Crankshaft Journal Diameter and Limits
Dimensional Specifications
Cylinder Bore:
Standard:
A 90.000 - 90.020 mm
B 90.020 - 90.040 mm
First oversize 90.500 - 90.520 mm
Second oversize 91.000 - 90.020 mm
Component Illustration (B235E/R):
Piston Types:
Dimension R 50 mm
Dimension O 70 mm
Dimension A 3.8 mm
Dimension H 56.9 mm
Classification Of Pistons And Cylinder Bores:
First oversize (+0.5 mm)
Second oversize (+1.0 mm)
The piston classification is stamped on the piston crown roof.
The piston classes for service are B
Piston Classification:
AB 89.964 - 89.975 mm
B 89.975 - 89.982 mm
First oversize (+0.5) 90.457 - 90.475 mm
Second oversize (+1.0) 90.957 - 90.975 mm
Piston Diameter:
Piston diameter is measured at right angles to the gudgeon pin holes, 11 mm from the bottom of the piston.
Piston Clearance:
nominal 0.025 - 0.056
Classification, Piston/Cylinder - Fits Cylinder Bore:
A/B piston fits both A and B cylinder bores 90.000 - 90.020 mm
B piston 90.007 - 90.020 mm
Permitted piston clearance 0.025 - 0.056 mm
Piston Rings:
Upper compression ring:
Thickness 1.475 - 1.490 mm
Side clearance in groove 0.035 - 0.080 mm
Working gap in cylinder 0.300 - 0.500 mm
Lower compression ring:
Thickness 1.475 - 1.490 mm
Side clearance in groove 0.040 - 0.075 mm
Working gap in cylinder 0.300 - 0.500 mm
Oil scraper ring:
Thickness 2.500 mm
Working gap in cylinder 0.75 - 1.00 mm
Gudgeon Pins:
Diameter 23.996 - 24.000 mm
Clearance, gudgeon pin/connecting rod bush 0.012 - 0.021 mm
Length 63 m
Connecting Rods:
Diameter at big-end 56.000 - 56.019 mm
Gudgeon pin bushing, inside diameter (fitted) 24.012 - 24.017 mm
Maximum difference in weight between connecting rod big-ends in the same engine 6 g (0.21 oz.) mm
Length Centre-Centre 153 mm
Crankshaft General Data:
Maximum variation in straightness 0.10 mm
Crankshaft end float 0.08 - 0.34 mm
Maximum journal out-of-round 0.005 mm
Maximum taper of journals 0.005 mm
Radius of main journal fillet 1.65 - 1.85 mm
Main bearing clearance 0.014 - 0.062 mm
Length 539.2 mm
Colour Coding Of Main Bearing And Big-end Bearing Shells:
Standard bearing shells are Yellow - Yellow or Red - Blue .
Red shells are thinnest, yellow are 0.005 mm (0.0002 in) thicker than red, and blue shells are 0.005 mm (0.0002 in) thicker than yellow ones.
Only yellow bearing shells are available as a spare part.
Component Illustration:
Crankshaft Bearing Dimensions
Big End Journal Diameter (1):
Standard 51.981 - 52.000 mm
1st undersize 51.731 - 51.750 mm
2nd undersize 51.481 - 51.500 mm
Main Journal Diameter (2):
Standard 57.981 - 58.000 mm
1st undersize 57.731 - 57.750 mm
2nd undersize 57.481 - 57.500 mm
Crankshaft Bearing Clearance
Big-end bearing clearance 0.020 - 0.068 mm
Main bearing clearance 0.014 - 0.062 mm
Balancer Shafts General Data:
Diameter of balancer-shaft journal (inner) 39.892 - 39.908 mm
Diameter of balancer-shaft bearing (inner) 39.988 - 40.043 mm
Bearing clearance, journal bearing (inner) 0.080 - 0.151 mm
Maximum permissible bearing clearance (inner) 0.18 mm
Diameter of balancer-shaft journal (outer) 19.947 - 19.960 mm
Diameter of balancer-shaft bearing (outer) 20.000 - 20.021 mm
Bearing clearance, journal bearing (outer) 0.040 - 0.074 mm
End float 0.060 - 0.460 mm