Engine Block - Inspection

INSPECTION

Special Tools:






ENGINE BLOCK





1. Clean the engine block thoroughly and check all core hole plugs for evidence of leaking and repair if necessary.
2. Examine the engine block and cylinder bores for cracks or fractures.

NOTE: Check the engine block deck surface with a precision straightedge and feeler gauge. The surface irregularities should not exceed 0.09 mm (0.0035 in.). Check the deck surface from one end to the other with the precision straightedge positioned across corners and parallel to the block centerline up and down the deck.

3. Check the engine block deck (1) surfaces for flatness using a precision straightedge (2) and feeler gauge (3).

CYLINDER BORE





1. 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.
2. 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°) to the axis of the crankshaft at point A (1).
3. Repeat the measurement near the middle of the bore then repeat the measurement near the bottom of the bore.
4. Determine the taper by subtracting the smaller diameter from the larger diameter.
5. Rotate the measuring device 90° to point B (1) and repeat the three measurements. Verify that the maximum taper is within specifications.
6. Determine out-of-roundness by comparing the difference between each measurement.
7. If the cylinder bore taper does not exceed 0.0127 mm (0.0005 inch) and out-of-roundness does not exceed 0.008 mm (0.0003 inch) then the cylinder bore can be honed. If the cylinder bore taper or out- of-round condition exceeds the maximum limits, replace the engine block.

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


MAIN BEARINGS





1. Wipe the main bearing inserts (1,2) 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.
7. Inspect the main bearing bores for signs of scoring, nicks and burrs.
8. If the engine block main bearing bores show damage, replace the engine block.