The piston of the engine 2105 has on the bottom two dredging under the valve, and at the piston 21011 instead of them on the bottom cylindrical dredging with a diameter of 55 mm and 1,9 mm in depth is executed.
Diameter of pistons of various classes measured perpendicular to a finger axis at distance of 52,4 mm from the bottom of the piston, mm:
class A...... 78,94–78,95
class B...... 78,95–78,96
class C...... 78,96–78,97
class D...... 78,97–78,98
class E...... 78,98–78,99
Till 1988 diameter of pistons was 0,01 mm less.
Fig. 10-7. The scheme of removal of metal from the piston for adjustment of its weight. Shooters specified places on which it is possible to delete metal
At adjustment of mass of pistons renting of metal should not exceed 4,5 mm on depth of rather nominal height of the piston (59,4 mm), and on width has to be limited (fig. 10-7) with a diameter of 66,5 mm.
At a press fitting of a piston finger in the piston it is necessary to use adaptation 02.7853.9500 instead of A.60325.