SAAB WIS ONLINE

Pistons

Pistons

General data

Engine

B204i/B204E/B205R/L

B235R

Mean piston velocity at 5000 rpm (m/s)

13

15



Important

Pistons of different manufacture must not be used in the same engine. The name of the piston manufacturer is cast inside the piston.


Piston types


Engine



R

Ø

A

H

B204i

mm

55

42.3

4.4

68.3

B204E

mm

150

70

4.4

68.3

B205L/R

mm

74

28.65

1.4

56.2

B235R

mm

50

70

3.8

56.9



Pistons B205L/R, B235R


Classification of pistons and cylinder bores

The piston classification is stamped on the piston crown roof. Piston classifications for service are:

AB

B

C

The cylinder classification is stamped on the cylinder face and is specified for each cylinder. The cylinder classifications are:

A

B

B+

They can all occur in the same cylinder block.

Piston classification

B204

B235R, B205L/R

Standard A

mm

89.971 - 89.980

Standard AB

mm

89.980 - 89.989

89.9664 - 89.975

Standard B

mm

89.989 - 90.000

89.975 - 89.982

Standard C

mm

90.000 - 90.013

1st oversize (0.5)

mm

90.472 - 90.488

90.457 - 90.475

2nd oversize (1.0)

mm

90.957 - 90.975

Piston clearance, nominal

mm

0.011 - 0.040

0.025 - 0.056



Classification, piston/cylinder



Clearance







A/A

mm

0.020-0.041

AB/A

mm

0.011 - 0.032

0.026-0.056

AB/B

mm

0.014 - 0.040

0.055-0.032

B/B

mm

0.006 - 0.031

0.025-0.055

B/B+

mm

0.011 - 0.041



Piston diameter

The piston diameter is measured at right angles to the gudgeon pin hole 11 mm from the bottom of the piston skirt.

Piston rings


Upper compression ring

Lower compression ring

Oil scraper ring

Thickness B204

mm

1.728 - 1.740

1.475 - 1.490

- 2.500

Thickness B235

mm

1.475 - 1.490

1.978 - 1.990

2.976 - 3.052

Side clearance in groove B204

mm

0.050 - 0.082

0.040 - 0.072

Side clearance in groove B235R, B205L/R

mm

0.035 - 0.080

0.040 - 0.075

Working gap in cylinder B204

mm

0.30 - 0.50

0.15 - 0.65

0.38 - 1.40

Working gap in cylinder B235

mm

0.300 - 0.500

0.300 - 0.500

0.260 - 1.020



Gudgeon pins

B204

B235R, B205L/R

Diameter

mm

23.996 - 24.000

23.996 - 24.000

Clearance, gudgeon pin/connecting rod bush

mm

0.005 - 0.014

0.012 - 0.021

Length

mm

68

63