Jabiru Gen 4

[kgwilson]

Yes from the BP document published in January 2010. Crikey that was 14 years ago and we are still debating it. I'll get me hat & coat.

[Bat6065]

Whatever… seeing as AVgas and Mogas are virtually the same thing… just slightly different components to get the different octane numbers … both change depending on where they’re used … be it in a cold climate or warm… be it summer or winter…. Even altitude

 

So the argument between one or the other is just silly…. One is 100 octane and contains Lead the other is a lower octane and doesn’t…. Seeing as most aero engines are low compression…. The engine doesn’t care…. Just as long as it doesn’t need the lead for lubrication

 

The Avgas I helped make was full of Alkylate made from C3’s and C4’s after passing through Hydrofloric acid

 

ask you chemist mate what that would do to aero engines if it wasn’t neutralised correctly…. I actually think BP knows…. Rather large compo bill I think…. Though happy to stand corrected

 

 

[Freizeitpilot]

HF Alky unit ? Sounds like Lytton, Bulwer Is or Kwinana. The rest used H2SO4 from vague memory.

[Bat6065]

Again… the point?

 

it’s acid…. Used as a catalyst

 

anyone tells you Avgas and Mogas are chalk and cheese…  ignore them

 

if your engine needs lead run 100LL avgas

 

if not…. 98 ULP won’t hurt…. Provided the compression and timing allows it

 

if an engine manufacturer says it can be used….. use it

 

full stop

 

now about those Gen4’s and feedback positive or negative 

Edited April 17 by Bat6065

[skippydiesel]

1 hour ago, RFguy said:

fresh ULP98. if in plastic container, or place where it can breath oxygen, ditch it or use it within a month. always filter and water check.
The octane doesnt fall with time- what happens is  some components react with oxygen and form non soluble solids....

Avgas only if nothing else is available, or the heads run red hot (>165 cruise, >180 climb) .

Fresh ULP 98RON, will store for over 6 months, in an airtight fuel rated (AU standard) container (plastic/metal whatever) that is 75%+ full.  The discussion, in this Forum, on fuel deterioration has been comprehensively done to death.

[Area-51]

1 hour ago, Bat6065 said:

Ooh!!!….. now I’m doing it!!!!

Yes its very contagious this drift phenomena... it can corrected using the 1:60 rule; at approximately 60 responses into a thread one response will be topic relevant and TMG is achieved however additional drift will always occur before the interception point and fuel starvation occurs shortly after due to compass error with no further transmissions heard of again...

[skippydiesel]

9 hours ago, jackc said:

Skippy, did you take your meds today 🤩 it’s just an opinion…..I am not forecasting the end of Aviation 🤩

Its unfounded opinions, like you expressed publicly, that gain traction, creating what is often called scutelbut, urban rumor, etc

 

I have traveled in Super Connie, with one engine shut down, somewhere over the Indian Ocean, "to conserve fuel" - give me a modern "jet" any day

[Area-51]

2 hours ago, BrendAn said:

wasn't that called a thruster. the first certified 2 seat ultralight in the world.

Not sure; could be. These days they strap a two stroke straight onto the bum and use bedsheet with strings to fly around slowly. Seems to work until it doesnt... 🤷🏼‍♂️

[Area-51]

Nobody has strapped a gen4 to a bedsheet with strings yet 🤔

[jackc]

1 minute ago, skippydiesel said:

Its unfounded opinions, like you expressed publicly, that gain traction, creating what is often called scutelbut, urban rumor, etc

 

I have traveled in Super Connie, with one engine shut down, somewhere over the Indian Ocean, "to conserve fuel" - give me a modern "jet" any day

Skippy, yeah it’s my useless opinion……people can make their own minds up 👍

[kgwilson]

I have always run  my Gen 3 3300A on 98 PULP after it became harder to get 95 PULP. A lot of petrol stations changed to 94 and stopped stocking 95. 94 though is just 91 with ethanol to boost the octane.

Avgas and 98 PULP are quite different chemically. Avgas is based on Paraffin which is what you find in candle wax & TEL is added to boost the octane whereas 98 PULP is based on aromatic hydrocarbons & uses xylene, benzene, toluene  & other light enes to boost its octane levels. The problem is that the light ene products evaporate off first so it will only store well in sealed full containers. 98 pulp also keeps your engine clean as it also contains detergents & there is no lead to foul plugs and valves & heads.

 

In a study done in the US related to developing lead free Avgas it was found that over 80% of all piston engined aircraft in the US were capable of running on unleaded petrol but few did mainly due to it not being available at aerodrome fuel depots.

 

The only down sides to 98 PULP are shelf life in the tank is much shorter than Avgas, vaporisation risk at high altitudes over 10,000 feet & that it stinks & permeates through the walls of my vinyl ester fuselage tank though it is only a problem when opening the canopy & clears fairly quickly.

[BrendAn]

7 hours ago, Area-51 said:

Nobody has strapped a gen4 to a bedsheet with strings yet 🤔

Yes that's true. I have never heard of a gen 4 powered strap on , it would be quite a sight although eye watering for the receiver.

[skippydiesel]

11 hours ago, jackc said:

Skippy, yeah it’s my useless opinion……people can make their own minds up 👍

For sure.

Just so that you know that we are not so far apart in our aesthetic tastes. I love the look of:

Super Constellations

DH Hornets

DH Comet

DH 88 Comet

VC 10

Straight wing Learjets

Straight Tail Cessnas

Bonaza's

Mooneys

and many more of the older/classic aircraft

[facthunter]

The VC 10 was called the "IRON DUCK".   Nev

[Thruster88]

14/4/2024OCC3655DubboNSWJabiruJ230JabiruGen 4 3300OCCURRENCE DETAILS SUBMITTED TO RAAUS: During the flight, the pilot heard a bang and the aircraft sh... 

OCCURRENCE DETAILS SUBMITTED TO RAAUS: During the flight, the pilot heard a bang and the aircraft shook violently. At first, the pilot thought they had collided with a large bird. The pilot disabled the autopilot and checked the readings, and temps and oil pressure were normal but RPM was erratic. The pilot closed the throttle to idle and made an immediate turn for Dubbo. Approximately 15nm east of Dubbo airport, the pilot contacted ATC with a Pan Pan. After 1-2 mins the prop began to spin slower than the RPM and was causing an excessive sink rate. The pilot switched to a MAYDAY call as the airframe was shaking even worse and affecting controls. The pilot made an uneventful landing into a paddock. The pilot shutdown the aircraft and advised ATC of landing.

End of RAAus report.

 

My comment

Bird, loose prop, dropped valve, we will never know. Got to love the way these reports are written. "After 1-2 mins the prop began to spin slower than the RPM and was causing an excessive sink rate". WTF does that mean.  

[jackc]

The quality of that report equals the same as a Billycart losing a back wheel 🤩

Need to do better than that….

[Blueadventures]

59 minutes ago, Thruster88 said:

14/4/2024OCC3655DubboNSWJabiruJ230JabiruGen 4 3300OCCURRENCE DETAILS SUBMITTED TO RAAUS: During the flight, the pilot heard a bang and the aircraft sh... 

OCCURRENCE DETAILS SUBMITTED TO RAAUS: During the flight, the pilot heard a bang and the aircraft shook violently. At first, the pilot thought they had collided with a large bird. The pilot disabled the autopilot and checked the readings, and temps and oil pressure were normal but RPM was erratic. The pilot closed the throttle to idle and made an immediate turn for Dubbo. Approximately 15nm east of Dubbo airport, the pilot contacted ATC with a Pan Pan. After 1-2 mins the prop began to spin slower than the RPM and was causing an excessive sink rate. The pilot switched to a MAYDAY call as the airframe was shaking even worse and affecting controls. The pilot made an uneventful landing into a paddock. The pilot shutdown the aircraft and advised ATC of landing.

End of RAAus report.

 

My comment

Bird, loose prop, dropped valve, we will never know. Got to love the way these reports are written. "After 1-2 mins the prop began to spin slower than the RPM and was causing an excessive sink rate". WTF does that mean.  

If in fact the prop spun slower than the rpm the crankshaft will be interesting now; glad aircraft got on the ground undamaged and pilot ok. If bird strike you would expect some noticeable signs or splatter on after landing inspection.  Therefore, maybe an engine matter.

[kgwilson]

Crankshaft or prop flange are possibles. I'd expect oil pressure to drop if there was a crankshaft fracture. I hope we find out what it was.

[skippydiesel]

On 17/04/2024 at 8:34 AM, justinjsinclair said:

Hi Glen, I guess we need to compare like with like, I know you are well versed in Jabs 😅 and are Lucid, intelligent and a great thinker.

 

I ..............................................................................................................................................................................................Justin 

 

Hi Justine, Me again - sorry!

 

I may have missed it in your lyrical support of Jab engines - did you fail to mention/cost that Rotax

• Recommend  100hr oil / filter change intervals. From imperfect, aging memory, this means that Jabs will have 4 oil/filter changes to one Rotax. Cost$$$
• In the same airframe, a Rotax of similar performance to a Jab (ie 80/80 or 100/120) will deliver markedly better fuel economy. Cost$$$ 
• Resale of used Rotax 9's (TBO sales from schools etc) looks pretty healthy. Cost $$$
• Just checked the approximate price of a Rotax 912UL (the equivalent of your Jab 2200) $30K - this is probably base price, so lets say $35K, a tad cheaper than the $40K you estimated.

Rotax 9's are expected to go to TBO (hrs) & well beyond, with little if any major life extending intervention. It can be a bit of a shock when the occasional one fails to deliver on this expectation but really all mechanical devices are subject to failure, it's just a matter of when and how much it may cost, in dollars, loss of amenity & crew health. (none of the later costed by you)

Dont know if Jab 4's have been around long enough to compare but the fact that you have costed sundry life extending intervention, would suggest that they still have some way to go from a reliability (crew health) perspective, loss of amenity (when aircraft in the shop for length repairs).

 

Speculation; Your costed list below  for the 80 hp Jab ".......from $..." could easily blow out to a replacement engine every 1000 hrs😈

 

"Current jabiru pricing is 

  2200 Engine Gen 4

** Top End Overhaul            from $5,200
** Full Overhaul                     from $6,300
** Bulk Strip                            from $6,300
**Does not include replacement of substantial items ie. crank, 
cam , conrods, cylinders and heads. Engines must still be running.. 

so in actual fact the Gen4 is cheaper to overhaul every 1000 hours by about $15,000. "

[justinjsinclair]

Hey Skippy, the name is Justin. 
just out of interest have you ever owned an aeroplane ? 
Justin

 

 

[jackc]

10 hours ago, skippydiesel said:

Hi Justine, Me again - sorry!

 

I may have missed it in your lyrical support of Jab engines - did you fail to mention/cost that Rotax

• Recommend  100hr oil / filter change intervals. From imperfect, aging memory, this means that Jabs will have 4 oil/filter changes to one Rotax. Cost$$$
• In the same airframe, a Rotax of similar performance to a Jab (ie 80/80 or 100/120) will deliver markedly better fuel economy. Cost$$$ 
• Resale of used Rotax 9's (TBO sales from schools etc) looks pretty healthy. Cost $$$
• Just checked the approximate price of a Rotax 912UL (the equivalent of your Jab 2200) $30K - this is probably base price, so lets say $35K, a tad cheaper than the $40K you estimated.

Rotax 9's are expected to go to TBO (hrs) & well beyond, with little if any major life extending intervention. It can be a bit of a shock when the occasional one fails to deliver on this expectation but really all mechanical devices are subject to failure, it's just a matter of when and how much it may cost, in dollars, loss of amenity & crew health. (none of the later costed by you)

Dont know if Jab 4's have been around long enough to compare but the fact that you have costed sundry life extending intervention, would suggest that they still have some way to go from a reliability (crew health) perspective, loss of amenity (when aircraft in the shop for length repairs).

 

Speculation; Your costed list below  for the 80 hp Jab ".......from $..." could easily blow out to a replacement engine every 1000 hrs😈

 

"Current jabiru pricing is 

  2200 Engine Gen 4

** Top End Overhaul            from $5,200
** Full Overhaul                     from $6,300
** Bulk Strip                            from $6,300
**Does not include replacement of substantial items ie. crank, 
cam , conrods, cylinders and heads. Engines must still be running.. 

so in actual fact the Gen4 is cheaper to overhaul every 1000 hours by about $15,000. "

As an aside,  yesterday I looked at an aircraft getting retrofitted with a new Rotax 912IS  and decided

after looking over the  complexity of the job and the differences to the 912 UL it replaced.

I would never consider doing that job.  I would simply have done that job with a Gen 4 Jab motor.  I would suggest ANYONE going to a 912IS is, DONT 🤢

You want to go 912IS?  Just go buy a new aircraft with a factory specced one. 

[skippydiesel]

10 hours ago, justinjsinclair said:

Hey Skippy, the name is Justin. 
just out of interest have you ever owned an aeroplane ? 
Justin

 

 

Sorry about the spelling fopa.

 

What has your question "ever owned an aeroplane" got to do with the cost of owning one?

 

So how come you didn't address any of my observations?

[skippydiesel]

16 minutes ago, jackc said:

As an aside,  yesterday I looked at an aircraft getting retrofitted with a new Rotax 912IS  and decided

after looking over the  complexity of the job and the differences to the 912 UL it replaced.

I would never consider doing that job.  I would simply have done that job with a Gen 4 Jab motor.  I would suggest ANYONE going to a 912IS is, DONT 🤢

You want to go 912IS?  Just go buy a new aircraft with a factory specced one. 

Speculation:

 

Compared with the 912ULS

• The main  benefit s of the 912iS would seem be lower fuel consumption, reduced chance of inlet icing and FADEC like engine controls.
• Its claimed 100 hp is the same however I have read reports that it is able to deliver the power such that TO/Climb Out is improved.
• The big downside is much higher upfront cost.
• It has been suggested and sounds logical, that the iS can only be justified (cost effect) by high time flight operations ie training/renting as the savings in fuel will only be returned by such operations.

 

For my flying, an iS could not possibly be justified, however I would simply go for a trusty 912ULS, as I have now.

[jackc]

Skip, get back to me when You have had a good look at one,  just getting the software out of Rotax, to setup and commission it is a nightmare and that, is only the start.

Interfacing to a Dynon or Gamin is another thing 🤢

[BrendAn]

20 minutes ago, skippydiesel said:

Sorry about the spelling fopa.

 

What has your question "ever owned an aeroplane" got to do with the cost of owning one?

 

So how come you didn't address any of my observations?

You are an angry kangaroo lately.

When you insult someone at least own it.