Mitsubishi 4G1 Service Manual page 122

Piston O.D. "A"
Upper bearing
(for No. 1,2.4,5)
Upper and lower bearings
(for center)
CYLINDER BORING
(1) Oversize pistons to be used should be determined on the
basis of the largest bore cylinder. .
Piston size identification '
Size
mm (.Ol in.) O.S.
0.25
mm (.02 in.) O.S.
0.50
mm (.03 in.) O.S.
0.75
NOTE
Size mark is stamped on the piston top.
(2) Measure outside diameter of piston to be used. Measure it
in thrust direction as shown.
(3) Based on the measured piston O.D.; calculate the boring
finish dimension.
Boring finish dimension = Piston O.D. + (clearance
between piston O.D. and cylinder) - 0.02 mm (.OOOS in.)
(honing margin)
(4) Bore all cylinders to the calculated boiing finish dimension.
Caution
To prevent distortion that may res -It from temperature
rise during honing, bore cylinders, x1 the order of No. 2,
No. 4, No. 1 and No. 3.
(5) Hone to final finish dimension [pisGn 0-D. + clearance
between piston O.D. and cylinder.],-
(6) Check the clearance between pisto?r and cylinder.
Clearance between piston and cdinder:
0.01 -
NOTE
When boring cylinders, finish all of four cylinders to the same
oversize. Do not bore only one cylinder to an oversize.
INSTALLATION SERVICE POINTS
CRANKSHAFT BEARING INSTALLATION
4 and 5 journals are provided with oil groove.
(2) The lower bearings (on the cap side) for Nos. 1, 2, 4 and 5
journals are not provided with oil groove.
(3) The upper and lower bearings for No. 3 journal are common
parts which are flanged and are not provided with oil
groove.
1 EN027:
Revision
TSB
I
m m (.0004 - .0012 in.)
0.03
0.25
0.50
0.75
1 .oo
I