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| Illustration 1 | g00579961 |
3408 Engine Cooling System (1) Aftercooler. (2) Water from the turbocharger. (3) Water cooled turbocharger. (4) Separate circuit water pump. (5) Water to the turbocharger. (6) Engine oil cooler. (7) Connections for water outlet. (8) Temperature regulator housings. (9) Water cooled exhaust manifold. (10) Bypass lines. (11) Oil cooler bypass. (12) Water pump. (13) Water inlet connection | |
Jacket Water System
This engine has a pressure type cooling system. A pressure type cooling system provides two advantages. This cooling system can be operated safely at a temperature that is higher than the normal boiling point of water. This cooling system prevents cavitation in the water pump. It is more difficult for an air pocket or a steam pocket to form within the cooling system.
This engine can be cooled by a radiator or by a heat exchanger. The following explanation covers only the cooling circulation of the engine.
During normal operation, the water pump (12) receives coolant through the inlet connection (13). The coolant is sent to the engine oil cooler (6) and the oil cooler bypass (11). The oil cooler outlet sends the coolant from the cooler and the bypass to the water cooled turbocharger (3). The coolant is also sent to the engine cylinder block. Coolant that is in the turbocharger flows through line (5). From the turbocharger, the coolant returns to the water cooled exhaust manifold (9). The coolant flows through the cylinder block. The coolant flows upward through the cylinder heads. From the cylinder heads, the coolant flows to the water temperature regulator housings (8). Part of the coolant in housing (8) flows into the water cooled exhaust manifolds (9). Some of the coolant passes through the open temperature regulators. Some of the coolant passes through the outlet connections (7). The coolant is cooled in the temperature regulators, and in the outlet connections. The coolant in the exhaust manifold flows into the cylinder block and flows through the head. The coolant flows back to housing (8). The water pump (12) will pump the coolant through the engine. This water pump maintains the coolant flow.
Note: The water temperature regulator is an important part of the cooling system. The water temperature regulator divides the coolant flow between the radiator and the bypass lines (10). This will maintain the correct temperature. There is no mechanical control if the water temperature regulator is not installed in the system. The coolant will take a path of least resistance and the coolant will go through the bypass. This will cause the engine to overheat in hot weather. In cold weather, a small amount of coolant that goes through the radiator or the heat exchanger is too much coolant. The engine will not reach normal operating temperatures.
When the engine is cold, the water temperature regulators are closed. The coolant in the temperature regulator housings (8) flows through the bypass lines (10). From the bypass lines, the coolant flows to the water pump (12). The coolant continues to flow through the entire system but the coolant does not flow through the outlet connections.
Total system coolant capacity will depend on the size of the radiator or heat exchanger. Use the correct amount of permanent antifreeze and pure water. The correct amounts will provide freeze protection to the lowest expected outside temperature. Add a 3 percent to 6 percent concentration of corrosion inhibitor to the antifreeze.
Separate Circuit Aftercooler
The aftercooler (1) is cooled by a separate water circuit. This separate water circuit is used to maintain a specific water temperature and a constant water temperature. Water is pumped from the separate water supply by the pump (4). The water is pumped through the aftercooler and back to the water supply.