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old man emu

More ado about Through Bolts etc

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Thanks OME. I wasn't singling your post out. I have to say quite honestly that i am really struggling to not be scared when I fly as a low hour pilot because to read endless stuff about jabirus is worrying. i went for a 2 hr flight last Monday and was waiting for the engine to stop the whole flight. I dont wish to berry my head in the sand but i also dont believe if a Jabiru was going to kill me so many of us would own them. I have just purchased a 170 and jabiru have sent over parts to replace the pistons and such due to the concerns about the circlips. They are not even sure if my engine is involved but have decided to get my engine rebuilt anyway. You wouldn't get that level of support from car companies. There are a lot of us very inexperianced pilots looking to you old hands for help. we dont need to be scared silly reading endless reports of how bad Jabirus are. Anyway enough ranting by me.

 

 

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They are not even sure if my engine is involved but have decided to get my engine rebuilt anyway. You wouldn't get that level of support from car companies.

No, because you wouldn't need it. !!!!

 

 

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Thanks OME. I wasn't singling your post out. I have to say quite honestly that i am really struggling to not be scared when I fly as a low hour pilot because to read endless stuff about jabirus is worrying. i went for a 2 hr flight last Monday and was waiting for the engine to stop the whole flight. I dont wish to berry my head in the sand but i also dont believe if a Jabiru was going to kill me so many of us would own them. I have just purchased a 170 and jabiru have sent over parts to replace the pistons and such due to the concerns about the circlips. They are not even sure if my engine is involved but have decided to get my engine rebuilt anyway. You wouldn't get that level of support from car companies. There are a lot of us very inexperianced pilots looking to you old hands for help. we dont need to be scared silly reading endless reports of how bad Jabirus are. Anyway enough ranting by me.

I'm glad they are looking after to you mate. Us low time pilots have enough on our plates without worrying if the fan is gunna stop lol.

 

As an aside, I've spent a few years in the car industry, and they do in fact send out nation (and sometimes world) wide recalls on vehicles to replace parts/engines/diffs/etc because a small minority could be effected. One that springs to mind was the fuel hose recall on VZ v6 commodores. I think one leaked somewhere causing a fire, so every vz within a certain VIN range had the recall. Thousands of vehicles. As they should too.

 

 

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i wonder what caused the piston/rings/barrels to wear out so quickly. Running too rich a mixture that is washing the oil off the cylinders?

 

 

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Thanks OME. I wasn't singling your post out. I have to say quite honestly that i am really struggling to not be scared when I fly as a low hour pilot because to read endless stuff about jabirus is worrying. i went for a 2 hr flight last Monday and was waiting for the engine to stop the whole flight. I dont wish to berry my head in the sand but i also dont believe if a Jabiru was going to kill me so many of us would own them. I have just purchased a 170 and jabiru have sent over parts to replace the pistons and such due to the concerns about the circlips. They are not even sure if my engine is involved but have decided to get my engine rebuilt anyway. You wouldn't get that level of support from car companies. There are a lot of us very inexperianced pilots looking to you old hands for help. we dont need to be scared silly reading endless reports of how bad Jabirus are. Anyway enough ranting by me.

Compulsion,

 

It's great to hear that you flew for 2hrs expecting an engine out the whole time. That should mean you had a plan in place for the event at all times should it happen.

 

It doesn't matter what you fly, you should be almost expecting it, that way you won't be surprised or panicked.

 

An engine failure should not be a death sentence!

 

Regards Bill

 

 

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I fly at Gawler. As a new flyer and as a Jabiru owner you guys make me scared to fly.

Compulsion , many of the points you raise are valid , however irrespective of what engine you fly behind , always be mindful of the potential of an engine failure and fly accordingly . Much , mainly well intentioned , comment has been said on these forums regarding Jabiru engines , some from authoratitive sources , some not . Whatever the engine , familiarise yourself with its operation and learn to detect any departure from normal operation. A 'one pilot/owner' should learn to detect any change from normal operation fairly early and act accordingly ,opposed to an aircraft in say a flying school , used by many different pilots with no real " ownership" of the aircraft .Ensure the maintenance is carried out regularly by someone really familiar with the engine . I find that some owner/maintainers are excellent , others not so , and the same applies to licensed maintainers .

 

Bob

 

 

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Compulsion , many of the points you raise are valid , however irrespective of what engine you fly behind , always be mindful of the potential of an engine failure and fly accordingly . Much , mainly well intentioned , comment has been said on these forums regarding Jabiru engines , some from authoratitive sources , some not . Whatever the engine , familiarise yourself with its operation and learn to detect any departure from normal operation. A 'one pilot/owner' should learn to detect any change from normal operation fairly early and act accordingly ,opposed to an aircraft in say a flying school , used by many different pilots with no real " ownership" of the aircraft .Ensure the maintenance is carried out regularly by someone really familiar with the engine . I find that some owner/maintainers are excellent , others not so , and the same applies to licensed maintainers .

Bob

Couldn't have said it better Bob 011_clap.gif.c796ec930025ef6b94efb6b089d30b16.gif

 

Brian

 

 

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I fly out of the same airfield as compulsion, and certainly there have been some engine problems among the training aircraft. I have had an engine failure myself luckily on final, I don't dwell on engine hassles, incidents are few and far between. However I have just purchased and will be wearing a new kevlar flying helmet...just in case. The laughter will not bother me. :-)

 

 

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I fly out of the same airfield as compulsion, and certainly there have been some engine problems. [/quote

G 'Day Pete ,

 

When travelling around I often see , what I consider to be , pilots not taking proper care of their aircraft , eg. doing run-up checks before the engine has time for a proper heat soak , allowing the expansions to settle out and the oil to reach recommended operating temp. Many also appear to ignore recommendations regarding climb-out speed to maintain even cooling . I could go on about , what I consider to be unwise operation mainly , but certainly not exclusively , in training aircraft .

 

Bob

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I don't have enough information to hand personally to 'bash' any engine.

 

I was simply comparing the state of that engine with what one would expect from a Rotax 912 with its TBO of 2000 hrs.

 

When the OP said that at 750hrs it needed reboring and oversize pistons, I thought that must have been a badly treated engine.

 

My observation was that nobody seemed to find that exceptional, and nobody commented about how the engine must have been operated.

 

I'm sure that if someone made the same statement about a 912, we would be asking WTF the owner had been doing.

 

Compulsion, one thing I would say is if you are that scared before going flying, then you may need to reconsider your choice of sport.

 

Engine failures are something we should and do train for, we should all be aware of where we would go if the engine stopped at any moment.

 

If the fan ever does stop, as previously said, it is not a death sentence, simply a long walk home.

 

 

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I have done MANY engine failures in both circuits and in out landings with an instructor. Doesn't mean I want to find out how it goes when the fan really stops. I did over 100 landings before going solo and probably 20 where practice engine outs. I have also logged thousands of ocean miles in both racing yachts and power boats. Doesn't mean I am not a little apprehensive every time I go out of sight of land. Sometimes the old term ignorance is bliss is quite true.

 

 

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I have done MANY engine failures in both circuits and in out landings with an instructor. Doesn't mean I want to find out how it goes when the fan really stops. I did over 100 landings before going solo and probably 20 where practice engine outs. I have also logged thousands of ocean miles in both racing yachts and power boats. Doesn't mean I am not a little apprehensive every time I go out of sight of land. Sometimes the old term ignorance is bliss is quite true.

Ignorance may well be bliss , but it won't help if the fan stops . Better to remember that " knowledge is power " and its application to your performance as a pilot in the normal course of events , or some unforseeable contingency .

 

Bob

 

 

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Actually, the engine involved hasn't been flogged by its pilot. While not being an anal retentive about it, he does make sure that everything that has to be done to it, is done. His flights are usually of long duration (full tank to empty + reserve). Oil changes are done at or before time. He was saying that Jabiru recommend a top overhaul at 1000 hrs, so he is not upset at doing it about 750 hours, considering the speed he racks up the hours.

 

Compulsion raises a valid point, and one which stops a lot of people taking up recreational flying: we dwell too much on what can go wrong.

 

Sure we need to know how to make a forced landing, and that low speed, powerless turns are inherently dangerous. BUT once we have trained to handle such situations, the majority of us will not experience them. But try convincing a nervous other half that our planes won't plummet to the ground when all that s/he has heard is that they do.

 

OME

 

 

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When the OP said that at 750hrs it needed reboring and oversize pistons, I thought that must have been a badly treated engine.

 

Gentreau

 

Some of the problems that are reported on these jabiru engines are simply caused by people maintaining them that are not following manufacturers specifications.

 

I had a look at a motor that was sent back to jabiru on the weekend after the owner decided to rebuild it himself. He is supposedly a mechanic but after he couldn't get it to run

 

he decided to ask jabiru to check the timing for him.

 

When questioned about how he had checked some of the clearances for bearings and which loctites where used etc he went quiet. Oil was leaking out of it just sitting in the bench.

 

On closer inspection the front crankshaft oil seal retainer was fitted up side down and hex headed bolts with big washers were fitted instead of the correct socket head cap screws. The engine thru bolts had not been replaced. The thread of the bolt was protruding by 8 threads on one side and was inside the nut by 3 threads on the other.

 

Engine thru bolts must be replaced for every overhaul.

 

This statement above also proves this point.

 

The Barrels on these motors are not to be rebored. You can't fit oversize pistons. This is just asking for trouble and goes against the manufactures recomendations.

 

Yes Jabiru motors do have some issues from time to time but what engine doesn't. If you have them built by the book and all the steps followed to the T generally you won't have any issue as many people out there flying Jabiru's never have. You only hear of the minority that have problems and i would be interested to know what the percentage of these where from factory built motors that have proper engine monitoring.

 

Now sometimes parts fail and that can't be avoided. We have seen this with some Valve Springs to name one. But incorrect maintenance practices can be.

 

Compulsion

 

If you haven't already done so i would recomend you have some form of engine monitoring fitted to your J170 to firstly check cylinder head temps on all cylinders and secondly the Exhaust gas temps.

 

This will give you a good idea of how the setup in your plane is working. I have been in some factory built planes that when checked actually have one or more cylinders running on the hot side and if left undetected would most certainly lead to an early overhaul due to loss of compression from either rings stuck in ring grooves or cylinders worn out of round. The one cylinder temp being monitored was showing in the green and the operator would fly acordingly but when the other cylinders were checked in the same conditions the cht's on other cylinders were too high.

 

The best thing you can do is learn more about your aircraft which in turn will make you a better pilot.

 

As many others here have said don't be afraid of an engine out. Continually practice forced landings and get into the habit of always having an option to land for your particular altitude.

 

You will have many hours of enjoyable flying ahead of you with your Jabiru 170. They are a great aircraft.

 

Safe Flying

 

JabSP6

 

 

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So I presume that the Jabiru 2200 is quite a bit cheaper to buy than a Rotax 912, considering the greater maintenance overhead ?

 

I can't find prices on the Jabiru website, which is why I'm asking here.

 

 

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So I presume that the Jabiru 2200 is quite a bit cheaper to buy than a Rotax 912, considering the greater maintenance overhead ?I can't find prices on the Jabiru website, which is why I'm asking here.

Jab 2200 is around $14000 aus and the Jab 3300 is around the $18500 aus

 

I believe the 912 rotax is around the $26000 aus but i could be wrong.

 

 

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Guest Howard Hughes
then we can set up a whole website for that, and we can include any man-made product because nothing's perfect.

But the PT-6 is damn close!022_wink.gif.2137519eeebfc3acb3315da062b6b1c1.gif

 

 

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"But the PT-6 is damn close!"

 

Are you working on a kit to fit to my Jabiru??

 

 

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Reboring is not officially sanctioned. The cylinder walls are not all that thick. "Normal" Jab pistons are Holden +2 oversize. However it is now possible to buy a +3 oversize. Rebore is feasible but it would be at the reborer's risk. We know because it was done here and we asked ......

 

This job will likely be new pots and pistons - not humungously cheaper than what one pays for a Lycoming pot/piston which also includes the head and rockers/valves. Jab engines do run nicely but are not famous for longevity relative to that other brand whose-name-we-shall-not mention.

 

 

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Reboring jab cylinders is a specialist job and not the normal thing for a rebore shop. They are 4130 and it doesn't machine like cast iron. Since they fail sometimes with the standard wall thickness, and you have a used cyl(fatigued?) and a thinner thickness wall as well, Not something I would recommend. I thought those parts were not expensive, so I would use new parts. The pistons are nothing flash. Has anyone ever run something different? Watch the circlips as there are two different types.. Nev

 

 

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Reboring jab cylinders is a specialist job and not the normal thing for a rebore shop. They are 4130 and it doesn't machine like cast iron. Since they fail sometimes with the standard wall thickness, and you have a used cyl(fatigued?) and a thinner thickness wall as well, Not something I would recommend. I thought those parts were not expensive, so I would use new parts. The pistons are nothing flash. Has anyone ever run something different? Watch the circlips as there are two different types.. Nev

The walls are about 120 thou thick (1/8 inch) or 3 mm if you prefer. A rebore reduces the thickness by 10 thou - 0.25 mm or a bit under 10%.

 

 

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My contention is that there is no excess strength to sacrifice. In any case old cylinders fatigue . ( something a bit hard to assess). Nev

 

 

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My contention is that there is no excess strength to sacrifice. In any case old cylinders fatigue . ( something a bit hard to assess). Nev

Fair enough Nev. I wasn't agreeing or disagreeing - just quoting numbers I know about. There's a 3300 (not mine) on our field that had a rebore and seems to have survived the exercise. The cylinders had done about 600 hours. A Jab piston + cylinder is about $600. For a Lyc 320/360 the cylinder + head + piston + valves (all comes as one) is about $1500 and you can expect it to last 2000-odd hours. That's just what I know from bills I have paid and engines I have seen/owned.

 

 

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Interesting figure here.

 

The difference between the piston diameter and cylinder diameter in a Jabiru engine is 0.11 mm or 4/1000". That means that the distance between the piston and cylinder wall at any point is 0.065 mm or 2/1000". That's extremely tight, and if there is any misalignment of the cylinder, you could expect the piston to scrape along the cylinder wall.

 

OME

 

 

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