Engine Coolant and Sea Water Flow (6068SFM50)

RG12079-UN-07MAR02

Engine Coolant And Sea Water Flow (6068SFM50 Shown)

A - Coolant Pump

B - Oil Cooler

C - Heat Exchanger/Thermostat Housing

D - Heat Exchanger Core

E - Coolant Outlet Hose

F - Sea Water Pump

G - Sea Water Inlet

H - Aftercooler Core

I - High-Temperature Coolant

J - Low-Temperature Coolant

K - Sea Water

Coolant is circulated from the coolant pump (A) into the oil cooler (B) and circulates around the oil cooler plates. From the oil cooler, coolant flows into the main coolant gallery. From the gallery, coolant flows into the coolant jacket, around the cylinder liners, up through the block deck passages, and into the cylinder head. In the cylinder head, the coolant flows through passages around the intake and exhaust ports, valve seats, and injection nozzles. Coolant flows from the cylinder head and exits into the heat exchanger/thermostat housing (C).

During the warm-up period, thermostats are closed and coolant bypasses heat exchanger core, exiting through hose (E) into the coolant inlet side of the water pump. The coolant continues circulating through the cylinder block, cylinder head, heat exchanger and coolant pump to provide a uniform and fast warm-up period.

Once the engine has reached operating temperature, the thermostats open and allow high-temperature coolant (I) to flow around tubes in the heat exchanger core (D), dissipating heat. Low-temperature coolant (J) flows out coolant outlet hose (E) and into coolant inlet side of the coolant pump. Coolant continues flowing through the engine and heat exchanger circuit until the coolant temperature drops below the thermostat opening temperature.

Sea water (K) flows into sea water pump (F) at inlet (G). Sea water then flows into the aftercooler core (H) and into the heat exchanger core (D). In the aftercooler core, the sea water flowing through the aftercooler core tubes absorbs heat from the turbocharged air passing around the core, and exits through the sea water outlet on the turbocharger. In the heat exchanger core (C), sea water (K) flowing through the heat exchanger core absorbs heat from high-temperature coolant (I) flowing around the core and exits through the sea water outlet on the turbocharger.