HEXA

ENGINE 57 L. Piston and Piston Rings : 1. Remove carbon deposits, if any, from the piston. 2. Clean piston and piston rings using appropriate cleansing agent. NOTE  The piston and piston rings can be reused if the bore taper and sphericity is within the specified limits. NOTE  Carefully examine the piston rings for cracks, scoring, ring groove/ clip groove wear, piston pin bore wear.  In case anyone piston is found to have any one of the above defects, replace the complete piston set. 3. Check for lateral clearance in piston ring groove. 4. Check for butt clearance in cylinder bore. 5. Check for piston pin dimensions. NOTE  Butt clearance of piston ring is measured in unworn portion of the cylinder bore.  Piston and piston rings of appropriate size should be used, if cylinder bores are re- bored.  If piston ring is found to be defective as started above, then complete ring set should be replaced. Piston and Cylinder Bore Sizes Type Grade Cylinder Bore Dia. (mm) Piston Stamped Dia. (mm) Standard A 84.995/85.005 84.921/84.931 B 85.005/85.015 84.931/84.941 C 85.015/85.025 84.941/84.951 Repair I A 85.095/85.105 85.021/85.031 B 85.105/85.115 85.031/85.041 C 85.115/85.125 85.041/85.051 Repair II A 85.195/85.205 85.121/85.131 B 85.205/85.215 85.131/85.141 C 85.215/85.225 85.141/85.151 Piston Rings Type of ring Ring Thickness (mm) Axial Clearance in Piston Groove (mm) Butt Clearance in Cylinder Bore (mm) 1 st Compression Ring 2.5(Nominal) 0.25 to 0.40 2 nd Compression Ring 1.99/1.97 0.04/0.08 0.4/0.6 3 rd Oil Control Ring 2.99/2.97 0.03/0.07 0.25/0.45