Jabiru Gen 4

[danny_galaga]

Faux pas 

[turboplanner]

Where are the Moderators?

[justinjsinclair]

45 minutes ago, turboplanner said:

Where are the Moderators?

Hey Turbo, 

I guess the answer is that the new world of opinions not based on fact or backed up by fact on forums is nearly over. If any member wants to give their opinion, that is perfectly acceptable but it needs to be patently pointed out that it is a “ opinion” and not necessarily based on proven data. If members of this forum want to bag Jabiru based on poor data then they should be made accountable. If members of this forum want to hide behind a pseudonym and  not stand up when questioned and be brought to account and provide data based on reliability they need to be accountable. 
There are many pilots and flying school owners out there that are doing it tough because some goose who has less than 3000 hours of instruction and has never owned or maintained  a 24 reg or better aeroplane sprouts utter rubbish based on what they have read on the internet. 
I have just had a beer with a very good mate of mine, GA CFI, RAA instructor and A330/B737 management pilot. He has just paid $2000 aud for a hose kit for his 912. That’s probably ok in Rotax circles but a Jabiru hose kit including fire sleeve is $200.00. I love rotax’s. ( well maybe not given their history 39-45) but am thoroughly sick of internet warriors who can’t run LoP, can’t do a 1:60, can’t fly in CTA, can’t land in max crosswind , leave the cockpit a shit fight after use, can’t make a radio call and can’t use a whizz wheel.

i guess it’s like this new age if STOL, what is the point if we fly into powerlines, 😫💁 because we are soy latte drinking city kids who can’t ride a horse, can’t strain a strainer post, can’t set a fox trap and certainly can’t do a good 3’ slope at full flap approach with half power at MLW with rear CoG into the western sun at dusk short of fuel.

 

 Without prejudice 
Justin

 

 

 

[BrendAn]

1 hour ago, justinjsinclair said:

Hey Turbo, 

I guess the answer is that the new world of opinions not based on fact or backed up by fact on forums is nearly over. If any member wants to give their opinion, that is perfectly acceptable but it needs to be patently pointed out that it is a “ opinion” and not necessarily based on proven data. If members of this forum want to bag Jabiru based on poor data then they should be made accountable. If members of this forum want to hide behind a pseudonym and  not stand up when questioned and be brought to account and provide data based on reliability they need to be accountable. 
There are many pilots and flying school owners out there that are doing it tough because some goose who has less than 3000 hours of instruction and has never owned or maintained  a 24 reg or better aeroplane sprouts utter rubbish based on what they have read on the internet. 
I have just had a beer with a very good mate of mine, GA CFI, RAA instructor and A330/B737 management pilot. He has just paid $2000 aud for a hose kit for his 912. That’s probably ok in Rotax circles but a Jabiru hose kit including fire sleeve is $200.00. I love rotax’s. ( well maybe not given their history 39-45) but am thoroughly sick of internet warriors who can’t run LoP, can’t do a 1:60, can’t fly in CTA, can’t land in max crosswind , leave the cockpit a shit fight after use, can’t make a radio call and can’t use a whizz wheel.

i guess it’s like this new age if STOL, what is the point if we fly into powerlines, 😫💁 because we are soy latte drinking city kids who can’t ride a horse, can’t strain a strainer post, can’t set a fox trap and certainly can’t do a good 3’ slope at full flap approach with half power at MLW with rear CoG into the western sun at dusk short of fuel.

 

 Without prejudice 
Justin

 

 

 

Don't forget your just another internet warrior like the rest of us.

Until proven otherwise 

[justinjsinclair]

7 hours ago, BrendAn said:

Don't forget your just another internet warrior like the rest of us.

Until proven otherwise 

I completely agree and that’s the whole point. If you are looking at building or buying  an aeroplane or thinking about learning to fly by all means use the web as it it’s a great tool. But please seek out qualified advice by a LAME, CFI or someone who has real world experience in or on the thing you are looking at.

if someone tells you that something is a bad choice then that’s fine but you really should be asking for facts.

Dont  trust me either 👍 but I do own a Gen 4 powered Jab. Happy for anybody to fly it as well.

 

[skippydiesel]

14 hours ago, facthunter said:

Skip is it JUST POSSIBLE your last post applies to you?. You are very scathing/dismissive of many other opinions, Nev

 

14 hours ago, Blueadventures said:

Exact same thought, absolutely agree. 

I do not dismiss other opinions - where I have something to contribute, I do. Scathing - for sure! where such a response is warranted.

 

Much depends on the logical progression of the writers case - if it doesn't sound right, it possibly isn't. If there are large gaps/omissions, the writer is either poorly informed or so biased he/she is unwilling to acknowledge information that does not support their assertions, alongside those that do ie not a balanced argument.

 

It is a shame that our debates, so often seem to, degenerate into personal attach.

Edited April 24 by skippydiesel

[skippydiesel]

2 hours ago, justinjsinclair said:

I completely agree and that’s the whole point. If you are looking at building or buying  an aeroplane or thinking about learning to fly by all means use the web as it it’s a great tool. Agreed But please seek out qualified advice by a LAME, CFI or someone who has real world experience in or on the thing you are looking at.

if someone tells you that something is a bad choice then that’s fine but you really should be asking for facts. The reality is we all tend towards bias, even "LAME, CFI". I absolutely agree with "asking for facts" however, in my limited association with the small aircraft world, it seems to me that bias, in the form of familiarity  unreasoned product loyalty, etc is on a par, if not trumping fact and this observation includes "LAME, CFI".  Confirmation bias is alive & well, reinforced by the retreat into the tribal gatherings, for reassurance/ afformaton. Difference of opinion is met by derision and even aggression.

Dont  trust me either 👍 Good advice but I do own a Gen 4 powered Jab. Happy for anybody to fly it as well.

 

 

 

[BrendAn]

2 hours ago, skippydiesel said:

 

I do not dismiss other opinions - where I have something to contribute, I do. Scathing - for sure! where such a response is warranted.

 

Much depends on the logical progression of the writers case - if it doesn't sound right, it possibly isn't. If there are large gaps/omissions, the writer is either poorly informed or so biased he/she is unwilling to acknowledge information that does not support their assertions, alongside those that do ie not a balanced argument.

 

It is a shame that our debates, so often seem to, degenerate into personal attach.

You asked what I was talking about the other day. This was it. You never used to be such a cranky old fart. That's my job 😁

[Methusala]

Hey! Just another forum. Nothing is 'gospel, nor 'truth. Opinions are matters for judgement. Each engine has its adherents or even 'fanboys. Never going to resolve questions of faith. I flew for 550 hrs behind a VW  conversion, fancy that.

[facthunter]

They can FAIL. ALL OF THEM.  and some ancillary part can cause it as much as an engine component. Simplicity is your friend. .Nev

[RFguy]

LOL.
trouble with trying to compare apples for apples with jab and rotax 2000 hour cost  is what value are you goign to use for normalizing the ULS (100hp) for the either 80hp jab or 120 hp jab.

Let's talk fixed pitch props and sea level and continuous power, all day, ULP.  

 

The Jab 120 hp jab is really only 115hp (for a fixed pitch prop) where you can actually run it up to  in the usual service pitch/RPM.

The Jab  80 hp, is really 80hp, since it likes to rev and generally they're propped finer and revs to 3300rpm  in normal service/pitch rpm use.  

The 100hp ULS should be called a 90hp, because that's all it is rated at continuously.

 

Prop spins a bit slower on the Rotax, that's worth a few % in efficiency.

Rotax runs lean in cruise. Jab runs compatratively rich, costing perhaps 5 to 10% in fuel 

 

What's good about a 3300 jab compared to the 912 ULS is that up high, the Jabiru has a fair bit of spare capacity to rev higher and make up for the altitude. 

 

AT 2000 hours, Rotax has had a gearbox service  @ 1000h maybe about a grand,  Jab has had a Jabiru factory TEO at 1000h

 

Both have had two sets of plugs. 

Both have had 1 set of hoses   (if you buy the rotax specified manufactuter's hoses from a sensible place they dont cost much at all) .

Both have had a fuel pump service (kit cost is similar) 

Both have had a carb service.(kit cost is similar but x2 for 2 carbs in the rotax ) 

Both have had 40 x  oil and filter changes.  if you buy oil filters from Jab, similar money. 

I'm a strong believer that a Gen4 should get to 1000 hours without incident if run on fresh ULP95/98 and 15W50 oil.

 

There's some teething problems at the moment with PD42J  carb changeover, and also ignition coil changes. (due to sourcing problems) .

 

2200 4 cyl Jab  is probably 5200+probably $1200 parts  = $6400 (valves, rings, rocker bushes, screws and bolts, o rings, seals ) 

3300 jab is 6400 +  1800 parts = $8200. 
Remember at 1000 hours, with the Jab,  you are goign to need to remove the engine and ship it both ways unless you do it on the plane (like I would) 
 

The rotax fuel consumption is worth a bit, at 2000 hours, youve probably put 1 litres more per hour into the 2200  = 2000 litres = $4000 more ! and proportionaly more for the 3300 6 cylinder.$6000.

Jabiru have lowered their max exhaust temps in recent manuals.... - but that doesnt necessarily mean they're running richer . EGTs generally follow CHT, so if the gen4 CHTs are lower, the EGTs will follow. Well the other possibility is that the manufacturer has become more nervous and is running richer than ever. Dunno.

 

$24000 for the 4 cylinder jabiru  (80hp)  and  $ 30500 for the 6 cylinder  (115hp) , $35000 for the rotax ( 90hp)...
(yes 1000$ more than the jab site but the jab site numbers dont include the accessories you need like the oil cooler.......)

 

My feeling is the 2200 you end up costing  about the same as  the rotax, 

and the 3300 end up costing quite alot more - but you have a far more powerful engine that can do 115 hp all day.

 

so the comparison needs have have proportionality in there

if we said $/hp, then the 34400/80, 44.7/115, and 37/90
80hp jab : $430/hp

90 hp rotax : $411 / hp

115 hp jab : $389/hp
210hp IO390 Lycoming : $720/ hp (hoses, lean etc) 

wow.....  so , it's about same.

 

 

[facthunter]

Rotax is time expired  after a specific number of years whether the engine hours have time remaining or not. Your capital investment should be taken into account also. IF this clone takes off how will THAT affect Rotax's future viability?.   Nev

[Thruster88]

The zongshen clone has the same usefulness as a time expired Rotax for flying schools.

 

The ready supply of good used time expired ex flying school rotax engines will limit the zongshen clones appeal for experimental users.

 

Some of the capital is recovered with a time expired rotax.

[RFguy]

Yes, agreed,

the 2000 hour rotax still has more than likely plenty of hours left in it. you might get a 2000 hour 912ULS for 3k-8k that will do another 1000 hours without cracking a  sweat

But if it breaks, be prepared to chuck it in the bin (with a set of four sets of rings = $1400 !!! ) 

 

The 2000 hour Jab is ready for another top end overhaul. 6k-8k inc new pistons, lifters etc . and

Then you could get another 1k hours from it if it was well looked after and had nice clean oil all its life.. 

 

 

 

[justinjsinclair]

20 minutes ago, RFguy said:

Yes, agreed,

the 2000 hour rotax still has more than likely plenty of hours left in it. you might get a 2000 hour 912ULS for 3k-8k that will do another 1000 hours without cracking a  sweat

But if it breaks, be prepared to chuck it in the bin (with a set of four sets of rings = $1400 !!! ) 

 

The 2000 hour Jab is ready for another top end overhaul. 6k-8k inc new pistons, lifters etc . and

Then you could get another 1k hours from it if it was well looked after and had nice clean oil all its life.. 

 

 

With Jabiru I am not sure but I suspect that they are going the way of the bigger engines, 2000hr full over haul, which is zero time and off you go again. I don’t know what a full zero time overhaul costs on a 912 but it’s probably expensive. It will be interesting to see if they end up with Cylinders going 2 or three times then cracking like the bigger engines. guess that’s 4000 hours tho. There are very few re-nickasil places left now as well so maybe new cylinders every time. Time will tell.

[jackc]

16 minutes ago, RFguy said:

Yes, agreed,

the 2000 hour rotax still has more than likely plenty of hours left in it. you might get a 2000 hour 912ULS for 3k-8k that will do another 1000 hours without cracking a  sweat

But if it breaks, be prepared to chuck it in the bin (with a set of four sets of rings = $1400 !!! ) 

 

The 2000 hour Jab is ready for another top end overhaul. 6k-8k inc new pistons, lifters etc . and

Then you could get another 1k hours from it if it was well looked after and had nice clean oil all its life.. 

 

 

 

A crate 582 complete with everything , except a prop cost me $14,500 delivered, people will say it’s a crap  investment but flying costs money and I don’t care. Gee I drive an old Landcruiser like 45 years old, needing a fuel tanker chasing me everywhere 🤩 who cares 

My Jabiru 230 blows up tomorrow?  I will just ring up Jabiru for a new Gen 4 out of their stock, chuck it in and happy days 🤩

Fun was never cheap and we only get one life……

[skippydiesel]

RF ,

 

Your logical presentation is heading in the right direction however some possible holes (I stand to be corrected):

 

"Prop spins a bit slower on the Rotax, that's worth a few % in efficiency. The Rotax prop spins a lot slower (a little over 2100 rpm at 75% cruise, to the Jab (guess) around 2700 rpm) and is not only more efficient it tends to be quieter - important in Europe now and in Australia in the future (fly neighbourly)

Rotax torque 128 NM @5000 rpm gives it an advantage in TO/Climb out.

Rotax runs lean in cruise. Jab runs compatratively rich, costing perhaps 5 to 10% in fuel " - My current Rotax aircraft seems to be delivering about 15 L/hr, 5200 rpm at 130 knots indicated - how would a Jab compare?

AT 2000 hours, Rotax has had a gearbox service  @ 1000h maybe about a grand, - 1200 hrs if run on ULP

Both have had two sets of plugs. - will need to check but I think Rotax recomend 200 hr/set of plugs = 10 sets

Both have had 1 set of hoses  - Rotax rubbers replaced every 5 years of service and likely at least twice as much hose involved - must be more costly than Jab

Both have had 40 x  oil and filter changes.  - Rotax recomend an oil change very 100 hrs (when run on ULP) so this would be 20 oil changes, compared with Jab X 80? (at today's prices, this is a difference of about $2,000)

The rotax fuel consumption is worth a bit, at 2000 hours, youve probably put 1 litres more per hour into the 2200  = 2000 litres = $4000 more ! and proportionaly more for the 3300 6 cylinder.$6000. - seems to me your fuel consumption for the Jab is a tad optimistic - More likely up to 5 l/hr difference (could easily be a 10,000L difference or $23K today, for 98 RON).

 

My feeling is the 2200 you end up costing  about the same as  the rotax, Nice thought

and the 3300 end up costing quite alot more -

but you have a far more powerful engine that can do 115 hp all day. True but this does not take into account the higher torque delivered by the Rotax at 5-5200rpm which I assume means a more efficient prop delivering the same/more thrust at 75% cruise..

 

Note: I have focused on the Rotax 912ULS , as I have no experience with the 912UL, comparing it with the little I understand of the Jab 3300

 

 

 

[RFguy]

skippy , your comment of : " My current Rotax aircraft seems to be delivering about 15 L/hr, 5200 rpm at 130 knots indicated - how would a Jab compare?"

 

Is not valid for this discussion.

 

We're talking about a specific fuel consumption for a specific shaft horsepower (in cruise for total fuel consumption argument ~ 75% ) .

The discussion is aircraft invariant  . 

And no correspondence will be entered into

 

Edited April 25 by RFguy

[RFguy]

Justin(e) , the Jabiru 2000 hour overhaul... might require a crankshaft , camshaft etc, likely raises the cost significantly.   If you are a 19- flyer, then you have your own discretion to assess things like camshaft and crankshaft condition. 

I understand a 2000 hour full overhaul of the 912 , replacing all the parts that rotax specified must be checked for wear .....is essentially uneconomical . I believe it runs more than 70% of a new engine (in parts)  to do all the items. Rotax make it that way intentionally I am sure . They want to sell engines. 

 

The Rotax at 2k hours still has plenty of reliable hours left in it , assuming it has a good life with clean oil and little  avgas . The Jabiru you really do need to pull it down and do a overhaul.

 

The Lycoming.. well they are known for going more cycles than cats have lives. Again, rebuild cost can vary in experimental categories.

 

As JackC said , flying is not cheap or free  to just open your chequebook.

 

 

Edited April 25 by RFguy

[justinjsinclair]

RF GUY or Guyette or they them are is now 🙏

If we leave the head oil heat GEN123 aside nearly all of the Jabs that I have  seen that are regularly flown have beautiful bottoms ends when the top  end comes off.
i suspect the secret to Jabs is that they must fly regularly, a friend of mine owns a Baron B58 and they get an extra 400 hours on TBO if they are doing 500-1000 hours a year. Perhaps we should investigate something along those lines. 💁 maybe 50-100 hours a year, I really enjoy doing annuals on regularly flown airframes but those 5 hours a year things are hard work as nothing is kept warm or moving .

For a Jab there is not a lot of extra work for the factory to open up the cases at top time so if it was me I would be just getting a full overhaul, I am still hoping the 1000 top requirement goes to the normal piston standards. Paul Cherna has opened a lot of engines lately and I think he is a fan of the bottom end. I am no engineer but the crank and rods look a bit like a race engine spec mmmm gear box, turbo, EFI mmmmm🤪

Ohhh I do love a good fuel efficiency chat 😈

The fuel economy question is one of my main passions, yes it’s very sad but it’s what I did for a living for a few years dealing with mainly jets and turbo props. Just like hull speed in a yacht each airframe has a sweet spot for the load it’s carrying. Fuel, power, weight, load CoG, cleanliness, level selection yadda yadda yadda all make a huge difference. It’s almost impossible to measure fuel economy unless it’s done by history and even then it’s hard to measure. I flew my Jab home from Wagga to Brisbane in one hit, it seemed to TAS at 103 at 7500 and seemed to be 15lph. Since then we just call it 17lph for safety. If it was in loiter/drone mode I suspect it’s back at 11 lph at 70kts. That’s over 10 hours fuel 😫, I would have thought a Virus with Rotax EFI would be even better but that’s a guess.

In my limited RAA experience it would appear that very few pilots fly long legs with enough granularity to really get down to useful efficiency figures. 

 

https://www.linkedin.com/in/justin-sinclair-29aaa175?utm_source=share&utm_campaign=share_via&utm_content=profile&utm_medium=ios_app

 

Edited April 25 by justinjsinclair

[justinjsinclair]

God knows why my linked in is there 😬😬  please ignore 

[RFguy]

if you change to the composite prop (from the wooden prop) you'll find its worth quite a few horses.... 

[danny_galaga]

13 hours ago, Thruster88 said:

The zongshen clone has the same usefulness as a time expired Rotax for flying schools.

 

The ready supply of good used time expired ex flying school rotax engines will limit the zongshen clones appeal for experimental users.

 

Some of the capital is recovered with a time expired rotax.

Agreed. While I'm coming on board with the ZD engines viability, I am very happy with my nearly time expired flying school engine. Always the same workshop, at the same airfield. And I already have maybe 20 hours experience with this engine from when it was in the plane I hired. Price difference is huge, and I am confident I have a reliable engine.

[skippydiesel]

4 hours ago, RFguy said:

skippy , your comment of : " My current Rotax aircraft seems to be delivering about 15 L/hr, 5200 rpm at 130 knots indicated - how would a Jab compare?"

 

Is not valid for this discussion.

 

We're talking about a specific fuel consumption for a specific shaft horsepower (in cruise for total fuel consumption argument ~ 75% ) .

The discussion is aircraft invariant  . 

And no correspondence will be entered into

 

So - for one comment, within many, you refuse to engage - Me thinks that puts all your commentary in doubt😈

 

I think you will find that Rotax 5-5300 rpm is about 75%  power.

[facthunter]

RPM is not enough . You need a torque figure or a thrust figure as well.   You could be way out. MP might suffice.  Nev