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Valve clearance for checking timing
Data Sheet Fiat 126 650cc
Detailed technical data for the Fiat 126 with 650 cc engine.
Our data sheet provides you with key values and specifications taken directly from the original technical table issued by Fiat Customer Service in October 1977.
From engine displacement and valve timing to carburetor dimensions and torque values – here you’ll find precise information on the engine, transmission, suspension and more. Please note that some measurements and units are no longer commonly used today, as materials and standards have evolved.
Chassis No.
126 A1
Engine No.
126 A 1.048
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Engine
Number of cylinders
2
Bore
77 mm
Stroke
70 mm
Engine displacement
652 cm³
Compression ratio
7,5
Maximum output (DIN)
24 PS
Maximum power speed
4500 rpm
Maximum torque (DIN)
4,2 mkg
Revolutions per minute (RPM)
3000 rpm
Top speed
Circa 105 km/h
Installation clearances in mm
Piston
0,070 - 0,090
Main bearing
0,045 - 0,080
Connecting rod bearing
0,024 - 0,074
Normal Dimensions in mm
Main bearing journal
53.970 - 53.990
Main bearing inner diameter front
53.500 - 53.600
Main bearing inner diameter rear
53.557 - 53.807
Connecting rod bearing journal
44.000 - 44.020
Connecting rod bearing shells
1.534 - 1.543
Connecting rod bearing bore
47.130 - 47.142
Torque values in kpm
Cylinder head bolt
4,0
Nut for rocker arm shaft support
2,5
Nut for camshaft gear
1.0
Nut for crankshaft pulley
15.0
Connecting rod bolt
3,5
Main bearing shield screws
3,5
Flywheel bolt
3,5
Valve timing
Intake opens before top dead center
26°
Intake closes after bottom dead center
57°
Exhaust opens before bottom dead center
66°
Exhaust closes after top dead center
17°
Valve clearance when cold
Intake
0,20
Exhaust
0,25
Intake
0,625
Exhaust
0,625
Camshaft lift
Intake
9,235 mm
Exhaust
9,235
Carburetor
Manufacturer
Weber
Type
28 IMB 5 / 250
Venturi
23 mm
Emulsion tube
4 mm
Main jet
1,15 mm
Idle jet
0,5 mm
Idle air jet
1,4 mm
Emulsion tube
F 8
Air correction jet
1,9 mm
Float needle valve
1,25
Float needle valve
7,0 mm
Fuel pump pressure
0,107 bar
Oil pressure
2,5 - 3 kg/cm²
Power transmission
Clutch
Pedal free play
28 mm
Transmission
Gear ratios1st gear
3,25
2nd gear
2,066
3rd gear
1,300
4th gear
0,871
Reverse gear
4,024
Differential
Final drive ratio
8/39
Backlash
0,08 - 0,13 mm
Tightening torques in mkg
Nut on bevel gear
5
Crown wheel bolt
4,5
Brakes
4-wheel drum brakes
Drum inner diameter
185,24 mm
Maximum permissible reboring diameter
186,83 mm
Minimum lining thickness
2 mm
Brake fluid
DOT 3
Capacity
0,350
Chassis
Axle dimensions
Loaded (4 persons):
Toe-in
-0°10' - +0°31'
Camber
0°30' - 1°30'
Caster
8° - 10°
Rear track width
0°26' - 0°47'
Rear camber
-0°22' - -1°22'
Unladen:
Toe-in
-0°5' - +0°37'
Camber
1°10' - 2°10'
Caster
8° - 10°
Rear track width
0°7' - 0°28'
Rear camber
1°30' - 2°30'
Wheelbase
1840 mm
Steering angle inside
33°
Steering angle outside
25°40'
Tires
Tire measurements
135 SR - 12
Normal tire pressure:
Front
1,4
Rear
2,0
Rim size
4,00 x 12
Turning radius
8,6 m
Torque for wheel bolts
7,0 kpm
Auxiliary supply
Engine oil
In summer
VS 30 / VS 20
In winter
15W - 40
Total capacity when refilled
2,7 l
Periodic oil change
2,5 l
Gear oil
Type
FIAT - oil ZC 90
Capacity
1,1 ltr.
Cooling system
Air cooling
Fuel tank
Capacity
21 l
Octane rating
90 min.
CO content at 850 rpm
2,0 - 3,0%
Operating temperature
Min. 80°C
Electrical system
Ignition timing before top dead center
Initial ignition advance
10°
Centrifugal advance mechanism
20° +/-2°
Revolutions per minute (RPM)
2300 rpm
Centrifugal ignition advance regulator
28° +/-2°
Revolutions per minute (RPM)
3000 rpm
Distributor
Manufacturer
Marelli
Type designation
S 152 A
Contact breaker gap
0,47 - 0,53 mm
Dwell angle
In °
78° +/- 3°
Spark plugs
Marelli
CW 7 8 LP
Champion
N 7 Y
Bosch
W 200 T 30
Electrode gap in mm
Marelli
0,6 - 0,7
Champion
0,6 - 0,7
Bosch
0,6 - 0,7
Starter motor
Type
FIAT B 76 - 05 / 12S
Rated power
0,5 kW
Alternator
Type
A108 - 14V - 33A Var.5
Maximum current output
35 A
Maximum continuous power output
10 A
Voltage regulator
AD1 / 14 V
??Regulated voltage
13,9 - 14,5 V
Battery
34 Ah
As of October 1977
All information provided without guarantee.