Usage:
3304 ( 37Y ),
3306 ( 07Y ) Spark-Ignited Engines
Description of Change: New piston body assemblies with three ring grooves and three new piston rings are used in new piston and rod groups. Formerly, pistons with two rings were used. The new three-ring pistons will help provide improved oil control.
(1) New 4P2655 (8:1 compression ratio) or new 4P2654 (10.5:1 compression ratio) Piston Body Assembly. (2) New 4P2656 Top Piston Ring. (3) New 4P2657 Intermediate Piston Ring. (4) New 4P2658 Oil Regulating Piston Ring. (5) 9H4015 Retainer. (6) 7N9804 Pin. (7) 8N1984 Rod Assembly. (8) 4W5739 Bearing.
Adaptable To: The new 4P2699 Rod And Piston Group (8:1 compression ratio) includes the 4P2655 Piston Body Assembly and the rest of the components identified in the illustration. The 4P2699 Rod And Piston Group is a direct replacement for the former 8L4446 Rod And Piston Group. The former rod and piston group is available for parts service only. The new rod and piston group is in effect with 3304 and 3306 Spark-Ignited Engines 37Y1852 and 07Y3663.
The new 4P2698 Rod And Piston Group (10.5:1 compression ratio) includes the 4P2654 Piston Body Assembly and the rest of the components identified in the illustration. The 4P2698 Rod And Piston Group is a direct replacement for the former 7L0472 Rod And Piston Group which is canceled. The new rod and piston group are in effect with 3304 and 3306 Spark-Ignited Engines 37Y1852 and 7Y3664.
The new three-ring piston is not compatible with engines equipped with the 7L0472 Rod And Piston Group. The 7L0472 Rod And Piston Group includes the 5S6360 Connecting Rod, which has a rectangular rod eye. Engines equipped with the 7L0472 Rod And Piston Group are 3304 Spark-Ignited Engines 37Y1-472 and 3306 Spark-Ignited Engines 07Y1-437, 68D1-Up.
It will be necessary to service engines equipped with the 5S6360 Connecting Rod with a 8N1984 or 0R0915 Connecting Rod and a three-ring piston.
The new three-ring piston body assemblies and new rings are a direct replacement for the former two-ring piston body assemblies and rings. Two- and three-ring pistons of the same compression ration can be used together in the same engine.