FIAT 127 1975 1.G Workshop Manual

Fiat 127
1049 cm
3


opis ásti servisního manuálu

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Supplement

Contents

Introduction ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1

Specifications ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 2

Engine … … … ... ... ... ... ... ... ... ... ... . .. ... ... ... ... ... ... ... ... ... ... ... 3
1049 cc engine - general
Crankshaft - refitting
Piston rings - refitting
Pistons and connecting rods - reassembly
Pistons - refitting
Connecting rods to crankshaft - reassembly
Oil pump - reassembly
Crankshaft oil seals and carriers - refitting
Sump - refitting
Auxiliary shaft and seal - refitting
Belt - pulleys and tensioner - refitting
Cylinder head and valve gear - reassembly
Distributor - refitting
Toothed drive belt - removal, refitting and adjust ing
Valve clearances - adjustment
Engine - final assembly
Engine removal – 127 Special and 127 from chassis number 1104290 onwards

Fuel system ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 4
Carburettors - general
Weber or Solex single venturi carburettors
Weber dual venturi carburettor
Carburettor overhaul - general

Ignition system... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 5
Automatic centrifugal advance curves
Braking system... ... ... ... ... ... ... ... ... . .. ... ... ... ... ... ... ... ... ... ... ... 6
Brake fluid reservoir and vacuum servo unit (Sport )

Electrical system... ... ... ... ... ... ... ... .. . ... ... ... ... ... ... ... ... ... ... ... . 7
Charging system
Fuses (127 Special)
Fuses (1049 cc models)
Bodywork and fittings ... ... ... ... ... ... ... . .. ... ... ... ... ... ... ... ... ... ... 8
Model variations
Wing mouldings and front spoiler (Sport) - removal and refitting
Rear spoiler (Sport) – removal and refitting

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1. Introduction

Since its first introduction in 1971 the FIAT
127 has undergone a continuing programme of
improvements concerned mainly with styling
and trim alterations. However, in 1977 a new
model range was introduced which included the
option of a larger engine of 1049 cc capacity
with a single overhead camshaft. In
appearance, cars in the new range are broadly
similar to the earlier models but they have a
lower bonnet line, larger glass area and
redesigned bumpers.
In October 1978, the FIAT 127-Sport was
launched. This is a high performance version of
the three door hatchback having the 1049 cc engine with a twin choke carburettor. Apart from
minor body styling changes, the Sport is
equipped with a larger capacity sump, twin
exhaust tailpipes, servo braking, additional
instrumentation and a laminated windscreen.

This supplement has been added to cater
for some of the production changes which have
been made, but principally to cover the 1049 cc
engine. The material given in Chapters 1 to 12
still applies unless superseded by information
contained in this Supplement. Therefore,
always read this Chapter in conjunction with the
rest of the book.

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2. Specifications

Capacities (1049 cc models )
Engine oil (including filter change)
L, C and CL ... ... ... ... ... ... ... ... … 5.5 pints (3.1 litres)
Sport ... ... ... ... ... ... ... ... ... 7.7 pi nts (4.4 litres)

Coolant ... ... ... ... ... ... ... ... … 9.7 pints (5.5 litres)

Fuel ... ... ... ... ... ... ... ... … 6.7 gallons (30 .5 litres) including 6.2 pints
(3.5 litres) reserve

Transmission oil ... … ... ... ... ... ... ... . 4.2 pints (2.4 l itres)


1049 cc OHC engine
General
Type number ... ... ... ... ... ... ... ... … 127 A 000 (C, L and CL);
127 A1.000 (Sport)
Bore ... ... ... ... ... ... ... ... … 2.992 in (76 mm)
Stroke ... ... ... ... ... ... ... ... ... 2.276 in (57.8 mm)
Capacity ... ... ... ... ... ... ... ... … 64 cu in (1049 cc)
Compression ratio ... ... ... ... ... … 9,3 : 1 (C, L and CL);
9,8 : 1 (Sport)
Maximum horsepower (DIN) ... ... ... ... 50 HP a t 5600 rpm (C, L and CL);
70 HP at 5600 rpm (Sport)

Valve mechanism C, L and CL Sport
Inlet :
Opens ... ... ... ... ... ... ... ... ... 2° B TDC 6° BTDC
Closes ... ... ... ... ... ... ... ... ... 42° ABDC 46°ABDC
Exhaust :
Opens ... ... ... ... ... ... ... ... ... 42° BBDC 47° BBDC
Closes ... ... ... ... ... ... ... … … 2° ATDC 7° ATDC
Valve clearances (cold) :
For checking valve timing:
Inlet ... ... ... ... ... ... ... ... 0.02 8 in (0.70 mm) 0.032 in (0.80 mm)
Exhaust ... ... ... ... ... ... ... 0.028 in (0.70 mm) 0.032 in (0.80 mm)
Adjustment for running (engine cold) :
Inlet ... ... ... ... ... ... ... ... 0.01 2 in (0.30 mm) 0.016 in (0.40 mm)
Exhaust ... ... ... ... ... ... ... 0.016 i n (0 40 mm) 0.020 in (0.50 mm)

Cylinder block and connecting rods inches mm
Cylinder bore diameter * 2.992 to 2.994 76.00 to 7 6.05
* Cylinder bores are graded and have a variation of 0.0004 inch (0.01 mm) between each grade
Main bearing housing bore diameter 2.044 to 2.045 51.921 to 51.934
Width of centre main bearing cap between

thrust washers 1.088 to 1.091 27.64 to 27.70
Connecting rod big-end diameter 1.85 to 1.8560 47. 130 to 47.142
Connecting rod small-end diameter 0.8638 to 0.8646 21.94 to 21.96
Big-end bearing shell thickness 0.0606 to 0.8646 1. 539 to 1.55

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Big-end bearing shell undersize range 0.01; 0.02; 0.03; 0.04 0.254; 0,508; 0.762; 1.016
Gudgeon pin interference fit in small-end:
C, L and CL 0.0004 to 0.0017 0.01 to 0.042
Sport 0.0004 to 0.0006 0.01 to 0.016
Crankpin to bearing fit clearance 0.0009 to 0.003 0 .022 to 0.076
Maximum misalignment between big and small-end axes measured 4.92 in (125 mm) from
Connecting rod ± 0.004 ± 0.10

Pistons, rings and pins inches mm
Standard piston diameter, measured 0.925 inch (23.5 mm) from piston skirt base :
Grade A 2.989 to 2.9894 75.92 to 75.93
Grade C 2.9898 to 2.9902 75.94 to 75.95
Grade E 2.9906 to 2.9909 75.96 to 75.97
Range of oversize pistons 0.0079; 0.0157; 0.02 36
0.2; 0.4; 0.6
Piston boss diameter (C, L and CL):
Grade 1 0.8654 to 0.8656 21.982 to 21.986
Grade 2 0.8655 to 0.8657 21.986 to 21.990
Grade 3 0.8657 to 0.8659 21.990 to 21.994
Piston boss diameter (Sport):
Grade 1 0.7874 to 0.7875 19.999 to 20.002
Grade 2 0.7875 to 0.7876 20.002 to 20.005
Ring groove width (C,L and CL) :
Top groove 0.0604 to 0.0612 1.535 to 1.555
Centre grove 0.0799 to 0.0807 2.030 to 2.050
Bottom groove 0.1562 to 0.1570 3.967 to 3.987
Ring groove width (Sport) :
Top groove 0.0604 to 0.0612 1.535 to 1.555
Centre grove 0.0793 to 0.0801 2.015 to 2.035
Bottom groove 0.1558 to 0.1566 3.957 to 3.977
Standard gudgeon pin diameter (C, L and CL):
Grade 1 0.8650 to 0.8651 21.970 to 21.974
Grade 2 0.8651 to 0.8652 21.974 to 21.978
Grade 3 0.8652 to 0.8654 21.978 to 21.982
Standard dudgeon pin diameter (Sport) :
Grade 1 0.7872 to 0.7873 19.994 to 19.997
Grade 2 0.7873 to 0.7874 19 997 to 20.000
Oversize gudgeon pin diameter 0.0079; 0.0157; 0.023 6 0.2; 0.4; 0.6
Piston ring thickness :
Top compression ring 0.0582 to 0.0587 1.478 to 1 .490
2nd oil control ring 0.0779 to 0.0783 1.978 to 1 .990
3rd oil scraper ring 0.1545 to 0.1550 3.925 to 3 .937
Piston to bore fit clearance 0.0028 to 0.0035 0.070 to 0.090
Gudgeon pin fit clearance in piston 0.0003 to 0.000 6 0.008 to 0.016
Piston ring side clearance in groove:
1st compression ring 0.0018 to 0.003 0.045 to 0.07 7
2nd oil control ring 0.0010 to 0.0022 0.025 to 0.0 57
3rd oil scraper ring 0.0008 to 0.002 0.020 to 0.05 2
Piston ring end gap:
1st compression ring (C, L and CL) 0.0079 to 0.015 7 0.20 to 0.40
1st compression ring (Sport) 0.0118 to 0.0197 0.30 to 0.50
2nd oil control ring 0.0118 to 0.0197 0.30 to 0.50
3rd oil scraper ring 0.0079 to 0.0138 0.20 to 0.35
Piston rings oversize range 0.0079; 0.0157; 0.0 236
0.2; 0.4; 0.6

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Crankshaft inches mm
Main bearing journal diameter 1.8972 to 1.898 48.1 89 to 48.209
Standard main bearing shell thickness 0.0721 to 0.0 726 1.831 to 1.845
Main bearing shell undersize range 0.01; 0.02; 0.03 ; 0.04 0.254; 0.508; 0.762; 1.016

Standard crankpin diameter 1.7318 to 1.7326 43.988 to 44.008
Main bearing journal fit clearance 0.0009 to 0.033 0.022 to 0.083
Width of centre main bearing cap between
thrust washers 1.2785 to 1.2805 32.475 to 32.525
Standard thrust washers thickness 0.0909 to 0.0929 2.31 to 2.36
Thrust washers oversize range 0.0959 to 0.0979 2.43 7 to 2.487
Crankshaft endfloat 0.0022 to 0.0104 0.055 to 0.265
Maximum misalignment of main bearing
journals 0.0012 0.030
Maximum misalignment of main bearing
journals to crankpins 0.0138 0.350
Maximum ovality of crankpins and main
bearing journals after grinding 0.0002 0.005
Maximum taper of crankpins and main
bearing journals after grinding 0.0002 0.005
Maximum run-out of crankshaft flange with
dial gauge stylus 31 mm (1.22 ins) from
crankshaft rotational axis 0.001 0.025
Maximum run-out between flywheel face
and crankshaft flange, and between
flywheel face and crankshaft axis 0.0039 0.10

Cylinder head inches mm
Standard valve guide housing bore 0.5886 to 0.5896 14.950 to 14.977
Standard valve outside diameter 0.5921 to 0.5928 15 .040 to 15.058
Oversize valve guide 0.002; 0.0039; 0.0098
0.05; 0.10; 0.25
Valve guide interference fit 0.0025 to 0.0043 0.063 to 0.108
Fitted valve guide internal diameter 0.3158 to 0.31 65 8.022 to 8.040
Valve stem diameter 0.3139 to 0.3146 7.974 to 7.992
Valve stem fit clearance in guide 0.0012 to 0.0026 0.030 to 0.066
Valve head diameter:
Inlet (C, L and CL) 1.3327 to 1.3445 33.85 to 34 .15
Inlet (Sport) 1.4311 to 1.4429 36.35 to 36.65
Exhaust 1.1358 to 1.1476 28.85 to 29.15
Valve seat width 0.0787 to 0.0866 2.0 to 2.2
Valve seat internal diameter:
Inlet (C, L and CL) 1.1063 to 1.1142 28.1 to 28. 3
Inlet (Sport) 1.2244 to 1.2323 31.1 to 31.3
Exhaust (C, L and CL) 0.9882 to 0.9961 25.1 to 2 5.3
Inlet (Sport) 1.0276 to 1.0354 26.1 to 26.3
Angle of valve seat 45° ± 5'
Angle of valve face 45° 30' ± 5'
Valve springs:
Inner spring part no. 4134900
Outer spring part no. 4170458
Valve gear inches mm
Camshaft journal diameter:
Valve gear end 1.1789 to 1.1795 29.945 to 29.96 0
Centre 1.0630 to 1.0636 27.000 to 27.015
Flywheel end 0.9843 to 0.9848 25.000 to 25.015

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Camshaft bearing bore diameter in head:
Valve gear end 1.1807 to 1.1817 29.990 to 30.015
Centre 1.0648 to 1.0657 27.045 to 27.070
Flywheel end 0.9860 to 0.9870 25.045 to 25.070
Camshaft journals fit clearance 0.0012 to 0.0028 0. 030 to 0.070
Cam lift (C, L and CL) 0.3425 8.700
Cam lift (Sport):
Inlet 0.3622 9.200
Exhaust 0.3642 9.250
Standard tappet bore diameter 1.4567 to 1.4577 37.0 00 to 37.025
Standard tappet outside diameter 1.4557 to 1.4565 36.975 to 36.995
Tappet fit clearance 0.0002 to 0.0020 0.005 to 0.05 0
Shim thickness 0.1279; 0.1299; then
0.0039 steps to 0.1850

3.2b; 3.30; then
0.10 steps to 4.70

Auxiliary shaft inches mm
Diameter of bush bores in crankcase:
Front 1.6339 to 1.6350 41.500 to 41.530
Rear 1.5733 to 1.5745 39.962 to 39.992
Fitted bush internal diameter:
Front 1.5143 to 1.5151 38.464 to 38.484
Rear 1.4553 to 1.4561 36.964 to 36.984
Diameter of shaft journals:
Front 1.5115 to 1.5125 38.393 to 38.418
Rear 1.4525 to 1.4535 36.893 to 36.918
Bush fit There must always be an interference fit
Shaft/bush fit clearance (front and rear) 0.0018 to 0.0036 0.046 to 0.091
Lubrication system
Oil pump Four lobe rotor type
Pump drive Through auxiliary shaft
Oil pressure relief valve Incorporated in pu mp
Pump rotors endfloat 0.0018 to 0.0047 0.045 to 0.120
Outer rotor to body clearance 0.0006 to 0.002 2 0.016 to 0.055
Inner to outer rotor clearance 0.0010 to 0.00 39 0.025 to 0.100
Oil pressure at 212°F (100°C) 50 to 70 Ibf/in
2 (3.5 to 5 kgf/cm2)

Cooling system
Radiator fan thermal switch
Cuts in . 194° to 201°F (90° to 94°C)
Cuts out 185° to 192°F (85° to 89°C)
Engine coolant thermostat
Starts to open 176° to 183°F (80° to 84°C)
Fully open 205°F (96°C)
Impellor vanes to pump body fit clearance 0.0315 to 0.0512 in (0.8 to 1.3 mm)

Radiator cap relief pressure 11.4 Ibf/in
2 (0.8 kgf/cm2)

Fuel system
Weber 32 ICEV 16/150 carburettor (C, L and CL model s)
Venturi diameter 0.8465 in (21.5 mm)
Main jet . 0.0453 in (1.15 mm)

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Air correction jet 0.0728 in (1.85 mm)
Slow running jet 0.0177 in (0.45 mm)
Emulsion tube type F74
Accelerator pump jet 0.0157 in (0.40 mm)
Needle valve seat 0.0591 in (1.50 mm)
Accelerator pump output (10 strokes) 2 to 3 cm
3
Cold starting device Automatic choke
Float level 1.4016 to 1.4213 in (35.6 to 36. 1 mm)
CO level 2.5%

Solex C32 TDI/4 carburettor (C, L and CL models)
Venturi diameter 0.8465 in (21.5 mm)
Main jet 0.0453 in (1.15 mm)
Air correction jet 0.0768 in (1.95 mm)
Slow running jet 0.0177 in (0.45 mm)
Emulsion tube type 71
Accelerator pump jet 0.0177 in (0.45 mm)
Needle valve seat 0.0630 in (1.60 mm)
Accelerator pump output I10 strokes) 3 to 5 cm
3
Cold starting device Automatic choke
Float level 0.8661 to 0.9449 in (22.0 to 24. 0 mm)
CO level 2.5%

Weber 34 DMTR 47/250 carburettor (Sport models) Primary venturi Secondary venturi
Venturi diameter 0.8661 in (22.0 mm) 0.9449 in (24.0 mm)
Main jet 0.0421 in (1.07 mm) 0.0500 in (1. 27 mm)
Air correction jet 0.0728 in (1.85 mm) 0.086 6 in (2.20 mm)
Slow running jet 0.0177 in (0.45 mm) 0.0276 in (0. 70 mm)
Slow running air bleed 0.0413 in (1.05 mm) 0.027 6 in (0.70 mm)
Accelerator pump jet 0.0157 in (0.40 mm) ---
Needle valve seat 0.0689 in (1.75 mm)
Accelerator pump output (10 strokes) 8.55 cm
3
Cold starting device Manually operated strangler ch oke
Float level 0.2657 to 0.2854 in (6.75 to 7.25 mm)

Fuel pump
Output 75 litres/hr (16.5 gal/hr)
Actuating lever stroke (C, L and CL) 2.4 to 2.6 mm (0.0949 to 0.1024 in)
Actuating lever stroke (Sport) 2.4 to 2.9 mm (0.09 49 to 0.1142 in)
Delivery pressure at 4000 engine rpm 0.17 kgf/cm2 (2.55 Ibf/in2)
and fuel temp 30°C (86°F)

lgnition system
Distributor
Type and code Magneti Marelli S155HX
Automatic centrifugal advance 25° ± 2° at 4500 rpm
Condenser capacity (50 to 1000 Hz) 0.20 to 0.25 µF

Clutch
Lining outer diameter 181.5 mm (7.146 in)

Lining inner diameter 127.0 mm (5.0 in)

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Maximum run-out of driven plate linings 0.2 mm (0.008 in)

Travel of release flange, corresponding
to a pressure plate displacement of not less
than 0.067 in ~1.7 mm) 8.5 mm (0.3346 in)

Transmission
Synchromesh 1st and 2nd, Borg-Warner baulk ring type,
3rd and 4th, Porsche spring ring type

Gear ratios
First 3.910 : 1
Second 2.055 : 1
Third 1.348 : 1
Fourth 0.963 : 1
Reverse 3.615 : 1

Final drive ratio (C,L and CL) 4.071 : 1 (14/57)

Final drive ratio (Sport) 4.462 : 1 (13/58)

Overall ratios
Gears 1st 2nd 3rd 4th Reverse
C, L and CL 15.92 8.7 5.49 3.92 14.72
Sport 17.45 9.17 6.01 4.30 16.13

Electrical system
Alternator
Type (C, L and CL) Magneti Marelli AA 108-14V-33A
Type (Sport) Lucas 18ACR-A4V-45A
Maximum output (approx) 570 watts
Maximum current (approx) 40 amps (C, L and CL) 50 amps (Sport)
Cut-in speed at 12V and 20°C (68°F) 1050 to 1150 r pm (C, L and CL)
1100 to 1200 rpm (Sport)
Field winding resistance across slip rings at 20°C (68°F) 3.4 to 3.8 ohms (C, L and CL)
3.18 to 3.22 ohms (Sport)
Direction of rotation (drive end) Clockwise
Engine/alternator drive ratio 1.8 : 1
Alternator regulator (C, L and CL models)
Type Magneti Marelli RTT 110 AB
Alternator speed for adjustment 6000 rpm
Current for thermal balance 20 amps
Regulating voltage 14.2
+0.3
–0.2 volts

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Lamps
Headlamps (C, L and CL)
Headlamps (Sport)
Brake and rear light
Turn indicators
Reversing lights
Parking lights
Number plate
Courtesy light
Boot light
Turn repeaters
Cigar lighter light
Instrument panel
Ignition warning
Turn indicator warning
Headlamp warning
Coolant temperature warning (L models)
Oil pressure warning
Fuel warning
Hazard warning
Sidelamp (out) warning (Sport only)
Brake warning (Sport only)
Heated rear window warning (Sport only)
40/45 watts
55/60 watts (Halogen)
5/21 watts
21 watts
21 watts
5 watts
5 watts
5 watts
5 watts
4 watts
4 watts
3 watts
3 watts
1.2 watts
1.2 watts
1.2 watts
1.2 watts
1.2 watts
1.2 watts
3 watts
1.2 watts
1.2 watts

Fuses
For fuse details (127 Special, L, C, CL and Sport) see Sections 23 or 24

Steering and suspension (Sport only)
Steering angles
Inner wheel 34° 50’
Outer wheel 32° 10’
Front wheel alignment (toe setting)
Laden 0.079 in (2.0 mm) toe-in to 0.079 in (2.0 mm) toe-o ut
Unladen 0.138 in (3.5 mm) to 0.217 in (5.5 mm) toe-in

Roadwheels
Size 4½ B x 13
Tyres 135 SR-13 or 155/70 SR-13

All 1049 cc models Ibf ft kgf m
Main bearing cap bolts 59 8.2
Engine mounting securing bolts 43 6
Cylinder head to block bolts and nuts:
1 st stage 30 4.1
2nd stage 45 6.2
Final stage 61 8.5
Manifold to head nuts 20 2.8
Connecting rod big-end nuts 38 5.2
Flywheel to crankshaft bolts 61 8.5
Driven gear (Plastic) to camshaft retaining bolt 87 12
Driven gear (steel) to camshaft retaining bolt 87 1 2
Camshaft cap nuts 14 2