3406E and C15 Marine Engines Caterpillar

• Four cycle

• Direct fuel injection

• Electronic unit injection

• Turbocharged

• Raw/sea water aftercooled or separate circuit aftercooled (SCAC)

The electronic engine control system provides the following features:

• Engine monitoring

• Electronic governing

• Automatic air/fuel ratio control

• Torque rise shaping

• Injection timing control

• System diagnostics

Electronic unit injectors combine the metering of fuel (duration and timing) and the injection of fuel. Electronic unit injectors produce very high injection pressures.

The Electronic Control Module (ECM) controls the amount of fuel that is injected by varying the signals to the electronic unit injectors. High injection pressures help to reduce fuel consumption and emissions. The use of this type of electronic unit injector helps to provide precise control of injection timing. The injection timing varies with engine operating conditions. This optimizes the engine's performance for starting, emissions, noise, and fuel consumption.

The timing advance is achieved through the precise control of electronic unit injector firing. Engine speed is controlled by adjusting the firing duration. A speed/timing sensor provides information to the ECM for detection of cylinder position and engine speed.

The engine has built-in diagnostics that are used in order to ensure that all of the components function properly.

The cooling system consists of the following components:

• Gear driven centrifugal pump

• One water temperature regulator which regulates the engine coolant temperature

• Oil cooler

• Auxiliary water pump or a SCAC water pump

• Raw/Sea water aftercooler

The engine lubricating oil, that is supplied by a gear type pump, is cooled. The engine lubricating oil is also filtered. Bypass valves provide unrestricted flow of lubrication oil to the engine components during the following conditions:

• High oil viscosity

• Plugged oil cooler or plugged oil filter elements (paper cartridge)

Engine Service Life

Engine efficiency and maximum utilization of engine performance depend on the adherence to proper operation and maintenance recommendations. In addition, use recommended fuels, coolants and lubricants. Use the Operation and Maintenance Manual as a guide for required engine maintenance.

Expected engine life is generally predicted by the average power demanded, based on fuel consumption of the engine over a period of time. Reduced hours of operation at full throttle and/or operating at reduced throttle settings result in a lower average power demand. Reduced hours of operation will increase the length of operating time before an engine overhaul is required. See the Operation and Maintenance Manual, "Maintenance Recommendations" for more information.

Engine Specifications