DETROIT DIESEL
AIR SYSTEM
In the scavenging system used in two-cycle engines,
illustrated in Figs. 6 and 7, a charge of air is forced
into the cylinders by the blower and thoroughly sweeps
out all of the burned gases through the exhaust valve
ports. This air also helps to cool the internal engine
parts, particularly the exhaust valves. At the beginning
of the compression stroke, each cylinder is filled with
fresh, clean a i r which provides for efficient
The air, entering. the blower from the air silencer or
air cleaner, is picked up by the blower rotor lobes and
carried to the discharge side of the blower. The
continuous discharge of fresh air from the blower
enters the air chamber of the cylinder block and
sweeps through the intake ports of the cylinder liners.
The angle of the ports in the cylinder liner creates a
uniform swirling motion to the intake air as it enters
the cylinder. This motion persists throughout the
compression stroke and facilitates scavenging and
Fig. 7 - Air Intake System Through Blower and
Engine (6V-53 Engine)
T h e air cleaners are designed for fast, easy
Air Cleaners
disassembly to facilitate efficient servicing. Maximum
protection of the engine against dust and other forms
Several types of air cleaners are available for use with
of air contamination is possible if the air cleaner is
industrial engines. The light-duty oil bath air cleaner
serviced at regular intervals.
is used on most models. However, a heavy-duty oil
The light-duty oil bath type air cleaner (Fig. 8) consists
bath type or a dry type air cleaner may be installed
w h e r e the engine is o p e r a t i n g in heavy dust
of a metal wool cleaning element supported inside of a
housing which contains an oil reservoir. A chamber
concentrations.
beneath the oil reservoir serves as a silencer for the
incoming air to the blower. Air is drawn into the
cleaner by the blower and passes over the top of the
oil bath, where a major portion of the dirt is trapped,
then up through the metal wool, where the finer
particles are removed, and then down the central duct
to the blower.
The heavy-duty oil bath type air cleaner (Fig. 9)
consists of the body and fixed filter assembly which
filters the air and condenses the oil from the air
stream so that only dry air enters the engine. The
condensed oil is returned to the cup where the dirt
settles out of the oil and the oil is recirculated. A
removable element assembly removes a major part of
the dust from the air stream thereby decreasing the
dust load to the fixed element. An inner cup, which
can be removed from the outer (oil cup), acts as a
baffle in directing the oil-laden air to the element and
also controls the amount of oil in circulation and
meters the oil to the element. The oil cup supports the
inner cup and is a reservoir for oil and a settling
chamber for dirt.
Fig. 6 - Air Intake System Through Blower and
Engine (In-line Engine)
Service the light-duty oil bath air cleaner as follows:
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