Oscar

I think the rocker mod reduces side loads on the valve stem thereby doing something about valve failure. LaurieBTW, is it a full moon?

Yes it does - and yes it is. Surely you could tell by the dogs howling in the night?

 

 

By way of some background, there's an old article by Phil Ainsworth that's really worth reading: http://www.aeromech.usyd.edu.au/AERO1400/Jabiru_Construction/jabiru.html

 

You need also to remember that FEA packages - at least on a scale of cost available to operations such as Jabiru - were not (as far as I know, anyway) readily available when Rod and Phil headed down the somewhat brave path of deciding to build their own engine. Yes, large organisations had been using it for years, but it required access to large computing resources (mainframes) and basically personnel dedicated to undertaking the data entry required to actually develop a useful model of the element itself. I do not know whether Rod Stiff had used FEA in developing the original Jab. engine so I am merely conjecturing when I suggest that, by and large, I think he was using his conventional engineering skills in making the decisions about components. Others may be able to fill in the blanks here.

 

Jabiru certainly tested their engines as best they could at the time; I remember visiting the factory in the early 90's and seeing the wee Diahatsu (I think)-mounted engine test rig that Alan Kerr would take down the end of Bundy airstrip, with his sandwiches and coffee, and run the things for hours on end. (there's a piccy of it in the 'Jabiru history' article in a recent Sport Pilot). It took me 10 minutes to stop laughing when I first saw it.. I also saw CAMit's engine production line, with an assembly-line of engines that would have looked entirely possible as Honda's motorcycle engine line - and those are jewels assembled by comparison with your average Lycoming/Continental/ and car engine. The only engine I have personally ever worked on (other than motorcycle engines) that even comes close in terms of plain beautiful engineering excellence is a Gardner diesel.

 

It's all-too-easy to toss-off derogatory statements about Jabiru engines, we see it on every thread here about Jab. engines. I don't recognise any of those who do as having achieved a comparable contribution to the development of ultralight activity in this country as Jabiru.

 

Let's look at a few companies who have ultimately failed/ceased operation in the production of small piston engines for aircraft. Rolls-Royce, with Continentals built under licence. Franklin. Porsche. Diamond. KFM. Where are the Gypsies of yesteryear? Seriously major companies who have never entertained the idea of using their engine-building expertise for the production of small, piston-engined aero engines: BMW, Mercedes, Volkswagen, GMH. Ford, Chrysler, Honda, Yamaha, Kawasaki. FIAT used to build aero-engines - but never for the ultralight market. There are only two manufacturers who have a serious presence in the market for ultralight engines: Rotax and Jabiru. Rotax is of course owned by Bombadier. Bombadier had an annual income for 2012 of 19 BILLION (Canadian) dollars. That's AUD$20 BILLION. One could, I think reasonably, suggest that Jabiru is punching somewhat above its weight in that company.

 

With that sort of corporate backing, you'd expect that Rotax would have unbreakable QA systems. Remind me of how many engines affected by recalls for a faulty crankshaft Rotax had on the 912 recently?

 

CAMit are, as they say, addressing issues with the Jabiru engines. If they succeed (and I personally believe they will), then that opens a way forward for what are now Jabiru-engined aircraft to expect a better factor of reliability in what twists the prop. The proof of that pudding is progressing at a decent rate. If you are a current Jabiru engine owner, you have but to wait for the results of operational experience to come in. Of course, if you are a rabid and fundamentally ignorant Jabiru knocker, nothing will stop you ranting on and this site has an adequate supply of those.

 

One side of the argument is going to be proven right. I know where my money has been put.

 

 

Having read through most of this forum I wonder what is wrong with the existing Jab engine. The way some people talk it seems that they must be failing daily.I ran a 1600 Jab that I couldn't stop leaking oil and was a bit short of power on a hot day, so I upgraded to a 2200 Jab with solid lifters, Factory zero timed. the only problem I haver had with it was caused by a bad batch of fuel.

In my opinion it would be a better engine if they ditched the Bing carbie and used a TBI with mixture control and fitted with 4 CHT and 4 EGT gauges. That way you could see any upcoming problems.

 

Camit seem to be fitting new rocker gear, but one of the problems seems to be failing valves, not rockers. The increased instrumentation would reduce that problem.

 

Oscar. Are you running an engine overhaul business in bundy?

Would be a bit difficult - I live south of Sydney.... and nope, I'm not running ANY sort of engine repair shop! Used to build (amateur, for my own car) a few racing engines way back in the day, but working on a Jab. has tricks and quirks that you'd get the flavour of from the Jab. engine manual but to be honest, having seen the real guys doing it (and realising just how much special tooling you really DO need to get things schmick-duck), I'd not attempt it for anybody else to fly behind. For a little while, 'between projects' as they say, I used to repair-weld alloy cylinder heads for an engine rebuilder shop in Canberra years ago and they'd allow me to use their gear to build my own engines (the owner was a fellow racing mate), but when you see the sort of tooling and equipment CAMit has, you quickly realise that your old 'hand-build' skills aren't any match for laser-measuring etc. in a controlled environment.

 

However: the upside of having 'built' our own engine is that we know what's in there. If anything changes - e.g. a nut or bolt goes soft on torque - we think we'll have have a pretty damn good idea of what might be going on and what to address - and how seriously to take notice of that change. Since ours is a thick-finned head engine, it's going to be a fairly rigorous test for some of the mods. / 'fixes' that CAMit have introduced. We'll absolutely be running 4 CHTs and 4 EGTs - and our heads are so old ( in years, not hours - think of them as NOS that's been sitting around for many years) CAMit had to build us a new jig to add the CHT probe pick-up points between the plugs! There is a reason we didn't move to new heads, but that's a future story.

 

 

Well guess what Oscar, I'll back Major's practical skills against exhaust gas any time.

You do that. It's your neck on the line. I'll rely on my own sources and resources that have a proven track record from F16's downwards, are (genuine) test pilots, have done the type certification of a number of significant Australian aircraft, have built 5,000 plus aero engines, blah yaddah. Each to his own, I say.

 

 

I own an original VFR750 - the direct result of Soichiro Honda decreeing that the the problems of the VF750R would be not just addressed but obliterated! It is a magnificent piece of engineering and urban legend says it was sold at a loss to the company. Of that I have no certainty, but what I do know is that the machine I have is the first in a line of the most successful sports/touring bikes produced in the world. Your appreciation of a particular situation at Honda is entirely correct, but I happen to be someone who already knew that. I completely agree with your summary.

 

Absolutely nobody who has accessed the reams of information available could reasonably argue that there are not design flaws in Jabiru engines. There is incontrovertible evidence of that. Whether these are 'major' depends on the definition of 'major'. I suggest that 'major' is a basic, fundamental lack of fitness for purpose. 'Major' is not, in my personal opinion, a problem that can be addressed by upgrading the size of a bolt here or adding a dowel there - but I concede that this is a subjective area. This is highly relevant to the discussion of this thread, because it brings into question the very basis of what CAMit is undertaking by way of addressing the issues attendant with Jabiru engines.

 

However, with regard to your latter point about stepping down from my plinth: both you and Major Millard have made extremely dogmatic assertions regarding various aspects of the discussion on Jabiru / CAMit engines. I have asked both of you to provide any - I repeat ANY - supporting evidence. In the absence of that, I have to conclude that these are simply unsupported statements of personal opinion that lack any measure of verification. There is a crude expression for such statements, that refers to the results of the bovine excremental process.

 

No, I am not going to 'step down from my plinth' in the face of unsupported opinions. You (and Major Millard, in whose corner you have evidently placed yourself) have made statements - now provide the explanatory material that will prove them. Can you do that?

 

And, I'm not a Mate. Don't presume a relationship with me that you have so far failed to earn.

 

 

I have no idea if Jab have things patented or not but there's quite a number of patentable features surrounding Jab engines.

I'm pretty sure that for the future existence of both (or either!) of Jabiru's engine production or CAMit's potential developments, this information would be of great value. Would you care to share your ideas?

 

 

Yes you do get the occasional crack in cast crankcases, but considering the numbers out there, it's really rare in the big picture. On the other hand , many do their TBOS and return for another go. The radial 985 crankcases for instances just keep going on, and on. Some of the total time hours on those is very impressive, and they are still flying daily in Beavers etc....Let me know when any Jab engine comes even close to that..................Maj......

Certainly an impressive record for the old Wasp Junior, one has to agree. I'm surprised we don't see more of them powering ultralights, actually; I reckon that'd put a stop to the EFATO problem completely. And they're cheap to buy, run and maintain.

 

 

All very interesting and good to see Camit at least trying to to improve something. It must be hard to ignore the trail of failed engines throughout this country, and indeed the world. Australia can and should produce better than that.Regardless, whilst they continue to use the billeted CNC case, in lue of what everbody else uses (cast or forged), I predict the failures will continue regardless of all the pretty stuff they hang off the exterior. The very basic design flaw needs to be addressed also......................Maj....

Perhaps you could share with us your reasons for making such a leading statement? No doubt you have a deeply informative well of analysis of metallurgy and manufacturing processes which you have summarised as a 'very basic design flaw' to help understanding of we less-well informed people? Obviously you wouldn't make such a statement simply on the basis that 'everybody else does it differently', and I'm sure we'd all like to know the in-depth story behind why billet/CNC is the wrong way to go. Don't hold back here, we'll do our best to follow the intricacies of the explanation.

 

 

I really hope these engines are a good ( better) thing, I'd have one for my next project if I was confident they're going to last,,,,,and really don't care if they have or have not breached some IP or copyright , so I'd like to know important stuff,,, like how much$$$ , what's the TBO, what's the warranty ,,,,I'd have thought these would be relevant questions , they are for me anyway , Oscar are you part of the company, will they be doing some promo at Natfly ,I'd love to have a talk to someone about themMatty

Nope, not part of the company at all, and I have no idea of whether they are planning any PR work. We ended up doing the rebuild there due to a really strange set of circumstances, and the quid pro quo for that opportunity is we have participated in developing background notes (observations) for the instructions for other rebuilders, and we will be providing a copy of all engine performance data. There's no warranty implied or expected for anything we've done / used: we used our own judgement of what we saw and the information provided to us (plus, I have to add, some advice from other people very experienced with Jab. engines), did the work and paid the going prices for all parts used (including some parts from Jabiru, where appropriate/useful). I won't have definitive figures for how this engine performs for several months, while the rest of the aircraft is finished and returned to service. However other engines are out there gathering data.

 

As they say: watch this space!

 

 

maybe the IP issues would be clearer if the origins of the design were known. I believe Camit were heavily involved in development of the originals so would "own" some of the IP anyway at some level.

It's no coincidence that CAMit and Jabiru are co-located at Bundaberg. When Rod Stiff and Phil Ainsworth set out to manufacture aircraft, they established a company that has (I believe, I am entirely happy to be proven incorrect) achieved aircraft sales in numbers never seen in this country. They did this using not just their own design and production management skills but by also calling in expert assistance - and selecting that wisely. The Jab airframes have a pretty unblemished reputation for decent performance, reliability, forgiving handling and toughness. Look at the numbers for an original LSA55 vs. Cessna's 162, and (remembering the LSA55 was designed to meet a more restrictive MTOW limit), the 20+ year-old LSA55 stacks up pretty damn well. The modern incarnation of that, the J120, is a fine little aircraft - at 1/3rd the purchase cost of the C162 before it was canned by Cessna (and remember, the C162 was being made in China, so you can extrapolate the excellence of Jabiru's production methodology in the light of Australia's so-called 'manufacturing disadvantages' (aka 'wages') against the global benchmark for cheap production: China).

 

 

 

When Jabiru were forced to produce an engine for their aircraft, they found CAMit on their doorstep. Can anyone show me a more successful aero-engine manufacturing plant worldwide, (after Rotax of course), for engines in this class? Rod and Phil were in no way any less savvy in their choice of engine design and manufacturing capability than they were for establishing the airframe manufacturing design and capability. More than 5,000 Jabiru engines have been produced, I believe.

 

Yes the new Jab engines will be possibly made elsewhere and incorporate plenty of changes too no doubt. Could go either way, either re-engineer and fix issues or create new ones.

 

The 'Chinese' engine seems to have been a long time in gestation. One could deduce either: Jabiru have been working overtime to make sure it addresses all of the evident problems, OR one could postulate that more work is required before they are ready to release it. Jabiru surely knows the answer to this; for the rest of us, well, we'll just have to wait and see.

 

Similar could be said for Camit however I do trust the skills of Ian and Aust experience in the field. Most changes he is making are incremental improvements. Keep in mind both these companies are tiny and R&D money, expertise and time is hard to come by.

 

Well said.

 

Id imagine Camit was restricted to NOT sell engines whilst providing to Jabiru or restrained simply by capacity, so the move by Jab may be freeing Camit up rather than a total loss.

 

Either way we, the AC owner, end up with 2 new Australian controlled versions of what most agree should be a solid reliable performer.

 

Again, spot-on. We can only be the beneficiaries of diversified lines of development. I know that I would rather have the option of one of two candidate 'screw-in' upgrades to my Jaburi rather than committing to a really complex engine swap that if found to be of no advantage, would again cost mega-dollars to remediate.

 

Id buy a new Camit engine before I sat behind a fully redesigned Jabiru.

That's where we've put our money! - with the full knowledge of what and why the changes we were incorporating in our engine were worth it- down to the last damn nut and bolt we used . But that recommendation is second-hand, and it's just my opinion. If you are in/likely to be in the market for a new/rebuild Jab. engine, you could do a heap worse than go to Bundaberg and visit both Jabiru and CAMit. Look at things for yourself, talk to the people. The Jabiru and CAMit facilities are a 5-minute drive apart. You can see every damn part, handle it, and in the case of CAMit, see it being made, from base material through to installation and dyno-testing. You can do that for a hell of a lot less investment than making a wrong decision on your next engine and having to replace it in 350 hours rather than 1000...

 

 

 

Stay overnight at least in Bundaberg, in a place you can do your own cooking (I can recommend one, within a long walking distance to the airport). Go down to the local fisherman's co-op (again, I can provide an address) and buy a couple of kilos of local-catch banana prawns and cook yourself garlic prawns with Caesar salad on the side. You'll end up making your next engine move decision with all the information you need - and you'll write-off the cost of the trip to Bundy against the dinner, I guarantee that (if you can cook, that is).

 

 

I'm told the heads on Camit engines are not the same as the Chinese made engines which Jabiru has now switched to: rather they are more similar to the earlier thick finned heads. UL power make a similar engine - wait - thats a clone of the Jab too....

Nope, CAMit are still making the current Jab. heads -the thin-finned ones. Externally, the CAMit heads are pretty much identical with the exception of the CAMit-branded rocker covers; however there are some differences under the skin, including new improved rocker arms, new rocker bushes (which really look the business - you can see them on CAMit's web-site, in the flesh they're even better-looking when you understand how the new oil-delivery grooves work: http://camitaeroengines.myshopify.com/collections/engine-components/products/rocker-bush Hopefully CAMit will add pictures of their new rocker arms to their site soon as well, they're a real work of art that changes the geometry to reduce the side loading on the valve stem. There are a few other 'tricks' being tested that will - when CAMit are completely satisfied about their performance - be introduced.

 

However, you are correct that Jabiru have been looking to change their heads on 'the Chinese engine' - but that's not yet been introduced as far as I know, I think they're still a work in progress.

 

 

good to see everybody playing nice and friendly..Question for Oscar, who seems to know about these engines... you said 40Watt alternator in an earlier post? Isn't that a trifle on the small side? A transmitting radio is going to draw something on the order of 41Watts. Once you start adding up the fancy electronic flight instruments, the blinking lights (strobe, nav, landing), any electronic gyros, flap motors, well, a 40 Watt alternator isn't going to cut it...

Yes, electrics has never been my strong point.. I run on coffee. By way of abject mitigation - I was concentrating on the beneficial aspect of the alternator drive system providing some additional harmonic balancing to reduce the flywheel bolt shear tendency (though the steel flywheel 'spider' is also a significant improvement on all later Jab. motors vs. the earliest ones) than the output.

 

 

Those heads look mighty similar. As you say would jab be stupid enough not to patent it. Those heads are what got my attention ...IP rights have escaped the thoughts of many far bigger businesses then these guys

You fairly obviously do not understand the basis of patent protection. May I politely suggest that before you try to dig yourself out of the hole, you put aside the shovel and seek knowledge of that of which you pontificate.

 

 

CAMit are neither commercially nor legally naive, FFS. They're not setting them selves up for any future problems vis-a-viz Jabiru and IP rights, nor for any owner IP rights problems with their engines. If you had the expertise to develop a multi-million $$ engine manufacturing business that's lasted for 25 years or so, do you think for a moment that IP rights issues would have escaped your focus? Give successful people some credit for intelligence before you spout off.

 

 

Oscar, everything you write is valid, appreciated and informative. If one could replace a Jab enginewith a Camit engine And keep the plane in the factory built LSA catorgory

I'm sure most would buy the more reliable engine. Will Jabiru allow it ?

 

Does any engine need to be certified to be in a LSA ? My belief is it just has to meet the ASTM standard.

 

If certified, will Jabiru allow it to be installed in a Jab LSA. ?

 

(as I understand it- and I'm no expert): Jabiru have to be the 'responsible' agent for their LSA (24-reg) aircraft. That means, if I understand if correctly, that they have to have all the test documentation etc. to prove that every component meets the required standards. Not a cheap exercise, and understandable that they don't want to do it for every 'candidate' optional component. That said, I think- but am not expert to state- that a certificated CAMit engine to the same standard as Jabiru use for 'their' engine ought to be allowable.

 

Jabiru have upgraded parts before, why are they not participating ?

 

I don't know - ask Jabiru!

 

An oil manufacturer has done tests on Jabiru engines and found a suitable oil not recommended by

 

Jabiru, why don't they participate ?

 

Same as the first point, really- they've found an acceptable oil.

 

Is Camit aware of oil tests and I wonder what they recommend ? Did they recommend oil to you ?

 

I also believe what you say Oscar about overheating Jab engine which is the start of the rot. And if every mod that others

 

have produced ie water cooled heads, fuel injection, ignition systems plus Camit mods and none of Jabs mods, what kind

 

of engine would we have ? Reliable or not ?

 

Wow, a mega-question. There are a whole heap of issues there, including 'no negative effects' (if that is the correct phrase): i.e. the changes do not introduce negative structural/performance issues that need to be certificated/proven. The Rotec water-cooled heads seem like a great idea, but I have NO idea whether they address other problems (such as the valve-guide loadings) negatively or positively. And you can't just ignore barrel cooling because you have head-cooling sorted. Any change needs to be evaluated for its overall effects. However: if we assume the basic Jab. engine as a base-line for reliability, certainly the CAMit engine (and for that matter, othger mods such as the Rotec water-cooled heads) have a set of figures against which they can demonstrate their performance.

 

My point is I think Jabiru are not participating in research and development of their own product and ignoring the demands of the customers who want their product, but want reliability. I am one of those people and I believe the J230 would be the best seller worldwide if they listened to the customers, lots have tried to tell them but it appears no one will listen. The problems are obvious to those in the know and would stick with it if they knew that the product would improve, as you say you have a Camit rebuild with mods, the legality in a factory build without jabiru approval is a problem, or is it ?

 

I can only comment that, if I had the wherewithal, I'd be flying a J2x-series aircraft with a CAMit-modifed (full fruit!) engine in a heartbeat - much as I have a serious connection to my hand-rebuilt ST1!

 

Thankyou again Oscar for taking the time to share.

Thanks Oscar, sound impressive. I wonder if they will go further in the future and adopt features like EFI and cast heads or are they sold on machining everything from billet? I reckon that would really make a nice unit. Interesting to see they use solid lifters also simple, reliable and effective. I hope they do well and develop a nice export market with this.

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.

 

 

If you can identify the actual responsibility for the 'ongoing quality control issues with the Jabiru engine' - then you have a valid point. In case you failed to recognise the distinction I made in my post: that CAMit produce engines to Jabiru's specification, (that Jabiru sell), let me spell this out in large, warm, friendly letters (again): if you buy an engine / rebuild from Jabiru, it is a Jabiru engine. If you buy a CAMit rebuild/new engine, it is a CAMit engine.

 

Is that sufficiently clear? Jabiru are responsible for the issues with Jabiru engines. If the engine has a Jabiru plate, it is a Jabiru engine, NOT a CAMit engine. Jabiru orders engines from CAMit to a particular specification - theirs. That is what CAMit build to supply to Jabiru. How difficult is it to understand the difference between a product that has been built to an external specification vs a 'home-grown' product?

 

(addendum:

 

If you mean: 'does the CAMit engine address the 'ongoing quality control issues with the Jabiru engine' - then please re-read the quote from the CAMit site. A heap of issues have been addressed - not just 'QC' but basic design issues. You cannot hold CAMit responsible for QC issues that can be sheeted home to Jabiru's selection of suppliers of certain components, nor can you expect CAMit to be able to redress problems that have resulted from that. That is Jabiru's responsibility.

 

 

[quote= DJP is almost certainly correct in ascribing it to a Von Karman vortex street; and the Jabiru fix tends to confirms that.

 

It's therefore a nuisance-value vibration - but if allowed to persist, it could - at least potentially, in the long term - reduce the fatigue life of the lift strut.

 

Would it be unreasonable to suggest that simple vg's applied to the lift-strut upper (or lower) surface would change the airflow so that the Von Karman effect would be negated? It seems to me that what is required is a change in a 'balanced' airflow condition that produces a harmonic interaction: change the characteristics of the airflow on one side and surely the harmonic condition would be dissipated? Thus no intrusion of the structural integrity of the strut - just Araldite the buggers on.

 

 

I've seen the 'improved' engines being built and investigated the changes in depth - and they're damn impressive. CAMit have looked at the problems (and believe me, they know ALL the problems, including ones you would not realise unless you are a very, very experienced engine manufacturer and have the result of inspection, testing and analysis using some seriously high-tech machinery to hand).

 

It's not my place, nor am I at all sufficiently knowledgeable to discuss the various mods. and how they interact. CAMit can - and I am sure would - tell an interested purchaser of one of their 'modified' re-builds just what and why things have been done. However, I think I can make some general observations that are valid.

 

Any engine is a conglomeration of 'systems' that have to interact. In a Jabiru engine, these include (and are not limited to!): engine case join integrity, barrel attachment security, head attachment security, rocker-gear loadings, oil supply, cooling, valve stem loading and crankshaft harmonic damping. That all of these are potential problems is no secret - all have been well documented. However, how many people have recognised that the 'through-bolts' issue is not just simply a problem with the nuts or the size of the bolts, but can start with the methodology of joining the engine cases plus the strength of the barrel base. Add over-temp flying and detonation and the engine is on the way to self-destructing. Individual owners (and some FTFs!) that are scrupulous in their usage parameter observance allow us to see examples of Jab. engines running 1000 hours or more. However, scrupulous is the operative word here: just one incident of 'abuse' outside of the limits starts the rot.

 

CAMit has looked at the problems and developed an engineering response on holistic principles (not that they'd necessarily use that term.) Its mods. are not just 'fix this particular problem', but looking at the system(s) interaction and ensuring that every element that contributes to the problem(s) is addressed as far as possible within the limitations of interchangeability with standard. That starts with a different case-joining regime, new through bolts that address case fretting and loss of torque, thicker barrel-bases to address the through-bolt leverage problem particularly in the event of detonation - a heap of inter-related subtle changes. There's no 'silver bullet' approach - because there is no 'silver bullet'. However, if I can introduce a somewhat tortured analogy here: the CAMit 'improved' engine changes crystal glass to Corning Ware.

 

Engine Certification requires an incredibly complex set of tests, and that's very, very expensive. Despite this: expect certification of the CAMit modifications in the not-unforeseeable-future. Right now, CAMit modified engines are out here accumulating service hours.

 

Jabiru sells engines that are certified and to a degree its hands are tied regarding changes that would impinge on the certification. CAMit builds engines to Jabiru's specifications - that's their role in the supplier chain. Do not confuse the role CAMit has in supplying engines to Jabiru: Jabiru does not buy 'CAMit' engine, it contracts CAMit to build engines to its specification. This is NOT a semantic issue: engines built for supply to Jabiru leave CAMit with a Jabiru engine plate attached, which has the legal responsibility placed on Jabiru. CAMit 'improved' engines leave CAMit with a CAMit engine plate ( I've had the priviledge of seeing both the #0001 2200 engine and the #0001 3300 engine completed and ready for delivery!) They are different - though externally similar - engines. They bolt up to your engine mounts with no modifications.

 

CAMit recognised that in developing its modifications, it needed to provide purchasers with as much confidence as it could provide that if they choose to go the CAMit engine route, they still have the back-up of Jabiru - in case CAMit is hit by a comet or similar. If you choose to replace your stuffed Jab. engine with a CAMit-modified one (at around the same cost as a Jab. zero-timed rebuild) you are not taking a step over the cliff. Hell, you can integrate many of the CAMit parts - such as the 40-watt alternator (with its attendant harmonic dampening of the flywheel bolt-shear characteristics) with your Jab. rebuilt engine. It's called 'legacy engineering'.

 

I've had the absolute privilege of rebuilding my 2200 at CAMit, incorporating many of the 'improved' mods and discussing the whys and wherefores with the CAMit engine gurus. I defy anybody to actually go to CAMit, watch the entire Jabiru engine manufacturing and assembly process, ask the people concerned: 'why it is done this way?' and not leave satisfied that your questions have been reliably and believably answered.

 

Jab. engines are not fundamentally bad things - in some respects they are state-of-the-art leading (hp/lb/cruise revs equation). But they are 'fragile': intolerant of use at 'out-of-limits' conditions. Rather than throwing the baby out with the bathwater, CAMit has developed a baby-friendly bathwater solution. It's worth more than just idle consideration.

 

 

This sounds to me to be a serious issue and should not be taken lightly. As far as I know, the lift strut end fittings are the most highly-loaded component in a Jabiru, and being aluminium, must be susceptible to fatigue by the nature of the material. While obviously they are sufficiently strong in normal conditions (Jabs don't lose wings), my inexpert engineering understanding is that heavy vibration in a highly-loaded alloy component is a pretty sure-fire way of introducing fatigue.

 

If the strut is fluttering then surely the attachment bolts are being in effect slammed sideways in their holes. It may be that the elasticity of the 'glass lift-strut pick-ups on the fuselage and wing main-spar plus perhaps some bending of the lift-strut attachment bolt itself (which as we know is not tightened down so the end-fitting clamps to the strut pick-ups) dampens the effect of this sudden twisting load-reversal sufficiently that it does not load the actual bolt holes in the lift-strut fittings, but I'd have thought this type of loading would be working the stainless-steel inserts in the lift-strut pick-ups in their holes in the 'glass 'plank' at the very least.

 

 

What's a Col?

Actually, a Koel, form of cuckoo, apparently migrates south from Asia. According to the locals, they come down looking to mate, so become (far less than affectionately, may I add) as 'Col's by the locals, (for the males, with the females being nicknamed by me at least as 'Eva' (Brickattit) )

 

 

What sounds we find offensive can be pretty subjective. Others may complain about the loud noise of a Ducati engine-braking into a corner; I find it one of the most stirring sounds in creation.Birds are another matter. While I am quite fond of the sound of a nesting pair of willy-wagtails, I know of one farmer who poked his shotty out the bedroom window and gave them both barrels.

Agree on both counts (and the noise of a Ducati pulsating along is delightful, especially when you're astride it (Darmah and just once, a 900ss round-case with Contis, of treasured memory) - and generally, it's gone again very quickly. I very recently spent two weeks in Bundaberg rebuilding my Jab. engine and there was a Col that started at 0300, that had the entire caravan park where I was staying at hair-tearing levels of irritation.

 

However, officialdom finds it far easier to arrive and slap a noise-order on the side of an aircraft than serve a cease-and-desist on a damn Col. If we set ourselves up as low-hanging fruit on the tree of complaints, we'll get picked. I don't think I'm being paranoid here, we've seen it happen.

 

 

Im a mx rider on a registered bike on public trails where its still 100% legal.... Not sure if you have a different bread doing illegal crap or you regard all as yobbos ... but I hope your just talking about the ones braking the rules / trespassing. The genuine trail riders, say Dads with sons pottering along on legal, quiet bikes (mainly 4-strokes) and 'treading lightly', I can approach, tell them they're on private property, they will without exception apologise and ride quietly away - no problems. The ones with no damn cans who tear up my fire trails with full-throttle every twenty yards to slide/wheelie everywhere, can get seriously aggressive ( I've had one threaten to 'punch your (fornicating) head in, you (fornicating female genital part) - while recording it on his Go-Pro (and while I was holding my doberman by the collar - that would have been a seriously bad career move on his part) after riding with several mates right past the house and sheds, and telling me he was on 'national park' area - problems. And it's not just me who perceives these as problems, or we wouldn't have the NSW Police recreational motorcycle squad routinely patrolling the area as a result of complaints.

 

Otherwise the same argument could be said about every yobo that flies over in an aircraft with noise encroaching on the residents below....

 

And that is exactly my point. There will always be someone who complains about something, but if that becomes a widespread community reaction, then local Councils are encouraged to 'do something about these noisy bastards' - i.e. close the airfield, sell it off for development. WE lose.

 

I ride a 450F which is about as noisy as they come but at 5m from exhaust at full throttle it has to be under 94db

 

At 50m at 75% throttle its less then 50db. If

 

And in a typical bush scenario about 70% of the time is spent under 75% throttle.

 

We have them measured at our race track and the sound is surprisingly low even with 40 bikes racing, once you get over about 30m from directly behind it.

 

A complaining neighbour had measurements taken at his place when the prevailing wind was in his direction. The sound was less then 5db. But we still got slapped with a 9am to 5pm curfew.

 

I think you have just superbly demonstrated the validity of my contention!

 

The unfair thing is he built inside a designated sports and motorsports precinct after the track was built.

And closed the case for the Prosecution, m'lud. Even if it's irrational, unreasonable or not even particularly demonstrable, a batch of complaints against noise WILL get the 'offenders' penalised by officialdom, and once an airfield is sold off and turned into houses, it's gone forever. We don't have any convincing arguments of social value for recreational aviation that we can use to try to combat community annoyance about our noise. Our best - and I think only - defence is to do our level best to ensure we do not become the target of such complaints.

 

 

Off-road motorcycles fought this battle decades ago: less sound=more ground.

Absolutely right - and yet, there are still yobbos who ride around and intrude on private property (mine, for example) on MX machines with shrieking exhaust notes and that generates huge angst and police presence - I am not kidding here. We need to understand the negative effect that 'intruding' with excessive and unpleasant noise has on people and both develop and preserve a reputation as decent members of society or we will lose 'ground'.

 

 

Irrespective of the actual db recording, the pitch, harmonics and frequency of noise intrusion is what drives people crackers. There used to be a float-equipped trike operating joyflights around Pittwater, flying around the hills that surround the water, and the whine from the Rotax gearbox combined with the constant (well, inconstant, really) changes of direction as it weaved around the houses had people tearing their hair out (and threatening ballistic retribution delivered in 80-gramme loads @ a muzzle velocity of around 1400 fps.) Imagine a dozen leaf-blowers on full song flying in formation 100 feet past your front porch, in an area that one can normally hear a possum fart... I live on a road that has about 80+ Harleys ride past twice a weekend - the place shakes, but they're done in two minutes; but the lone motocross rider that practices on his bloody two-stroke for six-eight hours a day about 0.5k away has me homicidal by day's end - and I happen to ride motorcycles..

 

I've had a Merlin on full noise pass about 100 feet away (utterly, utterly glorious noise that shook the cutlery off my galley); a 582-equipped Drifter five times that distance is really annoying. Guess which one of those generates more db?

 

If you want to drive someone mad, place them in a silent room with a clock that ticks irregularly. You think I am being silly?: look at line 4 of this song: http://www.abrsm.org/forum/index.php?showtopic=29174

 

Think about this: as a pilot, if you hear an engine suddenly change its revs, you look skywards. I'll guarantee you cannot ignore sudden and unexpected changes in engine noise.

 

The Pawnee glider tug operating out of Camden is the noisiest aircraft I have heard in ages (other than the Queen Air that sometimes passes over my farm which sounds like a coarse-tooth saw blade being passed through sheet stainless steel) and it flies out over a heavily-populated area - it will single-handedly kill Camden airport if it is not remediated. By comparison, the rumbling of a couple of Yaks/Numchuckas in formation that pass over my place fairly frequently is a peaceful, almost warm-feeling drone.

 

As a group, we cannot afford to ignore the effect that our noise may have on the non-aviation community if we wish to have access to airfields within a reasonable distance of 'civilisation'. I'm talking about airfields that have reasonable access to things like taxi services into a place to stay for the night when we are travelling; reliable fuel supplies, a sufficiently large flying population catchment area for a LAME or L2 to operate to be available to help us when we need repairs out the back of buggery..

 

We don't need to be irritatingly noisy - it's not as if we gain safety or performance by creating excess and annoying noise. Noise annoys people (pun intended!) and they take action: witness the rise of legislation against 'doof-doof' equipped vehicles, noisy motor vehicles, use of Jake Brakes for heavy vehicles, db limits for racing cars and road vehicles.. A properly-designed muffler system does not introduce back-pressure issues.

 

This is not an issue where 'our freedoms' should be questioned: the 'freedoms' that really matter are far more important than any imagined intrusion on our right to make as much noise as we like. We all live with this restriction every time we start our car to go to the shops. More than any other factor, if we get the backs up of the general population by demanding the right to create objectionable noise, we will be excreting in our own nests.