0390318 JOHNSON COVER ASSY.

Engines with a Heat Exchanger
Engines with an Aftercooler
Illustration 1 g01163433
Turbocharged engine (A) Coolant circuit (B) Sea water circuit (1) Aftercooler (2) Exhaust manifold (3) Engine (4) Water temperature regulator housing (5) Engine oil cooler (6) Vent line (7) Recovery bottle (if equipped) (8) Expansion tank (9) Water pump (10) Vent line (11) Pre-heater (if equipped) (12) Heat exchanger (13) Auxiliary water pumpCoolant Circuit
During engine operation, water pump (9) draws engine coolant from heat exchanger (12). The water pump creates coolant flow through the system. The water pump is installed on the front of the timing case. The water pump is gear-driven by the fuel injection pump gear.Water pump (9) forces the coolant through a passage in the front of the timing case to the water jacket in the top left side of the cylinder block. One-third of the coolant flows around the element of oil cooler (5) to the rear of the cylinder block. Two-thirds of the coolant is used in order to cool the cylinder block. The coolant continues to the rear of the cylinder block and the coolant is diverted to the following locations:
Exhaust manifold (2)
Cylinder head
Preheater (11) (if equipped)The coolant flows forward through the cylinder head and into water temperature regulator housing (4). If the water temperature regulator is closed, the coolant goes directly through a bypass to the inlet side of water pump (9). If the water temperature regulator is open, the bypass is closed and the coolant flows to heat exchanger (12) in order to be cooled. After the coolant flows through the heat exchanger, the coolant is mixed with coolant that is returning from exhaust manifold (2) and preheater (11) (if equipped).The recovery bottle (7) provides space for expansion of the coolant volume while the engine is running. Also, the recovery bottle provides space for expansion during the warm up cycle.Sea Water Circuit
During engine operation, auxiliary water pump (13) draws cool sea water into the system. The auxiliary water pump pumps the sea water to aftercooler (1). The cool sea water flows through aftercooler (1) in order to cool the hot inlet air. From the aftercooler, the sea water flows to heat exchanger (12) in order to cool the hot engine coolant. After leaving the heat exchanger, the sea water is then discharged.Engines without an Aftercooler
Illustration 2 g01163627
Turbocharged engine or naturally aspirated engine (A) Coolant circuit (B) Sea water circuit (2) Exhaust manifold (3) Engine (4) Water temperature regulator housing (5) Engine oil cooler (6) Vent line (7) Recovery bottle (if equipped) (8) Expansion tank (9) Water pump (10) Vent line (11) Preheater (if equipped) (12) Heat exchanger (13) Auxiliary water pumpCoolant Circuit
During engine operation, water pump (9) draws engine coolant from heat exchanger (12). The water pump creates coolant flow through the system. The water pump is installed on the front of the timing case. The water pump is gear-driven by the fuel injection pump gear.Water pump (9) forces the coolant through a passage in the front of the timing case to the water jacket in the top left side of the cylinder block. One-third of the coolant flows around the element of oil cooler (5) to the rear of the cylinder block. Two-thirds of the coolant is used in order to cool the cylinder block. The coolant continues to the rear of the cylinder block and the coolant is diverted to the following locations:
Exhaust manifold (2)
Cylinder head
Preheater (11) (if equipped)The coolant flows forward through the cylinder head and into water temperature regulator housing (4). If the water temperature regulator is closed, the coolant goes directly through a bypass to the inlet side of water pump (9). If the water temperature regulator is open, the bypass is closed and the coolant flows to heat exchanger (12) in order to be cooled. After the coolant flows through the heat exchanger, the coolant is mixed with coolant that is returning from exhaust manifold (2) and preheater (11) (if equipped).The recovery bottle (7) provides space for expansion of the coolant volume while the engine is running. Also, the recovery bottle provides space for expansion during the warm up cycle.Sea Water Circuit
During engine operation, auxiliary water pump (13) draws cool sea water into the system. The cool sea water flows from the pump to heat exchanger (12) in order to cool the hot engine coolant. After leaving the heat exchanger, the sea water is then discharged.Engines with a Keel Cooler
Engines with an Aftercooler
Illustration 3 g01163657
Turbocharged (1) Aftercooler (2) Purge line (3) Purge line (4) Remote tank (5) Exhaust manifold (6) Engine (7) Water temperature regulator housing (8) Engine oil cooler (9) Water pump (10) Auxiliary water pump (11) Keel cooler (12) Keel cooler for aftercoolerDuring engine operation, water pump (9) draws engine coolant from keel cooler (11). The water pump creates coolant flow through the system. The water pump is installed on the front of the timing case. The water pump is gear-driven by the fuel injection pump gear.Water pump (9) forces the coolant through a passage in the front of the timing case to the water jacket in the top left side of the cylinder block. One-third of the coolant flows around the element of oil cooler (8) to the rear of the cylinder block. Two-thirds of the coolant is used in order to cool the cylinder block. The coolant continues to the rear of the cylinder block and the coolant is diverted to the following locations:
Exhaust manifold (5)
Cylinder headThe coolant flows forward through the cylinder head and into water temperature regulator housing (7). If the water temperature regulator is closed, the coolant goes directly through a bypass to the inlet side of water pump (9). If the water temperature regulator is open, the bypass is closed and the coolant flows to keel cooler (11) in order to be cooled. After the coolant flows through the keel cooler, the coolant is mixed with coolant that is returning from exhaust manifold (5) .An auxiliary water pump (10) is also used in order to supply coolant flow to aftercooler