Nissan Altima L32. Instruction — part 671
EM-220
< DISASSEMBLY AND ASSEMBLY >
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CYLINDER BLOCK
Cylinder bore inner diameter
If it exceeds the limit, rebore all cylinders. Replace cylinder block
if necessary.
2. Check for scratches and seizure. If seizure is found, hone it.
• If both cylinder block and piston are replaced with new
ones, select piston of the same grade number punched on
cylinder block rear position. These numbers are punched
in either Arabic or Roman numerals.
3. Measure piston skirt diameter.
4. Check that piston-to-bore clearance is within specification.
• The piston-to-bore clearance is measured at the (B) level in
the cylinder as shown.
Grade No.
Standard inner diameter
Wear limit
No. 1
95.500 - 95.510 mm (3.7598 - 3.7602 in)
0.20 mm (0.0079 in)
No. 2
95.510 - 95.520 mm (3.7602 - 3.7606 in)
No. 3
95.520 - 95.530 mm (3.7606 - 3.7610 in)
SEM843E
Out-of-round (Dif-
ference between X
and Y)
: limit 0.015 mm (0.0006 in)
Taper (Difference
between A and C)
: limit 0.015 mm (0.0006 in)
SEM321AA
SEM756G
Piston diameter (A)
: Refer to
Measuring point (a)
(Distance from the top)
: 38.0 mm (1.496 in)
SEM258C
Piston-to-bore
clearance at (B)
: 0.010 - 0.030 mm (0.0004 - 0.0012 in)
SEM321AA
CYLINDER BLOCK
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5. Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter (A).
6. Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted
after boring.
7. Cut cylinder bores.
• When any cylinder needs boring, all other cylinders must also be bored.
• Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 in) or so in diameter
at a time.
8. Hone cylinders to obtain specified piston-to-bore clearance.
9. Measure finished cylinder bore for out-of-round and taper.
• Measurement should be done after cylinder bore cools down.
CRANKSHAFT
1. Check the crankshaft main and pin journals for scoring, wear, or
cracks.
2. Measure the journals for taper and out-of-round.
3. Measure crankshaft runout.
a. Place a V-block on a precise flat table to support the journals on
the both ends of the crankshaft.
b. Place a dial gauge straight up on the No. 3 journal.
c. While rotating the crankshaft, read the movement of the pointer
on the dial gauge.
BEARING CLEARANCE
• Use either of the following two methods, however method (A) gives more reliable results and so is the pre-
ferred method.
Method A (Using Bore Gauge and Micrometer)
Main Bearing
Rebored size calculation : D = A + B
− C
where,
D
: Bored diameter
A
: Piston diameter as measured
B
: Piston-to-bore clearance
C
: Honing allowance 0.02 mm (0.0008 in)
Standard
Out-of-round (X - Y) : 0.002 mm (0.0001 in)
Taper (A - B)
: 0.002 mm (0.0001 in)
SEM316A
Runout limit (total indicator
reading)
: 0.10 mm (0.0039 in)
SEM346D
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< DISASSEMBLY AND ASSEMBLY >
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CYLINDER BLOCK
1. Set the main bearings in their proper positions on the cylinder
block and the main bearing cap.
2. Install the main bearing caps and bearing beam to the cylinder
block. Tighten all bolts in the numerical order as specified. Refer
EM-206, "Disassembly and Assembly"
.
3. Measure the inner diameters (A) of each main bearing as
shown.
4. Measure the outer diameters (Dm) of each crankshaft main jour-
nal as shown.
5. Calculate the main bearing clearance.
Main bearing clearance = (A) - (Dm)
• If it exceeds the limit, replace the bearing.
• If clearance cannot be adjusted using any standard bearing
grade, grind crankshaft journal and use an undersized bear-
ing.
• When grinding the crankshaft journal, confirm that the (L)
dimension in the fillet role is more than the specified limit.
6. If the crankshaft or the cylinder block is replaced with a new one, select thickness of the main bearings as
follows:
SEM175F
SEM845E
Standard
: 0.035 - 0.045 mm (0.0014 - 0.0018 in)
Limit
: 0.065 mm (0.0026 in)
AEM033
(L)
: 0.10 mm (0.0039 in)
SEM964
CYLINDER BLOCK
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a. The grade number of each cylinder block main journal is
punched on the respective cylinder block. These numbers are
punched in either Arabic or Roman numerals. If measured diam-
eter is out of the grade punched, decide suitable grade from
available main bearings.
b. The grade number of each crankshaft main journal is punched
on the crankshaft end. These numbers are punched in either
Arabic or Roman numerals. If measured diameter is out of grade
punched, decide the suitable grade from available main bear-
ings.
c. Select the main bearing suitable thickness according to the following table:
SEM756G
SEM452G
PBIC0814E
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