Pistons
| Pistons |
| Classification of pistons and cylinder bores |
Piston class is stamped into the piston crown roof. The piston classes are
Cylinder class is stamped into the cylinder plane and specified for each cylinder. The cylinder classes are A, B and C.
All classes can be found on the same cylinder block.
Diameter is measured 12 mm from the bottom edge of the piston.
|
Class
|
Piston diameter (mm)
|
Cylinder bore (mm)
|
|
A
|
87.460 - 87.469
|
87.500 - 87.510
|
|
B
|
87.470 - 87.479
|
87.511 - 87.520
|
|
C
|
87.480 - 87.489
|
87.521 - 87.530
|
| Piston rings |
|
Upper compression ring
|
Lower compression ring
|
Scraper ring
|
||
|
Thickness
|
mm
|
2.47 - 2.49
|
1,47 - 1,1,49
|
2.97 - 2.99
|
|
Side clearance in groove
|
mm
|
0.08-0.112
|
0.05 - 0.09
|
0.03 - 0.07
|
|
Ring end's opening in piston
|
mm
|
0.15 - 0.25
|
0.40 - 0.50
|
0.20 - 0.40
|
|
Ring end's opening in piston
|
mm
|
2.47 - 2.49
|
1.47 - 1.49
|
2.97 - 2.99
|
The piston ring opening should be offset 120°
| Gudgeon pin |
|
Diameter
|
mm
|
28.495 - 28.500
|
|
Piston bearing diameter
|
mm
|
28.502 - 28.507
|
|
Bearing clearance
|
mm
|
0.008 - 0.020
|
|
Gudgeon pin end float
|
mm
|
4.6
|
|
Gudgeon pin in relation to connecting rod
|
mm
|
Floating bearing
|
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