Cummins 3935591 Piston Kit Assembly

The 3935591 piston kit is designed for Cummins B series 3.9L and 5.9L diesel engines including 4B, 4BT, 6B, 6BT, and 6BTA configurations. The piston is manufactured from eutectic aluminum alloy with ductile iron or steel alloy components for structural integrity. The crown features anodizing for thermal resistance while ring grooves receive nitriding treatment for wear durability. Anti-friction coatings such as graphite, phosphate, or tinning are applied to the skirt to prevent scuffing during initial break-in. The kit includes the piston body, piston ring set, piston pin, and retaining clips. It meets OEM dimensional specifications for standard bore size 102 mm.