Installation manual
COOLING
SYSTEM
THERMOSTAT
A thennostat, located in the coolant filler cap housing -
(illustrated below), controls the coolant's temperature by
allowing more or less coolant through it to the engine's heat
exchanger. When the engine is first started, the closed
thennostat prevents coolant from flowing through it to the
heat exchanger.
Some coolant is by-passed via a by-pass
hose
on
the sump plate to the exchanger. This provides for
coolant circulation in the engine and for coolant temperature
rise. As the coolant
wanns
up, the thennostat gains control
of
the engine operating temperature by allowing more
or
less
coolant flow to the exchanger. The thennostat is accessible
and can be replaced easily. Carry a spare thennostat and
housing gasket.
Replacing
the
Thermostat
Remove the cap screws and disasseinble the thennostat
housing as shown. When installing the new thennostat and
gasket, apply a thin coat
of
sealant
on
both sides
of
the -
gasket before pressing
it
into place.
Run the engine and check for nonnal temperatures and that
there are no leaks around the thennostat housing/gasket.
~
~~".v.
'~
/~
THERMOSTAT
#048157
,GASKET
ADD
SEALANT
.-
AT
ASSEMBLY
#048150
THERMOSTAT
ASSEMBLY
HEAT
EXCHANGER
/TOCOOLANT
l'RECOVER
::.JANK
...
(":
Cool raw water flows through the inner tubes
of
the heat
exchanger. As the engine coolant passes around these tubes,
the heat
of
the internal engine is conducted to the raw water
which is then pumped into the exhaust system and
discharged. The engine coolant (now cooled) flows back
through the engine and the circuit repeats itself.
The
engine coolant and raw water are independent
of
each
other; this keeps the engine's water passages clean from the
harmful deposits found in raw water.
Heat
Exchanger
Service
After approximately 1000 hours
of
operation, remove, clean
and pressure test the engine's heat exchanger. (A local
automotive radiator shop should be able to clean and test the
heat exchanger.)
NOTE:
Operating in silty and/or tropical waters may require
that a heat exchanger cleaning be performedmore often than
ZINC
ANO'DE
TO
WATER
COOLED
EXHAUST
~::k-----'-
COOLANT
DRAIN
~t::J1'(------RAW
WATER
DRAIN
A zinc anode,
or
pencil, is located in the raw water cooling
circuit within the heat exchanger. The purpose
of
the zinc
anode is to sacrifice itself to electrolysis action taking place
in the raw water cooling circuit, thereby reducing the effects
of
electrolysis on other components
of
the system. The
condition
of
the zinc anode should be checlq!d monthly and
the anode cleaned
or
replaced as required. Spare anodes
should be carried
on
board.
NOTE:
Electrolysis is the result
of
each particular installation
and
vessel location; not that
of
the engine.
NEW
REPLACE
CLEAN
&
REUSE
If
the zinc pencil needs replacement, hold the hex boss into
which the zinc pencil is threaded with a wrench while
loosening the anode with another wrench. This prevents the
hex boss from possibly tearing off the exchanger shell. After
removing the zinc, note the condition
of
it.
If
the zinc is in
poor condition, there are probably zinc flakes within the
exchanger. Remove the end
of
the heat exchanger and clean
the inside
of
all zinc debris. Always have a spare heat
exchanger end gasket in case the present one becomes
damaged when removing the end cover. Replace the gasket
(refer to your engine model's heat exchanger end gasket part
number), o-ring, cover, and install a new zinc anode.
NOTE:
The threads
of
the zinc anodes are pipe threads
and
do
not require sealant. Sealant should not be used as it may
insulate the zinc from the metal
of
the heat exchanger
housing preventing electrolysis action
on
the zinc.
every
1000 hours.
~
WESTERBEKE
Engines & Generators
17