1948-1952 Shop Service Manual - - Hudson-Essex-Terraplane Club

LUBRICATION 1 - 7
ENGINE OILING CIRCUIT
Normal oil pressure causes the plunger to recede and the
circuit is broken.
8 CYLINDER
Engine lubrication is by the Duo-Flow system which
delivers oil in direct ratio to engine speed to bearing surfaces
immediately from the first turn of the crankshaft. The oil is
drawn from the oil pan by the double acting oscillating
plunger type pump driven by the camshaft.
The oil is drawn from the sump and forced through oil
lines to the front and rear of the engine where it is delivered
to the front and rear troughs in the oil pan upper tray.
The oil is then picked up by the connecting rod dippers
and distributed to the interior working surfaces through
splash and a system of channels which convey it into wells
over the crankshaft and camshaft bearings and timing gear
compartment. Overflow oil running down the crankcase
walls is diverted by drains in the oil pan tray into adjacent
splash troughs until it reaches the center of the engine.
At this point, it is returned through the opening in the
tray, then to the main oil supply where it is cooled and
screened before again being used. The new design oil pan
with sump at rear is provided with a floating type screened
intake. This permits only the cleanest oil to be drawn off by
the pump.
Both rear and front main bearing caps are packed to
prevent oil leakage and a large oil retainer collects oil from
the outside of the rear main bearing and returns it to the oil
pan. The oil return tube leading from the rear main bearing
to oil pan has a floating disc or "flapper valve", pinned on
the lower end to prevent any loss of oil on extreme grades
or on quick stops.
An oil check valve is mounted at the rear right side of
crankcase, through which the oil from rear lead pipe of oil
pump flows and controls a light on the instrument panel. A
spring loaded, movable cup shaped plunger lies in the path
of the oil flow. When oil pressure is too low, the plunger
completes an electric circuit and lights the red dash signal.
oil pres
FIGURE 4
OILING CIRCUIT
6 CYLINDER
Full pressure lubrication to bearings of the engine is
maintained by a rotor type oil pump mounted on the right
side of lower crankcase and driven from a worm gear on the
camshaft. Oil is drawn by the suction side of the pump
through a pipe connecting with a floating screen in the
sump, Figure 4.
The oil pump parts consist of an inner and outer rotor, a
shaft, and the body and cover. Outstanding characteristics
of the pump are longer life and high pressure maintained at
low speeds.
Oil pressure is regulated by a built-in nonadjustable release
valve and spring accessible through a plug at the left
rear side of the engine.