ALTROZ SERVICE MANUAL

1.2L REVOTRON ENGINE 58 I. 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.  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. Details Specification (mm) Piston pin diameter 17.995/18.000 Piston pin length 46.7/47.0 Piston pin bore in piston 18.003/18.008 Height of piston 43.8 Piston to bore clearance 0.055/0.075 Piston and Cylinder Bore Sizes (REVOTRON 1.2L) Type Grade Cylinder Bore Dia. (mm) Piston Dia. (mm) Standard A 77.015/77.025 76.950/76.960 B 77.025/77.035 76.960/76.970 Piston Rings (REVOTRON 1.2L) Type of ring Ring Thick -ness (mm) Axial Clearanc e in Piston Groove (mm) Butt Clearance in Cylinder Bore (mm) 1 st Compression Ring 1.170/ 1.190 0.06 / 0.1 0.17 / 0.32 2 nd Compression Ring 1.47 / 1.49 0.05 / 0.09 0.4 / 0.6 3 rd Oil Control Ring 1.95 / 1.89 0.06 / 0.014 0.2 / 0.7