NEW World Speed Records for the Risen Aircraft - Just amazing !

[Reynard]

Jabiru has set a self-imposed deadline of July ‘26 for commercialising their fuel injected engines.

[skippydiesel]

2 hours ago, BurnieM said:

Injected engines are not new.

Turbo charged engines are not new.

True !

2 hours ago, BurnieM said:

 

I cannot recall any motorcycle you could buy in the last 30 years without injection and no car in the last 40 years.

 

Up until very recently (may be still) small capacity motorcycle engines were still carburetted. Most small industrial engines have carburettors (larger ones have an injected option). I suspect that infection has a diminishing return, the smaller the engine capacity ie the fuel savings are less.

 

Yes there are more moving parts but most kinks were worked out years ago.

Injection is a very good solution to the mixture problem.

Engines should give better economy, better power and last longer with injection.

Injection has merit - not against it, however there is no denying that it is a substantial increase in complexity. Complexity brings with it increased cost & potential for failure. The usual response to this is to have back up/redundant system that will hopefully get you home/to a safe landing. Back up systems add cost.

2 hours ago, BurnieM said:

 

912is are a very nice engine with similar performance to a ULS but better cruise economy.

True again! BUT the additional complexity & cost needs to be weighed against the improved fuel efficiency. Assuming the same power setting, the IS may deliver 10L/hr in Cruise to the ULS 14L/hr. 

A 912is will set you back about $51,000Au, a 912ULS $37,000Au - The difference $14,000 Au. 98 Ron is about $2 /L at the moment. Say you fly 100 hrs/annum (unlikly), your saving is $8/hr x 100 =$800 in savings. You will have to fly for 17.5 years to break even with the purchase cost of your IS.

All of this is assuming that other running costs will be the same - I think this unlikly with the potential for the IS computer/electric pump reliance, a potential money burner.

A clever person would calculate the interest/investment  potential on the $14 K X 17 years and add that to the equation.

I suggest that for most Au pilots the savings are illusory.

The IS has real potential for commercial application (training, etc) especially when the sale price of the used engine is taken into consideration.

 

There are two  addition benefits with injection;

• Much reduced chance (nil?) of carb/inlet ice. This is not so attractive in the Rotax 912 range as the placement of the carburetors , on top of the engine, mitigates against ice. Having said that nil chance is obviously better than mitigated.
• Injection & turbo charging are a marriage made in heaven.

 

2 hours ago, BurnieM said:

 

Yes these engines have diferrent failure risks but I wonder when I hear 'carbs are reliable' whether both engines are being intelligently assessed.

Carburettor are simple, well known technology that rarely have a catastrophic failure ie incredibly reliable. Their main drawbacks (compared with computer managed fuel injection) are is less accurate fuel metering, inferior atomisation, continued fuel flow, even when throttle closed, leading to higher fuel consumption and  carburettor ice. From a reliability point of view - hard to beat.

2 hours ago, BurnieM said:

 

Turbo chargers carry their own potential issues which is probably why these engines come with many performance and warning sensors. 

Turbo chargers are not in themselves a particularly complex efficiency enhancer. They are essentially a centrifugal air pump driven by a centrifugal exhaust (waste) gas engine. The increased air flow, to the cylinders allows for more fuel to be burnt and or more efficiently, delivering greater volumetric efficiency. They become complex when even higher levels of efficiency are demanded with simpler pilot application.  This is where computers make things seem simple, by doing the job for the pilot. Unfortunatly the computer requires all sorts of sensor to achieve this = much more complexity & cost.

 

Modern efiss like the Garmin G3X Touch give useful messages to hopefully prempt any issues.

 

But how else do you get a decent performance package in a light weight engine ?

Rotax have done it with their naturally aspirated 912 range. Then there are 2/ but thats a whole other story.

If you don't need  to fly at high altitude (well over 10,000ft) a turbo may have little benefit. Sure you can start to look at larger aircraft with higher hp engines, at some point a turbo may be the answer to your power/weight consideraton.

 

Sorry Jabiru dont do it for me, at any cost.

Not fair! - the Jab engine is evolving. The future looks good. Dont forget the Jab aircraft is possibly one of the most cost effective aircraft you can buy today. They are amazingly tough, comfortable to fly in - sure there have been engine issues but as I said this is being attended to.

😈

[BurnieM]

Carbs are a risk point.

Because they have been around for 100 years they are viewed as low risk. They are not low risk and there is no backup for them.

The likelhood of the risk occurring is small but it is still a significant risk.

This risk has been accepted for a long time causing some to believe this risk is small.

 

This is what I mean by "whether both engines are being intelligently assessed".

 

The risk points in the 912ULS and 912IS are very different.

Some have suggested that severity of risk and likelyhood of the risk occurring are less in a 912is.

 

 

Edited yesterday at 03:06 AM by BurnieM

[RFguy]

IMO the 914 is a good option. takes care of altitude (turbo) , simple control system. I dont know one that has stoopped. compare with many 912is and 915 I know that have stopped.

 

[skippydiesel]

Risk is part of life. 

 

Whats constitutes a high/low risk will depend on may factors, including personal perception, risk aversion/acceptance.

 

Cost will always be a factor in risk - an additional  $14k to reduce an already very low risk machines chances of stoppage, may seem like money well spent to you but not so attractive to me.

 

For the record; I don't see the Rotax 912iS being significantly safer/ more reliable than the ULS. Note the word "significantly" - this means that I acknowledge that with redundant/"get you to a safe landing" systems the engine may have the edge over the ULS when it comes to reliability but for me the advantage is very small.

 

The iS main benefit is fuel efficiency but even this is not enough to make the engine a cost effective purchase for your run of the mill 50 hrs/year pilot - would work for a flying school though.😈

 

 

[RFguy]

JABIRU PRICES FYI for the record 23 October 2025

Australian local buy price.

2200 Gen 4 Engine = AU$27,720 (GST Incl) + freight & insurance costs

3300 Gen 4 Engine = AU$34,870 (GST Incl) + freight & insurance costs

Both engines come supplied with Ram Air Ducts / Exhaust / Accessory Pack. The Oil Cooler is not included in the purchase of an engine.

 

My comment : allow about AUD$800 for the preferred/ shop installed for J230D  3300 oil cooler (8000075 aero classics- same as in many pipers and cessnas with 320/360s)