DETROIT DIESEL Engine Systems Heat Exchanger Cooling water used. Soft water plus rust inhibitor or high boiling point type antifreeze should be used as the engine coolant. In the heat exchanger cooling system, the coolant is drawn by the fresh water pump from the heat exchanger and is forced through the engine oil cooler, cylinder block, cylinder heads, exhaust manifolds and to the thermostat housings. A by-pass tube from the thermostat housings to the inlet side of the water pump permits circulation of the coolant through the engine while the thermostats are closed.
When the thermostats open, the coolant can flow through the heat exchanger and then, after being cooled, to the engine fresh water pump for re-circulation. When foreign deposits accumulate in the heat exchanger, to the extent that cooling efficiency is impaired, such deposits can, in most instances, be removed by circulating a flushing compound through the fresh water circulating system without removing the heat exchanger. If this treatment does not restore the engine’s normal cooling characteristics, contact an authorized Detroit Diesel Allison Service Outlet.
While passing through the core of the heat exchanger, the coolant temperature is lowered by raw water which is drawn by the raw water pump from an outside supply. The raw water enters the heat exchanger at one side and is discharged at the opposite side. Keel Cooling In the keel cooling system, the coolant is drawn by the fresh water pump from the keel cooler and is forced through the engine oil cooler, cylinder block, cylinder heads, exhaust manifolds and to the thermostat housings. A by-pass tube from the thermostat housings to the inlet side of the water pump permits circulation of coolant through the engine while the thermostats are closed.
When the thermostats open, the coolant can flow through the keel cooling coils and then to the suction side of the fresh water pump for re-circulation. To protect the heat exchanger element from electrolytic action, a zinc electrode is located in both the heat exchanger inlet elbow and the raw water pump inlet elbow and extends into the raw water passage. The length of time a heat exchanger will function satisfactorily before cleaning will be governed by the kind of coolant used in the engine and the kind of raw The heat of the engine coolant is transferred through the coils of the keel cooler to the surrounding water.
ENGINE COOLING SYSTEM MAINTENANCE Engine Coolant For the recommended coolant, refer to the section on Engine Coolant. The function of the engine coolant is to absorb the heat, developed as a result of the combustion process in the cylinder, from the component parts such as exhaust valves, cylinder liners, and pistons which are surrounded by water jackets. In addition, the heat absorbed by the oil is also removed by the engine coolant in the oil-to-water cooler. Cooling System Capacity The capacity of the basic engine cooling system (cylinder block, head, water manifold, thermostat housing and oil cooler housing) is shown in Table 1.
COOLING SYSTEM CAPACITY To obtain the complete amount of coolant in the cooling system of a unit, the additional capacity of the radiator, hoses, etc. must be added to the capacity of the basic engine. The capacity of radiators and related equipment should be obtained from the equipment supplier. (BASIC ENGINE) Engine gallons litres ‘WBP Block 6V 7 27 12v 8V 13-314 52 7-3/4 29 “16VTl 16V 19-314 75 22 83 Fill Cooling System *Water-below-port cylinder block Before starting the engine, close all of the drain cocks and fill the cooling system with water. If the unit has a raw water pump, it should also be primed, since operation without water may cause impeller failure.
The use of clean, soft water will eliminate the need for ‘*Estimated TABLE 1 Page 27