(4) Inspect cylinder sleeves for scoring
damage or wear. Replace damaged or excessively worn
sleeves. Inside diameter of a new sleeve is 4.500 to
4.501 inches. Replace sleeves when worn 0.004 inch or
more, measured at top of ring travel. Sleeve flange
thickness is 0.408 to 0.405 inches. Block counterbore is
0.400 to 0.402 inches. Cylinder block main bearing
original bore is 3.8155 to 3.8165 inches. Main bearings
specified clearance is 0.0030 to 0.0059 inch. Replace
bearing when clearance is 0.008 inch or more.
(5) Inspect all valves for cracked, pitted,
dished, warped, or excessively worn condition.
Check for dimensions and tolerances as follows:
(a) Be sure 0.094 inch of material
remains above face after grinding. Grind to a 29 1/4
face. Stem diameter of a new valve is 0.3715 to 0.3725
inches. Replace valves that are worn or damaged
beyond repair.
(b) Grind valve seats to a face of 30,
with a maximum face width of 0.076 inch. Height of
valves above surface of cylinder head must be between
a minimum of 0.082 inch and a maximum of 0.128 inch.
(c) Valve guide to stem clearance is
between 0.003 and 0.005 inch. Replace guides when
clearance measures 0.007 inch (with a new valve).
(d) Valve springs
should
require
between 58.20 and 58.80 pounds of force to compress
them to 21%2 inches in length.
(e) Lifter bore is 1.3125 to 1.3135 inch.
New lifter diameter is 1.3100 to 1.3110 inches. Replace
lifters when clearance is 0.009 inch.
(6) Inspect precombustion chamber for
cracks, breaks, or other damage. Replace defective
chambers. Inspect compression release mechanism for
Figure 3-61. Positioning the precombustion chamber
bent shaft, weak spring, or damaged plunger. Repair or
and sequence for cylinder head bolt tightening.
replace damaged shaft. Replace defective spring or
plunger.
shown in figure 3-61) to torque specified in paragraph 1-
4f(2) above.
e. Reassembly and Installation.
(1) Install bearing caps and sleeves by
NOTE
reversing the procedures in c above.
(2) Reassemble and install cylinder head by
Be sure water directors, seals, and
reversing procedures in b above. Tighten cylinder head
holddown bolts (in the numerical sequence.
ferrules are properly installed. Align
notch on director with V-mark on
head.
Also,
assure
that
precombustion chamber is correctly
positioned (fig. 3-61 and 3-62).
(3) Complete
installation
by
reversing
procedures in steps (1) through (6) of a above.
AGO 20051A
3-72
