(2) L i g h t l y coat the entire seat with
lift out the valve (10) and remove the
water-soluble valve grinding com-
spring from the cylinder block (13).
pound. Grind the valves by rotating
Remove the seven other valves in the
them back and forth with a recipro-
cating advancing valve tool. Occa-
Note. Tag or otherwise identify each valve
its related parts to assure reinstallation
sionally lift the valve and reseat it in
the same valve chamber.
a different position to insure a uni-
b. Cleaning and Inspection.
form seat. After the valves have been
ground in evenly, remove them and
(1) Clean the valves with a wire wheel
clean the valves and blocks thoroughly
b r u s h to remove carbon from the
with an approved cleaning solvent.
valve faces and gum deposits from the
(2) Clean all other removed parts with an
(1) Position the spring (9, fig. 26) in the
approved cleaning solvent and dry
cylinder block (13) and insert the
valve (10) in the valve stem guide
(3) Clean the valve guides in the cylinder
b l o c k s and blow clean with com-
(2) Compress the valve spring and install
the valve spring seat (8), retainer
(4) Clean the valve seat inserts in the cyl-
locks (7), and the rotator cap (6) on
inder blocks and the top of the blocks.
the valve stem. Install the seven other
valves in a similar manner.
(5) Inspect the valves for burned, pitted,
or cracked faces. Replace a defective
(3) Adjust the valve lifters (par. 125).
(4) Install the cylinder heads (par. 124).
(6) Inspect the valve springs for cracks
(5) Install the intake and exhaust mani-
or pitting. Replace cracked or pitted
fold (par. 123).
valve springs. Check spring tension
with a dial-type spring tester. If the
187. Valve Seat Inserts and Valve Guides
scale reading is less than 85 pounds
a. Cleaning and Inspection.
when spring is compressed to 1 7/8
(1) Remove the valves (par. 186).
inches, replace the spring.
(2) Use a valve guide cleaning tool to
(7) Inspect the valve seat inserts for loose
ream carbon from the valve guides.
or worn condition. Replace loose valve
Blow carbon from the guides with
clean compressed air.
(8) Measure the clearance between the
(3) Clean the face of the valve seat in-
valve stems anti the valve guides, Re-
serts with a wire brush or buffing
place the valve guides if the clearance
exceeds 0.007 inch.
(4) Clean the valve stem and insert the
c. Valve and Valve Seat Refacing.
valve into the guide. Check the side
(1) Using a valve face grinder, reface the
play of the valve in the guide with a
valves to a 45° angle. Replace any
dial indicator. If. the clearance be-
valve that measures less than 0.0625
tween the stem and the guide exceeds
inch from the top of the head to the
0.007 inch replace the valve guide.
edge of the refaced outer circle.
(5) Inspect the valve seat inserts for pit-
(2) Install a pilot in the valve guide. Set
ting, cracks, abrasions or uneven
the stone at 45° and dress the stone.
wear. If the inserts cannot be re-
Grind the seat just enough to remove
paired by grinding (par. 186) they
must be replaced.
pits and abrasions.
d. Valve Grinding Procedure.
(1) Remove all traces of carbon from the
(1) Use a drift to drive the valve stem
face of the cylinder block.
guide (12, fig. 26) down through the