Porsche 1989 944 S2, Workshop Manual

Page: 66 / 167

13
Engine/Crankcase, Pistons 944
Checking pistons and cylinder bores
Motortype M 44.40
Repair Stage Piston Ø
(mm)
Fa. Kolbenschmidt
Cylinder bore dia.
(mm)
tolerance group
code
Standard size 99.980
99.990 +- 0.007
100.000
100.000
100.010 +- 0.005
100.020
0
1
2
Oversize 1 100.480
100.490 +-0,007
100.500
100.500
100.510 +- 0.005
100.520
I 0
I 1
I 2
Checking pistons
Measure approx. 61 mm from piston crown,
90° offset from piston pin axis.
Checking cylinder bores
Measure approx. 61 mm from upper edge of
cylinder bore, transverse to engine block.
Mount lower crankcase section and tighten
bolts to specified torque for measuring.
Note
It recommended that the stocks of the relevant tolerance group are checked befare machining
the cylinders. If necessary, hone to the piston size available.
In some cases, certain tolerance groups may be in short supply.
13 - 102 Checking pistons and cylinder bores
Printed in Germany - XXV, 1992