TM 5-4310-354-14
Table 7-2. Cylinder Bore Dimensions
Manufacturing tolerance
Maximum allowable
diameter
Cylinder bore diameter
Inches
Millimeters
Inches
Millimeters
3/4
3
inch (95.25 mm)
3.749/3.751
95.225/95.275
3.756
95.402
0.020 oversize (0.508 mm)
3.769/3.771-
95.773/95.783
3.776
95.910
0.040 oversize (1.016 mm)
3.789/3.791
96.241/96.291
3.796
96.418
(5) The out-of-round must not exceed 0.003
or length.
Out-of-flatness should vary
inch (0.0762 mm) or the taper must not be
gradually and uniformly from end to end
more than 0.002 inch (0.0508 mm) in each
and side to side. If it is necessary to
bore. Irregularities in the cylinder bore
machine the top surface of the block to
(out-of-round and taper) may result in
correct for the above conditions, do not
galling and seizing of new pistons.
remove more than 0.005 inch (0.127 mm)
of metal.
The dimension from the
(6) If the cylinder bores are worn excessively,
centerline of the crankshaft to the top of
they can be rebored for 0.020 and 0.040-
the block must not be less than 13.12
inch (0.508 and 1.016 mm) oversize
inches (333.248 mm).
pistons and piston rings. After boring,
check the bore finish to be sure it is
(9) Remove and replace any damaged or
smooth.
broken cylinder head studs (figure 7-63).
With studs removed, inspect the tapped
(7) Hone the cylinders and ridge ream, if
stud holes in the block and, if the threads
necessary. After honing the cylinders,
are damaged, use a tap (same size as
visually check the honed surface of each
hole) to clean up the threads or retap
cylinder bore. There must not be any low
larger and install a helical thread insert.
spot with an area larger than a half dollar.
Add Locktite, or equivalent, in hole and
Recheck the cylinder tolerance as
install new studs in the cylinder block to
described above.
the dimensions indicated in table 7-3.
Install the end oil passage studs so that
(8) Check the top of the block for flatness with
the oil holes are within a 40-degree angle
an accurate straightedge and a feeler
with the center line of the rocker arm
gauge. The top surface must not vary
shaft, as shown in figure 7-37.
more than 0.005 inch (0.127 mm) on width
7-72
