Jabiru 3300- 120HP Aircraft Engine


Jabiru 3300 refers to a six-cylinder air-cooled engine made by Jabiru Aircraft Pty. Ltd. The company designed this aircraft engine to run on AutoGas Octane-Minimum or AVGAS 100LL.

This aircraft engine is amongst the most preferred engines because of its power rated 120 horsepower @3300. It’s a smooth-running aircraft engine that maximizes the six-cylinders’ inherent dynamic benefits. Smooth operation and good power make this engine the perfect option.

Jabiru 3300 Engine Details


● Electrical starter

● Ramair cooled

● Four-stroke

● Six-cylinder

● Overhead valves

● Direct propeller drive

● Bearing crankshaft

● One central camshaft

● Tractor and pusher exhaust systems

● Wet sump lubrication

● Pressure compensating carburetor

● The integrated alternating current generator

● Aluminum alloy crankcase

● Mechanical fuel pump

Oil Pump & Valve Gear

This aircraft engine’s valve gear is the product of bronze and aluminum, as observed on high-performance race and larger aero engines. The replaceable valve seats, shrinking into aluminum’s cylinder heads, are the products of nickel steel.

For the oil pump steered by the camshaft, it plays a pivotal role in ensuring valve gear lubrication takes place smoothly. Also, the valve gear features pushrods that run from the camshaft. Next to the camshaft are the valve rockers that are induction hardened, CNC mass-produced from structural steel, and polished on their contact surfaces. Finally, an aluminum bronze bush has been used to mount the valve rockers on the shaft.

Internal Gear Pump

The internal gear pump attached to the camshaft plays a crucial role in providing engine lubrication. Also, an oil cooler ensures most installations take place as per the required oil temperature limits.

Ram Air Cooling

For the standard engines, they feature two ram air cooling ducts. Jabiru developed these ducts to enhance cooling and ensure propeller air gets directed to the Jabiru 3300 engine’s critical areas. Mostly, the ducts direct this air to barrels and cylinder heads.

No Baffles

The absence of a plenum chamber and baffles ensures a cleaner engine and a much easier installation process. As a result, this promotes easy engine maintenance and component inspection.

Exhaust & Fuel System

The fuel system features a BING pressure carburetor. After the carburetion process, the fuel or air mixture gets transported to the sump casting’s small plenum chamber. The mixture gets warmed in this chamber before entering the short induction tubes featured on the cylinder heads.


Designed Using CNC Machine Tools

As per the Jabiru 3300 engine design, the manufacturing process needs to take place in small group quantities with the latest CNC machine equipment’s help. Manufacturing of the engines several components is made possible by various high-tech small companies.

The companies apply CNC machine equipment to machine gearbox cover, crankcase halves, coil mounts, starter motor housings, cylinder, and crankshaft. The only casting, in this case, is an oil pan.

Jabiru machined the cylinders using 4140 chrome alloy steel. Also featured are the pistons that run in the steel bores. Moreover, Jabiru machined the crankshaft from 4140 chrome alloy steel with precision ground and Magna flux inspected journals. For the camshaft, it’s the product from the specialist manufacturer.

This camshaft drives the propeller, which doesn’t feature a reduction gearbox. As a result, this explains the propeller’s lightweight design – a feature that ensures minimum maintenance costs. There is a removable prop flange in the crankshaft that makes it easy to replace the forepart crankshaft seal. With the removable prop flange, it becomes easy to fit the propeller’s extension for particular applications.

The cylinder heads are the products of aluminum billet that Jabiru purchases from Australia’s top-rated aluminum companies. Also, Jabiru uses 4130 alloy steel to machine automotive slipper con rods.

Also, there is an integral alternator that uses rare earth magnets. It plays a pivotal role in providing alternating current for an electrical accessory drive and battery charging. The crankshaft drives this engine component mounted to the flywheel.

Another crucial component of the Jabiru 3300 engine is the ignition system. This transistorized system features two fixed coils attached next to the flywheel, and they get their energy from the rare earth magnets fixed to the flywheel.

The positioning of the two coils next to the rare earth magnets creates a high voltage current. This current gets transported to the two automotive type distributors’ center post by high tension leads before getting distributed to spark plugs.

Designed to Prevent Radio Interference Issues

With the ignition system, there’s no requirement for timing adjustment because it’s fixed timing. It’s a suppressed component that prevents all radio interference issues. Moreover, the ignition system is a self-generating and redundant component that doesn’t rely on battery power.

A double bearing is another component of this engine located at the crankshaft’s propeller flange end. Also, there is a leading bearing featured between the crankshaft’s bid ends. Therefore, there are no flying webs attached to the crankshaft. These main bearings that measure 48mm fall under the category of automotive slippers. Moreover, thrust bearings are at the front side of the double bearing that enhances pusher installation or tractor installation.

Jabiru-designed pistons are the products of a professional piston manufacturer. These pistons feature three rings, whereby the top rings are the products of cast iron material to match well with the cylinder bores. The valves measure exactly 7 mm so that they work excellently with the Jabiru 3300 engine.

The engine’s valve gear features pushrods on the roller follower. Next are the hardened and forged valve rockers attached to the shaft with the help of a pressure-lubricated bush. Moreover, these valve guides are bronze and aluminum products as the replaceable valve seats shrunk into the aluminum heads are nickel and steel products. Besides this, the valve gear oil lubrication takes place with the help of pushrods.

Engine lubrication becomes possible with the help of the Jabiru 3300 engine’s internal gear pump. This pump mounted directly on the camshaft also incorporates a small spin-on filter. Another pivotal component of this engine is the oil cooler adapter. This component helps in ensuring all installations take place as per the oil temperature limits.

Jabiru 3300

Engine Cooling Design

This aircraft engine has two main ram air cooling ducts. Jabiru developed these ducts to enhance engine cooling and direct the propeller air to the engine’s critical areas, specifically the barrels and cylinder heads. The ducts’ fitment is an excellent benefit for engine installers or home builders because they do away with the need to blueprint and manufacture the plenum chamber’s baffle establishment.

A plenum chamber refers to the traditional technique used to cool air-cooled aircraft. The absence of a plenum chamber and baffles also results in a cleaner Jabiru 3300 engine installation. As a result, these features’ lack ensures easy maintenance, engine component inspection, and engine inspection. Therefore, Jabiru’s design team has made the engine installation process hassle-free. Ramair ducts work excellently for pusher configurations or tractor configurations, while other special ducts work explicitly with specific installations.

A 1.2-kilowatt starter motor is another excellent feature of this aircraft engine. This engine features low vibration levels, but it gets massive support from four rubber shocks connected to the aircraft engine’s rear.

Furthermore, there is a fuel induction system that features a BING carburetor. After the carburetion process, the air and fuel mixture gets transported to the sump casting’s small plenum chamber. The mixture gets warmed at the sump casting before getting its way to the short induction tube position at the cylinder heads.

Moreover, the Jabiru 3300 engine is the perfect option for those desiring to see their aircrafts having vacuum instruments. This engine features a vacuum pump drive that’s attached to the crankshaft’s rear side.

Finally, Jabiru designs and manufactures these engines as per ASTM F2279, ASTM F2339, and CASA quality assurance standards.


Jabiru 3300 engine has a compensation ratio of eight-to-one and one-to-ten kW/kg horsepower to weight ratio. This engine’s predicted performance points include:

  • 80 horsepower at 2200 rpm.
  • 90 horsepower at 2475.
  • 93 horsepower at 2551 rpm.
  • 100 horsepower at 2750 rpm.
  • 110 horsepower at 3000 rpm.
  • 120 horsepower at 3300 RPM.


Engine TBO and Engine overhaul is a task carried out solely by Jabiru Aircraft Pty Limited or by an authorized Jabiru Engine Service Station. The engine should be forwarded in a completed condition, with a logbook, to an authorized Service station or Jabiru after attaining the TBO limit. Also, a questionnaire can be sent relating to the engine’s service life. Here, the questionnaire will be filled out entirely and taken back with the Jabiru engine.

It’s only Jabiru that will advise through Service Bulletin on the TBO changes relating to operational experience. Jabiru 3300 engine complete overhauls stand at 2000 hours as the Top End is done approximately 1000 hours. However, all this depends on certain conditions because conditions have a direct impact on overhauls.

Full Overhaul

Full overhauls should be handled as per the latest updates from the Jabiru 3300 engine overhaul manual. As per this manual, a full overhaul should involve cleaning, measuring, inspecting all the parts, and recording the prescribed sheets’ results. Parts that need replacement during this exercise include rotors, conrod bearings, oil hoses, conrod bolts, valves, oil filter, thrust bearings, intake or exhaust studs, main bearings, pistons, rings, oil feed tees, circlips, and gudgeons, induction hoses, spark plugs, oil pump, crankcase studs, crankcase bolts, prop flange bolts, fuel pump, seal and gasket o-rings, flywheel bolts, and head bolts. For dizzy shafts, heads, and cylinders, they get replaced depending on the condition.

Running in the Jabiru 3300 engine is a pivotal step under the overhaul process. Also, the process should be undertaken as per the steps highlighted in the overhaul manual. Running in the engine on the ground should involve using a large oil cooler and large air cooling ducts. Jabiru runs in the engines before dispatching them, meaning you don’t have to repeat this process.

Top End Overhaul

Top End Overhaul is another process carried out as per Jabiru’s updates relating to the Jabiru 3300 engine overhaul manual. The parts that need a replacement include valves, gaskets, o rings, pistons, rotors, conrod bearings, rings, the fuel line, circlips, gudgeon pins, cap screws, head bolts, and induction hose joiners. Parts like barrels, heads, exhaust cap screws, oil seals, induction cap screws, coils, alternators, ignition leads, starter, fuel pump, and oil pump need an inspection, measuring, and cleaning.

Running-in the Jabiru 3300 engine is a pivotal step under the top-end overhaul process. Also, the process should be undertaken as per the steps highlighted in the overhaul manual. Running in the engine on the ground should involve using a large oil cooler and large air cooling ducts. Jabiru runs in the engines before dispatching them, meaning you don’t have to repeat this process.

Jabiru 3300 Reliability/Problems

Jabiru 3300 engine uses a carburetor, which is not ideally made to compensate for air density variations. Thus, this suggests that the engine is likely to operate richer/leaner than recommended as the atmospheric conditions keep changing. Besides this, a carburetor cannot manage fuel division between the cylinders. The peculiarities of individual induction systems are the reason for this effect.

These deficiencies are likely to cause several issues, such as high fuel consumption, fouled spark plugs, and engine roughness. However, Jabiru has innovated an automatic mixture control system that works excellently with the Jabiru 3300 engine to handle these issues.


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The way to the Jabiru 5100

Later, Jabiru Aircraft upgraded their Jabiru 3300 engine and developed the direct-drive Jabiru 5100 engine. These engines share the 97.5 mm bore. The only difference is that Jabiru Aircraft increased the stroke from 74 millimeters to 85 millimeters for Jabiru 5100.

Final Thoughts

Jaribu 3000 is the work of aircraft designers, specifically meant for aircraft applications. Jabiru Aircraft manufactures these engines using high-quality billet materials and as per the approved production quality standards.

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