Cooling System With Standard Vertical Radiator
(1) Radiator cap. (2) Radiator top tank. (3) Radiator top hose. (4) Shunt line. (5) Housing (water temperature regulators). (6) Return to housing for water temperature regulators. (7) Cylinder heads (two). (8) Vent tube. (9) Surge tank. (10) Inside bypass. (11) Radiator bottom tank. (12) Radiator bottom hose. (13) Water pump. (14) Outlet line from JWAC. (15) JWAC. (16) Outlet line (from oil cooler). (17) Oil cooler. (18) Inlet line (for oil cooler). (19) Cylinder block. (A) Orifices between cylinder heads and front cover. (B) Orifice in oil cooler inlet.
Cooling System With Cross Flow Radiator
(1) Radiator cap. (2) Radiator left side tank. (3) Radiator top hose. (4) Shunt line. (5) Housing (water temperature regulators). (6) Return to housing for water temperature regulators. (7) Cylinder heads (two). (8) Vent tube. (9) Surge tank. (10) Inside bypass. (11) Radiator right side tank. (12) Radiator bottom hose. (13) Water pump. (14) Outlet line from JWAC. (15) JWAC. (16) Outlet line (from oil cooler). (17) Oil cooler. (18) Inlet line (for oil cooler). (19) Cylinder block. (A) Orifices between cylinder heads and front cover. (B) Orifice in oil cooler inlet.
Cooling System With Vertical Radiator And Separate Surge Tank
(1) Radiator cap. (2) Radiator top tank. (3) Radiator top hose. (4) Shunt line. (5) Housing for water temperature regulators. (6) Return to housing for water temperature regulators. (7) Cylinder heads (two). (8) Vent tube. (9) Surge tank. (10) Inside bypass. (11) Radiator bottom tank. (12) Radiator bottom hose. (13) Water pump. (14) Outlet line from JWAC. (15) JWAC. (16) Outlet line (from oil cooler). (17) Oil cooler. (18) Inlet line (for oil cooler). (19) Cylinder block. (A) Orifices between cylinder heads and front cover. (B) Orifice in oil cooler inlet.
Flow Of Coolant
(3) Radiator top hose. (5) Housing (water temperature regulators). (6) Return to housing for water temperature regulators. (10) Inside bypass. (20) Water temperature regulators (two). (C) Flow with warm coolant. (D) Flow with cold coolant.
Water pump (13) is installed on the front face of the front cover for the engine and is driven by belts from the crankshaft pulley. The inlet opening of water pump (13) is connected to radiator bottom hose (12). The outlet flow of coolant from water pump (13) goes through inside passages in the front cover for the engine.
As the coolant goes from the water pump, it divides and goes through the inside passages in the front cover for the engine to cylinder block (19). Most of the coolant goes through cylinder block (19) and up to cylinder heads (7). From cylinder heads (7) the coolant goes forward through orifices (A) to the front cover for the engine.
Part of the coolant going to the left side (as seen from the flywheel) of cylinder block (19) goes through orifice (B) to inlet line (18) and on to oil cooler (17), to cool the oil for lubrication of the engine, and back to the front cover for the engine through outlet line (16).
From the front cover for the engine, the coolant either goes to the inlet for water pump (13) or to the radiator.
If the coolant is cold (cool), the water temperature regulators (20) will be closed. The coolant will go through inside bypass (10) to water pump (13). If the coolant is warm, the water temperature regulators (20) will be open. When the water temperature regulators (20) are open, they make a restriction in the inside bypass (10) and the coolant goes through radiator top hose (3) and into radiator top tank (2) or left side tank (2). Coolant then goes through the core of the radiator to the radiator bottom tank (11) or radiator right side tank (11), where it is again sent through the cooling system. A small amount of coolant goes through inside bypass (10) when temperature regulators (20) are open.
NOTE: The water temperature regulators (20) are an important part of the cooling system. They divide coolant flow between radiator (2) and inside bypass (10) as necessary to maintain the correct temperature. If the water temperature regulators are not installed in the system, there is no mechanical control, and most of the coolant will take the path of least resistance through bypass. This will cause the engine to overheat in hot weather. In cold weather, even the small amount of coolant that goes through the radiator is too much, and the engine will not get to normal operating temperatures.
Cooling System With Cross Flow Radiator And Separate Surge Tank
(1) Radiator cap. (2) Radiator left side tank. (3) Radiator top hose. (4) Shunt line. (5) Housing for water temperature regulators. (6) Return to housing for water temperature regulators. (7) Cylinder heads (two). (8) Vent tube. (9) Surge tank. (10) Inside bypass. (11) Radiator right side tank. (12) Radiator bottom hose. (13) Water pump. (14) Outlet line from JWAC. (15) JWAC. (16) Outlet line from oil cooler. (17) Oil cooler. (18) Inlet line for oil cooler. (19) Cylinder block. (A) Orifices between cylinder heads and front cover. (B) Orifice in oil cooler inlet.
Location Of Water Temperature Regulators
The vertical radiator is made with a top tank (2) above the core and a surge tank (9) either above or separate from the top tank. Vent tube (8) connects radiator top tank (2) and surge tank (9). The cross flow radiator is made with a left side tank (2) and a right side tank (11). The surge tank (9) is either a part of right side tank (11), separated by an inside baffle, or a tank separate from the radiator. Vent tube (8) connects the surge tank (9) to the radiator.
Surge tank (9) has a shunt line (4) that connects to the inlet of water pump (13). This shunt type system keeps a positive pressure on the inlet of water pump (13) at all times. When putting coolant in the cooling system, coolant from surge tank (9) goes through shunt line (4) to the inlet of water pump (13) and fills cylinder block (19) from the bottom. By filling the system from the bottom, any air in the system is pushed out through radiator top tank (2), through vent tube (8) into surge tank (9).
Radiator cap (1) is used to keep the correct pressure in the cooling system. This pressure keeps a constant supply of coolant to water pump (13). If this pressure goes too high, a valve in radiator cap (1) moves (opens) to get a reduction of pressure. When the correct pressure is in the cooling system, the valve in radiator cap (1) moves down (to the closed position).
Location Of Vent Valve
The vent valve is located in the front housing next to the temperature regulators. The vent valve is used to let the air out of the cooling system when the cooling system is filled. When the engine is in operation, the vent valve will close and not let coolant go through. This will help increase the temperature of the coolant at low engine loads.
Locations Of Heater Connections
The front housing has several plugs that give access to water passages inside the housing. For the correct access points to install heater hoses, see the preceding photo.