Usage:
General Information
NOTE: For Specifications with illustrations, make reference to Specifications For 3406E Marine Engine, SENR1167. If the Specifications in SENR1167 are not the same as in the Systems Operation and the Testing & Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.
The Caterpillar 3406E Marine Engine is an inline 6 cylinder arrangement with a bore of 137 mm (5.4 in) and a stroke of 165 mm (6.5 in) giving a total displacement of 14.6 liter (893 cu in) displacement. The firing order is 1, 5, 3, 6, 2, 4 and the direction of crankshaft rotation is counterclockwise, as viewed from the flywheel. The engine is turbocharged and aftercooled with electronic unit injection.
The electronic control system was designed to provide electronic governing, automatic fuel ratio control, torque rise shaping, injection timing control, and system diagnostics.
The electronic unit injector system eliminates many of the mechanical components of a "pump-and-lines" system. It also provides increased control of timing and fuel/air ratio control. Timing advance is achieved by precise control of injection timing. Engine speed is controlled by adjusting the injection duration. A special pulse wheel provides information to the electronic control module for detection of cylinder position and engine rpm.
The engine has built-in diagnostics to insure that all components are operating properly. In the event of a system component failure, the operator will be alerted to the condition via the diagnostic lamp. A Caterpillar electronic service tool can be used to read the numerical code of the faulty component or condition, or the code can be "flashed" using the diagnostic lamp. Intermittent faults are "logged" and stored in memory.
Starting The Engine
The ECM will automatically provide the correct amount of fuel to start the engine. Do not hold the throttle down while cranking the engine. At temperatures below 0°C (32°F), it may be necessary to spray starting fluid into the air cleaner inlet. If the engine fails to start in 30 seconds, release the starting switch. Allow the starting motor to cool for two minutes before using it again.
| NOTICE |
|---|
Excessive ether (starting fluid) can cause piston and ring damage. Use ether for cold weather starting purposes only. |
Cold Mode Operation
The Coolant Temperature Sensor is used to indicate the "Cold Mode" operation and for Engine Monitoring. Cold Mode Operation is activated whenever the coolant temperature is at or below 18°C (64°F). The engine runs on three cylinders while in cold mode. Cold Mode remains active until Coolant Temperature exceeds 19°C (66°F), the engine has been running for 5 minutes, or when the desired engine speed reaches 1200 rpm or greater. In Cold Mode, engine power is limited, timing is advanced, and the low idle speed is adjusted to 600 rpm. The time needed for the engine to reach the normal mode of operation is usually less than the time taken for a walk-around-inspection of the engine.
After cold mode is completed, the engine should be operated at low rpm until normal operating temperature is reached. The engine will reach normal operating temperature faster when operated at low rpm and low power demand than when idled at no load. Typically, the engine should be up to operating temperature within a few minutes. Cold Mode is not disabled if Engine Monitoring is programmed to OFF.
Customer Specified Parameters
The engine is capable of being programmed for several customer specified parameters. For a complete list of the customer specified parameters see the topic: Electronic Control Module (ECM), and Personality Module. For a brief explanation of each of the customer specified parameters, see the Operation and Maintenance Manual.
Glossary of Electronic Control Terms
- After Market Device
- As used here, a device or accessory installed by the customer or machine OEM after the engine is delivered.
- Alternating Current (AC)
- The direction of current flow changes (alternates) regularly and constantly.
- American Wire Gauge (AWG)
- A measure of the diameter (and therefore the current carrying ability) of electrical wire. The smaller the AWG number, the larger the wire.
- Atmospheric Pressure Sensor
- This sensor measures atmospheric air pressure in the crankcase and sends a signal to the ECM.
- Before Top Center (BTC)
- The 180 degrees of crankshaft rotation before the piston reaches Top Center (normal direction of rotation).
- Bypass Circuit
- A circuit, usually temporary, to substitute for an existing circuit, typically for test purposes.
- Calibration
- As used here, is an electronic adjustment of a sensor signal.
- Check Engine Lamp
- Sometimes referred to as the "Diagnostic Lamp", it is used to warn the operator of the presence of an active diagnostic code.
- Component Identifier (CID)
- Two or three digit code which is assigned to each component.
- Coolant Level Sensor
- This sensor detects the absence/presence of coolant at the probe and sends a signal to the ECM.
- Code
- See Diagnostic Code.
- Coolant Temperature Sensor
- This sensor detects the engine coolant temperature for Cold Mode operation and Caterpillar Engine Monitoring (provided the Engine Monitoring is not programmed OFF).
- Customer Specified Parameter
- A Parameter that can be changed and whose value is set by the customer and protected by Customer Passwords.
- Data Link
- An electrical connection for communication with other microprocessor based devices that are compatible with a SAE Standards such as electronic displays and maintenance systems. A Data Link is also the communication medium used for programming and troubleshooting with Caterpillar electronic service tools.
- Desired RPM
- An input to the electronic governor within the ECM. The electronic governor uses inputs from the Throttle Position Sensor, Engine Speed/Timing Sensor and Customer Parameters to determine "Desired RPM".
- Desired Timing Advance ("Des Timing Adv" on electronic service tool)
- The injection timing advance calculated by the ECM as required to meet emission and performance specifications.
- Diagnostic Code
- Sometimes referred to as a "fault code", it is an indication of a problem in the electronic system.
- Diagnostic Event Code
- These codes indicate an event. They are not necessarily (or usually) an indication of problem with in the electronic system.
- Diagnostic Fault Code
- These codes indicate an electronic system malfunction indicating a problem with the electronic system.
- Diagnostic Flash Code
- These codes are flashed out using the Check Engine/Diagnostic Lamp to indicate an electronic system malfunction or an event detected by the electronic system.
- Diagnostic Lamp
- Sometimes referred to as the Check Engine Lamp, it is used to warn the operator of the presence of an active diagnostic code.
- Direct Current (DC)
- The type of current where the direction of current flow is consistently in one direction only.
- Duty Cycle
- See Pulse Width Modulation.
- Electronic Control Analyzer Programmer (ECAP)
- An electronic service tool developed by Caterpillar used for programming and diagnosing a variety of Caterpillar electronic controls.
- Electronic Control Module (ECM)
- The engine control computer that provides power to the system electronics, monitors system inputs and acts as a governor to control engine rpm.
- Electronic Engine Control
- The complete electronic system that monitors and controls engine operation under all conditions.
- Electronic Technician (ET)
- A Caterpillar electronic service tool used for diagnosing and programming a variety of electronic controls.
- Electronically Controlled Unit Injector
- The injection pump which is a mechanically actuated, electronically controlled unit injector combining the pressurizing, electronic fuel metering and injecting elements in a single unit.
- Engine Monitoring
- The part of the Caterpillar Electronic Engine Control that monitors Coolant Temperature, Oil Pressure, Inlet Manifold Air Temperature and Coolant Level to flag the operator of detected problems. The Coolant Temperature, Inlet Manifold Air Temperature, and Oil Pressure Sensors are supplied by Caterpillar and monitored by the ECM. The Coolant Level Sensor is OEM installed, but still monitored by the ECM. After market Engine Monitoring Systems do not interface with the Caterpillar Electronic Engine Control.
- Engine Oil Pressure Sensor
- This sensor measures engine oil pressure and sends a signal to the ECM and is part of Caterpillar Engine Monitoring.
- Estimated Dynamic Timing
- The ECM estimation of actual injection timing.
- Failure Mode Identifier (FMI)
- Type of failure the component experienced (adopted from SAE standard practice J1587 diagnostics).
- Flash Code (FC)
- The Caterpillar proprietary code numbers which are flashed out on the diagnostic lamp.
- Fuel Ratio Control (FRC)
- FRC Fuel Pos - is a limit based on control of the fuel/air ratio and is used for emissions control purposes. When the ECM senses a higher boost pressure (more air into cylinder), it increases the "FRC Fuel Pos" limit (allows more fuel into cylinder).
- Fuel Position
- An internal signal within the ECM, from the Electronic Governor to Fuel Injection Control. It is based on Desired RPM, FRC Fuel Position, rated fuel position and engine rpm.
- Fuel Temperature Sensor
- This sensor detects the fuel temperature. The ECM monitors the fuel temperature and adjusts calculated fuel rate accordingly.
- Full Load Setting (FLS)
- Number representing fuel system adjustment made at the factory to "fine tune" the fuel system. Correct value for this parameter is stamped on the 9L6531 Engine Information Plate. This parameter must be programmed or a Diagnostic Code 253-02 Check Customer Or System Parameters (Fault Code 56) will be generated.
- Full Torque Setting (FTS)
- Similar to Full Load Setting. This parameter must be programmed or a Diagnostic Code 253-02 Check Customer or System Parameters (Fault Code 56) will be generated.
- Harness
- The wiring bundle (loom) connecting all components of the 3406E System.
- Hertz (Hz)
- Measure of frequency in cycles per second.
- Histogram
- A bar graph indicating the relative frequency of engine operation in specific operating ranges.
- Inlet Manifold Air Pressure Sensor
- This sensor measures inlet manifold air pressure and sends a signal to the ECM.
- Inlet Manifold Air Temperature Sensor
- This sensor detects the inlet manifold air temperature. The ECM monitors the inlet air temperature and coolant temperature to adjust injection timing. It is also part of Caterpillar Engine Monitoring.
- Integrated Electronic Controls
- The engine is designed with the electronic controls as a necessary part of the system. The engine will not operate without the electronic controls.
- Marine Gear Oil Pressure Sensor
- The ECM monitors marine gear oil pressure with a sensor located on the high pressure side of the marine gear from 0 kPa (0 psi) to 3100 kPa (442 psi).
- Marine Gear Oil Temperature Sensor
- The ECM monitors marine gear oil temperature with the sensor up to 120°C (248°F).
- Open Circuit
- Condition where an electrical wire or connection is broken, so that the signal or the supply voltage can no longer reach its intended destination.
- Original Equipment Manufacturer (OEM)
- As used here, the manufacturer of the marine vessel.
- Parameter
- A programmable value which affects the characteristics, performance or behavior of the engine.
- Passive Data Booster
- The passive data booster is an external CAT Data Link signal booster designed to be water tight and easy to install on an ECM.
- Passive Magnetic Speed Sensor
- A speed sensor not requiring a power and ground connection. It produces a signal based on the change in magnetic flux of a ferrous metal gear near the sensing tip.
- Password
- A group of numeric or alpha-numeric characters, designed to restrict access to parameters. The electronics system requires correct passwords in order to change Customer Specified Parameters (Customer Passwords) or certain engine specifications (Factory Passwords). Passwords are also required to clear certain diagnostic codes.
- Personality Module Or Ratings Personality Module
- The module attached inside of the ECM which contains all the instructions (software) for the ECM and performance maps for a specific horsepower family.
- Power Take Off (PTO)
- Front PTO, operated by a lever mounted on the unit itself, stub shaft and hydraulic pump drive are available for operating auxiliary equipment on the vessel.
- Pulse Width Modulation (PWM)
- A signal consisting of variable width pulses at fixed intervals, whose "TIME ON" versus "TIME OFF" can be varied (also referred to as "duty cycle").
- Rated Fuel Position
- ("Rated Fuel Pos" on electronic service tool) - this indicates the maximum allowable fuel position (longest injection pulse). It will produce rated power for this engine configuration.
- Reference Voltage
- A regulated voltage supplied by the ECM to a sensor. The reference voltage is used by the sensor to generate a signal voltage.
- Remote Mounted Throttle Position Sensor
- This sensor measures throttle position and sends a signal to the ECM. The sensor is mounted to the throttle assembly, usually at the bridge station or in the engine room, not on the engine.
- Sensor
- A device used to detect and convert a change in pressure, temperature, or mechanical movement into an electrical signal.
- Service Program Module (SPM)
- A software program on a factory programmable computer chip, designed to adapt an electronic service tool to a specific application.
- Short Circuit
- A condition where an electrical circuit is unintentionally connected to an undesirable point. Example is a wire which rubs against the frame until it wears off its insulation and makes electrical contact with the frame.
- Signal
- A voltage or waveform used to transmit information typically from a sensor to the ECM.
- Speed "burp"
- A sudden brief change in engine speed.
- Speed Circuit
- Includes the speed sensor, harness and ECM.
- Speed/Timing Sensor
- Provides a Pulse Width Modulated signal to the ECM, which the ECM interprets as crankshaft position, direction of rotation and engine rpm and sends the signal to the ECM.
- Standard SAE Diagnostic Communications Data Link
- Refer to ATA Data Link.
- Subsystem
- As used here, it is a part of the engine system that relates to a particular function, for instance the throttle subsystem, etc.
- Supply Voltage
- A constant voltage supplied to a component to provide electrical power for its operation. It may be generated by the ECM, or it may be vessel battery voltage supplied by the vessel wiring.
- "T" Harness
- A test harness designed to permit normal circuit operation while measuring voltages, typically inserted between the two ends of a connector.
- Throttle Position
- The ECM interpretation of the signal from the Throttle Position Sensor.
- Throttle Position Sensor
- An electronic sensor which is connected to the throttle and sends a Pulse Width Modulated Signal to the ECM.
- Total Tattletale
- Total number of changes to all Customer Specified Parameters.
- Transducer
- A device which converts a mechanical signal to an electrical signal.
- Warning Lamp
- Used to warn the operator of the presence of a Caterpillar Engine Monitoring detected problem.
Electronic Control System Components
Electronic Control System Components (Left Side View)
Electronic Control System Components (Right Side View)
Engine Monitoring
The electronic control system includes an Engine Monitoring feature which monitors engine oil pressure, coolant temperature, inlet manifold air temperature, and coolant level. All engines are shipped with the Caterpillar oil pressure sensor, coolant temperature sensor, and inlet manifold air temperature sensor. The OEM is responsible for providing and installing the coolant level sensor. The coolant level sensor is standard on heat exchanger equipped engines and optional for keel cooled engine arrangements. The coolant level sensor is standard on heat exchanger equipped engines and optional for keel cooled engine arrangements. The coolant level sensor is the only individually selectable sensor for the Engine Monitoring feature. It is enabled/disabled through a Customer Programmable Parameter, with a default factory setting of enabled. There are three Customer Programmable Levels for Caterpillar Engine Monitoring.
- * Off
- * Warning (Factory Default)
- * Derate
- * Warning (Factory Default)
Engine Monitoring "Off" Mode
The ECM will ignore the oil pressure sensor and coolant level sensor (if installed). Coolant Temperature is still used for Cold Mode. Inlet Manifold Air Temperature is used for cold air operation regardless of the engine monitoring mode.
Engine Monitoring "Warning" Mode
Warning mode uses Oil Pressure, Coolant Temperature, Inlet Manifold Air Temperature, and the Coolant Level Sensor (if installed and enabled). The following table indicates the diagnostic codes available, and their effect on engine performance when active. The Check Engine Lamp will flash and the Warning Lamp will come on as indicated in the table when the diagnostic code is active.
Engine Monitoring "Derate" Mode
Derate mode allows the ECM to alter engine performance to help the engine avoid damage and return to normal conditions. Whenever the engine is derated, the Check Engine Lamp (due to active diagnostic) and Warning Lamp will flash. For the Derate column in the following table, mph indicates vessel speed is derated (maximum derate is 45 mph), hp indicates engine horsepower is limited (maximum derate is 160 hp), and rpm indicates engine speed is limited (maximum derate is 1350 rpm). For operating conditions causing these codes see the appropriate section for the sensor under consideration.
Electronic Control System Operation
The electronic control system is integrally designed into the engines fuel system and air inlet system to electronically control fuel delivery and injection timing. It provides increased control of timing and fuel/air ratio control in comparison to conventional mechanically controlled engines. Injection timing is achieved by precise control of injector firing time, and engine power is controlled by adjusting the firing duration. The ECM energizes the injector solenoids to start injection of fuel, and de-energizes the injector solenoids to complete or stop injection of fuel. See the topic, Electronically Controlled Unit Injector, for a complete explanation of the fuel injection process.
The engine uses three types of electronic components which are: input, control and output.
An input component is one that sends an electrical signal to the ECM. The signal sent varies in either voltage or frequency in response to change in some specific system of the engine (examples are: speed/timing sensor, coolant temperature sensor, etc.). The electronic control module sees the input sensor signal as information about the condition, environment, or operation of the engine.
A system control component receives the input signals. Electronic circuits inside the ECM evaluate the signals and then supply electrical energy to the output components of the system in response to predetermined combinations of input signal values.
An output component is one that is operated by the ECM. It receives electrical energy from the ECM and uses that energy to either:
1) Perform work (such as a moving solenoid plunger will do) and thereby take an active part in regulating or operating the vessel.
2) Give information or warning (such as a light or an alarm) to the operator of the vessel or other person.
These components provide the ability to electronically control the engine operation to improve performance, minimize fuel consumption, and reduce emissions levels. A brief description of sensors used in the system are given as follows:
Atmospheric Pressure Sensor
The Atmospheric Pressure Sensor is an absolute pressure sensor measuring crankcase pressure. Both the Inlet Manifold Air Pressure and Engine Oil Pressure communicated to service tools and over the data link are calculated by subtracting the Atmospheric Pressure Sensor reading.
The Atmospheric Pressure Sensor measures pressure from 0 kPa (0 psi) to 116 kPa (17 psi). The sensor is supplied by the ECM with +5 VDC.
Coolant Level Sensor
The coolant level sensor is standard on heat exchanger equipped engines and optional for keel cooled arrangements. The sensor is the only optional sensor for Caterpillar Engine Protection equipped engines, selectable through a Customer Programmable Parameter (protected by Customer Passwords).
Coolant Temperature Sensor
Engine coolant temperature is measured by an electronic sensor mounted on the water outlet housing. This sensor signal is used to modify engine fueling and timing for improved cold start and white smoke cleanup. The ECM supplies the coolant temperature sensor with 5.0 ± .5 VDC and the sensor output voltage is 0.5 to 4.5 VDC depending upon engine coolant temperature. Coolant Temperature is used to indicate "Cold Mode" operation and for Engine Monitoring.
Cold Mode Operation (Part Of Coolant Temperature Sensor)
Cold Mode Operation was previously discussed under the Systems Operation topic.
Coolant Temperature Engine Monitoring Operation (Part Of Coolant Temperature Sensor)
If Engine Monitoring is programmed to Derate, the ECM will cause the diagnostic lamp to flash, and will cause the Warning Lamp to flash when the associated diagnostic code is active. The flashing Warning Lamp indicates the engine is in Derate Mode.
Engine Oil Pressure Sensor
The Engine Oil Pressure Sensor is an absolute pressure sensor measuring oil pressure in the gallery. The difference between the pressure measured by this sensor (oil pressure) and atmospheric pressure is Engine Oil Pressure as displayed by service tools and communicated over the data link. The ECM uses this sensor input only if the parameter for Engine Monitoring is programmed to Warning or Derate.
The Engine Oil Pressure Sensor measures pressure from 0 kPa (0 psi) to 690 kPa (100 psi). The sensor is supplied by the ECM with +5 VDC.
Fuel Temperature Sensor
Fuel Temperature is monitored to adjust fuel rate calculations, and for fuel temperature power correction when fuel temperatures exceed 30°C (86°F) to provide constant power. Maximum power correction is achieved at 70°C (158°F).
Inlet Manifold Air Pressure Sensor
The Inlet Manifold Air Pressure Sensor is an absolute pressure sensor measuring inlet manifold air pressure. The difference between the pressure measured by this sensor (inlet manifold air pressure) and atmospheric pressure is Boost Pressure as displayed by service tools and communicated over the data link. The inlet Manifold Air Pressure Sensor measures pressure from 20 kPa (3 psi) to 882 kPa (128 psi). The sensor is supplied by the ECM with +5 VDC.
Inlet Manifold Air Temperature Sensor
Inlet Manifold Air Temperature is used for Engine Monitoring, Inlet Manifold Air Temperature is used to warn the operator of an excessive inlet manifold air temperature, but will not cause the ECM to derate the engine, if Engine Monitoring is programmed to Derate.
Before a diagnostic code is logged immediately following engine startup, Inlet Manifold Air Temperature must exceed the triggering temperatures indicated for thirty seconds. A High Inlet Manifold Air Temperature Warning diagnostic code is triggered at 90°C (194°F), and a Very High Inlet Manifold Air Temperature at 109°C (228°F). Unlike the other diagnostic codes associated with Engine Monitoring, those codes associated with Inlet Manifold Air Temperature are still available when Engine Monitoring is programmed OFF. The Warning Lamp is also turned on if Engine Monitoring is programmed to Warning or Derate.
Speed/Timing Sensor
The engine speed/timing sensor is used to determine both engine speed and fuel injection timing. There is a primary and a backup speed/timing sensor. The backup sensor takes over governing if the primary sensor fails. The sensor detects this information from a wheel on the camshaft. Timing calibration is performed by connecting a magnetic sensor. The sensor is connected through the circuit, sensing motion of the crankshaft.
Throttle Position Sensor
An electronic sensor which is connected to the throttle and sends a Pulse Width Modulated Signal to the ECM.
Diagnostic Lamp
The standard equipment control panel for the 3406E Marine Engine has a diagnostic lamp that is used to communicate status or operation problems of the electronic control system.
The diagnostic lamp will be ON and blink every five seconds whenever a diagnostic fault is detected by the ECM. The light should also be ON and flashing Diagnostic Code 55 whenever the START switch is turned ON, but the engine is not running. This condition will test whether the light is operating correctly.
If the diagnostic lamp comes on and stays on after initial start-up, the system has detected a fault. The "check engine" light or service tools can be used to identify the diagnostic code.
The diagnostic lamp will begin to flash to indicate a two digit diagnostic code. The sequence of flashes represent the system diagnostic message. The first sequence of flashes adds up to the first digit of the diagnostic code. After a one second pause, a second sequence of flashes will occur which represents the second digit of the diagnostic code. Any additional diagnostic codes will follow, after a three second pause, and will be displayed in the same manner.
Control Panel Features
The standard control panel features include a start switch, hour meter, stop button, breaker reset button (15 amp breaker), maintenance indicator lamp, maintenance clear switch, diagnostic lamp, and warning lamp. The other switches and lamps defined for the control panel are optional and customer installed.
Start Switch
The start switch has three positions: OFF, RUN and START. When the start switch is turned clockwise to the RUN position, the lamps will illuminate for five seconds during the system test and then shut off. In the RUN position, the ECM and electronic systems are powered up.
When the switch is turned to the START position, the starting motor mag switch is energized and engages the electric starting motor. The starting motor will continue to crank as long as the start switch is held in the START position. The start switch is spring loaded to return to the RUN position when released.
The engine may be shut down by turning the start switch to the OFF position. This mode of shut down removes power the ECM.
Hour Meter
This monitors the hours of engine running time. It will operate only when the engine is running.
Stop Button
The OUT position is for normal engine operation. When pressed, the button will lock IN and shut down the engine via a shutdown signal to the ECM. The ECM will remain powered. The start switch is locked out and will not energize the starting motor mag switch when the stop button is pushed in. Twist the stop button clockwise to release and allow start-up.
Breaker Reset Button (15 amp Breaker)
Contained within the control panel are two breakers. They include a 3 amp breaker with auto reset and a 15 amp breaker with a manual reset button. Check this reset button if there is a total loss of electrical power to the engine.
Maintenance Indicator Lamp
This lamp will light when scheduled maintenance is to be performed. Refer to the Maintenance Schedule, Operation & Maintenance Manual, SEBU7005 for the maintenance item for each hour interval.
Maintenance Clear Switch
After the appropriate maintenance item has been performed this button is pushed to clear the maintenance indicator lamp.
Diagnostic Lamp
This lamp will illuminate when a diagnostic fault code has been generated by the ECM and flash the appropriate fault code.
Warning Lamp
This lamp will illuminate when a critical condition has occurred such as low oil pressure or high coolant temperature.
Engine Synchronization Switch
The Engine Synchronization Switch will allow multiple engine ECM's to be linked to a single vessel throttle.
Low Coolant Level Lamp
The Low Coolant Level Lamp is used to indicate engine coolant level status. On power up (keyswitch ON, engine OFF) the ECM will turn the lamp ON for five seconds, then turn the lamp OFF unless the ECM detects a low coolant level condition.
High Coolant Temperature Lamp
The High Coolant Temperature Lamp is used to indicate engine coolant temperature status. On power up (keyswitch ON, engine OFF) the ECM will turn the lamp ON for five seconds, then turn the lamp OFF unless the ECM detects a high coolant temperature condition.
Low Engine Oil Pressure Lamp
The Low Engine Oil Pressure Lamp is used to indicate engine oil pressure status. Low engine oil pressure diagnostics provided by the ECM is based on engine rpm and actual engine oil pressure. On power up (keyswitch ON, engine OFF) the ECM will turn the lamp ON for five seconds, then turn the lamp OFF unless the ECM detects a low engine oil pressure condition.
Trolling Mode Switch
During the Trolling Mode operation, the full range travel of the throttle lever will cause the engine speed to change from low idle engine speed to the maximum programmed trolling speed. The Trolling Mode Switch will only engage when the engine speed is within 30 rpm of low idle. The Trolling Mode Switch can also be activated when the engine is not running.
Slow Vessel Mode Switch
When the Slow Vessel Mode Switch is activated, the ECM will reduce the programmed low idle speed to 550 rpm. This feature allows the operator better vessel maneuverability during docking and no-wake zones.
Trip Clear Switch
When the Trip Clear Switch is activated the ECM clears the trip data and starts a new trip. This clears both the trip totals (not lifetime) as well as the trip histograms.
Remote Shutdown Switch
When the Remote Shutdown Switch is activated, the ECM disables the fuel injection signal. This action causes the engine to shut down while leaving the ECM powered and active to monitor all engine functions.
Electronic Control Module (ECM) and Personality Module
Electronic Control Module (Typical Example)
The engine uses a microprocessor based Electronic Control Module (ECM) which is isolation mounted on the rear left side of the cylinder block. The Electronic Control Module (ECM) (3) temperature is maintained by fuel as it circulates through a manifold between two circuit boards in the control module. The fuel enters the control module, at fuel inlet (5), and exits the control module at fuel outlet (2).
All inputs and outputs to the control module are designed to tolerate short circuits to battery voltage or ground without damage to the control module. Resistance to radio frequency and to electromagnetic interference is designed into the system.
The ECM power supply provides electrical power to all engine mounted sensors and actuators. Reverse voltage polarity protection and resistance to vessel power system voltage "swings" or "surges" (due to sudden alternator load, etc.) have been designed into the ECM. The ECM also monitors all sensor inputs and provides the correct outputs to ensure desired engine operation.
The ECM stores engine settings and rating information along with the customer specified parameters. The customer specified parameters include: Engine Power Rating, Low Idle, Maximum Trolling Speed, Fuel/Air Ratio, Transmission Pressure Warning Set Point, Transmission Temperature Warning Set Point, Engine Monitoring Mode, Coolant Level Sensor (Enable/Disable), Vessel ID, Engine Location, Transmission Pressure (Enable/Disable), Transmission Temperature (Enable/Disable), Transmission Temperature (Enable/Disable). The customer specified parameters may be secured by customer passwords.
An ECM may have all parameters programmed or any combination of parameters programmed. For a brief explanation of each of the customer specified parameters, see the Operation and Maintenance Manual.
The personality module is contained within the ECM and provides the programming (instructions) necessary for the ECM to perform its function. The personality module contains all the engine performance and certification information such as, the timing, air/fuel ratio and rated fuel position control maps for a particular ratings group that utilizes common engine components.
The ECM is programmed to run diagnostic tests on all inputs and outputs to partition a fault to a specific circuit. Once a fault is detected, it can be displayed (flashing coded display, representing a diagnostic fault code) on a diagnostic lamp (see the topic, Diagnostic electronic service tool. An electronic service tool or multimeter can be used to check or troubleshoot most problems. The ECM also will log or record most diagnostic codes generated during engine operation. These logged or intermittent codes can be read by an electronic service tool.
The wiring harness provides communication or signal paths to the various sensors (inlet manifold air pressure sensor, speed/timing sensor), the Data Link Connector, and the engine connectors.
Fuel System
Fuel System Schematic
The fuel supply circuit is a conventional design for unit injected engines. It uses a fixed clearance gear type fuel transfer pump (10) to deliver fuel from the fuel tank to the electronically controlled unit injectors (2). Fuel is pulled from the fuel tank by the fuel transfer pump. The fuel transfer pump incorporates a check valve (12) to permit fuel flow around the gears for hand priming and a relief valve (11) to protect the system from extreme pressure. The excess fuel flow provided by the fuel transfer pump cools and purges the air from the unit injectors.
NOTE: When the engine has reached its normal operating temperature, inlet fuel temperature to transfer pump must not exceed 79°C (175°F). Fuel temperatures above 79°C (175°F) reduce the life of the electronics in the ECM and transfer pump check valves. When fuel temperature increases from 30°C (86°F) to 70°C (158°F) fuel efficiency and engine power output are reduced. Be sure fuel heaters are turned OFF in warm weather operating conditions.
The fuel flows from the fuel transfer pump through cored passages of the distribution block to the fuel filter (five micron). A fuel priming pump (7) is located on the fuel filter base to fill the system after filter changes or after draining the fuel supply and return passages in cylinder head to replace unit injectors.
The filtered fuel enters the housing of the Electronic Control Module (ECM) (4) in order to cool the module. Fuel leaves the ECM and enters the fuel manifold at the rear of the cylinder head. The fuel flows continuously from the fuel supply manifold in the cylinder head through the unit injectors when the supply or fill port in the injector is not closed by the injector body assembly plunger and is returned to the tank. Fuel displaced by the plunger when not injecting fuel into the cylinder, is also returned to the tank. For a complete explanation of the injection process, see the topic Electronically Controlled Unit Injector.
A pressure regulating valve is located in distribution block (8) to maintain sufficient pressure in the system to fill the unit injectors. Excess fuel flow travels back to the fuel tank (13) to receive cooling effect from the tank.
The fuel transfer pump (10) is located at the left front corner of the engine. It is mounted to either the front timing gear cover or plate and is driven by the gear train.
Fuel System Electronic Control Circuit
Electronic Governor
This engine was designed for electronic control. The injection pump, fuel lines and nozzles used in traditional Caterpillar Diesel Engines have been replaced with an electronically controlled, mechanically actuated unit injector in each cylinder. A solenoid on each injector controls the amount of fuel delivered by the injector. An Electronic Control Module (ECM) sends a signal to each injector solenoid, to provide complete control of the engine.
Electronic Controls
The Engine Electronic Control System consists of two main components: the Electronic Control Module (ECM) and the Personality Module. The ECM is the computer and the personality module contains the software for the computer (the personality module stores the operating maps that define horsepower, torque curves, rpm, etc.). The two work together (along with sensors to "see" and solenoid/injectors to "act") to control the engine.
The ECM determines a "desired rpm" based on the throttle signal. The ECM then maintains the desired engine rpm by sensing actual engine rpm and deciding how much fuel to inject in order to achieve the desired rpm.
Fuel Injection
The ECM controls the amount of fuel injected, by varying signals to the injectors. The injectors will inject fuel ONLY if the injector solenoid is energized. The ECM sends a signal to the solenoid to energize it. By controlling the timing and duration of the signal, the ECM can control injection timing and the amount of fuel injected.
The ECM sets certain limits on the amount of fuel that can be injected. "FRC Fuel Pos" is a limit based on boost pressure to control the fuel/air ratio, for emissions control purposes. When the ECM senses a higher boost pressure (more air into cylinder), it increases the "FRC Fuel Pos" limit (allows more fuel into cylinder). "Rated Fuel Pos" is a limit based on the horsepower rating of the engine. It is similar to the rack stops and torque spring on a mechanically governed engine. It provides horsepower and torque curves for a specific engine family and rating.
Injection timing depends on engine rpm, load, and other operation factors. The ECM knows where top-center of cylinder number one is from the signal provided by the engine Speed/Timing Sensor. It decides when injection should occur relative to top-center and provides the signal to the injector at the desired time.
Unit Injector Mechanism
Unit Injector Mechanism
The unit injector mechanism provides the downward force required to pressurize the fuel in the unit injector pump. The electronically controlled unit injector (1), at the precise time, allows fuel to be injected into the combustion chamber. The camshaft gear is driven by a series of two idler gears and a cluster gear driven off the crankshaft gear. Timing marks on the crankshaft gear to the cluster gear, and the camshaft gear to the timing cover housing when aligned, provide the correct relationship between the piston and valve movement. The camshaft has three cam lobes for each cylinder. Two lobes operate the inlet and exhaust valves, and one operates the unit injector mechanism. Force is transmitted from the unit injector lobe on camshaft (4), through rocker arm assembly (3) and to the top of the unit injector. The adjusting nut (2) allows setting of the injector lash. See the topic, Injector Lash Adjustment, in the Testing & Adjusting Section for proper setting of the unit injector lash.
Electronically Controlled Unit Injector
Electronically Controlled Unit Injector
Low pressure fuel in the cylinder head, enters the electronically controlled unit injector at the fill port. As the unit injector mechanism produces force to the top of the unit injector, spring (1) is compressed, and plunger (4) is driven downward, displacing fuel through the valve in the solenoid valve assembly (3). Excess fuel is returned to tank through solenoid valve. The fill passage into barrel (5) is closed by the outside diameter of the plunger, and the passages within body (10) and along check valve (11) to the injector tip are filled with fuel as the plunger moves down. After the fill passage in the plunger barrel is closed, fuel can be injected at any time depending on the start of injection timing requirements programmed into the electronic control module.
When solenoid valve assembly (3) is energized, from a signal across solenoid connection (2), the solenoid valve closes and pressure is elevated in the injector tip. Injection starts at 34 474 ± 1 896 kPa (5000 ± 275 psi), as the force of spring (8) above spacer (9) is overcome and the check lifts from its seat. The pressure continues to rise as the plunger cycles through its full stroke. After the correct amount of fuel has been discharged into the cylinder, the electronic control module de-energizes the solenoid and the solenoid valve is opened. Now, the high pressure fuel is dumped through the spill port to the fuel return manifold and tank.
The length of injection determines the amount of fuel injected into each cylinder. Injection duration is controlled by the ECM, which performs the function of the fuel system governor.
After reaching the maximum lift point, the force to the top of the unit injector is removed as spring (1) expands. The plunger returns to its original position, uncovering the fuel supply passage into the plunger barrel to refill the injection pump body. Low pressure fuel then circulates through the injector body and out the spill port until the solenoid valve assembly (3) is again energized.
Air Inlet and Exhaust System
Pleasure Craft Air Inlet and Exhaust System (Closed Crankcase)
Standard Air Inlet and Exhaust System (Open Crankcase)
The components of the air inlet and exhaust system control the quality and the amount of air available for combustion. These components are the air cleaner, turbocharger, aftercooler, cylinder head, valves and valve system components, piston and cylinder, and exhaust manifold.
Inlet air is pulled through the air cleaner, compressed and heated by the compressor wheel in the compressor side of the turbocharger to about 200°C (392°F), then pushed through the aftercooler core and moved to the air inlet plenum in the cylinder head at about 45°C (113°F). Cooling of the inlet air increases combustion efficiency, which helps to lower fuel consumption and increase horsepower output.
From the aftercooler core the air is forced into the cylinder head to fill the inlet ports. Air flow from the inlet port into the cylinder is controlled by the inlet valves.
There are two inlet and two exhaust valves for each cylinder. Inlet valves open when the piston moves down on the inlet stroke. When the inlet valves open, cooled compressed air from the inlet port is pulled into the cylinder. The inlet valves close and the piston begins to move up on the compression stroke. The air in the cylinder is compressed. When the piston is near the top of the compression stroke, fuel is injected into the cylinder. The fuel mixes with the air and combustion starts. The force of combustion pushes the piston down on the power stroke. When the piston moves up again, it is on the exhaust stroke. The exhaust valves open, and the exhaust gases are pushed through the exhaust port into the exhaust manifold. After the piston makes the exhaust stroke, the exhaust valves close and the cycle (inlet, compression, power, exhaust) starts again.
Exhaust gases from exhaust manifold (9) enter the turbine side of the turbocharger and cause the turbine wheel to turn. The turbine wheel is connected to the shaft which drives the compressor wheel. Exhaust gases from the turbocharger pass through the exhaust outlet pipe, the muffler and the exhaust stack.
Turbocharger
The turbocharger is installed on the rear section of the exhaust manifold. All the exhaust gases from the engine go through the turbocharger. The compressor side of the turbocharger is connected to the aftercooler by a pipe.
Turbocharger
The exhaust gases go into turbine housing (7) through exhaust inlet (11) and push the blades of turbine wheel (8). The turbine wheel (8) is connected by a shaft to compressor wheel (3).
Clean air from the air cleaners is pulled through the compressor housing air inlet (1) by the rotation of compressor wheel (3). The action of the compressor wheel blades causes a compression of the inlet air. This compression gives the engine more power because it makes it possible for the engine to burn more air and fuel during combustion.
When the load on the engine increases, more fuel is injected into the cylinders. This makes more exhaust gases, and will cause the turbine and compressor wheels of the turbocharger to turn faster. As the compressor wheel turns faster, more air is forced into the engine. The increased flow of air gives the engine more power because it makes it possible for the engine to burn the additional fuel with greater efficiency.
Bearing (4) and bearing (6) for the turbocharger use engine oil under pressure for lubrication. The oil comes in through the oil inlet port (5) and goes through passages in the center section for lubrication of the bearings. Oil from the turbocharger goes out through the oil outlet port (10) in the bottom of the center section and goes back to the engine lubrication system.
Valves and Valve System Components
Valve System Components
The valves and valve system components control the flow of inlet air and exhaust gases into and out of the cylinder during engine operation.
Timing Gear Components
The inlet and exhaust valves are opened and closed by the valve mechanism as rotation of the crankshaft causes rotation of camshaft (3). The camshaft gear (9) is driven by a series of two adjustable idler gears (10), (11) and a cluster gear (13) driven off the crankshaft gear (14). Timing marks (12), and (8) are aligned to provide the correct relationship between piston and valve movement.
The camshaft has three cam lobes for each cylinder. Two lobes operate the inlet and exhaust valves, and one operates the unit injector mechanism. As the camshaft turns, the cam lobes causes the rocker arms to move up and down. Movement of the rocker arms will make the inlet and exhaust bridges move up and down. These bridges let one rocker arm open, or close, two valves (inlet or exhaust) at the same time. There are two inlet and two exhaust valves in each cylinder. One valve spring for each valve holds the valves in the closed position when the rocker arm moves off the camshaft lobe.
Rotocoil assemblies cause the valves to have rotation while the engine is running. This rotation of the valves keeps the deposit of carbon on the valves to a minimum and gives the valves longer service life.
The front gear train is a combination of spur and helical gears. The engine oil pump, crankshaft gear (14), front cluster gear (13) and water pump gear are helical gears. The remainder of the gears are spur gears.
The adjustable idler gear (10) is designed to provide the required gear backlash between the non-adjustable idler gear (11) and the camshaft drive gear (9). If the cylinder head is removed, tolerances of the components (cylinder head and head gasket) will change. The adjustable idler gear must be relocated per the Disassembly and Assembly Service Manual to provide the optimum gear to gear spacing.
The camshaft drive gear contains integral pendulum rollers. These rollers are designed to negate the injector pulses which would radiate through the gear train causing vibration and noise. The engine runs smoother at all operating speeds, and performance can be optimized with the use of the pendulum damped camshaft drive gear.
Air Starting System
The air starting motor is used to turn the engine flywheel fast enough to get the engine running.
Air Starting System (Typical Example)
The air starting motor is on the left side of the engine. Normally the air for the starting motor is from a storage tank which is filled by an air compressor installed by the customer. The air storage tank should be capable of holding 297 liter (10.5 cu ft) of air at 1720 kPa (250 psi) when filled.
For engines which do not have heavy loads when starting, the regulator setting is approximately 690 kPa (100 psi). This setting gives a good relationship between cranking speeds fast enough for easy starting and the length of time the air starting motor can turn the engine before the air supply is gone.
If the engine has a heavy load which cannot be disconnected during starting, the setting of the air pressure regulating valve needs to be high in order to get high enough speed for easy starting.
The air consumption is directly related to speed, the air pressure is related to the effort necessary to turn the engine flywheel. The setting of the air pressure regulator can be up to 1030 kPa (150 psi) if necessary to get the correct cranking speed for a heavily loaded engine. With the correct setting, the air starting motor can turn the heavily loaded engine as fast and as long as it can turn a lightly loaded engine.
Other air supplies can be used if they have the correct pressure and volume. For good life of the air starting motor, the supply should be free of dirt and water. The maximum pressure for use in the air starting motor is 1030 kPa (150 psi). Higher pressures can cause problems.
Air Starting Motor
The air from the supply goes to relay valve (3). The starting control valve (1) is connected to the line before the relay valve (3). The flow of air is stopped by the relay valve (3) until the starting control valve (1) is activated. Then air from the starting control valve (1) goes to the piston (10) behind the pinion (8) for the starter. The air pressure on the piston (10) puts the pinion spring (7) in compression and puts the pinion (8) in engagement with the flywheel gear. When the pinion is in engagement, air can go out through another line to the relay valve (3). The air activates the relay valve (3) which opens the supply line to the air starting motor.
Lubrication for the air starting motor is provided by a flexible fuel line connection from the fuel block to the oiler (2) on the starting motor. This fuel supply line provides a charge of fuel to lubricate the motor. When the starting control valve is activated, the charge of fuel is delivered to lubricate the motor.
The air with lubrication oil goes into the air motor. The pressure of the air pushes against the vanes (5) in the rotor (9). This turns the rotor which is connected by the gear (6) to the starting pinion (8) which turns the engine flywheel.
When the engine starts running the flywheel will start to turn faster than the starting pinion (8). The pinion (8) retracts under this condition. This prevents damage to the motor, pinion (8) or flywheel gear.
When the starting control valve (1) is released, the air pressure and flow to the piston (10) behind the starting pinion (8) is stopped, the pinion spring (7) retracts the pinion (8). The relay valve (3) stops the flow of air to the air starting motor.
Lubrication System
The lubrication system has the following components: oil pan, engine oil pump, engine oil cooler, engine oil filter, oil lines to and from the turbocharger and oil passages in the cylinder block.
Oil Flow Through The Engine Oil Filter And Engine Oil Cooler
Flow Of Oil (Engine Warm)
With the engine warm (normal operation), oil comes from oil pan (6) through suction bell (9) to engine oil pump (7). The engine oil pump sends warm oil to the engine oil cooler (10) and then to engine oil filter (4). From the engine oil filter, oil is sent to oil manifold (1) in the cylinder block and to oil supply line (2) for the turbocharger. Oil from the turbocharger goes back through oil return line (3) to the oil pan.
Flow Of Oil (Engine Cold)
With the engine cold (starting conditions), oil comes from oil pan (6) through suction bell (9) to engine oil pump (7). When the oil is cold, an oil pressure difference in the bypass valves (installed in the engine oil filter housing) causes each valve to open. These bypass valves give immediate lubrication to all components when cold oil with high viscosity causes a restriction to the oil flow through the engine oil cooler (10) and engine oil filter (4). The engine oil pump then sends the cold oil through bypass valve (8) for the engine oil cooler and through bypass valve (5) for the engine oil filter to oil manifold (1) in the cylinder block and to supply line (2) for the turbocharger. Oil from the turbocharger goes back through oil return line (3) to the oil pan.
When the oil gets warm, the pressure difference in the bypass valves decreases and the bypass valves close. Now there is a normal oil flow through the engine oil cooler and engine oil filter.
The bypass valves will also open when there is a restriction in the engine oil cooler or engine oil filter. This action does not let an engine oil cooler or engine oil filter with a restriction prevent lubrication of the engine.
Oil Flow In The Engine
Engine Oil Flow Schematic
From oil manifold (7), oil is sent under pressure through drilled passages to the crankshaft main bearings (9). Oil goes through drilled holes in the crankshaft to give lubrication to the connecting rod bearings. A small amount of oil is sent through piston cooling tubes (8) to cool the pistons.
The sea/raw water pump gets oil from passage (2) in the cylinder block, through passages in the timing gear housing and the accessory drive gear.
The adjustable idler gear, fixed idler stub shaft and cluster idler gear gets oil from oil passages (4), (5), and (6) in the cylinder block through a passage in the idler gear shaft installed on the front of the cylinder block.
There is a pressure control valve in the engine oil pump. This valve controls the pressure of the oil coming from the engine oil pump. The engine oil pump can put more oil into the system than is needed. When there is more oil than needed, the oil pressure goes up and the valve will open. This allows the oil that is not needed to go back to the inlet oil passage of the engine oil pump.
Oil feeds into the cylinder head via a hollow locating dowel in the cylinder block top deck. Through drilled passages in the cylinder head, oil travels to camshaft bearing journals (3) and to the three center rocker arm shaft supports. These supports supply oil to each rocker shaft. Holes in the rocker arm shaft (1) allow lubricating oil to enter the valve and injector rocker arm bushings and rollers. Pressurized oil flows through drilled passages in the rocker arms to lubricate the roller, valve bridge and unit injector actuator contact surfaces. Splash oil lubricates the remaining valve system components.
After the lubricating oil has done its work, it goes back to the engine oil pan.
Cooling System
The 3406E Marine Engine has arrangements for heat exchanger cooling and keel cooling.
This engine has a pressure type cooling system equipped with a shunt line. A pressure type cooling system has two advantages. The first advantage is that the cooling system can operate safely at temperatures higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (the sudden making of low pressure bubbles in liquids by mechanical forces) in the water pump. In a pressurized system, it is more difficult for an air or steam pocket to form.
Heat Exchanger
There are two different circuits in the heat exchanger system. They include the jacket water circuit which is a closed system and the sea water circuit which is an open system.
Heat Exchanger Cooling Schematic
Jacket Water Circuit
The expansion tank (4) located behind the heat exchanger (23) stores the additional coolant volume and provides a pressure head on the jacket water pump inlet. The jacket water pump (15) sends engine coolant to the engine oil cooler (12) and then to the marine gear oil cooler (7) (if equipped). The coolant flow is then divided and part goes into the cylinder block (10) and up through the cylinder head (9), then forward to the front of the head and into the deaerator housing (13). The other part of the coolant flow goes to the watercooled turbocharger (1) and watercooled exhaust manifold (2), then flows forward into the deaerator housing (13). As the coolant enters the deaerator it swirls forcing the water to the outside and the air to the inside. The air returns to the expansion tank (4) through the vent line (6) and the engine coolant flows from the deaerator into the regulator (thermostat) housing (14). If the engine coolant is cold the thermostat remains closed and the coolant bypasses the heat exchanger (23) and goes to the jacket water pump (15). If the engine coolant is warm the thermostat opens and the coolant flows through the heat exchanger (23) and then to jacket water pump (15).
Shunt line (3) provides a positive pressure at the water pump inlet to prevent pump cavitation.
The vent line (6) is a line that allows the air, separated from the coolant in the deaerator housing (13), to return to the expansion tank (4).
Sea Water Circuit
Sea water is drawn into the system, passes through a strainer (19) and then to the fuel cooler (18) (if equipped). The auxiliary or sea water pump (17) moves the water through the sea water aftercooler (22) and then to the heat exchanger (23). Following the heat exchanger the sea water may flow through a marine gear oil cooler (11) (if equipped) or a water cooled exhaust elbow (8) (if equipped). The sea water is then discharged overboard.
Keel Cooled
The keel cooling system has two circuits. They include the jacket water circuit and a separate circuit for the aftercooler. The jacket water circuit is a closed system and the separate sea water circuit can be an open system or a closed system. In a keel cooled system the water flows through a keel cooler on the bottom of the vessel instead of the heat exchanger.
Keel Cooling Schematic (With A Closed Sea Water Circuit For The Aftercooler)
Jacket Water
The additional volume of engine coolant is typically stored in a expansion tank (4) located above the engine. This also provides a pressure head on the jacket water pump inlet. The jacket water pump (14) sends coolant to the engine oil cooler (12) and then to the marine gear oil cooler (11) (if equipped). The coolant flow is then divided and part goes into the cylinder block (10) and up through the cylinder head (9), then forward to the front of the head and into the deaerator housing (6). The other part of the coolant flow goes to the water cooled turbocharger (1) and water cooled exhaust manifold (2), the flows forward into the dearetor housing (6). As the coolant enters the dearator it swirls forcing the water to the outside and the air to the inside. The air returns to the expansion tank (4) through the vent line (5) and the engine coolant flows from the deaerator into the regulator (thermostat) housing (7). If the engine coolant is cold the thermostat remains closed and the coolant bypasses the engine coolant keel cooler (15) and goes to the jacket water pump (14). If the engine coolant is warm the thermostat opens and the coolant flows through the engine coolant keel cooler (15) and then to the jacket water pump (14).
Shunt line (3) provides a positive pressure at the water pump inlet to prevent pump cavitation.
The vent line (5) is a line that allows the air, separated from the coolant in the deaerator housing (6) to return to the expansion tank (4).
Separate Circuit
The separate aftercooler circuit in a keel cooled system can be an open circuit or a closed circuit.
In an open circuit, sea water is drawn into the system, passes through a strainer (if equipped) and then to the fuel cooler (if equipped). The auxiliary or sea water pump moves the water through the sea water aftercooler and is then discharged overboard.
In a closed circuit, coolant from the engine jacket water system is circulated by the auxiliary or sea water pump (18) to the sea water aftercooler (8) and through the fuel cooler (16) (if equipped). The coolant then flows through the separate circuit keel cooler (17) and is drawn up by the auxiliary or sea water pump (18).
Aftercooler Condensate Drain
An aftercooler condensate drain system is provided with the 3406E Marine engine. Under certain conditions, moisture can collect on the air side of the aftercooler core and pool in the bottom of the housing. If enough water collects in the housing, it could be drawn into the air inlet and cause engine damage. The conditions when this may occur are cold sea water, warm, humid air and the engine is stopped.
When a vessel that has been operating in cold water is shutdown the aftercooler core will also be cold. Moisture in the warm inlet air surrounding the core will collect on the fins, drip off and pool in the bottom of the aftercooler housing. This water is allowed to drain from the housing through the condensate drain (5). At the bottom of the drain is a check valve (6) which is open when the engine is stopped to allow the moisture to drain, but closes when the turbocharger boost pressure is present.
All 3406E Marine engines are equipped with the condensate drain (5), however most engines will not normally see conditions that will cause condensation. Nevertheless, the condensate drain (5) and check valve (6) should be regularly inspected to insure proper operation in the event that is needed. The volume of water that may drain from the aftercooler housing will be small and any additional installation work is unnecessary. Do not install a hose to the end to the drain that could be submerged in bilge water or collect debris.
Two condensate drain groups are available. The standard condensate drain is for engines mounted level or nose-up, which drains from the rear of the housing. An optional condensate drain is for nose down installations, which drains from the front of the housing.
Basic Block
Cylinder Block Assembly
The deep skirt cylinder block assembly has retained the rigidity ad durability found in the 3406C block. The primary change involves the removal of the camshaft and lifter bores and casting design changes to eliminate the push rod passages. Lubrication of bottom end components such as the crankshaft bearings and piston crowns is suppled by cast-in oil supply manifolds. The top deck of the block maintains the high piston top ring cooling passages found in the 3406C. This configuration also provides improved rigidity to resist deflection caused by combustion loads.
The cylinder lines are induction hardened and maintain the triple seal configuration at the bottom. A steel spacer plate provides improved reusability and durability. The spacer plate design eliminates block cracking problems prevalent with a counterbored block design.
Cylinder Head Assembly
The one piece cast iron cylinder head supports the camshaft for improved valve train rigidity. Steel backed aluminum bearings are pressed into each journal and are pressure lubricated. Bridge dowels have been eliminated as the valve train uses floating valve bridges.
The unit injector mounts into a stainless steel adapter pressed into the cylinder head injector bore. O-rings in addition to a tapered press fit, seal the fuel to coolant interface.
Pistons, Rings and Connecting Rods
The piston is a two piece articulated design consisting of a forged steel crown and a cast aluminum skirt. Both parts are retained by the piston pin to the small end of the connecting rod. An oil cooling chamber is formed by the lip forge at the top of the skirt of the piston and the cavity behind the ring grooves in the crown. Cooling jet oil flow enters the cooling chamber through a drilled passage in the skirt and returns to the sump through the clearance gap between the crown and skirt. The pistons have three rings located in grooves in the steel crown to seal combustion gas and provide oil control. The top ring is a barrel faced KEYSTONE type with plasma face coating. The second ring is taper faced and has a chrome plated face coating. The third ring, oil rings, is double railed, profile ground, and chromed face coated. The third ring as a coil spring expander. Four hoes drilled from the piston oil ring groove to the interior of the piston drain excess oil from the oil ring.
The connecting rod is a conventional design with the cap fastened to the shank portion by two bolts threaded into the shank. Each side of the small end of the connecting rod is machined at an angle of 12 degrees to fit within the piston cavity allowing maximum utilization of the available space for gas load.
Crankshaft
The crankshaft converts the cylinder combustion forces into rotating torque which powers equipment. On this engine a vibration damper is used at the front of the crankshaft to reduce torsional vibrations (twist on the crankshaft) that can cause damage to the engine.
The crankshaft drives a group of gears (front gear train) on the front of the engine. The front gear train provides power for the camshaft, water pump, oil pump, air compressor, and hydraulic pump.
The crankcase has seven main bearings to support the crankshaft, with two bolts holding the bearing cap to the block. Oil hoes and grooves in the upper bearing shell are located at all main bearing journals. The crankshaft has eight integral forged counterweights located at cheeks 1, 2, 5, 6, 7, 8, 11 and 12.
To seal the crankcase, crankshaft seals are installed in the front timing gear housing and the flywheel housing.
Camshaft
The camshaft has three lobes at each cylinder to operate the unit injector, exhaust valves, and the inlet valves. The camshaft is supported in the cylinder head by seven journals with aluminum bearings pressed into each journal. The camshaft gear contains integral roller dampers that counteract the torsional vibrations generated by the high injector operation pressure. This design reduces noise and increases gear train life. The camshaft is driven by an adjustable idler gear turned by a fixed idler gear which is turned by a cluster idler gear in the front gear train. Each bearing journal is lubricated from the oil manifold in the cylinder head. A thrust plated located at the front, positions the camshaft. Timing of the camshaft is accomplished by aligning marks on the crankshaft gear and idler gear, and camshaft gear with a mark on the front timing plate.
Electrical System
Reference
For the complete electrical system schematic, refer to the Electrical Schematic.
Grounding Practices
Grounding (-Battery Bus Bar Connections)
| NOTICE |
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All negative battery connections MUST have a common ground that terminates at the negative battery bus bar. Refer to Battery Circuit Requirements And considerations: Grounding in this guide for additional information. |
Proper grounding for vessel and engine electrical systems is necessary for engine/vessel performance and reliability. The problems with intermittent power connections are often very difficult to diagnose and repair.
| NOTICE |
|---|
Improper grounding will cause uncontrolled and unreliable circuit paths. This can result in damage to the engine crankshaft main bearings, crankshaft journal surfaces or other engine components. This may also cause electrical activity which may degrade vessel electronics and communication equipment. |
The alternator, starting motor, and all electrical systems MUST be grounded to -Battery. The alternator and starting motor must also meet marine isolation requirements. For engines which have an alternator grounded to an engine component, a ground strap MUST connect that component to -Battery and the component MUST be electrically isolated from the engine.
A Bus Bar with a direct path to -Battery is permissible and recommended to use for all common ground connections. Refer to Power Supply Connections to Start (Ignition) Switch(es) and Starting Motor in this guide for additional information.
Operator Station Grounding Connections
The engine ECM in the engine room must be connected to -Battery Bus Bar. Caterpillar recommends a dedicated bus bar for all engine ECM connected electronics as well. This connection ensures that the ECM and all components, including switches, sensors and electronic display modules have a common reference point.
Figure 1 - Operator Station Battery Grounding
Wire Size Requirements
The wire size (AWG) to battery bus bar to which components are grounded MUST be of adequate size to handle maximum current for the circuit.
Marine Engine Electronic Monitoring And Control System
Electrical System Ground Requirements
Proper grounding for vessel and engine electrical systems is necessary for proper performance and reliability.
| NOTICE |
|---|
Improper grounding will cause uncontrolled and unreliable circuit paths. This can result in damage to the engine's crankshaft main bearings, crankshaft journal surfaces or other engine components, and can cause electrical activity which may degrade the vessel's electronics and electrical communication equipment. |
Starting Motor And Alternator
The engine's starting motor MUST be grounded directly to -Battery post. The alternator and ALL electrical systems MUST be grounded to -Battery Bus Bar. The alternator and starting motor MUST meet marine society isolation requirements.
For engines which have the alternator grounded to an engine component, the component MUST be electrically isolated from the engine and a ground strap MUST connect that component to -Battery Bus Bar.
If equipped with an alternator ground plate, the ground plate should have a direct path to -Battery Bus Bar (common ground point).
The wire size from a ground plate MUST be of adequate size to handle full alternator charging current.
Engine Electrical System
The electrical system can have three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the battery are all common in each of the circuits.
The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output to keep the battery at full charge.
The starting circuit is in operation only when the start switch is activated.
The low amperage circuit and the charging circuit are both connected through the voltmeter. The starting circuit is not connected through the voltmeter.
Charging System Components
Alternator
This alternator is a three phase, brushless, self-rectifying charging unit, and the regulator is part of the alternator.
This alternator design has no need for slip rings or brushes, and the only part that has movement is the rotor assembly. The conductors are: the field winding, stator windings, six rectifying diodes, and the regulator circuit components.
The rotor assembly has many magnetic poles like fingers with air space between each opposite pole. The poles have residual magnetism (like permanent magnets) that produce a small amount of magnetic lines of force (magnetic field) between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced in the stator windings from the small magnetic lines of force made by the residual magnetism of the poles. This AC current is changed to direct current (DC) when it passes through the diodes of the rectifier bridge. Most of this current goes to charge the battery and to supply the low amperage circuit, and the remainder is sent on to the field windings. The DC current flow through the field windings. The DC current flow through the field windings (wires around an iron core) now increases the strength of the magnetic lines of force. These stronger lines of force now increase the amount of AC current produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator.
The voltage regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output.
| NOTICE |
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Never operate the alternator without the battery in the circuit. Making or breaking an alternator connection with heavy load on the circuit can cause damage to the regulator. |
Typical Alternator Components
Starting System Components
Solenoid
Typical Solenoid Schematic
A solenoid is an electromagnetic switch that does two basic operations.
- a. Closes the high current starting motor circuit with a low current start switch circuit.
- b. Engages the starting motor pinion with the ring gear.
The solenoid has windings (one or two sets) around a hollow cylinder. There is a plunger (core) with a spring load inside the cylinder that can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is made that pulls the plunger forward in the cylinder.
This moves the shift lever (connected to the rear of the plunger) to engage the pinion drive gear with the ring gear. The front end of the plunger then makes contact across the battery and motor terminals of the solenoid, and the starting motor begins to turn the flywheel of the engine.
When the start switch is opened, current no longer flows through the windings. The spring now pushes the plunger back to the original position, and at the same time, moves the pinion gear away from the flywheel.
When two sets of windings in the solenoid are used, they are called the hold-in winding and the pull-in winding. Both have the same number of turns around the cylinder, but the pull-in winding uses a larger diameter wire to produce a greater magnetic field. When the start switch is closed, part of the current flows from the battery through the hold-in winding, and the rest flows through the pull-in windings to motor terminal, then through the motor to ground. When the solenoid is fully activated (connection across battery and motor terminal is complete), current is shut off through the pull-in windings. Now only the smaller hold-in windings are in operation for the extended period of time it takes to start the engine. The solenoid will now take less current from the battery, and heat made by the solenoid will be kept at an acceptable level.
Electric Starting Motor
The starting motor is used to turn the engine flywheel fast enough to get the engine to start running.
The starting motor has a solenoid. When the start switch is activated, the solenoid will move the starting pinion to engage it with the ring gear on the flywheel of the engine. The starting pinion will engage with the ring gear before the electric contacts in the solenoid close the circuit between the battery and the starting motor. When the circuit between the battery and the starting motor is complete, the pinion will turn the engine flywheel. A clutch gives protection for the starting motor so that the engine can not turn the starting motor too fast. When the start switch is released, the starting pinion will move away from the ring gear.
Typical Starting Motor Cross Section