1948-1952 Shop Service Manual - - Hudson-Essex-Terraplane Club

ENGINE 3 - 23
a 3 to 4 pound pull. Use tool J-888 Piston Feeler Scale to
measure this pull as in Figure 27.
CAUTION: A thousandth of an inch variation will
change the pull on the feeler only a few pounds and the
use of this scale will eliminate guessing.
FIGURE 25
FIGURE 27
CAUTION: When pistons are fit to reconditioned bores,
the cylinder block should be allowed to cool to normal
room temperature and the piston fit rechecked before
Installing pin in piston.
Cylinder bores can be readily checked for wear with
"Cylinder Checking Gauge KMO-913".
Reconditioned cylinder bores should be he ld to not more
than .005" out-of-round or taper.
FIGURE 26
The piston skirt is cam ground to an elliptical shape and tapered.
Maximum skirt diameter is at "A", Figure 23 and 27, just below the
third ring groove at right angles to the piston pin. The cam grinding
makes it necessary that a .002" feeler blade 1/2" wide be used
directly opposite the skirt slot when checking piston clearance, at the
thrust side of the piston.
After inserting the piston in the cylinder with the .002" feeler gauge
in the position described above, the feeler should be movable under
NOTE: It is important that reconditioned cylinder bores
are thoroughly washed to remove all traces of abrasive
material.
PISTON PINS
Piston pins are of full-floating design. The pin rotates in
the connecting rod bushing and has sufficient movement in
the piston to equalize wear. The piston pin hole in the
piston is diamond bored for close fitting of the pin.