Hudson 63 1936, Руководство по механическим процедурам

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MECHANICAL PROCEDURE MANUAL
SECTION 7
Page 9
the rod and piston assemblies removed from the top of the cylinder.
Connecting Rod Bearings
The connecting rod bearings are spun virgin babbitt. They are
adjustable by removing shims from between the rod and bearing
cap. They should be adjusted to .001" clearance.
IMPORTANT: If a rod bearing is burnt out the oil troughs in the
crankcase walls and webs leading to the main and camshaft bear-
ings must be thoroughly cleaned of babbitt which may have been
thrown into them.
Selecting and Fitting Piston Rings
When fitting the pinned type piston ring, the gap between the
ends of the ring and the clearance between the pan and the ends of
the ring are equally important.
The rings are cut and notched to accept the pin so that the
clearance on the pin is equal to the gap between the ends of the
ring (Figure 713). In other words, if the ring is compressed so
that the ends come together there will be no clearance on the
pin.
If the ends of the ring are filed in fitting the ring it is
necessary to file an equal amount in the pin notch to maintain
the pin clearance. Filing should, however, not be necessary.
Piston rings of the pinned type are supplied in exact sizes to
give a minimum gap of .005" when installed in a cylinder of
the size for which the ring is designated. Since it is necessary
to hone or otherwise recondition a cylinder bore when over-
sized pistons are being fitted, they should be brought to an
exact size for which piston rings are available. For example, a
cylinder may clean up at .009" oversize. However, since no
ring is available in this size it is advisable to hone the cylinder
to .010" oversize rather than file the gap of a set of .010"
oversize rings to permit their use in a .009" oversize cylinder.
The sizes in which piston rings are available are given in the
Table on Page 10. When ordering rings, both the part number
and the size desired should be given on the order.
Selection of Pistons
The code letters stamped on the cylinder block along the
lower face of the valve chamber, as shown in Figure 714,
designate the original size of each cylinder. The size code
letters and piston weight, in ounces and quarter ounces
(Figure 714), stamped on the heads of the pistons will help in
selecting pistons correctly from stock. In addition to the size
and
Figure 7I3—Piston Ring Clearances
Printed in U. S. A. ISSUED MAY, 1937