Hudson 1955 Rambler, Technical & Service Manual

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to bore clearance is .0006" to .0012".
PISTON RINGS
The pistons are fitted with four piston
rings, two compression and two oil control
rings.
A chrome plated upper ring is used to resist
corrosion.
Before assembling the rings to the piston,
carbon must be cleaned from all ring grooves.
The oil drain holes in the oil ring grooves
must be cleared. Care must be exercised not
to remove metal from the grooves, since that
will change their depth, nor from the lands,
since that will change the ring groove
clearance and destroy ring to land seating.
Checking Ring Groove Clearance
Side groove clearance is measured with a
feeler gauge. Roll the rings around the
piston in the grooves in which they operate.
Check for freedom all the way around.
The groove clearances are listed below by
ring number with the top ring as number one.
Ring Number 1 2 3 4
"Hornet" .002"-.004" .002"-.004" ,001"-.003" ..001"-.003"
"Wasp" .002"-.004" .002"-.004" .001"-.003" .001"-.003"
"Rambler" .002"-.004" .002"-.004" .002"-.004" .002"-.004"
Checking Ring Gap Clearance
Piston ring gap clearance is measured in the
bottom of the cylinder near the end of the
ring travel area. To square the ring in the
bore for checking gap clearance, place the
ring in the bore. Then, with an inverted
piston, push the ring down near the lower end
of the ring travel area. When other than
standard ring sizes are used, rings should
be individually fitted to their respective
bores.
The ring gaps for fitting rings are listed below:
"Hornet" .006"-.014"
"Wasp" .004"-.009"
"Rambler" .010"-.020"
Piston Ring Installation
Removal of glaze from the cylinder wall for
quicker ring seating can be accomplished by
various methods. If the expanding flexible
type hone is used, do not use more than 10
strokes (each stroke down and return) to
recondition a cylinder wall.
Successful ring installation depends upon
cleanliness in handling parts and while
honing the cylinder walls. The engine bear-
ings and lubrication system must be protected
from abrasives.
Rigid type hones are not to be used to
remove cylinder glaze as there is always a
slight amount of taper in cylinder walls
after the engine has been in service.
Rings must be installed on pistons with a
ring installation tool to prevent distortion
and ring breakage.
Detailed instructions in service ring pack-
ages must be followed.
"Hornet" and "Wasp" Series
Four piston rings are used; three rings are
located above the piston pin and one below
the pin. The rings are pinned in place to
prevent movement (Figs. 23 and 24).
FIGURE 23— Ring Arrangement
"Hornet" Series
The rings are notched on the inner diameter
at the gap slot. The width of the notch is
.125". Approximately .075" is at one end of
the ring and .050" at the other end. This
off-setting of the notch enables a single pin
pressed in from the top of the piston to
locate the three top rings without having the
gaps on adjacent rings aligned (Fig. 25).
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T E C H N I C A L S E R V I C E M A N U A L