Jabiru Aircraft Pty Ltd, II
An aircraft and engine company from Australia and their aim is to develop and sell reasonably priced aircraft and engines. We do not know of many companies building both aircraft and engines, but Jabiru Pty is one of them. Development started when the need came to power their in house designed aircraft when their engine supplier ceased production.
They started with a 60 bhp 1600cc engine to power their aircraft and after many moons this resulted in the 80 bhp four cylinder Jabiru 2200, followed later by the 120 bhp six cylinder Jabiru 3300. At one time they were also working on an eight cylinder Jabiru 5100.
They also manufacture a successful line of experimental and certified aircraft ranging from two to four seaters, all developed around and powered by their own engines. We will concentrate on the powerplants here.
This part two is going to take a look at the internal engine part as valve gear, oil pump and cooling of the engine.
Jabiru engine design, Part II
Lubrication is accomplished by an oil pump driven by the camshaft, as seen in so many aero engines.
Valve Gear & Oil Pump
The valve gear includes push rods 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 an aluminium bronze bush.
Valve guides are manufactured from aluminium/bronze, as is found in larger aero engines and high performance race 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.
Internal gear pump
An internal gear pump, directly mounted on the camshaft and incorporating a small automotive spin-on filter, provides engine lubrication. An oil cooler adapter is provided. Most installations will require an oil cooler to meet oil temperature limits.
The recommended oil to be used in the engine is any standard aviation type multigrade oil.
Ram Air Cooling
The standard engines are supplied with two RAMAIR cooling ducts, which have been developed by Jabiru to facilitate the cooling and direct air from the propeller to the critical areas of the engine, particularly the cylinder heads and barrels.
The fact that these baffles and plenum chamber are not required also ensures a "cleaner" and much easier engine installation, which in turn facilitates easy maintenance and inspection of the engine and components. RAMAIR ducts are available for tractor or pusher configurations. Special ducts are available for certain installations.
Fuel System & Exhaust
The fuel induction system comprises one BING pressure compensating carburetor. Following carburation, the fuel/air mixture is transported to a small plenum chamber in the sump casting, in which the mixture is warmed prior to entering short induction tubes attached to the cylinder heads.
An effective stainless steel exhaust and muffler system is also fitted as standard equipment.
Text partially from Jabiru.