Jabiru 3300 Instruction And Maintenance Manual Download

Page: 6 / 103

Page No: 6

Issue No: 1

Date: 031100

Issued By: PJA

The ignition coils are also sourced from Honda, but are modified by Jabiru for their own
particular application.

An integral alternator using rare earth magnets, provides alternating current for battery
charging and electrical accessory drive. The alternator is attached to the flywheel and is
driven directly by the crankshaft. The ignition system is a transistorised electronic system;
two fixed coils mounted adjacent to the flywheel are energised by rare earth magnets
attached to the flywheel. The passing of the coils by the magnets creates the high voltage
current which is then transported by high tension leads to the centre post of two
automotive type distributors (which are simply rotors and caps) before distribution to
automotive spark plugs, two in the top of each cylinder head. The ignition system is fixed
timing and, therefore, removes the need for timing adjustment. It is suppressed to prevent
radio interference. The ignition system is fully redundant, self-generating and does not
depend on battery power.

The crankshaft is designed with a double bearing at the propeller flange end and a main
bearing between each big end; it therefore does not have flying webs. 48mm main
bearings are also of the automotive slipper type. Thrust bearings are located for and aft of
the front double bearing allowing either tractor or pusher installation.

Pistons are General Motors aftermarket made in Australia and are re-machined to include
a piston pin circlip groove. They are fitted with 3 rings, the top rings being cast iron to
complement the chrome molybdenum cylinder bores. Valves are 7mm (stem dia) which
are purpose manufactured for the Jabiru engine in England.

The valve gear includes pushrods from the camshaft from the camshaft followers to valve
rockers which are CNC machined from steel plate, induction hardened and polished on
contact surfaces and mounted on a shaft through a teflon bronze-steel bush. Valve guides
are manufactured from aluminium/bronze, as is found in larger aero engines and high
performance racing engines. Replaceable valve seats are of nickel steel and are shrunk
into the aluminium cylinder heads. The valve gear is lubricated from the oil gallery.

An internal gear pump, direct mounted on the camshaft and incorporating a small
automotive spin-on filter, provides engine lubrication. An oil cooler adapter is provided.
Most installations require an oil cooler to meet oil temperature limits.

The standard engines are supplied with two RAMAIR cooling ducts, which have been
developed by Jabiru to facilitate the cooling of the engine and direct air from the propeller
to the critical areas of the engine, particularly the cylinder heads and barrels. The fitment
of these RAMAIR cooling ducts is a great bonus for the home builder or engine installer,
as they obviate the need to design and manufacture baffles and the establishment of a
plennum chamber, which is the traditional method of cooling air-cooled aircraft engines.
The fact that these baffles and plennum chamber are not required also ensures a "cleaner"
engine installation, which in turn facilitates maintenance and inspection of the engine and
engine component. So the hard work of engine installation has largely been done for you
by the Jabiru design team. RAMAIR ducts are available for tractor or pusher
configurations. Special ducts are available for certain installations.