Porsche 944 - Manual (Page 67)

944 Engine/Crankshaft, Pistons
13
Pistons from Model 89 onwards
Engine M 44. 41 (3.0 I) worldwide
Compression ratio: 10.9 : 1
Nominal Ø 104.00 mm
The installation position is indicated by the
enlarged intake-valve pockets.
171/13
Checking pistons and cylinder bore
Engine type M 44.41 (3.0 l)
Repair size Piston Ø
(mm)
MAHLE
Cylinder bore
(mm)
Tolerance groups
Code
Standard 103.980
103.990 +- 0.007
104.000
104.000
104.010 +- 0.005
104.020
0
1
2
Oversize 1 104.480
104.490 +- 0.007
104.500
1 04.500
104.510 +- 0.005
104.520
I 0
I 1
I 2
Checking pistons
Measure approx. 52 mm from crown of pis-
ton, 90' offset to axis of piston bolt.
Checking cylinder bore
Measure approx. 52 mm from top edge of
cylinder bore, across cylinder block.
For measurement, mount lower crankcase
section and tighten with prescribed tightening
torque.
Note
It is recommended that the stocks of the relevant tolerance group are checked before
machining
the cylinders. If necessary, hone to the piston size available.
In some cases, certain tolerance groups may be in short supply.
Pistons from Model 89 onwards
Printed in Germany - XXV, 1992
13 - 103