Cooling System; Raw Water Intake; Draining The Raw Water System - Westerbeke 29.0 EGED 60Hz Operator's Manual

COOLING SYSTEM
DESCRIPnDN
Westerbeke marine diesel engines are designed and equipped
SEALING
for fresh water cooling. Heat produced in the engine by com-
GASKET
bustion and friction is transferred to fresh water coolant·
which circulates throughout the engine. This circulating fresh
water coolant c.ools
the
engine block; its internal moving
parts, and the engine oil. The heat is transferred externally
from the fresq water coolant to raw water by means of a heat
STRAINER
--rJM""'
exchanger, similar in function
to
an automotive radiator. Raw
' F ILTER
water flows through the tubes of the heat exchanger while
fresh water coolant flows around the tubes; engine heat trans-
ferred to the fresh water coolant is conducted through the
tube walls to the raw water which is then pumped into the
exhaust system where finally it is discharged overboard. In
other words, the engine is cooled by fresh water coolant, this
coolant
is
cooled by raw water, and the raw water carries the
transferred heat overboard through the exhaust system. The
fresh water coolant and raw water circuits are independent of
each other. Using only fresh water coolant within the engine
allows the cooling water passages to stay clean and free from
harmful deposits.
RAW WATER INTAKE STRAINER
A major part of the raw water cooling system is a proper
boatyard/builder installed intake strainer.
NOTE:
Always install
the
strainer at or below the waterline so
the strainer will always be self-priming.
A clean raw water intake strainer is a vital component of the
engine's cooling system. Include a visual inspection of this
strainer when making your periodic engine check The water
in the glass should be clear.
Perform the following maintenance after every 100 hours of
operation:
1.
Close the raw water seacock.
2. Remove and clean the strainer filter.
3. Clean the glass.
4. Replace the washer if necessary.
5. Reassemble and install the strainer.
6. Open the seacock.
7. Run the engine and check for leaks.
NOTE:
Also follow
the
above procedure after having run hard
agroun4.
If the engine temperature gauge ever shows a higher than
· normal reading, the cause may be that silt, leaves or grass
may have been caught up in the strainer, slowing the flow of
·raw water through the cooling system.
TYPICAL RAW WATER INTAKE STRAINER
(Owner Installed)
SEA COCK
~
DRAINING THE RAW WATER SYSTEM
INSPECT AND
' CLEAN EVERY
100HOURS
When freezing temperatures are expected,
it
is best to
protect the raw water cooling circuit and engine exhaust
· from damage.
This procedure is best accomplished by disconnecting the
water intake hose from the vessels thru-hull fitting. Close the
intake
valve before disconnecting the hose. Insert the hose
end into a large container of fresh water.
Provide an external fresh water supply for the bucket to
maintain the water level in the bucket while the unit is being
operated during the flushing process.
Run the unit for 10 minutes or longer to adequately flush the
raw water system.
Once the raw water system has been flushed, replace the
buckets content with a 50/50 antifreeze mixture. Run the
engine and allow this mixture to be pumped through the raw
water circuit. Once this antifreeze mixture is visible being
discharged from the exhaust opening, shut the engine down.
This antifreeze
mixture
should protect the raw water cooling
system and exhaust from freezing.
Re-attach .the water intake valve and remember to open the
intake valve before starting the engine.
When recommissioning, make certain the valves and
seacocks are open so the engine will quickly receive fresh
water. If the engine is stowed where it is warm, the fresh
water can stay in the engine.
Engines & Generatol"$
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