12239A 1 Mariner CAM FOLLOWER ASSEMBLY

Illustration 1 g03876527
Air inlet and exhaust system
(1) Air-to-air aftercooler (ATAAC)
(2) Exhaust manifold
(3) Turbocharger
(4) Clean Emissions Module (CEM)
(5) NOx Reduction System (NRS) cooler
(6) NRS venturi
(7) NRS valve
(8) Exhaust valve solenoid
(9) Intake manifold
(10) Cylinder headThe engine has an electronic control system. The system controls the operation of the engine and communicates with the Clean Emissions Module (CEM) Aftertreatment Electronic Control Module (ECM). The CEM consists of the following components: Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and systems.The system consists of the following components:
Electronic Control Module (ECM)
Wiring
Sensors
ActuatorsInlet air is pulled through the air cleaner . The inlet air is then compressed and heated by the compressor wheel of turbocharger to about 150 °C (300 °F). The inlet air is then pushed through air-to-air aftercooler core and the inlet air is moved to the air inlet elbow. The temperature of the inlet air at air inlet elbow is about 43 °C (110 °F). Cooling of the inlet air increases the combustion efficiency. Increased combustion efficiency helps to lower fuel consumption. Also, increased combustion efficiency helps to increase horsepower output.Aftercooler core is a separate cooler core. The aftercooler core is installed in front of the core of the engine radiator. Air that is ambient temperature is moved across the aftercooler core by the engine fan. The aftercooler core cools the turbocharged inlet air.From 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.
Illustration 2 g01880505
Air inlet and exhaust system
(11) NRS cooler
(12) Exhaust manifold
(13) Aftercooler
(14) Exhaust outlet from turbocharger
(15) Turbine side of turbocharger
(16) Compressor side of turbocharger
(17) Air inlet
(18) Inlet valve
(19) Exhaust valveThere are two inlet valves 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 will 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. During the power stroke, the combustion force pushes the piston downward. After the power stroke is complete, the piston moves upward. This upward movement is the exhaust stroke. During the exhaust stroke, the exhaust valves open, and the exhaust gases are pushed through the exhaust port into the exhaust manifold. After the piston completes the exhaust stroke, the exhaust valves close and the cycle will start again. The complete cycle consists of four stages:
Inlet stroke
Compression stroke
Power stroke
Exhaust strokeExhaust gases from the exhaust manifold enter the turbine side of turbocharger to turn the turbine wheel. The turbine wheel is connected to a shaft which drives the compressor wheel. Exhaust gases from the turbocharger pass through the exhaust outlet pipe, the muffler, and the exhaust stack.NOx Reduction System (NRS)
The NRS sends hot exhaust gas from the exhaust manifold that is connected to cylinders one, two, and three through the NRS system. In order for exhaust gas to be able to mix with pressurized air from the ATAAC, back pressure is needed in the exhaust system. This back pressure is created by the turbocharger and DPF. The hot exhaust gas is first cooled in the NRS cooler. The now cooled exhaust gas passes through the NRS venturi. The venturi takes a measurement of the flow of exhaust gas through the NRS system. After the gas flow is measured by the NRS venturi, the gas flows through the electronically controlled NRS valve. The electronic controlled NRS valve is hydraulically actuated. When the NRS valve is in the full OFF position, the only source of air is from the turbocharger compressor. As the valve starts to open the flow of cooled exhaust gas from the NRS cooler mixes with the air flow from the turbocharger. As the demand for more cooled exhaust gas increases, the valve opens wider. The increase in the flow of cooled exhaust gas from the NRS cooler. As the demand for more cooled exhaust gas increases, the demand for air flow from the engines turbocharger decreases.Turbocharger
Illustration 3 g01945375
Turbocharger
(20) Air inlet
(21) Compressor housing
(22) Compressor wheel
(23) Bearing
(24) Oil inlet port
(25) Bearing
(26) Turbine housing
(27) Small path
(28) Balance Valve chamber
(29) Large path
(30) Turbine wheel
(31) Exhaust outlet
(32) Oil outlet portThe turbocharger is installed on the exhaust manifold. Most of the exhaust gases flow through the turbocharger. A metered amount of exhaust gases flow through the NRS system. The compressor side of the turbocharger is connected to the aftercooler by a pipe.The exhaust gases go into turbine housing (26) through the exhaust inlet. The turbine housing of the turbocharger is of the asymmetric design. The asymmetric design consists of the turbine housing that has two different-sized paths for the exhaust to flow. Path (27) receives exhaust gas from cylinders one, two, and three. Path (29) receives exhaust gas from cylinders four, five, and six. The smaller path restricts the flow of the exhaust. This restriction helps force the exhaust gas through the NRS system to the intake manifold of the engine. The energy from the heat in the exhaust gases pushes the blades of turbine wheel (30). The turbine wheel is connected by a shaft to compressor wheel (22). The turbine housing also contains the exhaust balance valve and the actuator for the exhaust balance valve. The actuator for the exhaust balance valve receives boost pressure from the intake manifold. This boost pressure is first regulated by the solenoid for the exhaust balance valve. The exhaust balance valve solenoid will open allowing the boost pressure to act on the exhaust balance valve actuator if the valve needs to open. The actuator then opens the exhaust balance valve. The exhaust balance valve allows the flowing exhaust gas from the small path of the turbine housing to enter the large path. This action causes less exhaust gas to act on the turbine wheel