C7 Engine Specifications
The Cat C7 engines are designed primarily for medium-duty applications. The engines have the following characteristics: air-to-air aftercooled, common fuel rail, four-stroke cycle, in-line six-cylinder and turbocharged.
Illustration 1 | g01075672 |
Cylinder and valve location (A) Exhaust valve (B) Inlet valve |
C7 Engine Specifications     | |
Arrangement and Cylinders     | In-Line six-cylinder     |
Bore     | 110 mm (4.3 inch)     |
Stroke     | 127 mm (5.0 inch)     |
Aspiration     | ATAAC (1)     |
Displacement     | 7.2 L (440 in3)     |
Firing Order     | 1-5-3-6-2-4     |
Rotation (flywheel end)     | Counterclockwise     |
( 1 ) | Air-to-air aftercooled |
C9 Engine Specifications
The Cat C9 Engine is designed for medium-duty applications. The engine has the following characteristics: air-to-air aftercooled, direct fuel injection, four-stroke cycle, in-line six-cylinder and turbocharged.
Illustration 2 | g00609479 |
Cylinder and valve location (A) Exhaust valve (B) Inlet valve |
C9 Engine Specifications     | |
Arrangement and Cylinders     | In-Line six-cylinder     |
Bore     | 112.0 mm (4.41 inch)     |
Stroke     | 149.0 mm (5.87 inch)     |
Aspiration     | ATAAC (1)     |
Displacement     | 8.8 L (537 in3)     |
Firing Order     | 1-5-3-6-2-4     |
Rotation (flywheel end)     | Counterclockwise     |
( 1 ) | Air-to-air aftercooled |
Electronic Engine Features
The Cat C7 and C9 Engines are designed for electronic controls. The integral on board computer controls the operation of the engine. Current operating conditions are monitored. The Engine Control Module (ECM) controls the response of the engine to these conditions and to the demands of the operator. These conditions and operator demands determine the precise control of fuel injection by the ECM. The electronic engine control system provides the following features:
- Engine speed governor
- Automatic air/fuel ratio control
- Torque rise shaping
- Injection timing control
- System diagnostics
The following programmable features are included in the electronic control:
- Cruise control
- Governing of the PTO
- Vehicle speed limiter
- Fast idle
Additional Features
The following additional features provide increased engine fuel economy and serviceability:
- Cold starting capability
- Tampering detection
- Diagnostics
- Idle shutdown timer
- American Trucking Association (ATA) data link (SAE J1587)
- Society of Automotive Engineers (SAE) data link (SAE J1939)
Engine Diagnostics
The engine has built-in diagnostics in order to ensure that all of the components are functioning properly. If a deviation from the programmed limits occurs, the operator is alerted to the condition by a "DIAGNOSTIC" lamp that is mounted on the dashboard. Under certain conditions, the engine horsepower and the vehicle speed may be limited. A Cat electronic service tool may be used to display the diagnostic code.
There are four types of diagnostic codes: active, logged, event and critical event.
Most of the diagnostic codes are logged and stored in the ECM. For additional information, refer to the Operation and Maintenance Manual, "Engine Diagnostics" topic (Operation Section).
The ECM provides an electronic governor that controls the injector output in order to maintain the desired engine rpm. The functionality of electronic governor is similar to the Cat mechanical governor, but the electronic governor includes additional features.
For more information on electronic engine features, refer to the Operation and Maintenance Manual, "Engine Features and Controls" topic (Operation Section).
Engine Cooling and Lubrication
The cooling system consists of the following components:
- Centrifugal pump that is driven by belts
- Water temperature regulator which regulates the engine coolant temperature
- Oil cooler and radiator which incorporates a shunt system
The engine lubricating oil that is supplied 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 that is demanded. The average power that is demanded is based on fuel consumption of the engine over a 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. For more information, refer to the Operation and Maintenance Manual, "Overhaul Considerations" topic (Maintenance Section).
Aftermarket Products and Cat Engines
When auxiliary devices, accessories, or consumables (filters, additives, catalysts, etc.) which are made by other manufacturers are used on Cat products, the Caterpillar warranty is not affected simply because of such use.
NOTICE |
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In order to meet expected fuel system component life, 4 micron(c) absolute or less secondary fuel filtration is required for all Cat Diesel Engines that are equipped with unit injected fuel systems. All current Cat Diesel Engines are factory equipped with Cat Advanced Efficiency 4 micron(c) absolute fuel filters. Caterpillar does not warrant the quality or performance of non-Cat fluids and filters. |
However, failures that result from the installation or use of devices, accessories, or consumables from other manufacturers are NOT Caterpillar defects. Therefore, the defects are NOT covered under the Caterpillar warranty.