torque

Mazda MX-5 Engine Tolerances/Specifications 1.8 BP (NA/NB)

Engine Assembly Tolerances/Specifications

ITEMMILLIMETRESINCHES
Camshaft End Play (min) .20 .008 
Camshaft End Play (standard) .07-.19 .0028-.0074 
Camshaft Journal Diameter 25.940-25.965 1.0213-1.0222 
Camshaft Journal Oil Clearance (min) .15 .006 
Camshaft Journal Oil Clearance (standard) .035-.081 .0014-.0031 
Camshaft Journal Out Of Round (max) .03 .0012 
Camshaft Lobe Height, Exhaust (min) 44.400 1.7480 
Camshaft Lobe Height, Exhaust (standard) 44.600 1.7559 
Camshaft Lobe Height, Intake (min) 43.894 1.7281 
Camshaft Lobe Height, Intake (standard) 44.094 1.7360 
Camshaft Runout (max) .03 .0012 
Connecting Rod Bending  .030 max per 100 mm .0012 max per 3.94 inches 
Connecting Rod Bushing Inside Diameter 20.003-20.014 .7876-.7879 
Connecting Rod Cap Oil Clearance (max) .10 .004 
Connecting Rod Cap Oil Clearance (standard) .020-.044 .0008-.0017 
Connecting Rod Length, Center to Center 132.85-132.95 5.231-5.234 
Connecting Rod Side Clearance (max) .30 .012 
Connecting Rod Side Clearance (standard) .110-.262 .0044-.0103 
Crankshaft End Play (max) .30 .012 
Crankshaft End Play (standard) .080-.282 .0032-.0111 
Crankshaft Main Journal Diameter 49.938-49.956 (max out of round, .05) 1.9661-1.9667 (max out of round, .0020) 
Crankshaft Pin Journal Diameter 44.940-44.956 (max out of round .05) 1.7693-1.7669 (max out of round .0020) 
Crankshaft Runout (max) .04 .0016 
Cylinder Block Distortion (max) .15 .006 
Cylinder Block Grinding (max) .20 .008 
Cylinder Block Height 221.5 8.720 
Cylinder Bore Concentricity (max) .019 .0007 
Cylinder Bore Taper (max) .019 .0007 
Cylinder Head Distortion (max) .10 .004 
Cylinder Head Manifold Surfaces Distortion (max) .15 .006 
Cylinder Head Manifold Surfaces Grinding (max) .20 .008 
Cylinder Head Surface Grinding (max) .10 .004 
Cylnder Head Height 133.8-134.0 5.268-5.275 
HLA Bore Concentricity (standard) 30.000-30.025 1.1811-1.1820 
HLA Outside Diameter Clearance (max) .18 .0071 
HLA Outside Diameter Clearance (standard) .025-.066 .00099-.00259 
HLA Outside Diameter Concentricity 29.959-29.975 1.1795-1.1801 
Piston Ring End Gap (max) 1.0 .039 
Piston Ring End Gap (Oil Rail) .20-.70 .008-.027 
Piston Ring End Gap (top/middle) .15-.30 .006-.011 
Piston Ring Groove Clearance (max) .15 .006 
Piston Ring Groove Clearance (middle) .03-.07 .012-.027 
Piston Ring Groove Clearance (top) .03-.065 .0012-.0025 
Piston to Cylinder Clearance (max) .15 .006 
Piston to Cylinder Clearance (standard) .032-.059 .0013-.0023 
Valve Guide Height (from head) 18.3-18.9 .721-.744 
Valve Guide Inside Diameter, In and Exh 6.01-6.03 .2367-.2374 
Valve Length, Eexhaust (min) 100.49 3.9563 
Valve Length, Exhaust (standard) 101.99 4.0153 
Valve Length, Intake (min) 100.39 3.9524 
Valve Length, Intake (standard) 101.89 4.0114 
Valve Margin Thickness, Exhaust (min) 1.0 .039 
Valve Margin Thickness, Intake (min) .9 .035 
Valve Seat Contact Width .8-1.4 .032-.055 
Valve Spring Free Length (min) 39.5 (Set load of 22.8-25.8kgf) 1.56 (set load of 50.2-56.7 lbf) 
Valve Spring Free Length (standard) 46.26 1.821 
Valve Stem Diameter, Exhaust (min) 5.915 .2329 
Valve Stem Diameter, Exhaust (standard) 5.965-5.980 .2349-.2354 
Valve Stem Diameter, Intake (min) 5.920 .2331 
Valve Stem Diameter, Intake (standard) 5.970-5.985 .2351-.2356 
Valve Step Protruding Length (from head) 45.0 1.772 
Valve to Guide Clearance, Exhaust (standard) .030-.065 .0012-.0025 
Valve to Guide Clearance, In and Exh (min) .20 .008 
Valve to Guide Clearance, Intake (standard) .025-.060 .0010-.0023 
Wrist Pin Diameter 19.987-19.993 .7869-.7871 
Wrist Pin Hole Diameter (piston) 19.988-20.000 .7870-.7874 
Wrist Pin to Connecting Rod Bushing Clearance .010-.027 .0004-.0010 
Wrist Pin to Piston Clearance .005-.013 .0002-.0005 


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