Fiat 127 - Page 5

Fiat 127 Internet Fan Club (http://fiat127.okruhy.cz) Fiat 127 - 1050
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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; 0.0236
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; 0.0236 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 0.0006 0.008 to 0.016
Piston ring side clearance in groove:
1st compression ring 0.0018 to 0.003 0.045 to 0.077
2nd oil control ring 0.0010 to 0.0022 0.025 to 0.057
3rd oil scraper ring 0.0008 to 0.002 0.020 to 0.052
Piston ring end gap:
1st compression ring (C, L and CL) 0.0079 to 0.0157 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; 0.0236
0.2; 0.4; 0.6