Usage:
3406B Truck Engines
Reference: Service Magazine; June 13, 1988; Page 10; "Piston Application Guide," for 3406B Truck Engines.
A new turbocharger, piston and fuel ratio control is used on some 3406B Truck Engines. The new turbocharger has reduced inertia for improved response. The new piston uses a low crevice volume (LCV) design with a double iron band and standard ring package for improved emission, performance and fuel consumption. The new fuel ratio control (FRC) activates by oil pressure only and reduces emissions.
The charts identify Caterpillar's 1990 truck engine ratings, action to be taken and effective serial numbers.
Illustration 1 is a typical example of the following current piston: (See reference article.)
- 1W9372 - Compression Ratio 14.5:1 - Parts Service
- 7C3406 - Compression Ratio 15.2:1 - Current Production
- 2W0865 - Compression Ratio 15.6:1 - Current Production
- 7C3406 - Compression Ratio 15.2:1 - Current Production
Illustration 1. Current pistons.
Illustration 2. New 7E0539 Piston with a low crevice volume (LCV) design (15.2:1 compression ratio).