Piston mass control (VAZ-2121)

The mass of pistons in one engine must not differ from each other by more than ±2.5 g.

If there is no set of pistons of the same weight group, it is possible to remove some of the metal at the base of the piston pin bosses. The location of the metal removal is indicated by arrows in Fig. 2-30. However, the metal removal should not exceed 4.5 mm in depth relative to the nominal piston height (59.40 mm), and the width is limited to a diameter of 70.5 mm.