NANO

ENGINE 273 MPFI

129

ENGINE

Piston Rings

•

Ring clearance in the groove:

Using a thickness gauge , check each piston ring in

its groove for side clearance and, if the limit stated

below is exceeded, measure the groove width and ring

width to determine whether the piston or the ring or

both have to be replaced.

PISTONRINGCLEARANCE INGROOVE

SR. ITEM STD VALUE

LIMIT

1. Top ring 0.03 to 0.07 mm 0.12 mm

2. 2nd ring 0.02 to 0.06 mm 0.1 mm

PISTON RING THICKNESS

TYPEOFRING

RINGSTHICKNESS(MM)

1st Compression Ring 1.2

-0.01-0.03

2nd Compression Ring 1.2

-0.01-0.03

3rd Oil Control Ring 2.0

-0.03-0.13

•

Piston ring end gap ( butt clearance ):

To measure the end gap, insert the piston ring into the

cylinder bore, locating it at the lowest part of the bore

and holding it true and square; then use a thickness

gauge to measure the gap. If the gap measured ex-

ceeds the limit, replace the ring.

PISTON RING END GAP

SR. ITEM STD VALUE LIMIT

1. Top ring 0.15 to 0.3mm 0.7 mm

2. 2nd ring 0.3 to 0.5 mm 0.7 mm

3. Oil ring 0.2 to 0.7 mm 1.8 mm

•

Butt clearance of piston ring should be measured

in unworn portion of cylinder bore.

•

In case of any piston ring with any defect, com-

plete ring set should be replaced.

•

When cylinder bores are re-bored or honed, pis-

tons and rings of appropriate size should be used.

•

Stagger piston rings gaps such that they are 120°

apart. (With butt gap not in line with piston pin).