J. CONNECTING RODS 1. Inspect the small end bush of connecting rod, and measure piston-pin bore. 2. Install connecting rod bearing caps without bearing shells. 3. Tighten connecting rod bearing caps mounting bolts to the specified torque. 4. Check for twist and bend of connecting rod by using new piston pin at connecting rod small end. 5. Using feeler gauge, measure twist and bend of connecting rod with respect to vertical face of connecting rod alignment gauge in both vertical and horizontal plane at distance of 50mm, from the line joining centers of connecting rod big and small end bushes. 6. Install new pair of connecting rod bearing shell, depending on the size of crank pin journal diameter. Make sure the securing lugs are in the grooves of connecting rod and its bearing cap. 7. Install connecting rod bearing cap with bearing shell on connecting rod. Tighten connecting rod bearing cap mounting nuts to specified torque. 8. Measure connecting rod big end parent bore dimension. If connecting rod big end parent bore is slightly more than maximum permissible limits, then the connecting rod can be reclaimed provided the wear is confined to connecting rod bearing cap. If the mating surface of the connecting rod bearing cap is slightly faced, then the parent bore should be given a finishing on a connecting rod boring machine. 9. If one or more connecting rods are to be replaced, the difference in weight of connecting rod should be within the permissible limit. NOTE Ensure that the connecting rod big end and • small end axes are parallel to each other. Ensure that the Centre distance between big • end and small end is maintained within the specified limits. CONNECTING ROD - SMALL END DIMENSIONS (1.2L NG TC REVOTRON) Stage Parent Bore Diameter (mm) Bush - outer Diameter (mm) Normal Ø 45 H6 23 +0.095 / +0.055 NOTE Straighten the connecting rod in cold • condition, if necessary. As there is a slight clearance between • connecting rod bolts and corresponding connecting rod bearing cap holes, it is possible while installing the connecting rod bearing cap will be off center, by which dimension of connecting rod big end parent bore will be different in different conditions. If difference exists, connecting rod bearing • cap can be centralized by lightly tapping with mallet, in the required direction after loosening connecting rod bearing cap mounting nuts. NOTE Correct bearing bore dimensions can be • achieved if connecting rod big end parent bore dimension is maintained. Measure pre-tension of connecting rod • bearing shell with a feeler gauge after loosening connecting rod bearing cap mounting nuts. Petrol Engine Ph-2 (CAFÉ)_DCT 71
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