VALVE 2990840 - Caterpillar

Illustration 1 g06237563
Air inlet and exhaust system
(1) Air-to-air aftercooler (ATAAC)
(2) Exhaust manifold
(3) Turbocharger
(4) Clean Emissions Module (CEM)
(5) Intake manifold
(6) Cylinder headThe engine has an electronic control system. The system controls the operation of the engine and Clean Emissions Module (CEM). The CEM consists of the following components: Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and electrical system components.Inlet 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. As the air flows through the aftercooler, the temperature of the compressed air lowers to about 50° C (122° F). Cooling of the inlet air assists the combustion efficiency of the engine. Increased combustion efficiency helps to lower fuel consumption and increase power 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 intake manifold. Air flow from the inlet manifold into the cylinders is controlled by the inlet valves.
Illustration 2 g06237576
(7) Exhaust manifold
(8) Air inlet heater
(9) Aftercooler core
(10) Exhaust valve
(11) Inlet valve
(12) Air inlet
(13) Exhaust outlet
(14) Compressor side of turbocharger
(15) Turbine side of turbochargerThere 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.Turbocharger
Illustration 3 g06237584
(1) Air intake
(2) Compressor housing
(3) Compressor wheel
(4) Bearing
(5) Oil inlet port
(6) Bearing
(7) Turbine housing
(8) Turbine wheel
(9) Exhaust outlet
(10) Oil outlet
(11) Exhaust inletThe turbocharger is installed on the center section of the exhaust manifold. All the exhaust gases from the engine go through the turbocharger. The compressor side of the turbocharger is