DDFP SERIES ENGINES FOR FIRE PUMP APPLICATIONS MP-4. Manual - part 8

DDFP

SECTION 3.3

Page 24

OIL VOLUME

For specific oil quantities please refer to Technical Data Sec-

tion 5 for each engine model listing.

Fig. 5 - Typical Oil Fill Location

▼

COOLING SYSTEM

SECTION 3.4

DDFP

Page 25

The Engine Cooling System Includes:

Coolant Pump

Heat Exchanger with Overflow Pipe

Oil Cooler

Pressure Cap-Fill Cap

Thermostat & Water Bypass

Raw Water Inlet and Discharge

Zinc Electrode

V-92

I-53

OPERATION

The heat resulting from combustion in the engine cannot be

fully converted into kinetic ener gy. A major portion of that

heat is absorbed by the coolant from the c ylinder walls and

cylinder heads and must be carried away from the engine. It

is the function of the Heat Exchanger to transfer w

aste

engine heat to the raw cooling water.

Inside the heat e xchanger tank Fig.  1 is a heat e xchanger

core, somewhat similar to a miniature radiator

. Engine

coolant circulates around the heat exchanger core while cool

raw water, from a tap on the pressure side of the f ire pump,

is circulated inside the core carrying a way the heat. The in-

stalling contractor mak es the ra w water discharge connec-

tion at time of system installation.

Fig. 1 - Heat Exchanger Cooling System

I-71

V-71

DDFP

SECTION 3.4

Page 26

Engine coolant is circulated by the engine coolant pump.

Engine coolant enters the side of the block upon dischar ge

from the oil cooler and coolant pump. Under lo w pressure,

the coolant flo ws past the c ylinders, up through the heads,

and then through the open thermostat into the heat exchang-

er tank.  After passing o ver the heat e xchanger core, the

coolant then re-enters the coolant pump and starts the c ycle

over. If the thermostat is closed, coolant would flow down a

bypass tube, back to the coolant pump. Under that condition,

the coolant bypasses the heat exchanger core and allows the

engine to retain some of the heat so it can quickly reach opti-

mum operating temperature.

ENGINE COOLANT

The following information is provided as a guide for Detroit

Diesel engine users in the selection of a suitable coolant.

The water/ethylene glycol/inhibitor coolant mixture used in

DDFP engines must meet the following basic requirements:

• Provide for adequate heat transfer.

• Provide protection from cavitation damage.

• Provide a corrosion/erosion resistant environment within

the cooling system.

• Prevent formation of scale or sludge deposits in the cool-

ing system.

• Be compatible with engine hose and seal materials.

• Provide adequate freeze and boil over protection.

WARNING
A 50% water and 50% anti-freeze solution is
required for pump installations. Premixing
this solution prior to installing is required.
This prevents possible pure anti-freeze chem-
ical reactions to block heater elements which
can burn out the element. Please see the tech-
nical data Section 5 for proper cooling sys-
tem capacities of each model.

WATER

Water can produce a corrosi ve environment in the cooling

system, and the mineral content may permit scale deposits to

form on internal cooling surfaces. Therefore, inhibitors must

be added to control corrosion, cavitation, and scale deposits.

Chlorides, sulfates, magnesium and calcium are among the

materials which mak e up dissolv ed solids that may cause

scale deposits, sludge deposits, corrosion or a combination

of these. Chlorides and/or sulf ates tend to accelerate corro-

sion, while hardness (percentage of magnesium and calcium

salts broadly classif ied as carbonates) causes deposits of

scale. Water within the limits specif ied in Fig. 2 is satisfac-

tory as an engine coolant when properly inhibited. Use of

distilled water is ideal.

ANTIFREEZE

Use an eth ylene glycol coolant (lo w silicate formulation)

that meets or exceeds the standard of either the GM 6038-M

formulation (GM 1899-M performance) or  ASTM D 4985

requirements.

A 50% coolant/water solution is normally used. Concentra-

tions over 70% are not recommended because of poor heat

transfer capability, adverse freeze protection and possible

silicate dropout. Concentrations belo w 30% of fer little

freeze, boil over or corrosion protection.

COOLANT INHIBITOR

The importance of a properly inhibited coolant cannot be

over-emphasized.  A coolant which has insuf ficient or no

inhibitors at all, invites the formation of rust, scale, sludge

and mineral deposits. These deposits can greatly reduce the

cooling systems efficiency and protection capabilities.

DDC-recommended supplemental coolant inhibitors are a

combination of chemical compounds which pro vide corro-

sion protection, cavitation suppression, pH controls and pre-

vent scale.  These inhibitors are a vailable in v arious forms,

such as liquid packages or integral parts of anti-freeze.

It is imperative that supplemental inhibitors be added to all

DDFP engine systems. A pre-charge dosage must be used at

the initial fill and the maintenance dosage used at each ser-

vice interval. Serious damage will occur unless inhibitors

are used. Some of the more common corrosion inhibitors

are borates, nitrates and silicates.

Inhibitors become depleted through normal operation, addi-

tional inhibitors must be added to the coolant as required to

maintain original strength levels. Refer to Fig. 3 for proper

concentrations of inhibitors.

Do not use soluble oils or chromate inhibitors in DDFP

engines. Detrimental effects will occur.

Chlorides (Maximum)

Sulfates (Maximum)

Total Dissolved Solids (Maximum)

Total Hardness (Maximum)

PARTS PER

MILLION

2.5

5.8

20

10

40

100

340

170

GRAINS PER

GALLON

Fig. 2 Satisfactory Water Limits

SECTION 3.4

DDFP

Page 27

Max.
PPM

Boron (B)

Nitrite (NO2)

Nitrates (NO3)

Silicon (Si)

Phosphorous (P)

pH

1000

800

1000

50

300

8.5

Min.

PPM

1500

2400

2000

250

500

10.5

To properly check inhibitor concentrations it may be neces-

sary to contact your local DDC Distributor/Dealer for assis-

tance. Refer to P arts Information Section 6, Page 45, to

obtain the DDC part number for the F

actory Coolant

Analysis Kit. This kit can be purchased for nominal fee for

analyzing the condition of the engine's coolant.

PROCEDURE FOR FILLING ENGINE

During filling of the cooling system, air pockets may form.

The system must be pur ged of air prior to being put in ser-

vice.  This is best accomplished by f illing with a pre-mix

solution, to the top of f iller neck. Install the pressure cap,

start and run engine until the temperature staabilizes at

approximately 170° - 190° F (77° - 91° C). During this

warming process, you may

see coolant coming from the o verflow tube attached at the

pressure cap location.  This is a normal condition since the

coolant expands as it heats up.  When the o verflow ceases,

stop the engine.

NOTE:

Air entrapment in I-53 engines is v ery lik ely to

occur due to cooling system design. Upon initial

fill with a pre-mix solution. It is recommended that

the coolant be allowed to stand for a four hour peri-

od prior to starting.

To verify that the coolant is at a safe operating level, it's best

to wait until the engine temperature drops to approximately

120°F (49°C), or lower, before removing the pressure cap.

After the cap is removed, the level should be within 2 inch-

es (51mm) of the filler neck.

NOTE:

I-71 engines have incorporated the use of a coolant

recovery bottle (white plastic bottle) Fig  4. During

initial filling of the cooling system, it will be nec-

essary to f ill the Reco very Bottle to the Cold Full

line with the pre-mix solution. Start and run the

engine as indicated abo ve. After reaching normal

operating temperature check the coolant le vel in

the recovery bottle to v erify that the le vel is at the

Hot Full line, if not add coolant to the bottle.

Following the same instructions as abo ve, wait for

the engine coolant temperature to drop before

removing the pressure cap. 

The coolant le vel

should be at the pre viously mention height.  The

coolant level must remain between Hot and Cold

run lines on the recovery bottle.

CAUTION:

Do not remove pressure cap while coolant is at

normal operating temperatures. Possible per-

sonal injury could result from the expulsion of

hot coolant.

PRESSURE CAP

Like most cooling systems, the Heat Exchanger type oper-

ates under pressure. A typical cap shown in Fig. 5 maintains

system pressure to raise the coolant boiling point and per-

mits a some what higher operating temperature without

coolant loss. Pressure cap values can vary in different engine

series. Refer to Section 5 for your engine type.
All pressure caps include a vacuum valve which opens dur-

ing cool down. This prevents an internal vacuum from being

formed which could contrib ute to leaking seals and hoses

collapsing.

NOTE:

I-71 engines use a coolant reco very bottle.  The

pressure cap includes a rubber ring-type seat.

When the cap installed this ring forms a positi ve

seal between the filler neck and cap. During engine

cool down, if the wrong type cap is used, coolant

cannot transfer back into the heat e xchanger from

the recovery bottle. This can progress into an over-

heated engine and possible damage.

Fig. 5 - Typical Coolant Cap

Fig. 3 - Proper Concentrations Of Inhibitors

Fig. 4 - Coolant Recovery Bottle