Specifications

1-16
GROUP 1-ENGINES AND EXHAUST SYSTEMS
A1201-B
FIG. 25-Checking Piston Fit
Example 2. If a 0.003-inch feeler
ribbon is used and it takes approxi-
mately 9-pounds pull to remove the
ribbon, the resultant clearance is ap-
proximately 0.0015 inch.
FITTING PISTON RINGS
1. Select the proper ring set for
the size piston to be used.
2. Position the ring in the cylinder
bore in which it is going to be used.
3. Push the ring down into the
bore area where normal ring wear is
not encountered.
4. Use the head of a piston to
position the ring in the bore so that
the ring is square with the cylinder
wall. Use caution to avoid damage to
the ring or cylinder bore.
5. Measure the gap between the
ends of the ring with a feeler gauge
'A1020-A
FIG. 27—Ring Side Clearance
(Fig. 26). If the ring gap is less than
the recommended lower limit, try
another ring set.
6. Check the ring side clearance
of the compression rings with a feeler
gauge inserted between the ring and
its lower land (Fig. 27). The gauge
should slide freely around the entire
ring circumference without binding.
Any wear that occurs will form a step
at the inner portion of the lower land.
If the lower lands have high steps,
the piston should be replaced.
Fitting Piston Pins. The piston pin
should be a light thumb press fit
at normal temperature (70 °F). Stand-
ard piston pins are color coded
green. Pins of 0.001-inch oversize
(color coded blue) and 0.002-inch
oversize (color coded yellow) are
available.
If the pin hole in the piston must
be reamed, use an expansion-type
piloted reamer. Place the reamer in
a vise and revolve the piston around
the reamer. Set the reamer to the
size of the pin bore, then expand
the reamer slightly and trial ream
the pin bore. Take a light cut. Use
a pilot sleeve of the nearest size to
maintain alignment of the bores.
Check the hole size, using the
new piston pin. If the bore is small,
expand the reamer slightly and make
another cut. Repeat the procedure
until the proper fit is obtained.
Check the piston pin for fit in the
respective rod bushing. If necessary,
ream or hone the bushing to fit
the pin.
Install the piston pin in the piston
and rod. Install a new retainer at
each end of the pin to hold it in
place. Spiral the retainers into posi-
tion with the fingers. Do not use
pliers. Make sure the retainers are
properly seated in their grooves.
MAIN AND CONNECTING
ROD BEARINGS
CLEANING AND INSPECTION
Clean the bearing inserts and caps
thoroughly. Inspect each bearing
carefully. Bearings that have a
scored, chipped, or worn surface
should be replaced. Typical ex-
amples of bearing failures and their
causes are shown in Fig. 28. The
copper lead bearing base may be
visible through the bearing overlay.
This does not mean that the bearing
is worn. Do not replace the bearing
if the bearing clearance is within rec-
ommended limits. Check the clear-
ance of bearings that appear to be
satisfactory with Plastigage. Fit new
bearings following the recommended
procedure (Part 1-2, 1-3, or 1-4).
FLYWHEEL—MANUAL-SHIFT
TRANSMISSIONS
INSPECTION
Inspect the flywheel for cracks,
heat check, or other defects that
would make it unfit for further serv-
ice. Machine the friction surface of
the flywheel if it is scored or worn.
If it is necessary to remove more
A1019-A
FIG. 26—Piston Ring Gap
OVERLAY GON
FROM ENTIRE SURFACE
TAPERED JOURNAL
FIG. 28—Bearing Failures
RADIUS RIDE
RADIUS RIDE
CRATERS OR POCKETS
FATIGUE FAILURE
A1021-A