The Fiat 850 Garage

This area will contain all specs on Fiat 850s.
I can also tell that some info is wrong and will fix it when everything is inputted.

Engine

Cycle 4-stroke, gasoline
Cylinders 4, in-line
Bore 2.559in (65mm)
Stroke 2.500in (63.5mm)
Sport Coupe stroke 2.68in (68mm)

Piston Displacement
US smogfree 49.85cid (817cc)
Standard 51.44cid (843cc)
Sport 55.10cid (903cc)

Compression
Standard 8.0 : 1
Super 8.8 : 1
Special 9.3 : 1
Coupe 9.5 : 1

Max HorsePower
Standard 40 / 5300rpm
Super 42 / 5300rpm
Special 47 / 5300rpm
Coupe (DIN) 52 / 6500rpm

Block and Crankcase
Cylynder bore 2.5591 to 2.5610
Tappet Seat Dia. 0.5516 to 0.5523
camshaft seat bushing:
.....valve gear end Class B 1.9882 to 1.9886
.....valve gear end Class C 1.9886 to 1.9890
.....valve gear end Class D 1.9961 to 1.9965
.....valve gear end Class E 1.9965 to 1.9969
.....intermediate 1.8276 to 1.8287
.....flywheel end 1.4142 to 1.4154
Length of interm. transverse member
between thrust ring seats 0.9149 to 0.9173
Piston Clearance 0.0008 to 0.0016
Wear limit 0.006

Cankshaft and main bearings:
Main bearing journal standard diameter 1.9994 to 2.0002
Standard main bearing shell thickness 0.0721 to 0.0725
Main bearing inserts for serice Standard, 0.01-0.02-0.03-0.04 US
Crankpin journal standard diameter 1.5742 to 4.5750
Main bearing-to-journal:
clearance of new parts 0.0008 to 0.0024
wear limit 0.004
Length of centre main bearing journal, shoulder-to-shoulder 1.1055 to 1.1071
Width of centre transverse member, between thrust ring seats 0.9149 to 0.9173
Centre main bearing thrust ring thickness 0.0909 to 0.0929
Oversize thrust ring thickness 0.0959 to 0.0979
Crankshaft end fit, thrust rings installed:
clearance of new parts 0.0024 to 0.0102
wear limit 0.014
Max misalignment of main bearing journals 0.0020
Max misalignment of crankpins to main bearing journals +/- 0.0197
Max out-of-round of crankpin and main bearing journals, after grinding 0.0002
Max taper of crankpin and main bearing journals, after grinding 0.0005
Squareness of flywheel resting face to crankshaft centreline:
Max out-of-true with dial indicator plunger set laterally
some 1 7/32 inch apart from crankshaft rotation axis 0.001
Flywheel:
parallel relationship of driven plate face to crankshaft mounting face: max out-of-true 0.004
squareness of above faces to roatation axis: out-of-true 0.004

The cylinder head
valve guide seat bore in head 0.5098 to 0.5109
valve guide outside diameter 0.5122 to 0.5130
bore of valve guides fitted in head 0.2765 to 0.2772
--for the Special 0.2768 to 0.2775
valve guide-to-seat press fit 0.0013 to 0.0031
valve stem diameter 0.2750 to 0.2756
valve stem-to-guide fit:
-clearance of new parts 0.0009 to 0.0022
--for the 850 Special 0.0012 to 00.25
wear limit 0.006
valve seat angle 45 deg. +/- 5'
valve face angle 45 deg 30 +/- 5'
valve head diameter:
-intake 1.063
-exhaust 0.984
-intake for 850 special 1.142
-exhaust for 850 special 0.906
valve spring inside diameter 0.8228
length of free spring 1.7087
850 special:
Inner: Inner diameter 0.552
Inner: free length 1.563
Outer: Inner diameter 0.8228
Outer: free length 1.7087
Sport Coupe:
Inner: Inner diameter 0.5276
Inner: free length 1.4488
Outer: Inner diameter 0.7874
Outer: free length 1.6220
valve lift: intake & exhaust 0.3386
850 special: intake & exhaust 0.3465
rocker shaft support-to-shaft fit:
-clearance of new parts 0.0004 to 0.0016
-wear limit 0.006
rocker-to-shaft fit:
-clearance of new parts 0.0004 to 0.0016
-wear limit 0.006
rocker spring:
inside diameter 0.6102
free height 2.0353

Engine
Cycle	4-stroke, gasoline
Cylinders	4, in-line
Bore	2.559in (65mm)
Stroke	2.500in (63.5mm)
Sport Coupe stroke	2.68in (68mm)

Piston Displacement
US smogfree	49.85cid (817cc)
Standard	51.44cid (843cc)
Sport	55.10cid (903cc)

Compression
Standard	8.0 : 1
Super	8.8 : 1
Special	9.3 : 1
Coupe	9.5 : 1

Max HorsePower
Standard	40 / 5300rpm
Super	42 / 5300rpm
Special	47 / 5300rpm
Coupe (DIN)	52 / 6500rpm

Block and Crankcase
Cylynder bore	2.5591 to 2.5610
Tappet Seat Dia.	0.5516 to 0.5523
camshaft seat bushing:
.....valve gear end Class B	1.9882 to 1.9886
.....valve gear end Class C	1.9886 to 1.9890
.....valve gear end Class D	1.9961 to 1.9965
.....valve gear end Class E	1.9965 to 1.9969
.....intermediate	1.8276 to 1.8287
.....flywheel end	1.4142 to 1.4154
Length of interm. transverse member
between thrust ring seats	0.9149 to 0.9173
Piston Clearance	0.0008 to 0.0016
Wear limit	0.006

Cankshaft and main bearings:
Main bearing journal standard diameter	1.9994 to 2.0002
Standard main bearing shell thickness	0.0721 to 0.0725
Main bearing inserts for serice	Standard, 0.01-0.02-0.03-0.04 US
Crankpin journal standard diameter	1.5742 to 4.5750
Main bearing-to-journal:
clearance of new parts	0.0008 to 0.0024
wear limit	0.004
Length of centre main bearing journal, shoulder-to-shoulder	1.1055 to 1.1071
Width of centre transverse member, between thrust ring seats	0.9149 to 0.9173
Centre main bearing thrust ring thickness	0.0909 to 0.0929
Oversize thrust ring thickness	0.0959 to 0.0979
Crankshaft end fit, thrust rings installed:
clearance of new parts	0.0024 to 0.0102
wear limit	0.014
Max misalignment of main bearing journals	0.0020
Max misalignment of crankpins to main bearing journals	+/- 0.0197
Max out-of-round of crankpin and main bearing journals, after grinding	0.0002
Max taper of crankpin and main bearing journals, after grinding	0.0005
Squareness of flywheel resting face to crankshaft centreline:
Max out-of-true with dial indicator plunger set laterally some 1 7/32 inch apart from crankshaft rotation axis	0.001
Flywheel:
parallel relationship of driven plate face to crankshaft mounting face: max out-of-true	0.004
squareness of above faces to roatation axis: out-of-true	0.004

The cylinder head
valve guide seat bore in head	0.5098 to 0.5109
valve guide outside diameter	0.5122 to 0.5130
bore of valve guides fitted in head	0.2765 to 0.2772
--for the Special	0.2768 to 0.2775
valve guide-to-seat press fit	0.0013 to 0.0031
valve stem diameter	0.2750 to 0.2756
valve stem-to-guide fit:
-clearance of new parts	0.0009 to 0.0022
--for the 850 Special	0.0012 to 00.25
wear limit	0.006
valve seat angle	45 deg. +/- 5'
valve face angle	45 deg 30 +/- 5'
valve head diameter:
-intake	1.063
-exhaust	0.984
-intake for 850 special	1.142
-exhaust for 850 special	0.906
valve spring inside diameter	0.8228
length of free spring	1.7087
850 special:
Inner: Inner diameter	0.552
Inner: free length	1.563
Outer: Inner diameter	0.8228
Outer: free length	1.7087
Sport Coupe:
Inner: Inner diameter	0.5276
Inner: free length	1.4488
Outer: Inner diameter	0.7874
Outer: free length	1.6220
valve lift: intake & exhaust	0.3386
850 special: intake & exhaust	0.3465
rocker shaft support-to-shaft fit:
-clearance of new parts	0.0004 to 0.0016
-wear limit	0.006
rocker-to-shaft fit:
-clearance of new parts	0.0004 to 0.0016
-wear limit	0.006
rocker spring:
inside diameter	0.6102
free height	2.0353