| |
| Illustration 1 | g01186344 |
|
(1) Cylinder head
(2) Return manifold (3) Cylinder liners (4) Temperature regulator housing (5) Expansion tank (6) Engine oil cooler (7) Precooler (8) Water pump (9) Radiator | |
The water pump is gear-driven. The water pump is located on the right hand side of the engine. The water pump supplies the coolant for the engine cooling system. The coolant is supplied to the following components:
- Cylinder head (1)
- Cylinder liners (3)
- Precooler (7)
- Engine oil cooler (6)
- Air compressor (not shown)
- Coolant conditioner element (not shown)
- Clean gas induction (CGI)
Note: In air-to-air aftercooled systems, a coolant mixture with a minimum of 30 percent ethylene glycol base antifreeze must be used for efficient water pump performance. This mixture keeps the cavitation temperature range of the coolant high enough for efficient performance.
| |
| Illustration 2 | g01219360 |
|
Right side view of engine (2) Return manifold (4) Temperature regulator housing (6) Engine oil cooler (7) Precooler (8) Water pump | |
Water pump (8) pulls the coolant from the bottom of radiator (9). The water pump is located on the right hand side of the front timing gear housing.
The water pump impeller rotates at 1.37 times the engine speed. The water pump is driven by an idler gear. The idler gear is turned by the crankshaft gear. The water pump shaft is supported by two ball bearings. One ball bearing is located in the water pump housing. The other ball bearing is located in the front timing gear housing. The water pump impeller face is open. The impeller and the rear cover are made out of cast iron. The water pump seal is a cartridge seal that is located on the inlet side of the water pump in order to provide good water flow around the seal for cooling.
The coolant is pumped through engine oil cooler (6). Some of the coolant from the water pump (8) is directed toward the precooler (7). The precooler is a heat exchanger that removes heat from the compressed air from the turbocharger. Coolant for the oil cooler flows to the supply manifold and the CGI cooler. The CGI cooler flow returns to the manifold for the coolant supply. The supply manifold, which is located in the cylinder block, distributes coolant around the upper portion of the cylinder liners. At each cylinder, the coolant flows from the cylinder liner to the cylinder head. The cylinder head is divided into single cylinder cooling sections. In the cylinder head, the coolant flows across the center of the cylinder and across the injector seat boss. At the center of the cylinder, the coolant flows around the injector sleeve over the exhaust port. The coolant then exits into return manifold (2). The return manifold collects the coolant from each cylinder and the return manifold directs the flow to temperature regulator housing (4). When the coolant temperature regulator is in the closed position, the coolant flows through the coolant temperature regulator. This allows the coolant to flow directly back to the water pump for recirculation by bypassing the radiator. When the coolant temperature regulator is in the open position, the coolant is directed through the radiator and back to the water pump inlet.
Cooling is provided for only the portion of the cylinder liner above the seal in the cylinder block. The coolant enters the cylinder block at each cylinder through slits in the supply manifold. The supply manifold is an integral casting in the cylinder block. The coolant flows around the circumference of the cylinder liner and into the cylinder head through a single drilled passage for each liner. The coolant flow is split at each cylinder liner so that 60 percent flows around the cylinder liner and the remainder flows directly to the cylinder head.
| |
| Illustration 3 | g01809816 |
|
Typical right front side of engine (4) Temperature regulator housing (10) Coolant temperature regulator | |
| |
| Illustration 4 | g01809819 |
|
Proper orientation of the vent valve (11) | |
The coolant temperature regulator is a full flow bypass type that is used to control the outlet temperature of the coolant. When the engine is cold, the coolant temperature regulator is in the closed position. This allows the coolant to flow through the coolant temperature regulator from the return manifold. This allows the coolant to bypass the radiator. The coolant goes directly to the water pump for recirculation. As the coolant temperature increases, the coolant temperature regulator begins to open directing some of the coolant to the radiator and bypassing the remainder to the water pump inlet. At the full operating temperature of the engine, the coolant temperature regulator moves to the open position. This allows all the coolant flow to be directed to the radiator. The coolant then goes to the water pump. This route provides the maximum heat release from the coolant. A vent line is recommended from the manifold to the radiator overflow tank in order to provide venting for the cooling system. The recommended vent line is a #4 Aeroquip.
| |
| Illustration 5 | g01809823 |
|
Left side of the engine (12) Outlet hose (13) Inlet hose (14) Air compressor | |
The coolant that is used for air compressor (14) comes from the cylinder head through inlet hose (13). The coolant exits the air compressor through outlet hose (12) and flows back to the cylinder head.