912 operating life

[Bluey]

Hi all:

 

Just wondering, how many hours are people getting out of their 912's?

 

Do most people reach tbo's and then overhaul them or do they just keep running them?

 

Bluey

 

 

[planedriver]

g'day Bluey - this has been discussed on a few threads here now in one form or another. For the record I've got 3580 hrs on my 912 with only a gearbox overhaul at around 800 hrs. I believe there are some out there doing a lot better than that.Cheers

Dexter

Thats amazing Bluey!

 

Like so many others, i'm always perusing the ads in the RAAA mag and see things which cause a bit of concern about reliability. I see an aircraft for sale which appeals to me, for example, a Jabiru which has only two or three hundred hours on the airframe, and the price is reasonable, yet the ad says it's had a top overhaul, new heads, etc; etc; and as a non owner, makes me wonder why this should be necessary at such low hours?

 

I'm aware that the Rotax has a very good reliability record, and is considerably more expensive than the jabiru, but if the fan suddenly stops without much warning, in many circumstances, it can be of a real concern.

 

Many two-strokes being basically simpler in design, also get a fairly good life if well maintained, then suddenly seem to quit at the most inconvenient time, sometimes with a sad outcome.

 

It still doesen't stop us from persuing what we love to do most though, go flying.

 

We'd just like the odd's to be the very best thats possible.

 

 

[Spin]

3580 hrs! That is impressive, I'm going to have to do a bit more reading on the subject. I was pretty impressed with one of the school aircraft that I fly and which has clocked up 1500hrs in just over a year, without missing a beat, but that pales into insignificance next to yours, Dexter.

 

I honestly think that the 912 is well on the way to becoming an aviation classic, lets face it with the exception of Jabiru, almost the entire fleet of modern RA type aircraft, rely on a 912 for motive power. I'll admit to a dose of scepticism prior to flying behind one (if it aint Lycoming, I aint going..), but I am a convert and would have no problem with owning one.

 

On the subject of low overhaul times for Jabiru engines, this is something which has concerned me too, being a potential purchaser. I have done quite a bit of digging around and the general thrust of advice has been that the general design is good, but that the engines are less tolerant of mishandling than a 912 say. Prop it right, operate it in the correct rev range (upper end of the scale), change the oil at required intervals and you'd have to be unlucky to have any trouble. Probably the subject for another thread, but interesting anyway.

 

 

[JG3]

I know a mechanic who services a 912 used in a gyro for mustering, so that engine is running full power much of the time. At 2400 hrs he put in new rings and hand lapped the valves. At 5400 did the same again, and now it's out there again working just as hard as ever.

 

Yes, the Rotax 912 will become an aviation legend. The 'Toyota Corolla of aircraft engines' - just keep up the liquids and change plugs and don't touch anything else.....

 

JG

 

 

[alf jessup]

Well guys,

 

This is the way i look at it, how many 4cylinder cars do 400000 kms before they are touched, this equates to 4000 hrs running time @ 100kph but infact with all the stop starting, traffic lights, idle time this could well be infact 6000 to 7000 hrs in that 400000 kms, mind you these car engines dont filter the fuel prior to going in the tank, only have a single ignition and are commonly abused throughout the rev range during there life.

 

The Rotax 912 is an air/ oil/ water cooled engine most likely made with more love and care than a mass produced car engine, it has fuel filtered before it goes in the tank (or it should be) runs a dual ignition system and usually is in cleaner air than a car will ever be, it also runs more constant rpm in its life than a car ever will so your total hrs are infact the total hrs the engine has worked.

 

Keep the oil, filters both air and oil clean and i cannot see a problem in attaining high hrs out of these.

 

It's like this, you look after it it might just look after you for a long time.

 

Thats my $2 worth seen as though it is a bit longer than 2 bobs worth.

 

Cheers

 

Alf

 

 

[dazza 38]

Hi Bluey, their have been alot discussed about 912's, jabiru's etc, in previous threads (engines).If you do a search and have a couple of hours to read it all, there is alot of imformation on the subject.PS- 912's are extremely reliable, but any a/c engine can and do fail.

 

 

[Guest Maj Millard]

I have considerable experience servicing and supporting 912s in past years, many working hard daily in the bush. The three areas that can, and do cause the rare odd failure, are all parts not manufactured directly by Rotax. That is the electronic ign and stator/roter assy (Ducati)., the carbs (Bing), and the carb mount rubbers which are made in Japan. The engine driven fuel pump (Pierburg) has also initiated some service bulletins in the past. Many reported failures of the above components are often caused or initiated unnecessarily by the owner/operator.

 

Even with those areas to keep an eye on, the 912 is still by far the best piece of metal you can hang off your aircraft, and well worth putting those hard earned bikkies into.

 

The first thing an aero engine should be is RELIABLE....and they are....................Maj...

 

 

[dazza 38]

I agree Major, with around 30 000 (912) engines produced in twenty years by rotax, IMO, reckon 912 would have to be one of the most reliable a/c piston engines produced today, if not the best.What do others think ?

 

 

[facthunter]

rotax reliability.

 

Some years ago the so-called statistics were considered to reflect the view that the Rotax 912 was the most reliable engine. I have always been sceptical of ascribing eternal life to anything mechanical especially reciprocating engines regardless of who makes them. I have been personally aware of some quality control problems with some of the engines (later mostly) but I do not know of all the faults but there must be logically plenty that I have not heard of.

 

No-one would call it a bad motor, but it has a lot of water and oil connections to leak and chafe and the quality of the installation has a lot to do with that.

 

The gear box should not be expected to run forever, If it did it would be overdesigned..

 

The carb connections are a worry and depending on how well the exhaust is designed,and mounted, being subject to vibrations and heat it won't go forever without cracking some where.

 

If you are mustering where there are plenty of landing opportunities, then why not let it run for a long period. Remember that you cannot compare car or motorbike usage to aircraft as you don't run cars and bikes at full throttle for the first 5 minutes and operate

 

them for most of their time at about 75% of their rated power either. The emphasis must be on reliability and it is probably the items EXTRA to the engine that will be what lets it down, moreso than the engine itself.

 

It is not just wear of components that you must consider and all highly loaded parts are subject to FATIGUE. They always have a finite USEFUL life and this has been factored back to address the required margin of safety, expected in aviation. Engine strip and component examination would require replacement of parts on an expected fatigue life or as the result of a NDT (non-Destructive Test) which would show the presence of cracks, etc. (It does not detect fatigue.) None of this is is available with the so-called life extension on an "on condition" basis, which only concerns itself with assessing things like power output, cylinder compression and oil pressure. This operation is infringing to some extent, the normal margins of safety in the concept of rated TBO. ( Time between Overhaul). IF you want to go further into it, research the difference between overhauled, Zero-timed, Remanufactured and New. (definitions/descriptions). Nev

 

 

[S.Drifter]

If you are mustering where there are plenty of landing opportunities, then why not let it run for a long period. Jees I'd love that sort of country to work over, bit different to where I have to fly .

 

My 912(Fisher) has been running on condition for over 2000 hrs, it has 4123hrs on it as of this morning and has not been touched except both carbs rebuilt at 2500hrs.

 

It's used mainly for mustering and commuting 400nm between our properties to muster.

 

Compressions are still good ,no oil use between changes.

 

On my second 205L drum of Castrol GPS -oil drops at 50 hrs as well as filter (RYCO Z314). Do a filter cut every 100hrs, I will run this motor untill there is a change in compressions or oil usage.

 

Now I wonder if I bought a JAB................Just joking, IMH I think the Fisher/Drifter has to be one of the best mustering platforms other than a Gyro

[bones]

If you are mustering where there are plenty of landing opportunities, then why not let it run for a long period. Jees I'd love that sort of country to work over, bit different to where I have to fly .

 

My 912(Fisher) has been running on condition for over 2000 hrs, it has 4123hrs on it as of this morning and has not been touched except both carbs rebuilt at 2500hrs.

 

It's used mainly for mustering and commuting 400nm between our properties to muster.

 

Compressions are still good ,no oil use between changes.

 

On my second 205L drum of Castrol GPS -oil drops at 50 hrs as well as filter (RYCO Z314). Do a filter cut every 100hrs, I will run this motor untill there is a change in compressions or oil usage.

 

Now I wonder if I bought a JAB................Just joking, IMH I think the Fisher/Drifter has to be one of the best mustering platforms other than a Gyro

Drifter i was thinking the same thing :)

 

Where abouts are you?

 

[HEON]

Just love to hear of them hours on Fisher 912 as in process of getting one up and running. Since I will not be mustering and over 60 seems I should only have to do fuel and oil until into my 80's or 90's! That will be cheap flying as total new cost is well under Jab 120 cost of $63,000. The engine is half the cost!

 

 

[facthunter]

Clarification.

 

I wasn't suggesting that ALL mustering situations have plenty of landing opportunities, Clearly you could have areas that are better than others, but they would be better than over water or heavily wooded mountain terrain

 

What I would advise against is a "myth of endless life" provided you just change the oil and filter. A couple of engines, or more, cannot be the basis for assuming that all is OK to just let these engines run on.

 

IF there was a general case for extending the life of the engine, the manufacturer would go for it. SOME of the range of engines has raised the TBO over time and the manufacturer has the responsibility and legal liability to have a realistic overhaul life.. Nev

 

 

[Guest Maj Millard]

Facthunter, We're not talking about "a couple of engines or more" we are talking about many, many, engines the world over now, (possibly thousands in the US alone) that are still giving good reliable service well over their stated TBOs. This is called "establishing a track record", and is no doubt due to superior engineering initially, good selection of proven parts, and good support back up, in stark contrast to others who have stumbled along with bad engineering initially, poor parts selection, constant changes, and bad product support..Additionally few of these engines by the way have required constant rebuilds, or parts replacements, to even make it to thier supposed TBO........................................Maj...

 

 

[HEON]

I was not implying that one can just change oil, filter and add fuel and continue into the never never.

 

Of course one has to check such things as compression, metal in oil, gearbox backlash, and replace items subject to "ageing" such as hoses and O rings (esp in Bing's); even some Rotax's break!

 

There seems to be a lot of evidience however that TBO is not a figure that is not only achievable, but is frequently exceeded by numerous Rotax's..

 

What I was implying was Rotax engines, especially the 80hp, should see an old "gentleman" (did not like my other word) like me never having to place an add when I eventually sell which reads something like those very common in RAA mag..."airframe 1000hr, engine 400hr"...for non Rotax engined aircraft.

 

My current 914 which produces 115hp at 39inHg from (I think) about 1070cc...in other words a high output for capacity with some complexity...has more hours than a number of non Rotax engines I personally know that broke big time.

 

I rearly do not wish to start another Holden/Ford p.....g contest and will be very happy when "the other brand" have people posting about their engine reaching 4000hr plus "on condition"

 

 

[Guest travis]

rotax oil

 

hi all , i have been running shell aero 100 in my 912 and have been told not to use it any more . i rang burt flood today and they recommended shell vsx 4 , or mobil extra 4t . just wondering if any one has been using any off these oils and what sort off run they are getting . or if any one has been using any other type off oil for any length off time .

 

 

[Guest Maj Millard]

Myself and a number of other flyers up here have been using Valvolene Durablend. It is on the Rotax recommended list, and we have been getting good service from it. The Shell VSX4 which is also on the recommended list, was used by many prior to us going to Castrol GPS, which many used for years, but is no longer recommended by Rotax. The Valvolene is preferred because it is a good product, and readily available from most auto stores...............................................................................Maj...

 

 

[Guest travis]

oil

 

ok , thanks for that . half my problem was no one here sells shell oil or even deals with shell .

 

 

[alf jessup]

Hi all,

 

Ive been using the aeroshell 100 for about 150 hrs in my 912 and haven't noticed anything out of the ordinary regarding oil consumption.

 

What is the deal on this oil.

 

What is the reason Rotax/Floods are recommending ditching it in preference to other oils???

 

Thanks

 

Alf

 

 

[Guest Maj Millard]

Alf, I am assuming you mean Aeroshell Sport plus 4 ??.....not Aeroshell 100 which is an aviation grade oil with no synthetic fortification as required for the Rotax gearbox. This mistake has been made in the past by GA type people, with resulting damage to gearboxes. Aeroshell 100 is definitly NOT on the Rotax 912 recommended list (SI-912-016R1)...Maj

 

 

[markendee]

Travis - VSX4 in 912

 

Travis,

 

We have been using VSX4 and have found it to be very good. One engine at 600 hrs and no problems at all. I do realise that this is a far cry from 3850 hours but we are working on it. We are a Honda motorcycle dealership and have used VSX4 in all manner of hard working engines with good results.

 

Did try Aeroshell but could only get it at certain outlets so went back to VSX4. Also the place we could buy Aeroshell only sold it in 1 ltr bottles - what's the idea there?

 

I have no allegiance with any oil company in fact they are possibly the most difficult to deal with, always changing the product, the name, the packaging and the prices.

 

Mark D

 

 

[Guest Maj Millard]

Markendee, Yes I agree, the Shell VSX4 has got a great track record in 912s now, and is easy to pick up. Many were very happy with the Castrol GPS. I used it for years, and it was real popular in the bush, so a bit of a mystery why Rotax didn't continue to recommend it, as it certainly did the job. As I say the Valvolene Durablend Synthetic fortified is doing well up this way in the heat...when it's not raining that is !.................................................................................Maj...

 

 

[facthunter]

Geared engines.

 

Have to back up Maj here . the aeroshell 100 W or the multigrade equivalent which is used in the Jabiru , is NOT suitable in the gearbox of the 912, which is lubricated by the oil the engine uses. Stick strictly to the maker's recommendations with this engine, which generally implies a synthetic.

 

Note years ago there were plenty of car gearboxes that used engine oil. Today there are very few engine oils that are suitable for gearboxes. (virtually none). The rotax gearbox has clutches and cam faced contact surfaces that absorb the drive pulsations, and have specific lubrication requirements. Nev

 

 

[Guest Maj Millard]

Well said facthunter, but wasn't that what I said in post #21 to Alf ?....please explain.................Maj...

 

 

[facthunter]

Explain.

 

I can't, Maj. I am a worrier about these little particulars that crop up, and need to be emphasised. (constantly it seems). Nev