Shibaura SX21 - Page 87

ENGINE SYSTEMS
86
Unit Part Inspection Items
Standard
Dimension
Standard Value To be Repaired
Allowable
Limit
Remarks
MAIN MOVING SYSTEM
CONNECTING ROD
Twist between small and large end holes (per 100
mm)
Less than 0.08 More than 0.2
Straightness at 100 mm between small and large
end hole
Less than 0.05 More than 0.15
Front-to-rear clearance between connecting rod
and crank pin
0.1 – 0.3 0.7
Connecting rod metal-to-crank pin clearance
0.035 – 0.083 0.2 Oil clearance
Connecting rod bearing
(inner diameter × width)
∅37 × 17.5
Connecting rod bolt torque N⋅m (kgf
⋅
m)
29 ~ 34
(3.0 – 3.5)
Weight difference with piston (g) Less than 10
Crush height of small end bush 0.034 – 0.079
CRANKSHAFT
Diameter of journal
∅46
∅
45.964 –
45.975
∅45.9
Under size
(0.25, 0.5)
Diameter of crank pin
∅39
∅
38.964 –
38.975
∅38.9
Same to above
Roughness, main journal and crank pin 1.6Z
Crankshaft deflection Less than 0.03 More than 0.06
Axial play of crankshaft 0.05 – 0.3 0.5
Thickness of thrust washer 21.85 – 21.95 21.55
O.D. × I.D. of bush (journal metal) ∅46 × 50
Under size
(0.25, 0.5)
Clearance between crankshaft and journal metal
(bush)
0.039 – 0.106 0.2 Oil clearance
I.D. × O.D. of center bearing ∅46 × 50
Under size
(0.25, 0.5)
Clearance between crankshaft journal and center
bearing
0.039 – 0.092 0.2
Oil clearance
Upper No. 2
and 3.
0.029 – 0.082 0.2
Oil clearance
Lower No.4
CAMSHAFT
81
For intake/exhaust 26.565 – 26.62 26.1
For injection pump 33.94 – 34.06 33.8
Backlash of cam gear 0.08 0.25
VA LV E
Diameter of intake valve stem 6.955 – 6.97 6.89
Diameter of exhaust valve stem 6.94 – 6.955 6.84
Clearance between valve stem and
valve guide
Inlet 0.03 – 0.06
More than
0.2
Exhaust 0.045 – 0.075
More than
0.25
82
1.0 0.775 – 1.075 0.5
VA LV E S Y S T E M