Porsche 928 Workshop Manual page 155

13
Engine, Crankshaft, Pistons
928
Checking pistons and cylinder bores (32~valve engine)
Engine Type M 28.43/44l45/48
Repair size Piston dia.
(mm)
Kolbenschmidt
Cylinder bore
(mm)
Tolerance group
identification
Standard 99,975 100,000 0
99,985
* 0,007
100,010 f 0,005 1
99,995
100,020
2
1 st oversize 100,475 100,500 1 0
100,485 * 0,007 100,510 f 0,005 1 1
100,495 100,520 1 2
Engine Type M 28.41/42/47
Repair size Piston dia.
(mm)
Kolbenschmidt
Cylinder bore
(mm)
Tolerance group
identification
Standard 99,980 100,000 0
99,990 k 0,007
100,010 * 0,005 1
100,000 100,020
2
1 st oversize
100,480 100,500
1 0
100,490 f 0,007 100,510 f 0,005 1 1
100,500 100,520 1 2
Note
It is recommended that the stocks of the relevant piston tolerance group are checked before machin-
ing the cylinders. If necessary, hone to the piston size available.
In some cases, certain tolerance groups may be in short supply.
13-24d Checking pistons and cylinder bores (32~valve engine)
Printed in Germany - XXVII. ISSl