Installation manual
COOLING
SYSTEM
DESCRIPTION
Westerbeke marine diesel engines are designed and equipped
for fresh water cooling. Heat produced in the engine
by
com-
bustion
and
friction
is
transferred to fresh water coolant
which circulates throughout the engine. This circulating fresh
water coolanteools the engine block
..
its internal moving
parts,
and
the engine oil. The heat is transferred externally
from
the
fresh
water
coolant
to
raw
water
by
means
of
a
heat
exchanger,
similar
in
function
to
an
automotive
radiator.
Raw
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
boatyardlbuilder 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.
S.
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
aground.
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.
WASHER-:!~~Sl1
FILTER
TYPICAL
RAW
WATER
INTAKE
STRAINER
(Owner
Installed)
INCOMING
RAW
WATER
SEACOCK
".-
".;
--=CCCO::;>-
.
DRAINING
THE
RAW
WATER
SYSTEM
INSPECT
AND
CLEAN
EVERY
100
HOURS
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.
Before starting the engine, remove the engine thermostat
(replace the gasket and cover). This will ensure a full flow
of
water thru the engine. Re-install
the
thermostat
once
flushing
is complete.
Run the unit for
IO
minutes or longer to adequately flush the
" cooling system.
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.
The fresh water will flush out the engines water passages and
, exhaust lines.
If
the engine is being stored and there is a
probability
of
freezing, flush the engine with fresh water and
then prior to shutting the unit down substitute the fresh water
supply with a concentrated antifreeze mixture and run this
through the engine
to
provide freeze and corrosion protection
for both the engine and exhaust system.
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
wann,
the
fresh
water
can
stay
in
the
engine.
-..:
WESTERBEKE
Engines & Generators
13