Suzuki SX4 Service Manual page 334

1D-52 Engine Mechanical:
Piston
Visual inspection
Inspect piston for faults, cracks or other damages.
Damaged or faulty piston should be replaced.
Piston diameter
As indicated in figure, piston diameter should be
measured at a position 19.5 mm (0.77 in.) ("a") from
piston skirt end in the direction perpendicular to piston
pin.
Piston diameter specification
Standard size (used piston): 77.953 – 77.968 mm
(3.0690 – 3.0696 in.)
Standard size (new piston with coating): 77.963 –
77.990 mm (3.0694 – 3.0704 in.)
Oversize (0.50 mm (0.0196 in.)) (used piston): 78.453
– 78.468 mm (3.0887 – 3.0893 in.)
Oversize (0.50 mm (0.0196 in)) (new piston with
coating): 78.463 – 78.490 mm (3.0891 – 3.0901 in.)
Piston clearance
Measure cylinder bore diameter and piston diameter to
find their difference which is piston clearance. Piston
clearance should be within specification as follows. If it is
out of specification, rebore cylinder and use oversize
piston.
NOTE
Cylinder bore diameters used here are
measured in thrust direction at two positions.
Piston clearance
Standard (used piston): 0.032 – 0.061 mm (0.0013 –
0.0024 in.)
Standard (new piston with coating): 0.010 – 0.051
mm (0.0004 – 0.0020 in.)
Limit: 0.161 mm (0.0065 in.)
Ring groove clearance
Before checking, piston grooves must be clean, dry and
I2RH01140157-01
free of carbon deposits.
Fit new piston ring (1) into piston groove, and measure
clearance between ring and ring land by using thickness
gauge (2). If clearance is out of specification, replace
piston.
Ring groove clearance
Top ring
2nd ring
Oil ring
"a": 19.5 mm (0.77 in.)
Standard
0.03 – 0.07 mm
0.12 mm (0.0047 in.)
(0.0012 – 0.0028 in.)
0.02 – 0.06 mm
0.10 mm (0.0039 in.)
(0.0008 – 0.0024 in.)
0.03 – 0.17 mm
(0.0012 – 0.0067 in.)
I4RS0A140022-01
Limit
—
I2RH01140159-01