Figure 8-13. Oil Pressure Regulator
Section IV. TYPES OF LUBRICATION SYSTEMS
the crankcase will vary greatly the amount of lubrication
Splash System (Fig.
received by the engine; a high level results in excess
lubrication system no longer is used in automotive
lubrication and oil consumption and a slightly low level
engines, though it is used in small equipment engines. In
results In inadequate lubrication.
a splash lubrication system, dippers on the connecting
rods enter the oil in the crankcase with each crankshaft
8-18. Combination Splash and Force-Feed System
revolution, thus splashing the oil. As the oil is thrown
upward, it finds its way into the various engine parts. A
(Fig. 8-15). In the combination system, oil is delivered
passage Is drilled In each connecting rod from the dipper
to some parts by means of splash and to other parts
to the bearing to ensure lubrication. This system Is too
through oil passages, under pressure from a pump In the
uncertain for modern automotive applications. One
crankcase. The main and the camshaft bearings are
reason is that the level of oil in
usually the items that are force fed while the connecting
rods are fitted with dippers that supply oil to the rest of
the engine by splash. Some configurations utilize small
troughs under each connecting rod that are kept full by
small nozzles that deliver oil under pressure from the oil
pump. These cil nozzles deliver an increasingly heavy
stream as speed increases. At very high speeds these
oil streams are powerful enough to strike the dippers
directly. This causes a much heavier splash so that
adequate lubrication of the pistons and the connecting
rod bearings is provided at higher speeds.
combination system is used on an overhead valve
engine, the upper valve train is lubricated by pressure
from the oil pump.
8-19. Force-Feed Lubrication System (Fig. 8-16). A
somewhat more complete pressurization of lubrication is
achieved in the force-feed lubrication system. Oil is
forced by the oil pump
Figure 8-14. Splash-Type Lubrication System.