Cylinder Block Assembly: Specifications

Main bearing clearance should be .001-.003 inch. Crankshaft endplay should be .003-.009 measured at main bearing No. 3. Connecting rod bearing clearance should be .0011-.0034 inch, and connecting rod side clearance should not exceed .015 inch. Main bearing journals are available in undersizes of 2.1170-2.1177, 2.1071-2.1079, and 2.0973-2.0981 inches. Connecting rod journals are available in undersizes of 1.8729-1.8737, 1.8630-1.8638, 1.8532-1.8540 inches. Main and connecting rod bearing shells are available in .010, .020 and .030 inch undersizes.




Connecting rods are installed so that forged marks point toward front of engine. Pistons are installed with arrow pointing toward timing gear.

Fig. 1 Cylinder bore checking dimensions:

Piston ring end gap should be .010-.018 inch. Piston ring side clearance should be .0008-.002 inch. When installing piston rings, ensure that TOP mark faces up, that recessed edge on outside of center ring faces piston pin, and that ring end gaps are spaced 120° apart. When checking cylinder clearance, refer to Fig. 1.
For 1988 80/90 models, piston diameters are as follows: standard, 3.2472 inches (82.48 mm); 1st oversize, 3.2570 inches (82.73 mm); 2nd oversize, 3.2669 inches (82.98 mm).