MAIN OIL SUMP. The main oil sump is a
are located at the ends of two of the four vertical oil
reinforced fabricated steel plate assembly that supports
galleries. These pressure regulating valves are similar in
construction to the pressure relief valves mounted at the
the engine on its base assembly. The main oil sump is
main oil pump. When the oil pressure at a regulating
equipped with a series of handholes along the sides for
valve exceeds 50 psig, the valve lifts and discharges the
access to the rod bearings, oil pump, and pressure
excess oil back to the engine oil sump.
regulating valves. Mounted on the handhole covers are
the lube oil discharge fitting, the lube oil fill and drain
OIL DISTRIBUTION SYSTEM. Oil from the
fittings, and the ribbon-type dipstick.
main oil gallery flows through drilled passages to each
main bearing and through drilled passages in the
OIL PUMP. The oil pump is mounted on the two
crankshaft to each adjacent journal bearing. A groove in
rear main bearing caps and is driven by the rear
the upper half of the rod bearing directs oil to the piston
crankshaft gear. The oil pump assembly consists of a
pin through a drilled passage in the connecting rod. A
main section and a scavenging pump section mounted
portion of the oil is used to lubricate the piston pin; the
in tandem. The scavenging oil pump is not used.
other part is sprayed on the underside of the piston dome
The main oil pump takes a suction from the sump
for cooling.
through the inlet screen and suction pipe and
discharges into the oil discharge line. When the pump
Oil from the main oil gallery is also picked up by
diagonal holes in the camshaft and directed through an
d i s c h a r g e pressure exceeds 100 psig, the
axial passage to the couplings and drive shafts located
spring-loaded relief valves mounted on the oil
at the rear of the camshaft. The valve and injector
discharge fitting lift to direct the excess oil back to the
operating mechanism is lubricated from both the
sump. The oil discharge pipe leads out of the sump
camshaft bearing caps and the grooves in the camshaft
through the rear hand hole cover on the right side and
bearings. The camshaft lobes and the rocker arm rollers
connects to the ship's lube oil piping system through
are lubricated by spray jets machined in the bearing
a flexible connection.
caps. Excess oil from the rocker arms lubricates the
LUBE OIL FILTER AND COOLER ASSEM-
valve stems.
BLIES. The lube oil filter and cooler are mounted off
The gear train is lubricated by oil from passages
the engine. Ship's piping routes the lube oil from the
drilled in the cam hubs and the idler gear retaining bolts,
engine oil outlet to the lube oil filter, where particulate
matter is filtered out.
and from splash from the main oil sump. A certain
amount of oil also spills into the gear train compartment
Filter Assembly. The lube oil filter is a four-
from the blower drive bearing and the idler gear
element, full-flow assembly. It is equipped with a bypass
bearings. The idler gear bearings are pressure lubricated
relief valve at each filter element. If one of the filter
from the main oil gallery.
elements should become clogged, the bypass valve for
The lube oil manifold is mounted between the
that element will open when the differential pressure
reaches 20 psid. The bypass valve will then maintain the
engine and the block. It supplies oil to the turbochargers
oil flow with only a slight reduction of filtration. Lube
manifold to the turbochargers through an external tube
oil is piped from the filter to the shell side of the oil
and flexible hose connections.
cooler.
Oil Cooler. The lube oil cooler is similar in design
MONITORING SYSTEM COMPONENTS.
The lube oil monitoring system consists of a pre-start
to the fuel return cooler. It is a single-pass, shell and tube
design heat exchanger. This oil cooler uses jacket water
lube oil pump, pressure gauges, transducers,
as the cooling medium. After passing through the oil
temperature sensors, pressure shutdown and alarm
cooler, the lube oil returns to the engine through a
switches, a low oil level switch, and an oil filter
flexible connector and the final lube oil strainer, which
differential pressure transducer. Except for the
is mounted on the left-hand side.
pre-start lube oil pump, these lube control and
monitoring system components are automatic without
REGULATING VALVES. The main oil gallery
any operator control.
extends the full length of the cylinder block and
connects with the main bearings, camshaft bearing, and
Pre-Start Lube Oil Pump. The pre-start lube oil
gear trains through drilled passages. Stable oil pressure
pump is provided to ensure the lube oil system is charged
with oil while the engine is in a standby condition. This
is maintained under various conditions by two
spring-loaded pressure regulating valves. These valves
pump permits the system to be charged after
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