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.

Cycle4-stroke, gasoline
Cylinders4, in-line
Bore2.559in (65mm)
Stroke2.500in (63.5mm)
Sport Coupe stroke2.68in (68mm)

Piston Displacement
US smogfree49.85cid (817cc)
Standard51.44cid (843cc)
Sport55.10cid (903cc)

Standard8.0 : 1
Super8.8 : 1
Special9.3 : 1
Coupe9.5 : 1

Max HorsePower
Standard40 / 5300rpm
Super42 / 5300rpm
Special47 / 5300rpm
Coupe (DIN)52 / 6500rpm

Block and Crankcase
Cylynder bore2.5591 to 2.5610
Tappet Seat Dia.0.5516 to 0.5523
camshaft seat bushing:
.....valve gear end Class B1.9882 to 1.9886
.....valve gear end Class C1.9886 to 1.9890
.....valve gear end Class D1.9961 to 1.9965
.....valve gear end Class E1.9965 to 1.9969
.....intermediate1.8276 to 1.8287
.....flywheel end1.4142 to 1.4154
Length of interm. transverse member
between thrust ring seats0.9149 to 0.9173
Piston Clearance0.0008 to 0.0016
Wear limit0.006

Cankshaft and main bearings:
Main bearing journal standard diameter1.9994 to 2.0002
Standard main bearing shell thickness0.0721 to 0.0725
Main bearing inserts for sericeStandard, 0.01-0.02-0.03-0.04 US
Crankpin journal standard diameter1.5742 to 4.5750
Main bearing-to-journal:
clearance of new parts0.0008 to 0.0024
wear limit0.004
Length of centre main bearing journal, shoulder-to-shoulder1.1055 to 1.1071
Width of centre transverse member, between thrust ring seats0.9149 to 0.9173
Centre main bearing thrust ring thickness0.0909 to 0.0929
Oversize thrust ring thickness0.0959 to 0.0979
Crankshaft end fit, thrust rings installed:
clearance of new parts0.0024 to 0.0102
wear limit0.014
Max misalignment of main bearing journals0.0020
Max misalignment of crankpins to main bearing journals+/- 0.0197
Max out-of-round of crankpin and main bearing journals, after grinding0.0002
Max taper of crankpin and main bearing journals, after grinding0.0005
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
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-true0.004

The cylinder head
valve guide seat bore in head0.5098 to 0.5109
valve guide outside diameter0.5122 to 0.5130
bore of valve guides fitted in head0.2765 to 0.2772
--for the Special0.2768 to 0.2775
valve guide-to-seat press fit0.0013 to 0.0031
valve stem diameter0.2750 to 0.2756
valve stem-to-guide fit:
-clearance of new parts0.0009 to 0.0022
--for the 850 Special0.0012 to 00.25
wear limit0.006
valve seat angle45 deg. +/- 5'
valve face angle45 deg 30 +/- 5'
valve head diameter:
-intake for 850 special1.142
-exhaust for 850 special0.906
valve spring inside diameter0.8228
length of free spring1.7087
850 special:
Inner: Inner diameter0.552
Inner: free length1.563
Outer: Inner diameter0.8228
Outer: free length1.7087
Sport Coupe:
Inner: Inner diameter0.5276
Inner: free length1.4488
Outer: Inner diameter0.7874
Outer: free length1.6220
valve lift: intake & exhaust0.3386
850 special: intake & exhaust0.3465
rocker shaft support-to-shaft fit:
-clearance of new parts0.0004 to 0.0016
-wear limit0.006
rocker-to-shaft fit:
-clearance of new parts0.0004 to 0.0016
-wear limit0.006
rocker spring:
inside diameter0.6102
free height2.0353