Service manual

181 CID (3.0L) 4 CYLINDER GM ENGINE
SERVICE MANUAL NUMBER 26
90-861329--1 MARCH 1999 Page 3A-65
7. Measure cylinder bores to ensure they meet specifications.
CAUTION
Measure cylinder walls for taper, out-of-round or excessive ridge at top of ring
travel. This should be done with a dial indicator or inside micrometer. Carefully
work gauge up and down cylinder to determine taper and turn it to different points
around cylinder wall to determine out-of-round condition. If cylinders exceed
specifications, boring and/or honing will be necessary.
72385
a
b
a
b
Cylinder Measurement
a-At right angle to centerline of engine
b-Parallel to centerline of engine
“Out-of-Round” = Difference between “A” and “B”
“Taper” =Difference between measurement “A” at top of cylinder bore and “A” measurement
at bottom of cylinder bore
72386
Measuring Cylinder Bore With Snap Gauge
72387
Measuring Cylinder Bore With Dial Indicator
Index