8M0046693 Mercury THERMOSTAT ASSEMBLY

Illustration 1 g00649044
This is an Illustration of the Cooling System With a Schematic of the Separate Circuit Aftercooler.
(1) Cylinder block
(2) Water cooled turbocharger
(3) Engine oil cooler
(4) Regulator housing
(5) Jacket water pump
(6) The source of coolant for the Jacket Water.
(7) Aftercooler
(8) Separate circuit water pump
(9) The source of coolant for the separate circuit. Coolant flows to the jacket water pump (5) through an elbow. The elbow connects to the source of coolant for the jacket water (6). The coolant flow is sent to the engine oil cooler (3).The coolant flows through the engine oil cooler (3). The coolant then flows into the water jacket of the cylinder block (1) at the right rear cylinder. The coolant flows to both sides of the block through the distribution manifolds. The distribution manifolds are connected to the water jacket of all the cylinders. The main distribution manifold is located just above the main bearing oil gallery.The coolant flows upward through the cylinder water jacket. The coolant flows around the cylinder liners from the bottom to the top. Near the top of the cylinder liners, the water jacket is made smaller. This is the area that has the hottest temperature. This shelf (smaller area) causes the coolant to flow faster for better liner cooling. Coolant from the top of the liners flows into the cylinder head which sends the coolant around the parts that have the hottest temperature. Coolant flows to the top of the cylinder head (one at each cylinder). The coolant flows out of the cylinder head through an elbow into a water manifold. Coolant then flows through the manifold to the regulator housing (thermostat) (4).The regulator housing (4) has an upper flow section and a lower flow section. The regulator housing uses four water temperature regulators. The sensing bulbs of the four water temperature regulators are in the coolant in the lower section of the housing. Before the regulators open, cold coolant is sent through the bypass line back to the inlet of the jacket water pump (5). The coolant flow in the bypass line is restricted, as the temperature of the coolant increases enough to start to open the regulators. Some of the coolant is sent through the outlets to the source of coolant for the jacket water (6).Coolant flows to the separate circuit water pump (8) through an elbow that connects to the source of coolant for the separate circuit (9). The coolant flow is sent through the aftercooler (7).Coolant flows through the aftercooler (7) and back to the source of the coolant for the separate circuit (9). The cold coolant is then sent to the separate circuit water pump (8). The coolant flow in the bypass line is restricted, as the temperature of the coolant increases enough to start to open the regulators. Some of the coolant is sent through the outlet to the source of the coolant for the separate circuit (9).Coolant for the water cooled turbochargers (2) is picked up from the rear of the water manifolds. The coolant flows through the water cooled turbochargers (2) and the coolant returns to the regulator housing (4).