SAAB WIS ONLINE

Pistons

Pistons

General data

Different makes of piston must not be fitted in the same engine.



Classification of pistons and cylinder bores

The piston is stamped on the piston crown roof.

Classification codes

piston diameter

Category A

mm

81.920 - 81.930

Category B

mm

81.930 - 81.940

Category C

mm

81.940 - 81.950

Oversize

mm

0.4

Piston clearance

mm

0.1



The cylinder classes available are

Classification codes



Cylinder bore

Category A

mm

82.000 - 82.010

Category B

mm

82.010 - 82.020

Category C

mm

82.020 - 82.030

Oversize

mm

0.1

Taper cylinder bore

mm

< 0,005

Ovality cylinder bore

mm

± 0,05



Max. weight difference pistons

g

5



Piston rings






Upper compression ring

Lower compression ring

Scraper ring

Piston ring opening

mm

0.20 - 0.35

0,60 - 0,80

0.25 - 0.50

Piston ring thickness

mm

1,970 - 1,995

1,970 - 1,990

1,970 - 1,990

Piston ring groove in piston

mm

2,080 - 2,100

2,020 - 2,040

2,020 - 2,040

Clearance piston ring in groove

mm

0,085 -0,130

0,025 -0,070

0,030 -0,070



All classes can be found on the same cylinder block.

The piston ring opening should be offset 120°

Gudgeon pin and piston bearing

Gudgeon pin outside diameter

mm

25.982 - 25.987

Gudgeon pin, length

mm

56,4 - 56,8

Piston bearing, inside diameter

mm

25.999 - 26.004

Gudgeon pin, bearing play in piston

mm

0,031 - 0,014

Gudgeon pin, bearing play in connecting rod

mm

0,019 - 0,003

Inside diameter, piston end's bearing bushing

mm

26.006 - 26.014

Gudgeon pin in relation to connecting rod

mm

Floating bearing