Jabiru Aircraft
Pty Ltd
Installation Manual
Jabiru 3300 Aircraft Engine
REVISION
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Dated : 1
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Dec 2016
Page: 13 of 56
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Engine Crankcase Breather, Catch Bottle & Dipstick
The Jabiru 3300 engine has a crankcase breather connection built into the dipstick housing. This is to be
connected as shown in Figure 8 below.
The catch bottle is designed to catch most oil vapour from the crankcase breather air. It must be monitored
in service and periodically emptied of waste oil.
Figure 58 shows more clearly the outlet from the catch bottle
– the catch bottle outlet is secured in the cowl
outlet. The position of this outlet and the catch bottle itself must be assessed and oriented so that the
crankcase of the engine is exposed to pressure close to ambient. If the breather is open to a high or low
pressure (partial vacuum) area the pressure inside the crankcases will also change, with unpredictable
effects on engine oil consumption, and oil flow within the engine. This is because several areas of the
engine are lubricated via low pressure or spray oil feeds, and drained by gravity
– pressure differences
cause airflow changes, and modified airflow can significantly affect the oil feeds in these areas.
When installed in a tail-dragger aircraft, re-calibration of the dipstick will be required by the owner so that it
can be read accurately with the aircraft sitting on it’s wheels.
Figure 8. Crankcase Breather Installation
Catch bottle
attached to firewall
Hose from engine
Hose to outlet
Hose from engine
to catch bottle
