Engine Block - Inspection

INSPECTION

Special Tools:










1. Wipe the main bearing inserts (1 and 2) clean.
2. Inspect the inserts for abnormal wear patterns, scoring, grooving, fatigue, pitting and for metal or other foreign material imbedded in the lining.
3. Inspect the back of the inserts for fractures, scrapes, or irregular wear patterns.
4. Inspect the insert locking tabs for damage.
5. Inspect the crankshaft thrust washers for scoring, scratches, wear or bluing.
6. Replace any bearing that shows abnormal wear Procedures
7. Inspect the main bearing bores for signs of scoring, nicks and burrs.
8. If the cylinder block main bearing bores show damage the engine block must be replaced.





9. Use Cylinder Indicator (2) to correctly measure the inside diameter of the cylinder bore (3). A cylinder bore gauge capable of reading in 0.003 mm (0.0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer.
10. Measure the inside diameter of the cylinder bore at three levels below the top of the bore (4). Start at the top of the bore, perpendicular (across or at 90 degrees) to the axis of the crankshaft at point A (1).
11. Repeat the measurement near the middle of the bore, then repeat the measurement near the bottom of the bore.
12. Determine taper by subtracting the smaller diameter from the larger diameter.
13. Rotate measuring device 90° to point B (1) and repeat the three measurements. Verify that the maximum taper is within specifications . Engine Specifications
14. Determine out-of-roundness by comparing the difference between A and B at each of the three levels. Verify that the maximum out of round is within specifications . Engine Specifications
15. If cylinder bore taper and out-of-roundness are within specification, the cylinder bore can be honed . Cylinder Bore Honing If the cylinder bore taper or out-of-round condition exceeds the maximum limits, the cylinder block must be replaced.

NOTE: A slight amount of taper always exists in the cylinder bore after the engine has been in use for a period of time.