COOLING SYSTEM SCHEMATIC
1. Sea water pump. 2. Expansion tank. 3. Exhaust risers. 4. Shunt line. 5. Heat exchanger. 6. Inside
bypass. 7. Outlet for sea water. 8. Housing for water temperature regulators. 9. Water pump. 10. Water
cooled exhaust manifolds. 11. Orifices between cylinder heads end front cover for the engine. 12. Cylinder
block. 13. Coolant for marine gear oil. 14. Cooler for engine oil.
exhaust manifolds the coolant goes to the front cover for
Water pump (9) is installed on the front face of the
front cover for the engine and is driven by V belts from
the crankshaft pulley. As the coolant goes from the water
From the front cover for the engine the coolant
pump it divides and goes through inside passages in the
either goes to the inlet for water pump (9) or to expansion
front cover for the engine to cylinder block (12) and up to
the cylinder heads. From the cylinder heads the coolant
goes forward through orifices (11) to the front cover for
If the coolant is cold (cool) the water temperature
regulators (17) will be closed. The coolant will go through
inside bypass (6) to water pump (9). If the coolant is
Part of the coolant going to the left side (as seen
warm the water temperature regulators (17) will be open.
from the flywheel) of cylinder block (12) goes to cooler for
When the water temperature regulators (17) are open
marine gear oil (13) and on to the cooler for engine oil
they make a restriction in the inside bypass (6) and the
(14). Both of these oil coolers are in a common housing
coolant goes to the lower part of expansion tank (2).
at the top rear of the engine.
(Expansion tank (2) is divided into an upper and lower
compartment by a baffle.) From the lower compartment of
After the coolant goes through the oil coolers it
expansion tank (2) most of the coolant goes through heat
divides and goes to the rear of water cooled exhaust
exchanger (5) and the inlet for water pump (9).
manifolds (10). After going through the water cooled