11971 Mercruiser NUT, OIL PAN STUD

Engine Specifications
Note: The front end of the engine is opposite the flywheel end of the engine. The left and the right sides of the engine are determined from the flywheel end. The number 1 cylinder is the front cylinder.
Illustration 1 g01387009
Cylinder and valve location
(A) Exhaust valve
(B) Inlet valve
Table 1
C15 Engine Specifications
Arrangement and Cylinders In-line six cylinder
Bore 137 mm (5.4 inch)
Stroke 171 mm (6.7 inch)
Aspiration ATAAC(1)
Displacement 15.2 L (928 cubic inch)
Firing Order 1-5-3-6-2-4
Rotation (flywheel end) Counterclockwise
(1) Air-to-air aftercooled
Table 2
C18 Engine Specifications
Arrangement and Cylinders In-Line six cylinder
Bore 145 mm (5.7 inch)
Stroke 183 mm (7.2 inch)
Aspiration ATAAC(1)
Displacement 18.1 L (1105 cubic inch)
Firing Order 1-5-3-6-2-4
Rotation (flywheel end) Counterclockwise
(1) Air-to-air aftercooledElectronic Engine Features
The Caterpillar C15 and C18 Engine are designed for electronic controls. The integral on board computer controls the operation of the engine. Current operating conditions are monitored. The Electronic 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
Aftertreatment control
Exhaust gas recirculation (EGR) reduction system controlAdditional Features
The following additional features provide increased engine fuel economy and serviceability:
Cold starting capability
Tampering detection
DiagnosticsEngine Diagnostics
The engine has built-in diagnostics to ensure that all the components are functioning properly. Under certain conditions, the engine horsepower and the vehicle speed may be limited. A Caterpillar electronic service tool may be used to display the diagnostic code.There are two categories of codes: diagnostic code and event code. These two categories of codes may be in two different states: active and logged.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).Aftertreatment
C15 and C18 engines are equipped with a clean emissions module (CEM) to meet Tier IV and Stage V emissions standards. The CEM includes:
Diesel oxidation catalyst (DOC)
Diesel particulate filter (DPF)
Selective catalyst reduction (SCR)
Aftertreatment regeneration device (ARD)Note: The C18 engines rating above 560 kW does not have a CEM, as it can meet emissions standards without a CEM.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 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 Caterpillar Engines
When auxiliary devices, accessories, or consumables (filters, additives, catalysts, etc.) which are made by other manufacturers are used on Caterpillar products, the Caterpillar warranty is not affected simply because of such use.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.