Cylinder Block Inspection; Boring Cylinder Inspection - Mitsubishi 4G9 User Manual

11A-12-6
4G9 ENGINE (E–W)
A
B
12 mm
Centre
Bottom
Piston O.D.
E
E
Mitsubishi Motors Corporation
Mitsubishi Motors Corporation
–
Crankshaft, Cylinder Block, Flywheel and Drive Plate
CYLINDER BLOCK
(1) Using a straightedge and thickness gauge, check the
(2) If the distortion is excessive, correct within the allowable
(3) Check the cylinder walls for scratches and seizure. If
(4) Using a cylinder gauge, measure the cylinder bore and
BORING CYLINDER
(1) Oversize pistons to be used should be determined on
Piston size identification
Size
Thrust
direction 0.50 mm O.S.
1.00 mm O.S.
(2) Measure outside diameter of piston to be used. Measure
(3) Based on the measured piston O.D., calculate the boring
(4) Bore all cylinders to the calculated boring finish dimension.
Nov. 1995
Mar. 2001
block top surface for warpage. Make sure that the surface
is free from gasket chips and other foreign matter.
Standard value: 0.05 mm or less
Limit: 0.1 mm
limit or replace.
Grinding limit: 0.2 mm
The total thickness of the stock allowed to be
removed from cylinder block and mating cylinder
head 0.2 mm at maximum.
Cylinder block height (when new):
243.5 mm <4G92>
263.5 mm <4G93>
286.7 mm <4G94>
defects are evident, correct (bored to oversize) or replace.
cylindricity. If worn badly, correct the cylinder to an
oversize and replace the piston and piston rings. Measure
at the points shown in illustration.
Standard value:
Cylinder inner diameter:
4G92, 4G93
4G94
Out-of-roundness and taper of cylinder bore: 0.01
mm or less
the basis of the largest bore cylinder.
NOTE
Size mark is stamped on the piston top.
it in thrust direction as shown.
finish dimension.
Boring finish dimension = Piston O.D. + (Clearance
between piston O.D. and cylinder) – 0.02 mm
(honing margin)
PWEE9502-A
PWEE9502-I
81.00 – 81.03 mm
81.50 – 81.53 mm
Identification mark
0.50
1.00
Revised
Revised