0396154 JOHNSON CAM FOLLOWER

Illustration 1 g03468059
Schematic for the lubrication system for the C175-16 Off-Highway Truck Engines
(1) Engine oil coolers
(2) Engine oil filters
(3) High-pressure fuel pump
(4) Turbochargers
(5) Turbocharger mounting support
(6) Rear gear train
(7) Pressure relief valve for the lubrication system
(8) Main oil gallery
(9) Engine block
(10) Engine oil cooler bypass valve
(11) Pressure regulator valve for the lubrication system
(12) Engine oil pump
(13) Suction screen
(14) Scavenge oil pump
(15) Engine oil pan
Illustration 2 g03177608
(16) Main oil galleryEngine oil pump (12) is a gear-type pump that generates flow for the lubrication system. The engine oil pump is mounted on the back side of the front gear housing. The pump gears are driven by a splined shaft connected to the front gear train. Oil is drawn into the inlet of the pump through a tube and through suction screen (13).The pressure regulator housing (11) is mounted to the engine oil pump. Within the regulator housing, a pressure regulator valve controls the engine oil pressure using pressure from the main oil galley as the control signal in most scenarios. A secondary control signal, taken from the oil pump outlet elbow, can sometimes adjust the regulator valve position, for example, during a cold start to mitigate the oil pressure spike that occurs with first crank. Which signal is used for controlling the regulator is determined by two check valves in each control signal line. Oil pressure is targeted at 600 100 kPa (87 15 psi) at rated speed of the engine. In the case of a problem with the pressure regulator valve, the pressure relief valve (7) limits the maximum pressure in the lubrication system to 850 kPa (123 psi). Both of the valves return excess engine oil to engine oil pan (10).Scavenge oil pump (14) transfers oil from the shallow end of the engine oil pan to the oil sump. The scavenge oil pump is driven by the front gear train.The pressurized oil is directed through engine oil coolers (1). The engine oil coolers lower the temperature of the engine oil before the engine oil is sent to the filters. If the oil coolers become restricted, engine oil cooler bypass valve (10) allows engine oil to bypass the oil coolers. If the pressure differential across the oil coolers exceeds 180 kPa (26 psi), the bypass valve will allow engine oil to bypass the oil coolers. The oil coolers are mounted to the left side of the engine.A supply line crosses the engine below the oil pan to supply oil to engine oil filters (2) on the right side. The cartridge-type filters clean the engine oil.An oil line connected to the filter base provides filtered oil to the high-pressure fuel pump (3). Return oil from the pump drains through the front cover and into the oil pan.Clean engine oil from the filters flows to the rear of the engine through a line into the cylinder block and main oil gallery (16). The main oil gallery is cast into engine block (8). The main oil gallery supplies oil to the camshaft bearings through drilled passages in the engine block. The engine oil flows around each camshaft journal to the camshaft follower and lifter assemblies. Engine oil flows from the main oil gallery to each cylinder head through extra drilled passages that provide oil to the rocker arms. There are also passages in the rocker arm supports that provide lubrication to the rocker arm shafts and valve guides.External oil lines connected to passages in the front cover supply oil to the front-mounted turbochargers (4). The return oil from the turbochargers drains back into the oil pan through mounting supports (5).The main oil gallery is connected to the main bearings by drilled holes. Drilled holes in the crankshaft connect the main bearing oil supply to the rod bearings. Oil flows to the connecting rod bushings and wrist pins through drilled passages in the connecting rods.
Illustration 3 g03177642
Piston cooling and lubrication of the piston pin
(17) Drilled passage
(18) Piston cooling jetsDrilled passage (17) that is in the connecting rod provides oil for the lubrication of the piston pin. Two piston cooling jets (18) are located below each piston. Each of the piston cooling jets direct a spray of engine oil toward the manifold that is behind the ring band of the piston. The manifold is used to direct heat away from the piston rings. The oil spray from the piston cooling jets is used to remove heat from the manifold.Engine oil is sent to the front gear group and rear gear group (6) through drilled passages. The drilled passages are in the front housing, the rear housing, and cylinder block faces. The passages are connected to the main oil gallery.