Operating instructions

5-2 MARCH 1982
since the corner radii at the bottoms of the grooves
must not be altered, nor any metal removed from the
sides. Discoloration and light scoring need not be
removed from piston skirts. The use of abrasive cloth
on the skirts is not recommended, because the
diameters and cam-ground contour must not be
altered. Heavily scored or burned pistons should be
discarded.
5-9. VALVES. After degreasing valves, inspect
them and discard any whose head is warped
excessively, or which has insufficient stock to permit
refacing within specified limits, or whose stem is
burned, scored, eroded or nicked. Carbon deposits
may be loosened by solvent action or they may be
scraped off while the valve is rotated in a, polishing
head or lathe collet. Apply crocus cloth moistened in
mineral spirit, and polish the stems with dry crocus
cloth.
5-10. ROCKER SHAFTS. Degrease these parts by
brushing on any mineral spirit solvent. Prior to
magnetic inspection, polish the steel bearing surfaces
with crocus cloth moistened with kerosene, then with
dry crocus cloth.
5-11. PUSHRODS, VALVE ROCKERS AND
OTHER SMALL STEEL PARTS. Degrease these
parts with mineral spirit solvent, paying special
attention to removal of sludge from all oil passages.
5-12. CAMSHAFT AND CRANKSHAFT. All
parts may be degreased by brushing or spraying with
mineral spirit solvent. Pay particular attention to
threads, oil holes and recesses. Before magnetic
inspection, the crankpins, main journals, oil seal race
of the crankshaft and all journals, cam lobes and gear
mount flange of the camshaft must be smoothed with
crocus cloth, moistened in a mineral spirit. If
possible, this should be accomplished while shaft is
rotated in a high speed lathe (about 100 RPM). All
gum (varnish) deposits must be removed to permit
reliable magnetic indications.
NOTE
Internal cleaning of the hollow camshaft in
Permold engines is not necessary. Therefore, do
not remove the rear pipe plug or front expansion
plug unless re- placement of either plug is
necessary. Failure to replace either or both
plugs at reassembly will result in loss of oil
pressure with little or no lubrication of moving
engine parts.
5-13. CRANKCASE. The oil passages should be
pressure-flushed with mineral spirit solvent and
inspected with the aid of a flashlight. If the castings
are immersed in an alkaline bath, it is strongly
recommended that such treatment be followed by
spraying with a jet of wet steam and this followed by
flushing of the oil passages with solvent. After the
castings dry, inspect them thoroughly for alkaline
residues, and remove any traces of scum.
5-14. GEARS. Gears without bushings may be freed
of hard deposits by immersion in a caustic stripping
bath, when cold solvents are not effective. Bushings
are discolored by such treatment, hence bushed gears
should be cleaned by other methods such as spraying
and/or brushing with a mineral spirit solvent and
brushing with a brass wire brush.
5-15. SHEET METAL PARTS. Clean these parts
with a mineral spirit spray or by brushing with the
same liquid, or use a cold emulsion type cleaner and
flush with water to rinse.
5-16. Immediately after cleaning bare steel parts
spray them with or dip them in clean engine oil or, for
longer storage, in a corrosion-preventive oil mixture.
Wrap ball bearings in waxed paper. Wrap or cover
other clean parts to protect them from abrasive dust in
the air.
5-17. CASTINGS. Remove the raised edges of nicks
in machined surfaces with a hard Arkansas stone.
Unobstructed flat surfaces, such as valve rocker cover
flanges, may be returned to true flatness by lapping if
a true lap plate is available. Use fine grade lapping
compound and move the casting in a figure 8 stroke
without rocking it.
Gasket surfaces must be thoroughly cleaned with a
suitable hydrocarbon solvent such as naptha, Methyl
Ethyl Ketone (MEK) or Trichloroethylene (TCE) to
remove dirt, oil and grease. Wipe surfaces dry before
re-use.
5-18. STUD REPLACEMENT. Remove damaged
whole studs with a standard pattern stud remover or a
small pipe wrench, turning slowly to avoid heating the
casting. Remove broken studs which cannot be
gripped by drilling on center to the correct diameter
for unscrewing them with a splined stud extractor.
(Splined extractors and drills are usually sold in sets.)
Examine the coarse thread end of the damaged stud
before discarding it to determine its size. Standard
studs have no marking. For oversize stud
identification refer to Table VII. Clean the casting
tapped hole with solvent and blow dry with
compressed air; then examine the thread. If it is not