Pontiac Fiero 1988 Service Manual page 291

6A-14 GENERAL ENGINE MECHANICAL
J-24086-8-
J-24086-10
J-24086-11
G20028-6A
1. Select a set of new piston rings
2. Piston ring end gap (Figure 33)
Place piston into the cylinder at the
bottom of the ring travel.
Place a piston ring on top of the
piston.
Back off the piston.
Measure the ring gap (Figure 33). If
the gap is below specification, increase
the gap by carefully filing off excess
material.
Figure 3 2 Removing Piston Pin Using Tool J 24086
Inspect
• Connecting rod for:
1. Bending or twisting
Install the connecting rod cap and
torque to specifications.
Place the connecting rod assembly on
a checking fixture and check for
bending or twisting.
2. Do not attempt to straighten the connecting
rod. If bent or twisted, replace it. Check new
connecting rods before using them.
3. Outside of the connecting rod bearing and
the I.D. of the connecting rod lower end for
wear indicating high spots in the connecting
rod lower end.
4. Connecting rod bolts for stretching by
comparing them with a new bolt.
5. Upper end for scoring
e Piston pin for:
1. Scoring
2. Galling caused by improper installation
3. Fit in connecting rod and piston
• Piston for:
1. Scoring of the skirt
2. Cracks.
3. Broken ring groove lands.
4. Wear
Measure
@. Piston Rings
1 —FEELER GAUGE
2-PISTON RING
-MEASURE RING GAP
CLEARANCE WITH RING
POSITIONED AT BOTTOM
RING TRAVEL AS SHOWN
G20029-6A
Figure 3 3 Measuring Piston Ring Gap
3. Piston ring side clearance (compression
rings)
Roll the piston ring around the groove
in which it is to be installed and
measure the side clearance (Figure
34). If the ring is too thick, try another
ring. If no ring can be found that fits
the specifications, the ring may be
ground to size with emery paper
placed on a plate of glass.
N O T I C E :
Do not attempt to cut the ring groove,
although high spots in the ring groove may be
cleaned up by careful use of a point file.
Assemble
Connecting rod and piston assembly
Tool required:
J 24086 Piston Pin Remover/Installer
important
1.
2.
• The piston must be mounted on the
connecting rod in such a manner that the
mark on the piston (Figure 35) lines up with
the side of the connecting rod that faces the
front of the engine.
Place piston and connecting rod into Fixture J
24086 (Figure 36)