Cummins Piston & Rings, .020, 4089976

replaces: 4089976, 3966675
Kit Includes the following items: 2 qty 3920691 Retainer - Piston Pin 1 qty 3934047 Pin - Piston 1 qty 3966675 Piston - Engine - .50mm 1 qty 4089181 Ring Set - Piston - .50mm
Our pistons are manufactured from special materials like eutectic aluminum, ductile iron and steel alloy. Surface treatments such as anodizing and nitriding are typically used in the ring grooves and crown area for durability. Anti-friction coatings like tinning, phosphate and graphite provide scuff protection during initial engine break in. HDP pistons are designed and manufactured to meet or exceed the most rigorous and stringent specifications.