Engine Systems
water used. Soft water plus rust inhibitor or high
Heat Exchanger Cooling
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
When foreign deposits accumulate in the heat
exchanger and is forced through the engine oil cooler,
exchanger, to the extent that cooling efficiency is
impaired, such deposits can, in most instances, be
to the thermostat housings. A by-pass tube from the
removed by circulating a flushing compound through
thermostat housings to the inlet side of the water
the fresh water circulating system without removing
pump permits circulation of the coolant through the
the heat exchanger. If this treatment does not restore
engine while the thermostats are closed. When the
the engine's normal cooling characteristics, contact an
thermostats open, the coolant can flow through the
authorized Detroit Diesel Allison Service Outlet.
heat exchanger and then, after being cooled, to the
engine fresh water pump for recirculation.
Keel Cooling
While passing through the core of the heat exchanger,
the coolant temperature is lowered by raw water which
In the keel cooling system, the coolant is drawn by the
is drawn by the raw water pump from an outside
fresh water pump from the keel cooler and is forced
supply. The raw water enters the heat exchanger at
through the engine oil cooler, cylinder block, cylinder
one side and is discharged at the opposite side.
heads, exhaust manifolds and to the thermostat
housings. A by-pass tube from the thermostat
To protect the heat exchanger element from
housings to the inlet side of the water pump permits
electrolytic action, a zinc electrode is located in both
circulation of coolant through the engine while the
the heat exchanger inlet elbow and the raw water
thermostats are closed. When the thermostats open,
pump inlet elbow and extends into the raw water
the coolant can flow through the keel cooling coils and
passage.
then to the suction side of the fresh water pump for
re-circulation.
The length of time a heat exchanger will function
The heat of the engine coolant is transferred through
satisfactorily before cleaning will be governed by the
the coils of the keel cooler to the surrounding water.
kind of coolant used in the engine and the kind of raw
ENGINE COOLING SYSTEM MAINTENANCE
For the recommended coolant, refer to the section on
Engine Coolant
Engine Coolant.
The function of the engine coolant is to absorb the
heat, developed as a result of the combustion process
Cooling System Capacity
in the cylinder, from the component parts such as
The capacity of the basic engine cooling system
surrounded by water jackets. In addition, the heat
(cylinder block, head, water manifold, thermostat
absorbed by the oil is also removed by the engine
housing and oil cooler housing) is shown in Table 1.
coolant in the oil-to-water cooler.
To obtain the complete amount of coolant in the
COOLING SYSTEM CAPACITY
cooling system of a unit, the additional capacity of the
(BASIC ENGINE)
radiator, hoses, etc. must be added to the capacity of
the basic engine. The capacity of radiators and related
*WBP Block
Former Block
Engine
equipment should be obtained from the equipment
gallons
litres
litres
gallons
supplier.
7
27
21
5-1/2
6V
10
38
29
7-3/4
8V
Fill Cooling System
13-3/4
52
40
101/2
12V
19-3/4
75
15-1/2
59
16V
Before starting the engine, close all of the drain cocks
*Water-below-port cylinder block
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.
TABLE 1
The use of clean, soft water will eliminate the need for
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