Major weaknesses addressed

[Oscar]

And a Merry Christmas to all, indeed! Yes, I was being cheeky - but the tendency of some posters to shoot from the lip does none of us any damn good in trying to get hold of engines that we can trust to fly behind.

 

I've had the opportunity of seeing the developments that CAMit are introducing first-hand and being able to sit down with Ian Bent in front of his computer and see his worked-up analysis of problems and solutions presented in FEA and CAD design packages; of having the rationale and the underlying analysis of changes explained. Ian has taken the time to take me through the development cycle of his changes starting with first-principle discussion of the function of components to the final design of changes to address issues. I've had the opportunity of people stopping CNC machines in mid-cycle to show me how the manufacture of parts in Jabiru engines progresses. I've watched the guys in the assembly shop put Jabiru engines together and had them tell me the little tips from experience of literally hundreds, probably thousands, of engine assemblies. Hell, I was able to use the tools - the torque wrenches, the sockets, the exquisitely developed special tools used for production assembly of these engines.

 

Just checking the tolerance of compression rings - not just the end-gap, but the production grinding of them, has a special tool to ensure they are seating on their full circumference. CAMit doesn't assemble a Jab. engine unless every damn compression ring is sealing properly - and they're all hand-checked! The new CAMit through-bolts have a better than 40% greater ultimate load strength than the Jabiru 7/16th through bolts and the new CAMit barrels eliminate the bending problem that over-stresses the through bolts under detonation anyway.

 

The engines we use in RAA-class (LSA for short, though that isn't a proper explanation) aircraft are built to optimise performance against weight. Every kg. of weight in the engine is a reduction of the useable load against the MTOW limits - which are completely arbitrary,when one comes down to analyse them. The only rationale for things like the MTOW limits happens to be the fact that there were a lot of 1,000-foot strips in the USA, so the FAA decided that a formula that allowed use of 1,000-foot strips was a decision point. From that, a minimum VSo was determined and some smart-arsed engineer decided that a particular MTOW should be imposed. A Westland Lysander could more than happily use 1,000-foot airstrips - but because some peanut equated airstrip length to MTOW instead of wing-loading, we are stuck with MTOW limits. If you read the article by Phil Ainsworth that I referenced above, you will see the decision process that Jabiru faced in producing its own engines- and extrapolate from that, the compromises that they had to make in the design of that engine.

 

I know from first-hand experience that the new CAMit (not Jabiru) through bolts are produced to a tolerance that means that the engine cases and the bolts themselves need to be at the same temperature to allow the bolts to be inserted. I know from the same experience why formed threads rather than cut-threads are mandated for certain components. I know why the pistons are placed in a certain direction vs. the gudgeon-pin offset with respect to the engine direction of rotation. I know that the new CAMit through-bolt nut base radius is matched to the barrel-flange base radius and doesn't require grinding. I know that the new CAMit through bolts are torqued to something like 40% of their yield stress at optimum torque for the case hold-down force required, rather than more like 95%. I know that the new CAMit rocker arms reduce the side-loads on the valve-stem by a great deal. I know why the new CAMit barrel-base thickness reduces the leverage load on the through bolts/studs even under detonation conditions by a handsome amount. I know why the new CAMit case-assembly technique is not critical on a five-minute start-to-torqued-up assembly time. I know why my oil pick-up won't have bits of silastic sticking in it when I come to re-build my new engine.

 

And more than anything else, I know now how various components in my Jab. engine interact in use. That is critical information in evaluation of how changes are going to affect the engine life and performance - and without that knowledge, the pontifications of self-important kibitzers as to how to 'fix' the issues with Jabiru engines are worth no more than flatulence in a jam-jar. If you're happy to base your choice of engine to turn your propellor on opinions worth no more than a T-shirt slogan saying 'Holdens rule - Fords suck' (or vice-vera) - then go right ahead. It's your money, not mine.

 

 

[dazza 38]

Tha

 

And a Merry Christmas to all, indeed! Yes, I was being cheeky - but the tendency of some posters to shoot from the lip does none of us any damn good in trying to get hold of engines that we can trust to fly behind. I've had the opportunity of seeing the developments that CAMit are introducing first-hand and being able to sit down with Ian Bent in front of his computer and see his worked-up analysis of problems and solutions presented in FEA and CAD design packages; of having the rationale and the underlying analysis of changes explained. Ian has taken the time to take me through the development cycle of his changes starting with first-principle discussion of the function of components to the final design of changes to address issues. I've had the opportunity of people stopping CNC machines in mid-cycle to show me how the manufacture of parts in Jabiru engines progresses. I've watched the guys in the assembly shop put Jabiru engines together and had them tell me the little tips from experience of literally hundreds, probably thousands, of engine assemblies. Hell, I was able to use the tools - the torque wrenches, the sockets, the exquisitely developed special tools used for production assembly of these engines.

 

Just checking the tolerance of compression rings - not just the end-gap, but the production grinding of them, has a special tool to ensure they are seating on their full circumference. CAMit doesn't assemble a Jab. engine unless every damn compression ring is sealing properly - and they're all hand-checked! The new CAMit through-bolts have a better than 40% greater ultimate load strength than the Jabiru 7/16th through bolts and the new CAMit barrels eliminate the bending problem that over-stresses the through bolts under detonation anyway.

 

The engines we use in RAA-class (LSA for short, though that isn't a proper explanation) aircraft are built to optimise performance against weight. Every kg. of weight in the engine is a reduction of the useable load against the MTOW limits - which are completely arbitrary,when one comes down to analyse them. The only rationale for things like the MTOW limits happens to be the fact that there were a lot of 1,000-foot strips in the USA, so the FAA decided that a formula that allowed use of 1,000-foot strips was a decision point. From that, a minimum VSo was determined and some smart-arsed engineer decided that a particular MTOW should be imposed. A Westland Lysander could more than happily use 1,000-foot airstrips - but because some peanut equated airstrip length to MTOW instead of wing-loading, we are stuck with MTOW limits. If you read the article by Phil Ainsworth that I referenced above, you will see the decision process that Jabiru faced in producing its own engines- and extrapolate from that, the compromises that they had to make in the design of that engine.

 

I know from first-hand experience that the new CAMit (not Jabiru) through bolts are produced to a tolerance that means that the engine cases and the bolts themselves need to be at the same temperature to allow the bolts to be inserted. I know from the same experience why formed threads rather than cut-threads are mandated for certain components. I know why the pistons are placed in a certain direction vs. the gudgeon-pin offset with respect to the engine direction of rotation. I know that the new CAMit through-bolt nut base radius is matched to the barrel-flange base radius and doesn't require grinding. I know that the new CAMit through bolts are torqued to something like 40% of their yield stress at optimum torque for the case hold-down force required, rather than more like 95%. I know that the new CAMit rocker arms reduce the side-loads on the valve-stem by a great deal. I know why the new CAMit barrel-base thickness reduces the leverage load on the through bolts/studs even under detonation conditions by a handsome amount. I know why the new CAMit case-assembly technique is not critical on a five-minute start-to-torqued-up assembly time. I know why my oil pick-up won't have bits of silastic sticking in it when I come to re-build my new engine.

 

And more than anything else, I know now how various components in my Jab. engine interact in use. That is critical information in evaluation of how changes are going to affect the engine life and performance - and without that knowledge, the pontifications of self-important kibitzers as to how to 'fix' the issues with Jabiru engines are worth no more than flatulence in a jam-jar. If you're happy to base your choice of engine to turn your propellor on opinions worth no more than a T-shirt slogan saying 'Holdens rule - Fords suck' (or vice-vera) - then go right ahead. It's your money, not mine.

Than you oscar for a very informative post, much appreciated but I come from military back ground where we just didn't have no where the problems jab seem to have. I will always have a soft spot for Jabiru as I passed my pilot certificate in one back in 1998. But I did feel like I was a student and test pilot at the same time

 

 

[Dafydd Llewellyn]

That 230 deg is nowhwere near the combustion temperature, but it is the average heat of the cylinder head. there are several reasons why the head is lower in temp than combustion, such as the fact that combustion only lasts less than a quarter of the cycle and also incoming air and fuel are acting as coolant as well as the cooling airflow over the fins.From memory to get an aero engine certified such as a Lycoming it has a test regime to follow, which includes some run time with no oil. I can't remember the exact requirements, but they are probably on the FAA web site.

No it does NOT require time with no oil. Look up FAR Part 33 on the FAA website, www.faa.gov

 

 

[SDQDI]

Gotta be careful in a thread like this or you get your head shot off.

 

IMHO it sounds like at least camit is trying to address the known problems with the jab engine which is a start, will it be more reliable or will other problems plague it? Who knows but I for one would like to see it succeed. I mean who wouldn't like to see an Australian built engine with good reliability. We have a rotax in ours I won't say it was mainly because of reliability but I will say that my wife is happy with their reputation (maybe she doesn't want to get rid of me yet:wink:)

 

 

[Oscar]

ThaThan you oscar for a very informative post, much appreciated but I come from military back ground where we just didn't have no where the problems jab seem to have. I will always have a soft spot for Jabiru as I passed my pilot certificate in one back in 1998. But I did feel like I was a student and test pilot at the same time

Hell, a military background is probably the most diametrically opposed to the civilian regulation regime for RAA-class aircraft that could be! The military don't give a flying fur-lined intercontinental sexual moment for arbitrary regulations - they specify what will do the job necessary! Type Certification doesn't exist as far as the military are concerned. Show me a military aircraft that cost less than $100k and I'll point out that it was a bloody CT-4 or a Jindivik.

 

Nobody gets let loose on military equipment without the proper training. Maintenance is carried out by specialists - pilots don't take spanners to their Blackhawks before they head up yonder. Nip into the local servo for a fill of whatever was in the bowser for your Eurocopter lately? Done the rocker settings on your F/A-18E/F within the last 25 hours?

 

You seriously can't expect something that has to weigh about twice that of a Harley, costs the purchase price of a schmicked-up Commodore, gets across country PTP faster than a turbo-Porsche and chews fuel at about the l/100k rate of a WRX also last like a Kenworth. Can I point out that 350 hours average life (to pick a figure that is not unexceptionable for a Jab. 2200) @ 90 knots average is about 550ks distance travelled? How many $85k cars can you name that will still be happily rolling along on first engine life if their lives were spent at 75% maximum power for those 550ks?

 

Yes, the Jab engine can be considerably improved. I've put my money where my mouth is on belief that that is what CAMit are doing. How much is it costing you to deny the possibility?

 

 

[fly_tornado]

350 (hours) times 90 knots is distance of 31,500knots which is about 60,000km

 

 

[rankamateur]

Bugger, I would be disappointed if my Proton or Cherry didn't make 60,000 km on the first rebuild.

 

 

[facthunter]

It's pointless to compare auto engines with aero engines. The average car is never flat out and your plane engine IS on every take off, the first one being from a cold start with minimum warm up. There's also plenty of auto car makers of good repute who have never made a good aero engine, and have tried. Aero engines have all parts shaved to the minimum size for lightness, making every part a critical design. Nev

 

 

[Camel]

The problem is Jabiru has faults and Jabiru are very slow at addressing them, certification may be part of the problem. Rotec have produced liquid cooled heads, TBI, 45amp alternator and electronic ignition many private owners have improved reliabity by various modifications. Now Camit for whatever reason have shown a huge initiative to improve the engine and as original manufacturer are well qualified for the job.

 

This is a huge leap forward and I would like to see the engine reliable and be able to be used and approved by Jabiru for factory built aircraft. There are not a lot of choices for aircraft engines and the 3300 is in a class of its own being direct drive, 120hp, light and compact.

 

Those people that don't want a light, reliable 120hp motor then your comments won't help those who want it. True Australian pioneers like Jabiru, Rotec and Camit in the world aviation market are doing a great job, they do not deserved to be knocked by people who have not owned, used or seen their product or understand the problems. I do want improvements and hope comments here may encourage it as there is a wealth of experience here, the fact that Jabiru are looking at China to produce engines now means that company's like Camit need our loyalty as an Australian manufacturer. Think about what you want, be part of the solution not part of the problem.

 

 

[Oscar]

It's pointless to compare auto engines with aero engines. The average car is never flat out and your plane engine IS on every take off, the first one being from a cold start with minimum warm up. There's also plenty of auto car makers of good repute who have never made a good aero engine, and have tried. Aero engines have all parts shaved to the minimum size for lightness, making every part a critical design. Nev

Absolutely true. Possibly a bit of a comparison can be achieved by looking at the history of Subaru conversions (and I drive and am very enthusiastic about Subaru's). The EJ22 engine is by and large very well regarded and if looked after moderately well (oil changes on schedule, mostly) will typically run 300,000k or so of normal daily driving before needing a rebuild. The EJ25 a bit less, and even the old EA81 was generally considered pretty bulletproof (provided one purged the cooling system properly and didn't cook the heads). At let's say an average achieved speed of 80kph (for mostly country work), that's - if my calculator isn't playing tricks on me - about 3750 hours. I haven't seen any TBO achieved figures for the aero conversions but I'm willing to bet if they've been getting those sort of hours, you'd be hearing about it..

 

The problem is Jabiru has faults and Jabiru are very slow at addressing them, certification may be part of the problem. Rotec have produced liquid cooled heads, TBI, 45amp alternator and electronic ignition many private owners have improved reliabity by various modifications. Now Camit for whatever reason have shown a huge initiative to improve the engine and as original manufacturer are well qualified for the job. This is a huge leap forward and I would like to see the engine reliable and be able to be used and approved by Jabiru for factory built aircraft.

Precisely. CAMit are working up experience right now of reliability in real-life useage plus continuing to do research, analysis, design, manufacture and testing on additional elements they aren't yet ready to release. The results will start to come in in the not too distant future. Nobody is being asked to take it on trust that these changes are real improvements. If these developments offer better reliability than standard Jab. engines on average there are well over 1,000 Jabs out there that stand to benefit from being able to slot in a 'better' engine without going through a FWF change with all the attendant problems of engineering justification, performance testing for the upgrade of the POH, etc. etc. , that's a lot of aircraft that will keep on flying with minimum hangar time.

 

 

[Yenn]

So how many Jab engines have had problems before 25 hours? How many Jab angines have had problems? how many Jab engines are problem free? Give us some facts and figures.

 

As far as the military go how many hours do they put on a Rotax drone engine before they replace it? the figure is published.

 

 

[turboplanner]

A fair few of them are listed on this site Yenn, but you'll have to search for them. A few had problems before 25 hours, I listed from memory a batch of about 20 forced landings due to engine failure, and a lot are operating normally.

 

 

[Oscar]

So how many Jab engines have had problems before 25 hours? How many Jab angines have had problems? how many Jab engines are problem free? Give us some facts and figures.As far as the military go how many hours do they put on a Rotax drone engine before they replace it? the figure is published.

The answer to your first question is, of course: too many. Even ONE is too many - but that needs to be qualified by what caused the failure: a basic design problem, faulty QA, or something that wasn't done properly? If we had authoritative figures by cause rather than mostly anecdotal evidence (which is not invalid but also isn't really qualitative), we could realistically sheet home blame.

 

The answer to the second can be fairly well assumed from the advertisements for used aircraft and comparing the engine to airframe hours. I spent a lot of time doing that over several years and there's no contest that a typical replacement/rebuild, mostly for 2200-engined Jabs., is done at around 300 - 350 hours.

 

The answer to the third question is: some. Interestingly, some commercial operators have numerous incidences of 1,000 hours-plus Jab engines, which suggests that careful operation and maintenance is a very large factor in the sort of life expectancy that can be achieved.

 

The question of Rotax engines used in military drones is a very, very interesting one. If you go to: http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CE0QFjAF&url=http://www.uadrones.net/military/research/acrobat/0302.pdf&ei=LyO6UtPdNISRigfNm4G4Cg&usg=AFQjCNHnaMmNjceBYJuTwoLdvDrXsdrCqQ&bvm=bv.58187178,d.dGI you'll find that for the RQ 1_B Predator (using originally 912s, now upgraded to 914s), the MTBF in operation over 5 years or so is - wait for it - 55.1 hours. Power/prop failures accounted for 53% of total failures; of that 53%, the engine was responsible for 'nearly 70%', or what I think means 37% of all failures.

 

I'm not sufficiently numerate to draw any conclusions from that but to me, if the average MTBF is 55.1 hours and 37% of the failures come from engine problems, a number of engines are giving trouble in fairly short times.. The Predator operational life is 'expected to be 2,000 hours.'

 

 

[Camel]

Facts and figures will prove there is a problem, most already know that there is a problem., but it relates to other things too including the way it is used and maintained. I have a Rotax 912 and a Jabiru 3300, I have had no problems. I have had a rotax 582, a Lycoming o-320. They all have some problems so I'm not interested in past problems as much as I'm interested in fixes and improvements. Jabiru is not the only engine that has any faults or room for improvement.

 

I am a Motor Mechanic by trade so I believe I am well qualified to share my opinion .

 

Try this read,

 

http://www.aviationsafetymagazine.com/airplane/LSA-Engine-Safety.html

 

Or this read copy and paste from http://www.trikepilot.com/forum/topic/736

 

My Rotax 912 sprag clutch just demolished itself. Engine has only 487 hours on it.

 

looking it up on many message boards, one can see that this happens often.

 

Questions:

 

Has this happened to anyone else here?

 

Why would an $17000 engine have such a faulty component?

 

Why does Rotax not repair this obvious design error at their expense?

 

At 487 hours with such a major problem, this aviation engine can hardly be considered "reliable". In researching it, I heard several cases of it having to be replaced earlier than this.

 

This is a problem Rotax! Get it together.

 

Copy and paste reply....

 

Todd you know the answers.

 

Rotax doesn't do that because sprag clutches they would have to replace would number in the thousands. Same with Rotax 912 fuel pump the last 4 years. They quietly changed them now to a new design because the failure and malfunction rate on the 912 fuel pumps made in the last 3 years is something like 25% but you won't see them telling to send yours in for free replacement.

 

In aviation the numbers are so small, the volume so low that doing these things would put a manufacturer out of business.

 

You can also see this with Lycoming and Cessna as well.

 

You can buy some brand spanking new Cessna 172 right off the Cessna Sales Centers and as soon as you step it out of their hanger, you have a $7000 costing crankshaft replacement AD on it.

 

Yes a brand spanking new airplane costomg $260000.00 and right out the door immediately you have to change the crankshaft of the Lycoming engine because the Brazilians didn't do the right job on them as Americans were doing. How's that and its perfectly legal and FAA allows it.

 

 

[Guest Maj Millard]

Camel,

 

I have been maintaining and flying 912s now for well over 20 years. In that time I have encountered one, count them, ONE faulty sprague clutch requiring replacement. And that was caused by the owner using a non Rotax recommended oil IE: Castrol Magnatec, which will contaminate a sprague clutch and cause it to become ineffective. I have never encountered any sprague clutch problems with owners using the recommended lubricants.

 

Additionally there has not been a lot of cases of actual fuel pump failures. One particular brand only was not performing well, and has been removed from service. This only accounts for a very small percentage of total pumps out there , the rest still performing fine. Rotax has now included all fuel pumps into the required 5 year rubber replacement program, which won't do any harm as they are not a high price item...........Maj.......

 

 

[Camel]

These are not my words only cut and paste from the link provided, I do not doubt what you say as that was to point out that fact and figures can't pinpoint the reasons and you clearly indicate the wrong oil is more of the problem than design. I am interested in design improvements we can't do much about bad practices without serious education.

 

This is also cut and paste below and also clearly states the facts and figure dilemma.

 

Cut and paste below.

 

http://www.aviationsafetymagazine.com/airplane/LSA-Engine-Safety.html

 

A review of NTSB accident records indicated 159 accidents between 1982 and 2007 involving aircraft powered by Rotax. And as you'd expect, a fair number of those involved much of the same-old-same-old causes you'd find examining general aviation accidents—fuel starvation, VFR into IFR conditions, loss of control, carb icing, runway loss of control.

 

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But reports also cited engine problems, some with no discernable explanation. Gearbox issues have occurred and reoccurred with the Rotax models, and recently the company issued a mandatory service bulletin regarding checking the magnetic plug for metal chips and for proper lubricant.

 

Accidents involving the other engines were far fewer—only three, for example, involving Jabiru-power; none cited the engine as a causal factor.

 

The higher number involving Rotax-powered aircraft is understandable since Rotax has thousands more engines in service than the other manufacturers combined.

 

The great problem in identifying engine-specific problems is that in the majority of installations, the engines power experimental/amateur-built category aircraft, where differences in mounting, accessory placement, cooling and vibration variations can instill issues that vary from one installation to another.

 

And accidents involving Continental O-200-powered craft were as numerous as you'd expect for the length and depth of its presence in general aviation aircraft. Here again, many occurred through no fault of the engine. Still, numerous reports involved engine stoppages, heat-related power loss and other engine problems.

 

Fuel starvation, poor maintenance, failure to observe operating limitations and some power losses lacking explanation populate the reports for both the conventional and unconventional engines.

 

To paraphrase the words of one long-time Rotax service-center operator, the main problems involving the engines stem from many of the same types of problems—poor judgment, misuse, mismanagement and poor maintenance—befalling all aircraft.

 

 

[Guest Maj Millard]

I'm a having trouble following you a little Camel. Are you trying to say that the majority of the problems with Jab engines are the result of Quote : "poor judgement, misuse, mismanagement and poor maintenance" as suggested above ?... Yes I agree all of these symptoms beset all aircraft engines at various times.

 

But can you please explain your lack of mention of :....unplanned low time mechanical failure, or, general lack of robustness of certain critical components leading to sudden, and unexpected engine failure ....IE: valve heads separating from valve stems, critical engine case through bolt failures, and flywheel/ ign rotors separating from crankshafts without warning ?........if I am missing something here please enlighten me................Maj....

 

 

[jeffd]

h

 

They are supplying engines right now to the Israeli drone manufacturers with efi - I've seen the injector attachment fittings on the inlet manifolds on built engines before they went into the export crates. I'd have bought a set on the spot except I need to re-register my aircraft as 55...I'm not a paid advocate for CAMit. But as a Jab. owner, I sincerely suggest that if you are coming up to an engine rebuild (and you're not stuffed by 24-reg): - visit the CAMit factory and see the differences for yourself. Plenty of people sit on the sidelines here and snipe - but talk is cheap and exposure to the facts is gold.

hey oscar im only new to flying and this site but am loving both, well mayb flying a bit more, havent looked into the number things yet so can u tell me what the diff is in 55 and 24 i only intend at this point to fly ra aus due to costs etc but certainly think the jab 230 is a good sized aircraft for touring.certainly would be a no brainer to install a camit motor as opposed to a rebuilt jab 1.thanks for your info was good reading and will be investigating further.

 

 

[Camel]

I'm a having trouble following you a little Camel. Are you trying to say that the majority of the problems with Jab engines are the result of Quote : "poor judgement, misuse, mismanagement and poor maintenance" as suggested above ?... Yes I agree all of these symptoms beset all aircraft engines at various times.But can you please explain your lack of mention of :....unplanned low time mechanical failure, or, general lack of robustness of certain critical components leading to sudden, and unexpected engine failure ....IE: valve heads separating from valve stems, critical engine case through bolt failures, and flywheel/ ign rotors separating from crankshafts without warning ?........if I am missing something here please enlighten me................Maj....

I accept these problems as reality, what I would like is Jabiru to accept this and with Camit now doing something about it on their own, I hope that Jabiru will approve these design modification to be used in factory built aircraft and see an end to unreliable engines.

 

I want to see the Jabiru engines improved and reliable. I'm not arguing the facts merely trying to put pressure on Jabiru to improve their product which many individual people have done modifications and now Camit have done the best thing, but Jabiru should be supporting this and seem to still have their head in the sand.

 

I hope I have enlighten you, it is in the RAA ops manual to foster and encourage the construction and safe operation of recreational aircraft, Section 1.01 organisation and administration. Also section 2.01 technical manager duty statement. Item 2 clearly states, technical matters include matters relating to aeronautical engineering, aircraft manufacture, aircraft maintenance, related legislation and quality control. Maybe RAA can bring change. Also I stated in the beginning that Casa should encourage modification to increase reliability in the interest of safety.

 

 

[Oscar]

hhey oscar im only new to flying and this site but am loving both, well mayb flying a bit more, havent looked into the number things yet so can u tell me what the diff is in 55 and 24 i only intend at this point to fly ra aus due to costs etc but certainly think the jab 230 is a good sized aircraft for touring.certainly would be a no brainer to install a camit motor as opposed to a rebuilt jab 1.thanks for your info was good reading and will be investigating further.

Jeff, there are plenty of people here better able to enlighten you about the subtleties, but there's a useful explanation of the rego class differences at: http://flysafe.raa.asn.au/regulations/regulations.html (if you wade down a bit, there's a 'summary table' that's pretty useful). VERY crudely speaking (and I'm sure that others will fill in the gaps I may have missed), in regard to your ideas: if it's 24-reg, you can only do what the manufacturer allows (though even that's not totally cut-and-dried, but unless Jabiru accept the CAMit version engine, it's going to be difficult, at least until the CAMit engine gets certification to the same level as the original engine installed by Jabiru, and even then it will probably need an engineer's certificate AND be a 'C'-model). A 55-reg aircraft (and it may be that there are no 2X series 55-reg. anyway, but the RAA register doesn't provide definitive information there) can be modified under an Engineering Order and still maintain its status as an aircraft available for training. 19-reg. is much more 'run what you brung' - within sensible limits - but has restrictions on its operation (you can't do your training in a 19-reg aircraft unless you have been the builder, for instance.)

 

I would LOVE to do exactly what you are saying: run a 2x series with a full fruit CAMit engine. There's no way my Doberman will fit in our ST1, even if I duct-tape him into a compact ball...

 

 

[jeffd]

t

 

Jeff, there are plenty of people here better able to enlighten you about the subtleties, but there's a useful explanation of the rego class differences at: http://flysafe.raa.asn.au/regulations/regulations.html (if you wade down a bit, there's a 'summary table' that's pretty useful). VERY crudely speaking (and I'm sure that others will fill in the gaps I may have missed), in regard to your ideas: if it's 24-reg, you can only do what the manufacturer allows (though even that's not totally cut-and-dried, but unless Jabiru accept the CAMit version engine, it's going to be difficult, at least until the CAMit engine gets certification to the same level as the original engine installed by Jabiru, and even then it will probably need an engineer's certificate AND be a 'C'-model). A 55-reg aircraft (and it may be that there are no 2X series 55-reg. anyway, but the RAA register doesn't provide definitive information there) can be modified under an Engineering Order and still maintain its status as an aircraft available for training. 19-reg. is much more 'run what you brung' - within sensible limits - but has restrictions on its operation (you can't do your training in a 19-reg aircraft unless you have been the builder, for instance.)I would LOVE to do exactly what you are saying: run a 2x series with a full fruit CAMit engine. There's no way my Doberman will fit in our ST1, even if I duct-tape him into a compact ball...

thanks for that info i shall check it out and c what i find

 

 

[Dafydd Llewellyn]

I'm a having trouble following you a little Camel. Are you trying to say that the majority of the problems with Jab engines are the result of Quote : "poor judgement, misuse, mismanagement and poor maintenance" as suggested above ?... Yes I agree all of these symptoms beset all aircraft engines at various times.But can you please explain your lack of mention of :....unplanned low time mechanical failure, or, general lack of robustness of certain critical components leading to sudden, and unexpected engine failure ....IE: valve heads separating from valve stems, critical engine case through bolt failures, and flywheel/ ign rotors separating from crankshafts without warning ?........if I am missing something here please enlighten me................Maj....

Maj, you sound like a prosecuting counsel, pursuing a reticent witness. Firstly this is a FORUM, not a law court. Secondly, nobody here is bound by the rules of evidence or an oath. Thirdly, most of us have only hearsay on these matters anyway. I suggest you re-read the title of the thread; it pre-supposes that Jabiru engines have or have had known major weaknesses; the whole discussion is about CAMit's current efforts to put out a product that addresses them. CAMit cannot force Jabiru to accept its engines in -24 registered aircraft; and Jabiru are unlikely to do so for the reasons OSCAR states. It's early days yet for CAMit's product to be approved formally as a substitute for a Jabiru engine in any aircraft that requires formal approval; however no doubt CAMit will be working towards that. For a -19 registered aircraft, it's up to the builder; he can use whatever powerplant he chooses - and accept whatever operating limitations flow from that choice. I, for one, am very tired of hearing that a Jabiru 2200 is not as good a 912 as a Rotax 912 is. That's not the point of this thread. Nor is the question of "what is Jabiru doing about it?" If you want to bang that drum, start another thread. FFS, get off your soap-box, man; we all know where you stand on this subject.

 

 

[Oscar]

I'm a having trouble following you a little Camel. Are you trying to say that the majority of the problems with Jab engines are the result of Quote : "poor judgement, misuse, mismanagement and poor maintenance" as suggested above ?... Yes I agree all of these symptoms beset all aircraft engines at various times.But can you please explain your lack of mention of :....unplanned low time mechanical failure, or, general lack of robustness of certain critical components leading to sudden, and unexpected engine failure ....IE: valve heads separating from valve stems, critical engine case through bolt failures, and flywheel/ ign rotors separating from crankshafts without warning ?........if I am missing something here please enlighten me................Maj....

Remind me again, if you will, of how many Jab. engines vs Rotax engines have had to be inspected and their crankshafts replaced if within the specified range of serial numbers? Or was Rotax just having a brain-fart when they sent out those several Emergency Safety Bulletins? I don't think that was a response to perceived faults of operation.. The Mandatory crankcase inspection SB was attributed to 'operation', though I note that Rotax changed the crankcase...the Mandatory replacement of gearboxes SB of '08 doesn't seem to me to be predicated on operation... The oil pump drive pin replacement Mandatory of '01 appears to be a manufacturer's problem, not one bought on by operational abuse...

 

If I am missing something here, please enlighten me.

 

If you want perfect safety in an engine, then go buy Rolls-Royce, at several $M a pop - oh wait, don't do that if you are running an Airbus 380...

 

 

[Marty_d]

There's no way my Doberman will fit in our ST1, even if I duct-tape him into a compact ball...

"In" being the operative word... Think ute...

 

 

[Guest Maj Millard]

"I'm not arguing the facts, merely trying to put pressure on Jabaru to improve their product"....Quote :...Camel...It's nice to have some company, I and others have been trying to do it for at least six years !....

 

The RAA is aware of the need to do something in the interest of safety and the goodwill of their members. Problem is they need solid facts, and lots of them. This is where the membership comes in to provide those concrete facts.....Maj.....