40138 6 Mercury NUT

3054 and 3054B Engines
Illustration 1 g00793830
Typical jacket water circuit for the 3054 and 3054B Marine engine
The solid arrows indicate the direction of flow. The dashed arrows indicate the direction of flow in piping for the expansion of the coolant in the vent passage. The dashed arrows indicate bypass lines or vent lines.
(1) Engine oil cooler
(2) Heat exchanger
(3) Water temperature regulator (thermostat)
(4) Water cooled exhaust manifold
(5) Cylinder head
(6) Expansion tank
(7) Vent lines
(8) Jacket water pump
(9) Cylinder block Coolant is pulled from the heat exchanger (2) into the jacket water pump (8) by impeller action. The jacket water pump is located on the front left side of the engine. The jacket water pump is gear-driven.The coolant is pumped through the cylinder block (9). The coolant is distributed around each cylinder. At each cylinder, coolant enters the cylinder head (5). The coolant then enters the water outlet manifold. The coolant then enters the water cooled exhaust manifold (4). The coolant then flows to the water temperature regulator (3). With the water temperature regulator in the closed position, the coolant bypasses the heat exchanger (2) and flows back to the jacket water pump (8) for recirculation. With the water temperature regulator in the open position, the coolant is directed through the heat exchanger (2) and back to the water pump inlet.3056 Engine
Illustration 2 g00794089
Typical jacket water circuit for the 3056 Marine engine
The solid arrows indicate the direction of flow. The dashed arrows indicate the direction of flow in piping for the expansion of the coolant in the vent passage. The dashed arrows indicate bypass lines or vent lines.
(10) Aftercooler
(11) Cylinder head
(12) Cylinder block
(13) Vent lines
(14) Expansion tank
(15) Jacket water pump
(16) Bypass for the water temperature regulator
(17) Heat exchanger
(18) Water temperature regulator (thermostat) Coolant is pulled from the heat exchanger (17) into the jacket water pump (15) by impeller action. The jacket water pump is located on the front left side of the engine. The jacket water pump is gear-driven.The coolant is pumped through the cylinder block (12). The coolant is distributed around each cylinder. At each cylinder, coolant enters the cylinder head (11). The coolant then enters the water outlet manifold. The coolant then enters the aftercooler (10). The coolant then flows to the water temperature regulator (18). With the water temperature regulator in the closed position, the coolant flows through the water temperature regulator. The coolant bypasses the heat exchanger (17) and flows back to the jacket water pump for recirculation. With the water temperature regulator in the open position, the coolant is directed through the heat exchanger (17) and back to the water pump inlet.Sea Water Circuit
Three types of external cooling systems can be used on the 3054 Marine engine, the 3054B Marine engine, and the 3056 Marine engine. The sea water circuit and a keel cooling system are two types of external cooling systems for the marine engine. Both systems are separate from the jacket water circuit. The sea water circuit is necessary in order to cool the jacket water. The sea water circuit removes the heat from the jacket water.3054 and 3054B Engines
Illustration 3 g00793829
Typical sea water circuit for the 3054 and 3054B Marine engine
The solid arrows indicate the direction of flow.
(1) Heat exchanger
(2) Water injection elbow
(3) Marine transmission oil cooler
(4) Engine
(5) Auxiliary water pump
(6) Inlet for the sea water The auxiliary water pump (5) pulls sea water into the sea water circuit through the inlet for the sea water (6). The auxiliary water pump (5) supplies a continuous flow of sea water through the marine transmission oil cooler (3). The sea water then flows to the heat exchanger (1). The sea water is discharged through the exhaust in the water injection elbow (2). The sea water mixes with the exhaust. The mixture exits the vessel. The sea water performs several functions:
The sea water cools the jacket water.
The sea water cools the exhaust.
The sea water silences the exhaust.3056 Engine
Illustration 4 g00794232
Typical sea water circuit for the 3056 Marine engine
The solid arrows indicate the direction of flow.
(7) Inlet and exhaust manifold
(8) Water injection elbow
(9) Marine transmission oil cooler
(10) Engine
(11) Auxiliary water pump
(12) Heat exchanger
(13) Inlet for the sea water The auxiliary water pump (11) pulls sea water into the sea water circuit through the inlet for the sea water (13). The auxiliary water pump (11) supplies a continuous flow of sea water through the marine transmission oil cooler (9). The sea water then flows to the heat exchanger (12). The sea water is discharged through the exhaust in the water injection elbow (8). The sea water mixes with the exhaust. The mixture exits the vessel. The sea water performs several functions:
The sea water cools the jacket water.
The sea water cools the exhaust.
The sea water silences the exhaust.Keel Cooling System
Two types of external cooling systems can be used on the 3054, 3054B and 3056 Marine engines. The sea water circuit and a keel cooling system are two types of external cooling systems for the marine engine. Both systems are separate from the jacket water circuit. The keel cooling system is necessary in order to cool the jacket water. The keel cooling system removes the heat from the jacket water.3054 and 3054B Engines
Illustration 5 g00793831
Typical arrangement of a keel cooling system for the turbocharged 3054 and 3054B Marine engine
The solid arrows indicate direction of flow. The dashed arrows indicate the direction of flow in piping for the expansion of the coolant in the vent passage. The dashed arrows indicate bypass lines or vent lines.
(1) Marine transmission oil cooler
(2) Water temperature regulator (thermostat)
(3) The heat exchanger is inside of the inlet and exhaust manifold.
(4) Engine
(5) Jacket water pump
(6) Vent lines
(7) Keel cooler for the jacket water
(8) Engine oil cooler
(9) Bypass for the expansion tank
(10) Expansion tank The jacket water pump (5) pumps coolant through the keel cooler for the jacket water (7). The coolant then flows to marine transmission oil cooler (1). The jacket water pump (5) pumps coolant through the engine (4). The c