ENGINE AR-COMPLETE 3787386 - Caterpillar

Illustration 1 g03723080
The dashed lines with arrows represent air flow and the solid lines with arrows represent coolant flow.
(1) Air cleaner
(2) Engine
(3) Aftercooler
(4) Turbocharger compressor
(5) Separate circuit aftercooler (SCAC) thermostat
(6) Turbocharger turbine
(7) Jacket water pump
(8) SCAC water pump
(9) Radiator
(10) SCAC heat exchanger Fresh air is drawn through air cleaner (1) into turbocharger compressor (4). The air is compressed and the air is warmed by the compression. The compressed air flows through aftercooler (3) where the compressed air is cooled by the flow of jacket water and separate circuit aftercooler water. The cooled, compressed air becomes more dense, enabling engine (2) to burn more fuel in order to provide more power. The exhaust from the engine flows through turbocharger turbine (5), which provides the energy that operates the turbocharger compressor.Jacket water pump (6) forces some of the coolant through the engine coolant passages. The coolant circulates through the engine and the engine exchanges heat with the coolant. Block outlet coolant flow is divided and an orifice forces part of the coolant directly to the thermostats, and the remainder of the coolant is routed through the top core of the aftercooler where the warm compressed air exchanges heat with the coolant. The coolant then flows to the thermostat housing and combines with the rest of the block outlet coolant. Air from the fan blows through radiator (9) in order to cool the coolant. The coolant is drawn back through the water pump.The compressed air then passes through two additional cores where the compressed air exchanges heat with the SCAC water, before flowing into the intake manifold. The SCAC water flows from SCAC water pump (8) to the lower section of the aftercooler, and the flow is split. The SCAC water flows through the center of the lower cores, loops within the aftercooler housing, then passes through the middle cores, and exists out the center. The SCAC water is carried to SCAC thermostats (5) and is either directed to the heat exchanger (10) or bypassing back to the SCAC water pump.