Illustration 32 Right Side View Of Engine

TM 9-2320-312-24-2

Systems Operation Section

The passage in front housing (16) sends the oil flow

Engine oil pump (24) is mounted to the bottom of

in two directions. At the upper end of the passage,

the cylinder block inside the engine oil pan (27).

oil is directed back into the block and up to cylinder

The engine oil pump (24) pulls oil from engine

head gallery (9) through passage (3) to the rocker

oil pan (27). The engine oil pump pushes the oil

arm mechanism. A passage (17) sends oil to the oil

through the passage to the engine oil cooler (23).

pump idler gear bearing.

Oil then flows through engine oil filter (21). The

filtered oil then enters the turbocharger oil supply

Oil from the front main bearing enters a passage

line (15) and main oil gallery (14).

(19) to the camshaft idler gear bearing. Oil

passages in the crankshaft send oil from all the

main bearings (11) through the connecting rods to

the connecting rod bearings.

The passages send oil from the camshaft bearing

(12) to an oil passage in the side covers. The oil

then enters a hole in the shafts to pushrod lifters

(10). The oil lubricates the bearings of the lifter.

Note: Engines that are equipped with an auxiliary oil

filter (26) will receive oil at a port. The filtered oil will

be returned to engine oil pan (27).

The hydraulic pump (1) is a gear-driven axial piston

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pump. The hydraulic pump raises the engine oil

Illustration 32

pressure from the typical operating oil pressure to

Right Side View Of Engine

the actuation pressure that is required by the unit

(15) Turbocharger oil supply line. (18) Oil filter bypass valve. (21)

injectors. The injection actuation pressure control

Engine oil filter. (22) Oil cooler bypass valve. (23) Oil cooler. (28)

valve (5) electronically controls the output pressure

Turbocharger oil return tube.

of the hydraulic pump (1).

The oil circuit consists of a low pressure circuit

and a high pressure circuit. The low pressure

circuit typically operates at a pressure of 240 kPa

(35 psi) to 480 kPa (70 psi). The low pressure circuit

provides engine oil that has been filtered to the

hydraulic pump (1). Also, the low pressure circuit

provides engine oil that has been filtered to the

lubricating system of the engine. Oil is drawn from

the engine oil pan (27). Oil is supplied through the

engine oil cooler (23) and engine oil filter (21) to

both the engine and the hydraulic pump (1).

The high pressure oil system provides actuation

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Illustration 33

oil to the unit injector. The high pressure circuit

operates in a pressure range typically between

Left Side View Of Engine

4 MPa (581 psi) and 23 MPa (3350 psi). This high

(1) Hydraulic pump. (4) Oil supply line (high pressure). (6) Oil

pressure oil flows through a line into the cylinder

manifold (high pressure). (7) Oil supply line (hydraulic pump).

head. The cylinder head stores the oil at actuation

pressure. The oil is ready to actuate the unit injector.

The main oil gallery (14) distributes oil to main

Oil is discharged from the unit injector under the

bearings (11), piston cooling jets (8), and camshaft

bearing (12). Oil from main oil gallery (14) exits the

valve cover so that no return lines are required.

front of the block. The oil then enters a groove that

After the lubrication oil's work is done, the lubrication

is cast in front housing (16).

oil returns to the engine oil pan.

Oil enters the crankshaft through holes in the

The oil pump bypass valve (25) limits the pressure

bearing surfaces (journals) for the main bearing

(11). Passages connect the bearing surface

of the oil that is coming from the engine oil pump

(24). The engine oil pump (24) can pump more than

(journal) for the main bearing (11) with the bearing

enough oil into the system. When there is more than

surface (journal) for the connecting rod.

enough oil, the oil pressure increases. When the oil

pressure increases, the oil pump bypass valve (25)

will open. This allows the oil that is not needed to go

back to the suction side of the engine oil pump (24).