HEAD 9T3503 - Caterpillar

General Information
Illustration 1 g00328150
Air Inlet And Exhaust System Schematic (1) Air inlet. (2) Turbocharger. (3) Air inlet choke. (4) Aftercooler. (5) Main gas supply. (6) Cylinder head inlet port. (7) Precombustion chamber gas supply. (8) Precombustion chamber. (9) Spark plug. (10) Exhaust valve. (11) Exhaust. (12) Inlet valve. (13) Exhaust bypass control valve.The components of the air inlet and exhaust system control the quality and the amount of air that is available for combustion. The inlet manifold (air plenum) is a passage inside the cylinder block. This passage connects the aftercooler to the inlet ports in the cylinder head. The camshaft controls the movement of the valve system components. Air Inlet And Exhaust System Components
Illustration 2 g00328151
Air Inlet And Exhaust System (1) Exhaust manifold. (2) Aftercooler. (3) Air choke. (4) Exhaust outlet. (5) Engine cylinder. (6) Air inlet. (7) Turbocharger compressor wheel. (8) Turbocharger turbine wheel. (9) Exhaust bypass valve.Clean inlet air from the air cleaners is pulled through air inlet (6) into the turbocharger compressor by the turbocharger compressor wheel (7) . The rotation of the turbocharger compressor wheel causes the air to compress. The rotation of the turbocharger compressor wheel then forces the air through an elbow to the aftercooler (2) . The aftercooler lowers the temperature of the compressed air before the air enters the air plenum. This cooled and compressed air fills the air plenum. The air fills the inlet chambers in the cylinder heads. Air flow from the inlet chamber into the cylinder is controlled by the inlet valves. Fuel (gas) flow into the cylinder is controlled by the gas admission valve.There are five valves in each cylinder head. There is one gas admission valve (refer to System Operation, "Fuel System" ), two inlet valves and two exhaust valves for each cylinder. Make reference to "Valve System Components". The inlet valves and the gas admission valve, open when the piston moves down on the intake stroke.The camshaft controls the opening of the valves. The cooled, compressed air is pulled into the cylinder from the inlet chamber along with the gas that is supplied through the gas admission valve. The gas admission valves and the inlet valves close and the piston starts to move up on the compression stroke. When the piston is near the top of the compression stroke, the rich air fuel mix in the precombustion chamber has been leaned to a combustible mix and is ignited by the spark plug. The force of the combustion pushes the piston down on the power stroke. When the piston moves up again the piston is on the exhaust stroke. The exhaust valves open and the exhaust gases are pushed through the exhaust port into the exhaust manifold (1) . After the piston makes the exhaust stroke, the exhaust valves close. The cycle (intake, compression, power, exhaust) starts again.Exhaust gases from the exhaust manifold