HOUSING 3W3828 - Caterpillar

The engine components of the air inlet and exhaust system control the quality of air and the amount of air that is available for combustion. The components of the air inlet and exhaust system are the following components:
Air cleaner
Turbochargers
Precooler
Aftercooler (If equipped)
Cylinder head
Valves and valve system components
Piston and cylinder
Exhaust manifold
Clean Gas Induction (CGI) cooler
Diesel Particulate Filter (DPF)
Valve for the Combustion Air
Aftertreatment Regeneration Device (ARD)The low pressure turbocharger compressor wheel pulls the inlet air through the air cleaner and into the air inlet. The air is compressed by the low pressure turbocharger. Pressurizing the inlet air causes the air to heat up. The pressurized air exits the low pressure turbocharger through the outlet and the air is forced into the inlet of the high pressure turbocharger.The high pressure turbocharger is used in order to compress the air to a higher pressure. This increase in pressure continues to cause the inlet air's temperature to increase. As the air is compressed, the air is forced through the high pressure turbocharger's outlet and into the air lines to the precooler.The pressurized inlet air is cooled by the precooler prior to being sent to the aftercooler. The precooler uses engine coolant to cool the air. Without the precooler, the inlet air would be too hot in order to be cooled sufficiently by the aftercooler. The inlet air then enters aftercooler core. The inlet air is cooled further by transferring heat to the ambient air. The combustion efficiency increases as the temperature of the inlet air decreases. Combustion efficiency helps to provide increased fuel efficiency and increased horsepower output. The aftercooler core is a separate cooler core that is mounted in front of the engine radiator. The engine fan and the ram effect of the forward motion of the vehicle causes ambient air to move across the core.Inlet air is forced from the aftercooler into the engine's intake manifold. The air flow from the intake manifold into the cylinders and out of the cylinders is controlled by engine's valve mechanisms.Each cylinder has two inlet valves and two exhaust valves that are mounted in the cylinder head. The inlet valves open when the piston moves downward on the inlet stroke. When the inlet valves open, cooled, compressed air from the intake manifold is pulled into the cylinder. The inlet valves close when the piston begins to move upward on the compression stroke. The air in the cylinder is compressed by the piston. As the air is compressed by the piston, the temperature of the air in the cylinder is heated. Fuel is injected into the cylinder when the piston is near the top of the compression stroke. Combustion begins when the fuel mixes with the hot, pressurized air. The force of combustion pushes the piston downward on the power stroke. The exhaust valves are opened as the piston travels upward to the top of the cylinder. The exhaust gases are pushed through the exhaust port into the exhaust manifold. After the piston completes the exhaust stroke,