Onan CCK Service Manual

Installation Guidelines
VENTILATION
The engine must be provided with asupply of fresh air
for cooling and for combustion. Figure 2.
Pressure Cooled Engine: Position the air inlet open¬
ing directly in front of the engine and as close to the
eng ine blower wheel as possible. The area of the inlet
should be not less than 65 square inches (419 cm 2 ). if
louvers or grill work are used, increase the area to
compensate for the reduced air flow. Provide extra
ventilation if the driven load generates heat during
operation.
The heated air outlet must allow the heated air to
escape freely and prevent recirculation with the
cooling air. A duct between the compartment air inlet
and the engine blower housing may be necessary.
Locate the air outlet opposite the intakeorat least at a
90 degree angle. The area of the outlet should be at
least 15 percent larger than that of the inlet Allow
sufficient room on ail sides to permit access for
servicing.
Open Air Installation: For installations where the
engine is operated outside, ventilation will be no
problem. However, in protecting the engine from the
elements, see that nothing obstructs the flow of air
around the engine.
Vacu-Flo Cooled Engine: The Vacu-Fio equipped
engine uses separate flywheel and a blowerwheelto
puli cool air into the engine shroud and over the
cooling fins and surfaces of the engine. Figure 2.The
heated air is directed through an airtight scroll which
encases the blower. The scroll may be positioned to
discharge heated air in the 12 o’clock or 3 o’clock
direction, (Figure 3). The scroll outlet has a mesh-
type screen for safety.
The outlet of the VACU-FLO scroll
must not be restricted or overheat¬
ing wUI result. Engine overheating can cause troubles
ranging from vapor lock to scored pistons and
cylinders.
The area of the air inlet must be at least 140 square
inches (903 m 2 ). If a filter, grille, or louvers are used,
the inlet opening must be increased accordingly. The
air outlet opening should be located as close to the
engine as possible.
FIGURE 2. AIRFLOW THROUGH ENGINES
If the duct length exceeds 5 feet (127 m) t increase
duct size 30 percent. Use no more than two 90 degree
radius-type (not square-type) elbows if it is necessary
to change air flow direction. When a duct is used
between the sc roil discharge and the outlet vent, its
unobstructed airflow area must be at least as large as
the scroll discharge. The cross-sectional area of the
duct must be increased if air flow is restricted by
bends, long runs, screens or the exhaust pipe.
Exhaust pipes running inside Vacu-Flo ducts should
be covered with asbestos tape.
9

Onan CCK Specifications

General

Cylinders	2
Ignition System	Battery ignition
Fuel Type	Gasoline
Cooling System	Air-cooled
Fuel System	Carburetor
Starter	Electric
Governor	Mechanical
Max RPM	1800 RPM
Engine Type	4-cycle
Bore and Stroke	3.25 x 3.625 inches (82.55 x 92.08 mm)