HEXA

93 / 1863

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
2nd Compression Ring 1.99/1.97 0.04/0.08 0.4/0.6
3rd Oil Control Ring 2.99/2.97 0.03/0.07 0.25/0.45