1987 MAZDA 626 Workshop Manual

INSPECTION AND REPAIR 1C
(2). Measure the inner diameter of the tappet hole
in the cylinder head.
Hole diameter:
34.99—35.01 mm (1.3776—1.3787 in)
2. Calculate the difference (clearance) between the
tappet diameter and hole inner diameter.
If the clearance exceeds the specification , replace
the tappet or the cylinder head.
Clearance: 0.10 mm (0.004 in) max.
76G01C-120
76G01C-121
76G01C-122
Camshaft
1. Set the front and rear journals on V-blocks.
Check the camshaft runout. Replace if necessary.
Runout: 0.10 mm (0.004 in) max.
2. Check the cam for wear or damage. Replace if
necessary.
3. Check the cam lobe height at the two points as
shown in the figure.
Height mm (in)
' " " Standard Mimimum
RF-CX IN 42.521 (1.6741) 42.11 (1.658) RF-CX EX 45.300 (1.7835) 44.90 (1.768)
RF-N IN 44.306 (1.7443) 43.90 (1.728) RF-N EX 45.300 (1.7835) 44.90 (1.768)
4. Measure wear of the journals in X and Y directions
at the two points as shown in the figure.
Diameter:
31.959—31.975 mm (1.2582—1.2589 in)
Out-of-round: 0.05 mm (0.002 in) max.

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INSPECTION AND REPAIR 1C
n a. n _ n
76G01C-124
76G01C-250
76G01C-125
5. Measure the oil clearance of the camshaft.
(1) Remove the tappets and adjusting discs from
the cylinder head, and separate them by
cylinder.
(2) Clean the camshaft and cylinder head journal.
(3) Install the camshaft into position.
(4) Set a Plasti-gauge on the camshaft journal in
the axial direction.
(5) Install the camshaft caps according to the num-
ber and arrow marks.
(6) Tighten the camshaft caps evenly and in ord-
er shown in the figure.
Tighten torque:
20—26 Nm (2.0—2.7 m-kg, 14—20 ft-lb)
(7) Remove the camshaft caps and measure the
oil clearance.
Oil clearance:
0.025—0.066 mm (0.0010—0.0026 in)
Maximum: 0.10 mm (0.004 in)
(8) If the oil clearance exceeds the maximum,
replace the cylinder head or camshaft.

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INSPECTION AND REPAIR 1C
76G01C-127
76G01C-128
Feeler gauge
76G01C-129
6. Measure the camshaft end play. If it exceeds the
maximum, replace the camshaft and/or the cylin-
der head.
End play:
0.02—0.15 mm (0.0008—0.0059 in)
Maximum: 0.20 mm (0.008 in)
Cylinder Block
1. Check the cylinder block. Repair or replace if
necessary.
(1) Leakage damage
(2) Cracks
(3) Scoring of wall
2. Measure the distortion of the top surface of the cyl-
inder block in the six directions as shown in the
figure.
Distortion: 0.10 mm (0.004 in) max.
3. If the distortion exceeds the maximum, replace the
cylinder block.
Caution
Do not grind the surface of the cylinder block.
4. Measure the cylinder bore in directions X and Y
at three levels in each cylinder as shown.
Cylinder bore mm (in)
Size Bore
Standard 86.000-86.022 (3.3858—3.3867)
0.25 (0.010) oversize 86.250—86.272 (3.3957—3.3965)
0.50 (0.020) oversize 86.500-86.522 (3.4055—3.4064)

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1C INSPECTION AND REPAIR
(1) If the difference between the measurement A
and C exceeds the maximum taper, rebore the
cylinder to oversize.
Taper: 0.022 mm (0.0009 in) max.
76G01C-131
Ot?
a
—-]
^y A
o ^r c^
O

n r
(2) If the difference between the measurement X
and Y exceeds the maximum out-of-round, re-
bore the cylinder to oversize.
Out-of-round: 0.022 mm (0.0009 in) max.
Caution
The boring size should be based on the size
of an oversize piston and be the same for all
cylinders.
76G01C-132
5. If the upper part of the cylinder wall shows uneven
wear, remove the ridge with a ridge reamer.
86U01X-102
Piston
1. Inspect the outer circumferences of all pistons for
seizure or scoring. Replace if necessary.
2. Measure the outer diameter of each piston at a right
angle (90°) to the piston pin, 19 mm (0.75 in)
above the bottom of piston.
Piston diameter mm (in)
Size Diameter
Standard 85.957-85.983 (3.3841-3.3852)
0.25 (0.010) oversize 86.207-86.233 (3.3940-3.3950)
0.50 (0.020) oversize 86.457-86.483 (3.4038-3.4048)
76G01C-133
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INSPECTION AND REPAIR 1C
-Clearance
3. Check the piston to cylinder clearance.
Clearance-
0.032—0.050 mm (0.0013—0.0020 in)
Maximum: 0.15 mm (0.0059 in)
4. If the clearance exceeds the maximum, replace the
piston or rebore the cylinders to fit oversize pistons.
Note
If the piston is replaced, replace the piston
rings also.
76G01C-134
69G01A-125
Piston and Piston Ring
1. Measure the piston ring to ring land clearance
around the entire circumference using a new pis-
ton ring.
Clearance (Top)
RF-CX: 0.18—0.22 mm (0.0071—0.0087 in)
RF-N : 0.05—0.09 mm (0.0020—0.0035 in)
Clearance (Second):
0.04—0.08 mm (0.0016—0.0031 in)
Maximum: 0.2 mm (0.008 in)
2.
If
the clearance exceeds the maximum, replace the
piston.
3. Inspect the piston rings for damage, abnormal
wear, or breakage. Replace if necessary.
4. Insert the piston ring into the cylinder by hand and
push it to the bottom of the ring travel in using the
piston.
86U01X-104
5. Measure each piston ring end gap with a feeler
gauge. Replace if necessary.
End gap (Top and second)
RF-CX: 0.20—0.35 mm (0.008—0.014 in)
RF-N : 0.20—0.40 mm (0.008—0.016 in)
End gap (Oil rail):
0.20—0.40 mm (0.008—0.016 in)
Maximum: 1.0 mm (0.039 in)

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INSPECTION AND REPAIR 1C
Piston and Piston Pin
1. Measure the piston pin hole diameter in X and Y
directions at four points.
Diameter mm (in)
RF-CX 29.997-30.007 (1.1810-1.1814)
RF-N 24.997-25.007 (0.9841-0.9845)
76G01C-137
76G01C-139
2. Measure the piston pin diameter.
Diameter mm (in)
RF-CX 29.994-30.000 (1.1809-1.1811)
RF-N 24.994-25.000 (0.9840-0.9843)
3. Determine the piston pin to piston clearance by
subtracting the two figures.
Clearance-
-0.003—0.013 mm (0.0001—0.0005 in)
4. If the clearance exceeds the specification, replace
the piston and/or piston pin.
Connecting Rod
1. Measure the connecting rod small end bore.
Diameter mm (in)
RF-CX 30.014-30.030 (1.1817-1.1823)
RF-N 25.014-25.030 (0.9848-0.9854)
2. Check the clearance between the small end bore
and piston pin.
Clearance*
0.014—0.036 mm (0.0005—0.0015 in)
Maximum: 0.05 mm (0.002 in)
3. If the clearance exceeds the maximum, replace the
connecting rod bushing.
(1) Apply engine oil to the connecting rod and the
bushing.
(2) Align the oil holes of the connecting rod and
the bushing, and press the bushing in.
(3) Correct the bushing inner diameter, so that the
clearance is within the specification, by using
a spiral expansion reamer.

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INSPECTION AND REPAIR 1C
4. Check each connecting rod for bending or twist-
ing. Repair or replace if necessary.
Bend:
0.080 mm (0.0031 in) max.
/50 mm (1.969 in)
Twist:
0.080 mm (0.0031 in) max.
/50 mm (1.969 in)
76G01C-141
Crankshaft
1. Check the journals and pins for damage, scoring,
or oil hole clogging.
2. Set the crankshaft on V-blocks.
3. Check the crankshaft runout at the center journal.
Replace if necessary.
Runout: 0.05 mm (0.002 in) max.
76G01C-142
76G01C-143
Crankpin
Main journal
4. Measure each journal diameter in X and Y direc-
tions at two points.
Main journal
Diameter:
59.937—59.955 mm (2.3597—2.3604 in)
Minimum: 59.89 mm (2.358 in)
Out-of-round: 0.05 mm (0.002 in) max.
Crankpin journal
Diameter:
50.940—50.955 mm (2.0055—2.0061 in)
Minimum: 50.89 mm (2.004 in)
Out-of-round: 0.05 mm (0.002 in) max.
5. If the diameter is less than the minimum, grind the
journals to match undersize bearings.
Undersize bearing: 0.25 mm (0.010 in),
0.50 mm (0.020 in), 0.75 mm (0.030)
Main journal diameter undersize mm (in)
Bearing size Journal diameter
0.25 undersize 59.687-59.705 (2.3499—2.3506)
0.50 undersize 59.437-59.455 (2.3400-2.3407)
0.75 undersize 59.187-59.205 (2.3302-2.3309)
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1C INSPECTION AND REPAIR
Rolled fillet
Crankpin journal diameter undersize mm (in)
Bearing size Journal diameter
0.25 undersize 50.690—50.705 (1.9957-1.9963)
0.50 undersize 50.440—50.455 (1.9858-1.9864)
0.75 undersize 50.190-50.205 (1.9760-1.9766)
Caution
Do not grind the rolled fillet area.
76G01C-145
Main Bearing and Connecting Rod Bearing
Check the main bearings and the connecting rod
bearings for peeling, scoring, or other damage.
79G01C-077
Timing Belt
1. Replace the timing belt if there is any oil or grease
on it.
2. Check the timing belt for damage, wear, peeling,
cracks, or hardening. Replace if necessary.
86U01X-113
Caution
a) Never forcefully twist, turn inside out, or
bend the timing belt.
b) Be careful not to allow oil or grease on the
belt.
86U01X-114
1C—60