. Thoroughly clean the valve guide bores after
knurling.
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