PRIN. OF INTERNAL COMBUSTION ENGINES - OD1619 LESSON 2/TASK 2
camshaft bearings. Unlike the combination system, the connecting rod bearings are
also fed oil under pressure from the pump. Oil passages are drilled in the
crankshaft in order to lead oil to the connecting rod bearings. The passages
deliver oil from the main bearing journals to the rod bearing journals. In some
engines, these openings are holes that index (line up) once for every crankshaft
revolution. In other engines, there are annular grooves in the main bearings
through which oil can feed constantly into the hole in the crankshaft. The
pressurized oil that lubricates the connecting rod bearings goes on to lubricate
the pistons and walls by squirting out through strategically drilled holes. This
lubrication system is used in virtually all engines that are equipped with
semifloating piston pins.
FIGURE 63. FULL FORCEFEED LUBRICATION SYSTEM.
d. Full ForceFeed Lubrication System (figure 63). In the full forcefeed
lubrication system, all of the bearings mentioned in paragraph 5b on page 76 are
lubricated by oil under pressure. This includes main bearings, rod bearings,
camshaft bearings, and the complete valve mechanism. In addition, the full force
feed lubrication system provides lubrication under pressure to the pistons
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