ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE) 6A1-59
Crank Pin and Connecting Rod Bearings
Inspect crank pin for uneven wear or damage. Measure crank pin
for out-of-round or taper with a micrometer. If crank pin is dam-
aged, or out-of-round or taper is out of limit, replace crankshaft or
regrind crank pin to undersize and use undersize bearing.
Connecting rod bearing size
Crank pin diameter
Standard41.982 – 42.000 mm
(1.6528 – 1.6535 in.)
0.25 mm (0.0098 in.)41.732 – 41.750 mm
(1.6430 – 1.6437 in.)
Out-of-round and taper limit: 0.01 mm (0.0004 in.)
Rod bearing:
Inspect bearing shells for signs of fusion, pitting, burn or flaking
and observe contact pattern. Bearing shells found in defective
condition must be replaced.
Two kinds of rod bearing are available; standard size bearing and
0.25 mm undersize bearing. To distinguish them, 0. 25 mm under-
size bearing has the stamped number (US025) on its backside as
indicated in figure, but standard size one has no number.
Rod bearing clearance:
1) Before checking bearing clearance, clean bearing and crank
pin.
2) Install bearing in connecting rod and bearing cap.
3) Place a piece of gaging plastic (1) to full width of crankpin as
contacted by bearing (parallel to crankshaft), avoiding oil hole.
4) Install rod bearing cap (1) to connecting rod.
When installing cap, be sure to point arrow mark (2) on cap to
crankshaft pulley side (3), as shown in figure. After applying
engine oil to rod bolts, tighten cap nuts to specified torque. DO
NOT turn crankshaft with gaging plastic installed.
Tightening Torque
(a): 35 N
.m (3.5 kg-m, 25.5 lb-ft)
1 or 2
Piston
No.1 Cylinder
No.2 Cylinder
No.3 Cylinder
No.4 Cylinder
Crank
pulley
side
Flywheel
side
6A1-60 ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE)
5) Remove cap and using a scale (2) on gaging plastic (1) enve-
lope, measure gaging plastic width at the widest point (clear-
ance).
If clearance exceeds its limit, use a new standard size bearing
and remeasure clearance.
Item
StandardLimit
Bearing
clearance0.020 – 0.050 mm
(0.0008 – 0.0019 in.)0.080 mm
(0.0031 in.)
6) If clearance can not be brought to within its limit even by using
a new standard size bearing, regrind crankpin to undersize
and use 0.25 mm undersize bearing.
ASSEMBLY
NOTE:
Two sizes of piston are available as standard size spare part
so as to ensure proper piston-to-cylinder clearance. When
installing a standard size piston, make sure to match piston
with cylinder as follows.
a) Each piston has stamped number 1 or 2 as shown. It represents
outer diameter of piston.
b) There are also stamped numbers of 1 and 2 on the cylinder block
as shown. The first number represents inner diameter of No.1
cylinder, the second number of No.2 cylinder, the third number
of No.3 cylinder and the fourth number of No.4 cylinder.
2. Arrow mark
4. Oil hole
The oil hole should
come on intake side
1. Arrow mark
2. 1st ring end
gap
3. 2nd ring end
gap and oil ring
spacer gap
4. Oil ring upper
rail gap
5. Oil ring lower
rail gap
6. Intake side
7. Exhaust side Crankshaft
pulley side
Circlip
or
ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE) 6A1-61
c) Stamped number on piston and that on cylinder block should
correspond. That is, install number 2 stamped piston to cylinder
which is identified with number 2 and a number 1 piston to cylin-
der with number 1.
PistonCylinder
Number
at the
top
(mark)
Outer diameterNumber
(mark)Bore diameter
Piston-to-cylinder
clearance
1
73.98 – 73.99 mm
(2.9126 –
2.9130 in.)
1
74.01 – 74.02 mm
(2.9138 –
2.9141 in.)0.02 – 0.04 mm
(0.0008 –
0.0015 in.)
2
73.97 – 73.98 mm
(2.9122 –
2.9126 in.)
2
74.00 – 74.01 mm
(2.9134 –
2.9138 in.)0.02 – 0.04 mm
(0.0008 –
0.0015 in.)
Also, a letter A, B or C is stamped on piston head but ordinarily
it is not necessary to discriminate each piston by this letter.
1) Install piston pin to piston (1) and connecting rod (3):
After applying engine oil to piston pin and piston pin holes in pis-
ton and connecting rod, fit connecting rod to piston as shown in
figure and insert piston pin to piston and connecting rod, and
install piston pin circlips.
NOTE:
Circlip should be installed with its cut part facing either up
or down as shown in figure.
2) Install piston rings to piston:
As indicated in figure, 1st and 2nd rings have “RN” or “R” mark
respectively. When installing these piston rings to piston, di-
rect marked side of each ring toward top of piston.
1st ring (1) difffers from 2nd ring (2) in thickness, shape and
color of surface contacting cylinder wall.
Distinguish 1st ring from 2nd ring by referring to figure.
When installing oil ring (3), install spacer first and then two
rails.
3) After installing three rings (1st, 2nd and oil rings), distribute their
end gaps as shown in figure.
1. Gaging plastic
ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE) 6A1-71
Main Bearings
General information
Service main bearings are available in standard size and 0.25
mm (0.0098 in.) undersize, and each of them has 5 kinds of bear-
ings differing in tolerance.
Upper half of bearing (2) has oil groove (3) as shown in figure.
Install this half with oil groove to cylinder block (1).
On each main bearing cap, arrow mark and number are em-
bossed as shown in figure.
When installing each bearing cap to cylinder block, point arrow
mark toward crankshaft pulley side and install each cap from that
side to flywheel side in ascending order of numbers “1”, “2”, “3”,
“4” and “5”. Tighten cap bolts to specified torque.
Inspection
Check bearings for pitting, scratches, wear or damage.
If any malcondition is found, replace both upper and lower halves.
Never replace one half without replacing the other half.
Main bearing clearance
Check clearance by using gaging plastic (1) according to the follow-
ing procedure.
1) Remove bearing caps.
2) Clean bearings and main journals.
3) Place a piece of gaging plastic to full width of bearing (parallel
to crankshaft) on journal, avoiding oil hole.
4) Install bearing cap as previously outlined and evenly toque cap
bolts to specified torque.
Bearing cap MUST be torqued to specification in order to assure
proper reading of clearance.
Tightening Torque
(a): 54 N
.m (5.4 kg-m, 39.0 lb-ft)
NOTE:
Do not rotate crankshaft while gaging plastic is installed.
6A1-72 ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE)
5) Remove cap and using scale (2) on gaging plastic (1) envelope,
measure gaging plastic width at its widest point. If clearance ex-
ceeds its limit, replace bearing. Always replace both upper and
lower inserts as a unit.
A new standard bearing may produce proper clearance. If not,
it will be necessary to regrind crankshaft journal for use of 0.25
mm undersize bearing.
After selecting new bearing, recheck clearance.
StandardLimit
Bearing clearance0.020 – 0.040 mm
(0.0008 – 0.0016 in.)0.060 mm
(0.0023 in.)
Selection of main bearings
STANDARD BEARING:
If bearing is in malcondition, or bearing clearance is out of specifica-
tion, select a new standard bearing according to the following pro-
cedure and install it.
1) First check journal diameter by using the following procedure.
As shown in figure, crank webs (1) of No.2 and No.3 cylinders
have five stamped numerals.
Three kinds of numerals (“1”, “2” and “3”) represent the following
journal diameters.
Numeral stamped
Journal diameter
144.994 – 45.000 mm
(1.7714 – 1.7716 in.)
244.988 – 44.994 mm
(1.7712 – 1.7714 in.)
344.982 – 44.988 mm
(1.7709 – 1.7712 in.)
The first, second, third, fourth and fifth (left to right) stamped nu-
merals represent journal diameters at bearing caps “1”, “2”, “3”,
“4” and “5” respectively.
For example, in figure, the first (leftmost) numeral “3” indicates
that journal dia. at bearing cap “1” is within 44.982 – 44.988 mm,
and second one “1” indicate that journal dia. at cap “2” is within
44.994 – 45.000 mm.
2. Scale
1. Paint
6A1-74 ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE)
4) From numerals stamped on crank webs (1) of No.2 and No.3 cyl-
inders and the alphabets stamped on mating surface of cylinder
block, determine new standard bearing to be installed to journal,
by referring to table given below.
For example, if numeral stamped on crank web is “1” and alpha-
bet stamped on mating surface is “B”, install a new standard
bearing painted in “Black” to its journal.
Numeral stamped on crank web
(Journal diameter)
123
Alphabet stamped
ti f
AGreenBlackColorless
on mating surface
(Bearing capboreBBlackColorlessYellow(Bearing ca bore
dia.)CColorlessYellowBlue
New standard bearing to be installed.
5) Using gaging plastic (1), check bearing clearance with newly se-
lected standard bearing.
If clearance still exceeds its limit, use next thicker bearing and
recheck clearance.
6) When replacing crankshaft or cylinder block due to any reason,
select new standard bearings to be installed by referring to nu-
merals stamped on new crankshaft or alphabets stamped on
mating surface of new cylinder block.
UNDERSIZE BEARING (0.25 mm):
0.25 mm undersize bearing is available, in five kinds varying in
thickness.
To distinguish them, each bearing is painted in the following col-
ors at such position as indicated in figure.
Each color represents the following thicknesses at the center of
bearing.
Color painted
Bearing thickness
Green & Red2.121 – 2.125 mm
(0.0835 – 0.0836 in.)
Black & Red2.124 – 2.128 mm
(0.0836 – 0.0837 in.)
Red only2.127 – 2.131 mm
(0.0837 – 0.0838 in.)
Yellow & Red2.130 – 2.134 mm
(0.0838 – 0.0839 in.)
Blue & Red2.133 – 2.137 mm
(0.0839 – 0.0840 in.)
ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE) 6A1-75
If necessary, regrind crankshaft journal and select under-size
bearing to use with it as follows.
1) Regrind journal to the following finished diameter.
Finished diameter: 44.732 – 44.750 mm
(1.7611 – 1.7618 in.)
2) Using micrometer, measure reground journal diameter.
Measurement should be taken in two directions perpendicular
to each other in order to check for out-of-round.
3) Using journal diameter measured above and alphabets
stamped on mating surface of cylinder block, select an under-
size bearing by referring to table given below.
Check bearing clearance with newly selected undersize bear-
ing.
Measured journal diameter
44.744 – 44.750 mm
(1.7616 – 1.7618 in.)44.738 – 44.744 mm
(1.7613 – 1.7616 in.)44.732 – 44.738 mm
(1.7611 – 1.7613 in.)
Alphabets stampedAGreen & RedBlack & RedRed only
on mating surfaceBBlack & RedRed onlyYellow & Red
of cylinder block
CRed onlyYellow & RedBlue & Red
Undersize bearing to be installed
Rear Oil Seal
Carefully inspect oil seal (1) for wear or damage. If its lip is worn or
damaged, replace it.
For oil seal installation, press-fit rear oil seal (1) so that oil seal
housing (2) end face is flush with oil seal end face.
“a”: 23 mm (0.91 in.)
6A1-76 ENGINE MECHANICAL (G13B, 1-CAM 16-VALVES ENGINE)
Flywheel
If ring gear is damaged, cracked or worn, replace flywheel.
If the surface contacting clutch disc is damaged, or excessively
worn, replace flywheel.
Check flywheel for face runout with dial gauge.
If runout exceeds its limit, replace flywheel.
Limit on runout: 0.2 mm (0.0078 in.)
Cylinder Block
Distortion of gasketed surface
Using straightedge and thickness gauge, check gasketed surface
for distortion and, if flatness exceeds its limit, correct it.
Item
StandardLimit
Flatness0.03 mm
(0.0012 in.)0.06 mm
(0.0024 in.)
Honing or reboring cylinders
1) When any cylinder needs reboring, all other cylinders must also
be rebored at the same time.
2) Select oversized piston according to amount of cylinder wear.
Size
Piston diameter
O / S 0.2574.220 – 74.230 mm
(2.9220 – 2.9224 in.)
O / S 0.5074.470 – 74.480 mm
(2.9319 – 2.9323 in.)
3) Using micrometer, measure piston diameter.
4) Calculate cylinder bore diameter to be rebored.
D = A + B – C
D: Cylinder bore diameter to be rebored.
A: Piston diameter as measured.
B: Piston clearance = 0.02 – 0.04 mm
(0.0008 – 0.0015 in.)
C: Allowance for honing = 0.02 mm (0.0008 in.)