MANIFOLD (EX.) 4L3008 - Caterpillar

Aftercooler
The aftercooler is located at the center of the vee. The aftercooler has a coolant charged core assembly (assemblies). Coolant from the water pump flows through a pipe into the aftercooler. Coolant then flows through the core assembly (assemblies). Coolant flows back out the aftercooler through a different pipe.Inlet air from the compressor side of the turbochargers flows into the aftercooler through pipes. The air then passes through the fins of the core assembly (assemblies) which lowers the temperature. The cooler air flows out of the bottom of the aftercooler and into the air chamber. The air flows through the elbows to the inlet ports (passages) in the cylinder heads.Turbocharger
Two turbochargers are used on the top of the engine. A turbocharger is located on each side of the vee. The turbine side of each turbocharger is mounted to the respective exhaust manifold. The compressor side of each turbocharger is connected by pipes to the top of the aftercooler housing.
Illustration 4 g00281664
Turbocharger (Typical Example) (1) Compressor wheel. (2) Bearing. (3) Oil inlet. (4) Bearing. (5) Turbine wheel. (6) Exhaust outlet. (7) Air inlet. (8) Coolant passages. (9) Oil outlet. (10) Exhaust inlet.The exhaust gases go into the exhaust inlet (10) of the turbine housing. The gases push the blades of turbine wheel (5). The turbine wheel and the compressor wheel turn at speeds up to 90,000 rpm.Clean air from the air cleaners is pulled through the compressor housing air inlet (7) by the rotation of the compressor wheel (1). The action of the compressor wheel blades causes a compression of the inlet air. This compression gives the engine more power because the compression allows the engine to burn additional fuel with greater efficiency.The maximum speed of the turbocharger is controlled by the engines electronic control of fuel delivery. When the engine is operating, the height above the sea level also controls the maximum speed of the turbocharger.Bearing (2) and bearing (4) in the turbocharger use engine oil under pressure for lubrication. The oil is sent through the oil inlet line to oil inlet (3) at the top. The oil then goes through passages in the center section for lubrication of the bearings. The oil goes out of oil outlet (9) at the bottom. The oil then goes back to the engine block through the drain line.The bearing housing in the turbocharger is also cooled by the jacket water coolant. Coolant from the coolant inlet line enters the side of the center section. The coolant travels through the coolant passages (8) in the bearing housing. The coolant then leaves the turbocharger at the other side of the center section. The coolant outlet lines then take the coolant back to the jacket water radiator top tank.Series Turbocharger System
Illustration 5 g00287174
Series Turbocharger System (1) Low-pressure turbochargers. (2) High-pressure turbochargers.The 793C engine is equipped with a series turbocharger system. The clean air from the filters enters the large low-pressure turbochargers (1). The compressed air from the low-pressure turbochargers flows to the inlet of the smaller