9
WORKSHOP MANUAL
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Piston grading
Grading
D 2
+ 0,000
- 0,010
Standard
A
57,972
B
57,982
C
57,992
1. re-bore
A
58,222
B
58,232
C
58,242
2. re-bore
A
58,472
B
58,482
C
58,492
3. re-bore
A
58,722
B
58,732
C
58,742
4. re-bore
A
58,972
B
58,982
C
58,992
Cylinder grading
Note:
The manufacturer delivers spare cylinders exclusively with the basic /standardú bore.
The other dimensions given in the table are guides for cylinder reboring. As it is very difficult
to rebore the cylinders accurately within the tolerance limits of hundredths of millimeters, it is
necessary to check the bore of the rebored cylinder by measuring it at several points, and to
use a piston of grading corresponding to the measured dimension. The grading mark on the
top face of the cylinder has to be changed accordingly.
In the engines (new or rebored) the right-hand and left-
hand may be of a different grading class (but not of
different rebore grading). In the case of cylinders with
rebores in between of two grading groups, it is possible
to use a piston of B or C group. With the B piston is
running in quicker, with C piston nocking is likely on
cold engine (after start).
Standard
Grading
D1
D2
D3
I.re-bore II.re-bore III.re-bore IV.re-bore
A
58,01+0,01 58,01+0,01 58,01+0,02
B
58,02+0,01 58,02+0,01 58,02+0,02
C
58,03+0,01 58,03+0,01 58,03+0,02
D
58,04+0,01 58,04+0,01 58,04+0,02
+0,25
+0,5
+0,75
+1,00