Usage:
3400 Family Of Engines
Reference: Service Magazine; June 13, 1988; Page 10; "Piston Application Guide."
Reference: 3400 Engine Major Component Performance Guide; SEBD0794.
Chrome top piston rings are no longer used on 3400 Engines. The chrome top piston ring has been replaced with a plasma top piston ring. The plasma top rings are more scuff resistant than the chrome top rings. However, since the plasma coating is more abrasive than cast iron, liner wear at the top ring turn-around point may increase when plasma top rings are used.
Low speed (1800 rpm or slower) marine engines changed to plasma top rings effective with 3412 Marine Engine 60M3696 and 3408 Marine Engine 99U6169. Chrome top rings have not been used in low horsepower truck engines effective with 3406B Truck Engine 7FB87310.
The chrome top rings have also been removed from service ring kits. However, the 2W1521 Chrome Top Ring is still available for Parts Service, if desired, for rebuild where liner reusability is a major concern.