Major weaknesses addressed

[Guest ozzie]

considering the piddling amount of oil a jab engine carries I'd consider the oil cooler a pretty important part of the engine package especially how hot they run. Maybe one that is a little larger and tougher than the Repco auto trans ones I saw fitted would help to keep temps down a bit on a long climb.

 

Hats off to Camit to take this on. Jab can only benefit as there are no doubt that prople would like to buy a jab but are hesitant with the current power plant issues No doubt says will rise considerably with increased reliability and ability ro achieve TBO without having to adjust things every 50 hrs.

 

Edit: great thread by the way. has brought the xmas spirit out in everyone participating.

 

 

[Dafydd Llewellyn]

considering the piddling amount of oil a jab engine carries I'd consider the oil cooler a pretty important part of the engine package especially how hot they run. Maybe one that is a little larger and tougher than the Repco auto trans ones I saw fitted would help to keep temps down a bit on a long climb.Hats off to Camit to take this on. Jab can only benefit as there are no doubt that prople would like to buy a jab but are hesitant with the current power plant issues No doubt says will rise considerably with increased reliability and ability ro achieve TBO without having to adjust things every 50 hrs.

Edit: great thread by the way. has brought the xmas spirit out in everyone participating.

Ozzie, I agree with you that the oil cooler is highly important. However, from a legal standpoint, it is NOT included in the engine type certificate, so it is NOT part of the engine. It's not part of the CAMit engine either, so far as I am aware. So it's a separate issue to the subject matter of this thread.

Re oil temp, the optimum oil inlet temp is usually taken as between 80 and 85 degrees C. Lycomings etc usually have thermostatically controlled oil cooler bypasses in order to keep the oil temp UP. "Optimum" is probably the wrong word - "least worse" might be more appropriate. The oil needs to be sufficiently hot as it comes out of the engine to boil-off water and whatever acids have formed as by-products of partial combustion. 80C at the inlet is about the lowest temperature that will achieve that to any useful degree. If the oil inlet temp gets much above 85C, the oil degrades at an accelerated rate due to oxidation. Many car engines do not have this feature, and neither does the Jabiru engine, so far as I am aware. Adding it means another failure mode to consider, so it's not automatically desirable. Jabiru try to keep things simple, in the interests of reliability; this may be the reason their oil coolers seem a bit on the small side.

 

 

[Oscar]

Jabiru changed from the small 'Repco-type' oil cooler to a five-row (from memory) Stewart-Warner type (and also changed from the finned-sump, that was not successful as an aid to oil cooling) a fair time ago. I think that happened with the introduction of the J160. If you care to do some checking, you will find that some at least operators - certainly of J160s - have more problems with under-temp oil than over-temp oil. I know that, for instance, the J160 on the line at the Darling Downs club has the cooler significantly taped over to get the oil temp up to scratch!

 

There's a thread: http://www.recreationalflying.com/threads/low-oil-temperature-on-cold-mornings.51270/ that discusses the problems of over-cooling of the oil in Jabs., which makes for interesting reading - not just for the reports of over-cooling but some of the sorts of owner responses that indicate how aircraft (in this case, and pertinently to this thread, Jabirus) are used in real life. The first post indicates that the owner regularly flies - in the full knowledge of the POH requirement for oil temp. - not getting to the POH minimum temp 'until about 1000' AGL' i.e. full power off the ground operating the engine out of limit. Same guy spends 10 minutes of idling trying to get the oil temp up - and if he's doing that in cross-wind conditions at a holding point, he's very likely cooking the heads on one side of the engine due to airflow reversal.

 

Or the guy who suggests: "Maybe keep the oil level barely on the stick. Less oil will help".

 

 

[Dafydd Llewellyn]

It may be worth clarifying a few things at this stage:

 

Firstly, CASR Part 21 (and likewise FAR Part 21) define what things can be type-certificated: These are called "Class 1 aeronautical products" and are Aircraft, aircraft engines, and aircraft propellers. (See CASR 21.011). So a TC for an engine usually has nothing to do with the aircraft or the propeller. Legally, they are quite separate entities - even though they may be supplied by the one manufacturer. There can be some variation to this, in cases like CAO 101.55, where the engine could be certificated as part of the aircraft package - that was done, as I recall, for the Jabiru 1600 - but that's a rarity; the Jab 2200 has its own TC, as you can find on the CASA website. A manufacturer who want to sell engines as a separate product, will need to certificate the engine separately, before it can be used in any Type certificated aircraft.

 

1. The various design standards are normally written to cover aircraft, engines and propellers separately. For instance, FAR 23 covers aircraft up to 19000 lbs MTOW; FAR 33 covers engines, and FAR 35 covers propellers. The same distinction is made in CASR Parts 23 thru 35. The reason for this is that engines and propellers are commonly manufactured quite independently of the aircraft on which they are used.

 

2. The aircraft design standards specify the requirements for things like fuel systems, lubrication systems, cooling systems, induction systems, exhaust systems, electrical systems, etc, all of which impinge on the powerplant, but are not generally supplied by the engine manufacturer. These things are NOT, in general, part of the engine package, tho some engine manufacturers may elect to supply some such parts.

 

3. To discover in any particular case, what items are part of the engine, and what are part of the aeroplane, look up the respective parts catalogues. You will find, for example, that the inter-cylinder baffles on Lycomings and Continentals are mandatory engine parts; however the rest of the baffling is left up to the airframe manufacturer.

 

Since this thread was about the engines supplied by CAMit under their own name, raising issues about Jabiru airframe components is not really relevantto this thread.

 

 

[kgwilson]

Jabiru changed from the small 'Repco-type' oil cooler to a five-row (from memory) Stewart-Warner type (and also changed from the finned-sump, that was not successful as an aid to oil cooling) a fair time ago. I think that happened with the introduction of the J160.

Not on the 3300. Mine is the new model with roller followers etc & the sump is finned. See attached pics. I also have a 7 row Positech cooler with a separate airflow via a NACA duct in the lower cowl so if I have any problem with oil temp being too low I can restrict the airflow easily by installing a butterfly valve. There is a 250mm sealed tunnel from the back of the duct to the cooler. I spent a fair bit of time reading various documents on cooling air cooled piston engines starting with the 1981 NASA report 3405, some EAA articles etc & found the information very valuable. Getting the airflow right is one of the most important aspects of maximising the life of your engine. The big cooler & long oil lines from the engine will probably add around 1/2 litre to the total oil capacity.

 

 

 

 

[Oscar]

Not on the 3300. Mine is the new model with roller followers etc & the sump is finned. See attached pics. I also have a 7 row Positech cooler with a separate airflow via a NACA duct in the lower cowl so if I have any problem with oil temp being too low I can restrict the airflow easily by installing a butterfly valve. There is a 250mm sealed tunnel from the back of the duct to the cooler. I spent a fair bit of time reading various documents on cooling air cooled piston engines starting with the 1981 NASA report 3405, some EAA articles etc & found the information very valuable. Getting the airflow right is one of the most important aspects of maximising the life of your engine. The big cooler & long oil lines from the engine will probably add around 1/2 litre to the total oil capacity.

My apologies - I haven't spent much time looking at 3300's! Strange that Jabiru has retained the finned sump, maybe just hasn't re-done the casting (the presence of fins is in no way a problem, it just does sod-all for cooling the oil..) That Positech should do the job a treat.. and by not having introduced high(ish) pressure air into the lower part of the cowl from the oil-cooler air dump side, you're certainly doing your heads and barrels cooling the best possible favour. That's a very nice looking install - we're trying to clean up the one in our ST1 but I don't think we could get it half as neat.

 

P.S. you might find it interesting to talk to CAMit about their oil take-off adaptor - could suit you rather well!

 

 

[Guest ozzie]

The aircraft that had the cooler problems was a Storch fitted with a six cylinder. Argued with him during the build that this was not the engine suitable for this airframe but he went with it anyway. Sure enough cooling was always a problem, low airspeed @ high angle of attack with poorly designed ducting had the guides lock up on the rear cylinders more than once. Oil cooler just kept cracking so made him up a really tough little unit. Owner was a couldn't be told type. Ended up selling the aircraft with out the engine and new owner fitted a 912 and has never had a problem with it. surprise surprise.

 

When I was in the States I saw a neat oil filter add on called a oil filter chiller. Aluminium finned device that clamped around the filter. Worked well.

 

 

[Oscar]

As an (obvious) Jab supporter - with due circumspection - I'd have to more than agree that any Jab engine is a poor match to a Storch. If that's a Slepchev Storch then the only thing I'd personally fit to it would be a basket to hold the kindling, but that's a different issue.

 

However: if the oil cooler just kept cracking - then surely you would have to agree that it's an installation problem? Even those rather cruddy Repco-supplied coolers generally didn't fail repeatedly in the original Jabiru installations (and I think they were pretty rudimentary and not very efficient, based on what was in our aircraft - but they did the job, sort of.) I don't think one can reasonably damn the manufacturer for problems caused by installations outside of their control.

 

 

[jetjr]

Some of the issues being discussed are OLD, cracking coolers was a problem nearly 10 years ago, using automotive oil coolers and everyone yelled they werent up to the job, investigation showed oil pressure pulses not seen in guages were fatiguing some, They were changed to positech in the J230 ~ 2005??

 

There are hundreds still running old cooler or NO cooler overseas. Also was a oil pump modification too. All detailed in SB's. New cooler and scoop available as a kit.

 

What about flywheel bolt problems..... Sb's and manatory upgrades and the problem is gone yet you still see examples flying with original setup and tears when something goes wrong.

 

The through bolt issues.... surely this has been discussed to death? Agree or not on theory and success, Jabiru have put a lot of effort into this, issueing free parts, free install, SB's and pretty open discussion. I believe the issue is probably related to timing or pre ignition. Didnt exist in Solid lifter engines as far as I know.

 

Cooling and head limits, multiple upgrades, information and setup documents available.

 

Still seeing through bolts fail where SB and other directives have not been implemented.

 

Burnt valves... still posters here just last week saying they are running 21 lph down to 16 lph in 3300 - fer fugs sake the correct lph is in the POH so is EGT and CHT limits but few can tell you what they were before a failure occurred.

 

Whole SB and update there about jetting and carbs - then another on fuel types and problems.

 

Now this agrees with Oscar, David and others which says the magazine incident report (from a recently pissed off owner) when their engine flames out is NOT the best place to get a assessment of problem. They are unlikely to say, "engine failed on take off.....after I left a bit sooner before oil warmed up, or ....after I watched EGT go over 750 and I kept it @ WOT.... through bolts not replaced cause I read on ??? website that bolt update from Jabiru was dodgy idea so I hadnt done it"

 

Next is the story they have had to tell insurers or Jabiru re warranty - being no fault of the pilot/maintainer of course.

 

These reports state something happened thats it. Extroplate what you like but it aint evidence or proof of problem or real cause. Doesnt mean they are worthless just need to be taken in context.

 

Now in regards to Camits work, what I can deduce from photo on website and here is they have :-

 

Importantly only working with old solid lifter models - these had very few issues historically and now have huge hours on them as a design.

 

New design through bolts and install system.

 

Oil control improvements - could be better regulation or maybe thermostat

 

Oil catch can and drain system

 

New cylinder design

 

Some sort of inhibiting setup

 

Redesigned heads to control guide wear and valve failure

 

Combined with monitoring of EGT and CHT would see big improvements - apparantly what Ross and others are calling for,

 

Why arent they supportive and throwing RAA support behind this?

 

Give them credit for looking at the data and known problems and are reading like having "adressed" many of the problems.

 

Im sure some wont give credit until it is certified for military applications (and priced accordingly). like never.

 

 

[Dafydd Llewellyn]

Some of the issues being discussed are OLD, cracking coolers was a problem nearly 10 years ago, using automotive oil coolers and everyone yelled they werent up to the job, investigation showed oil pressure pulses not seen in guages were fatiguing some, They were changed to positech in the J230 ~ 2005??There are hundreds still running old cooler or NO cooler overseas. Also was a oil pump modification too. All detailed in SB's. New cooler and scoop available as a kit.

What about flywheel bolt problems..... Sb's and manatory upgrades and the problem is gone yet you still see examples flying with original setup and tears when something goes wrong.

 

The through bolt issues.... surely this has been discussed to death? Agree or not on theory and success, Jabiru have put a lot of effort into this, issueing free parts, free install, SB's and pretty open discussion. I believe the issue is probably related to timing or pre ignition. Didnt exist in Solid lifter engines as far as I know.

 

Cooling and head limits, multiple upgrades, information and setup documents available.

 

Still seeing through bolts fail where SB and other directives have not been implemented.

 

Burnt valves... still posters here just last week saying they are running 21 lph down to 16 lph in 3300 - fer fugs sake the correct lph is in the POH so is EGT and CHT limits but few can tell you what they were before a failure occurred.

 

Whole SB and update there about jetting and carbs - then another on fuel types and problems.

 

Now this agrees with Oscar, David and others which says the magazine incident report (from a recently pissed off owner) when their engine flames out is NOT the best place to get a assessment of problem. They are unlikely to say, "engine failed on take off.....after I left a bit sooner before oil warmed up, or ....after I watched EGT go over 750 and I kept it @ WOT.... through bolts not replaced cause I read on ??? website that bolt update from Jabiru was dodgy idea so I hadnt done it"

 

Next is the story they have had to tell insurers or Jabiru re warranty - being no fault of the pilot/maintainer of course.

 

These reports state something happened thats it. Extroplate what you like but it aint evidence or proof of problem or real cause. Doesnt mean they are worthless just need to be taken in context.

 

Now in regards to Camits work, what I can deduce from photo on website and here is they have :-

 

Importantly only working with old solid lifter models - these had very few issues historically and now have huge hours on them as a design.

 

New design through bolts and install system.

 

Oil control improvements - could be better regulation or maybe thermostat

 

Oil catch can and drain system

 

New cylinder design

 

Some sort of inhibiting setup

 

Redesigned heads to control guide wear and valve failure

 

Combined with monitoring of EGT and CHT would see big improvements - apparantly what Ross and others are calling for,

 

Why arent they supportive and throwing RAA support behind this?

 

Give them credit for looking at the data and known problems and are reading like having "adressed" many of the problems.

 

Im sure some wont give credit until it is certified for military applications (and priced accordingly). like never.

Right on the button - except I understand CAMIT also have a kit to convert hydraulic lifter engines back to solid lifters.

 

 

[Oscar]

JJ - that's a pretty complete list, though I don't think there is a new oil catch can and drain, and I'm not sure you'd call it a new head design, rather new rockers (much easier to adjust accurately and quickly, far better geometry), rocker bushes and a bit more to come (work in progress when we left). Certainly better oil pressure regulation AND thermo cooling control (the latter still under final testing), improved harmonic balancing for the flywheel end to improve flywheel bolt life, an inhibiting set-up that allows you to (very easily) squirt a shot of hot engine oil into each cylinder after shut-down, better than twice the alternator capacity, top-quality spark leads and coils with epoxy potting of the LT lead into the coil. Yep, stronger cylinder barrel bases, through-bolts and nuts and a civilised case joining technique that can't degrade under use/abuse and start the whole through-bolt failure dance. Some subtle changes in certain critical tolerances that are tailored to air-cooled engine operating characteristics.

 

If you like that lot, there's another quite significant 'tweak' that I think you'll really like (that is so far showing under testing to have a good effect on lowering CHTs) - but I'm not CAMit's PR person and it's not my place to talk about it, but that will I am sure be announced when CAMit is happy to do so. Suffice it to say that with it in place, you can shut down your engine and immediately pull it through quite easily rather than the usual 'tight' condition.

 

Yes, obviously I'm enthusiastic about what we've seen and incorporated into our engine - but what the hey, I'm just shooting so much hot air, apparently... but we'll be putting CHTs and EGTs on all four cylinders and recording the results when our beastie is back in the air. CAMit is not in the business of claiming anything that won't be backed-up with proven results; we are happy to be testing candidates.

 

Of course, and as you say, any success on the part of CAMit to improve the reliability of Jabiru-based engines would pretty much destroy the apparent leitmotiv of some contributors to this forum. Who was it who said 'you can't please all of the people all of the time'?

 

 

[Oscar]

Right on the button - except I understand CAMIT also have a kit to convert hydraulic lifter engines back to solid lifters.

Yes, CAMit does. I've seen the communication from a US user of that kit saying that he'd like to come out to Australia and do (something intimate concerning his lips and their backside) for the results he's had from installing it...

 

 

[Marty_d]

Do the statistics on engine failure identify the cause of the engine failure? I've been trying for years to get authoritative data on any aero engines that breaks down the causes in sufficient detail to allow one to identify design priorities. However, the term "engine failure" includes fuel starvation, fuel mismanagement, misuse of mixture controls (tho not on Jabirus, obviously), carbie icing, failure of accessories such as magnetors, fuel pumps etc. Hell, one of the things Zoos mentioned was a leaky oil cooler. The oil cooler is an AIRFRAME part, you goose, not an engine part - except on those Continentals that build it into the engine. So how the blazes can anybody pin anything down onto the engine design, given such sloppy handling of the data? All right, there's an issue with Jabiru through bolts. Can you identify exactly what is the cause of that issue? I bet you cannot; and don't just tell me "it's because they are not strong enough" - if that were the case, the cylinders would fly off the first time the throttle was opened. It's much more subtle than that, and likely has a number of contributing factors. So, there have been some valve failures. Where's the metallurgical analysis to show why they failed? Without that, the only conclusion one could reach is that we'd be better off with 2-strokes that do not have valves. These data are simply too superficial to be useful. So people like Maj can rant, but it cuts no ice at all. First, fix the data base so it provides some fundamental engineering data - and mind you make sure it's correct.I'm more than ever reminded of the dog that chases cars, but wouldn't know what to do with one if he caught it. Pray tell me, exactly what could RAA do, that would be really useful, with your data base, if they had it? Duty of care my foot; they do not have the technical know-how.

Just wanted to congratulate Dafydd on his post #169 for the use of a few terms & phrases not seen much any more:

 

- "you goose"

 

- "how the blazes"

 

- "cuts no ice"

 

- "pray tell me"

 

- "my foot"

 

No idea what you were on about Dafydd, but I enjoyed reading it!

 

 

[jetjr]

I think Jabiru can offer this hyd to solid upgrade too but in both cases its a full tear down

 

I believe the plan is to offer new engines only from Camit which will make it expensive (but its a new engine not rebuilt)

 

Re oil catch setup, i think theres a new drain port in the rear of the engine to do with catching vapour - might be me making stuff up too.

 

Jabiru have new catch can attachment also which replaces top of oil filler.

 

Throw in an EFI port in intake runners, electrical harness, SDS kit and fuel issues including MOGAS would be sorted too.

 

 

[MarcK]

As a new member of the rec aviation community I made a decision to train in a rotax powered aircraft based on what I have read and been told about jab engines it's the only way I had to make the decision on what to do in this instant I admit that my research was not exhaustive but it was enough to judge the jab option as to risky . I have flown in a jab for a couple of hours and it was great they are pretty quick and look the part. If the reputation of jab had have been better I would have picked them as a trainer over the other options I had.

 

I am not an expert on the faults or the fixes for different aero engines but I would think of myself as an average minded consumer and I think that buying an aircraft with a reputation of needing and engine at maybe 500 hours puts a sour taste in my mouth. Why would I spend say 50k on an aircraft that has a perceived reputation that it might stop on me or cost me a further 10 plus k on the engine. With my limited knowledge it's not my place to say weather it is deserved or not but I have made my decision based on what I have come across which is to not train in or buy a jab powered aircraft.

 

Now with that reputation available so easily to new starters in rec aviation if they are looking for it can't be good for business. And not only that I would go as far as to make the assumption that a fair percentage of people who buy their own plane would buy what they train in. And this could have something to do with the success of the Jabiru brand

 

I think that Camit are on a great thing here if they can get an equivalent of a jab engine to be proven more reliable than what jab have I think it will force the hand of jabiru to one of either 2 things. The first is tying up Camit in the courts and not allowing them to get the product out there( If that is even an option I'm not a lawyer ). Or the better option is to reinstate Camit as the manufacturer of jab engines and run with a good thing. Perhaps that is what Camit are looking for here I would have to think the market for jab engines internationally would be quite a good market.

 

All this R&D being done by Camit can't be cheap and if not supported by the industry will come to an end. If I was the owner of a Jab and I didn't need the class of registration I would support it for sure . I don't think that there product would be worse than the existing jab option so why not.

 

In the end of it all if it turns out that you get a certified jab engine that is without the apparent concerns faced by the existing product it will only have a positive impact on the existing owners through both piece of mind and resale value. And I might get to buy one and support an Australian business.

 

I think logically the only way forward is to support these guys someone has to pay for the R&D these guys are investing. If Jab themselves are not trying to improve the product themselves there is no reason they wouldn't want to jump on board with a proven product based on their own design to improve / save their reputation in a marketplace that will only become more competitive over time.

 

Just my idealistic view of it all after reading this thread.

 

Marc

 

 

[Dafydd Llewellyn]

As a new member of the rec aviation community I made a decision to train in a rotax powered aircraft based on what I have read and been told about jab engines it's the only way I had to make the decision on what to do in this instant I admit that my research was not exhaustive but it was enough to judge the jab option as to risky . I have flown in a jab for a couple of hours and it was great they are pretty quick and look the part. If the reputation of jab had have been better I would have picked them as a trainer over the other options I had.I am not an expert on the faults or the fixes for different aero engines but I would think of myself as an average minded consumer and I think that buying an aircraft with a reputation of needing and engine at maybe 500 hours puts a sour taste in my mouth. Why would I spend say 50k on an aircraft that has a perceived reputation that it might stop on me or cost me a further 10 plus k on the engine. With my limited knowledge it's not my place to say weather it is deserved or not but I have made my decision based on what I have come across which is to not train in or buy a jab powered aircraft.

 

Now with that reputation available so easily to new starters in rec aviation if they are looking for it can't be good for business. And not only that I would go as far as to make the assumption that a fair percentage of people who buy their own plane would buy what they train in. And this could have something to do with the success of the Jabiru brand

 

I think that Camit are on a great thing here if they can get an equivalent of a jab engine to be proven more reliable than what jab have I think it will force the hand of jabiru to one of either 2 things. The first is tying up Camit in the courts and not allowing them to get the product out there( If that is even an option I'm not a lawyer ). Or the better option is to reinstate Camit as the manufacturer of jab engines and run with a good thing. Perhaps that is what Camit are looking for here I would have to think the market for jab engines internationally would be quite a good market.

 

All this R&D being done by Camit can't be cheap and if not supported by the industry will come to an end. If I was the owner of a Jab and I didn't need the class of registration I would support it for sure . I don't think that there product would be worse than the existing jab option so why not.

 

In the end of it all if it turns out that you get a certified jab engine that is without the apparent concerns faced by the existing product it will only have a positive impact on the existing owners through both piece of mind and resale value. And I might get to buy one and support an Australian business.

 

I think logically the only way forward is to support these guys someone has to pay for the R&D these guys are investing. If Jab themselves are not trying to improve the product themselves there is no reason they wouldn't want to jump on board with a proven product based on their own design to improve / save their reputation in a marketplace that will only become more competitive over time.

 

Just my idealistic view of it all after reading this thread.

 

Marc

Fair comment, Marc; however, I suggest you look at my thread "Caveat Emptor" before you choose an aeroplane. Also, look at the practical experience the training organisation has with their aircraft. Some operators are sufficiently knowledgable and disciplined in how they use their aircraft, that they get good reliability from whatever engine they use; you should look for that sort of training organisation. It's not always the big operators that are the best at this. And of course, keep an eye on what CAMit are actually doing (as opposed to the scuttlebut you may hear around the place).

 

 

[Old Koreelah]

Oscar, all this has got me excited, especially

 

"...an inhibiting set-up that allows you to (very easily) squirt a shot of hot engine oil into each cylinder after shut-down, better than twice the alternator capacity..."

 

Can you tell me more about this oil squirt system, as I was about to bodgy up some way to squirt lube down the carby throat before stopping the engine.

 

Regarding CAMit's extra alternator, why would it be needed if the recent Jabiru winding modification worked?

 

 

[Dafydd Llewellyn]

Oscar, all this has got me excited, especially"...an inhibiting set-up that allows you to (very easily) squirt a shot of hot engine oil into each cylinder after shut-down, better than twice the alternator capacity..."

Can you tell me more about this oil squirt system, as I was about to bodgy up some way to squirt lube down the carby throat before stopping the engine.

 

Regarding CAMit's alternator, why would it be needed if the recent Jabiru winding modification worked?

Why not get it from the horse? The link is in the first post in this thread: [email protected]

I don't know about Jabiru's alternator winding modification; however CAMit's belt-driven alternator is, firstly, a field-current regulated device (same as a car alternator), which should in principle produce less electrical noise than the permanent-magnet type; and secondly, it - in conjunction with its belt drive - acts as a dynamic damper for the crankshaft.

 

 

[Oscar]

Oscar, all this has got me excited, especially"...an inhibiting set-up that allows you to (very easily) squirt a shot of hot engine oil into each cylinder after shut-down, better than twice the alternator capacity..."

Can you tell me more about this oil squirt system, as I was about to bodgy up some way to squirt lube down the carby throat before stopping the engine.

 

Regarding CAMit's extra alternator, why would it be needed if the recent Jabiru winding modification worked?

I would - as Dafydd as suggested - absolutely and unequivocally suggest that anybody who is interested in any of the CAMit mods, contact Ian Bent to discuss them. That way you'll not only get the full skinny on what is done, how it is done, what material and process is used and all of those questions you'd probably want to know about, but also how it all fits with the overall 'system' that is the engine - i.e. what might be termed, rather badly on my part, as 'secondary effects'. Something we found while we were at CAMit is that for many of the changes, there was more than one good reason for choosing the design, material and methodology. The new through-bolts, for example, have been developed not just for additional strength, but also for their utility in improving case-pinning, the type of nuts used and the threading for them etc. - but also for their harmonic characteristics. Yep, through bolts can - apparently - vibrate at certain harmonics, affecting their performance! CAMit's through bolts go in one way only to the cases, though the difference to look at is very subtle (ask me how I know about this...or have you already guessed..? Suffice it to say that CAMit, having watched us do it incorrectly first time, now add a 'this way around' indicator on their new through-bolts... having observed that no matter how fool-proof you thought your dooberry is, there's a more inventive fool than you thought about out there lurking. It's kind of reassuring when, encased in the pink cloud of acute embarrassement, you not just hear people saying 'well, you wouldn't be the only person to make that mistake' but see 'that mistake' positively addressed..)

 

The new alternator, as Dafydd says, not only provides more and 'cleaner' power but adds some harmonic balancing to the flywheel. You might not need the extra output, but I seem to remember a thread on here regarding iPads catching fire (??) that seemed to conclude that the car-type alternators were a better bet (electrics isn't my strong point..) and I imagine that if you were going to run LiFePo4 batteries they might be a better source of in-flight charging power too - but let's not open another front in the electronic war on here if I'm wrong, just say: 'nope, that's incorrect'.

 

WRT the inhibitors - and again, Ian Bent is your man to explain the things in proper detail - they are a very fine, almost hypodermic-syringe needle size insert in the inlet tract for each head. Each cylinder gets a wee squirt of hot engine oil. You have to have the heads drilled to install them, and that means removing the heads and using a (good-quality!) drill press and the special guide jig (CAMit made one up for us because our heads are almost the first-type used on 2200s and have the narrower rocker-cover bolt spacing, where the jig bolts to ) but I think you'd like the way they have been designed to operate, it's rather delightfully elegant. I imagine CAMit have closed down for the end-of-year break, but it could be well worth the wait to talk to them (though what you were thinking wouldn't in any way preclude doing the CAMit mod later, I'd have thought.)

 

 

[Camel]

Jabiru recomend to run their engines hard, that is cruise at 2850rpm, they say do not baby the engine. I tend to run my engine at lower revs and tend to baby it. Can't really see why the engine should be run hard and the gumming rings thing is not a good reason or using Avgas to burn lead off plugs. As using a different oil and Mogas cancel these problems. Using fuel to cool the engine does not seem to be the case either. I know someone who has run several engines to TBO, doesn't run them hard and uses non aviation oil. Any thoughts ?

 

 

[DrZoos]

Re ipad: One ipad fire ever. SAFEST to use an apple brand charger and DEFINITELY do not keep charging it past 100% while in an aircraft. Do not use a third party brand chargers in your aircraft as there have been too many cases of iphone fires/smoke/electrocution issues caused by dodgy 3rd party chargers to take the risk.

 

Only iPad fire ever was initiated by flames/sparks coming from the charging port while on left on constant charge with a 3rd party charger. Lots of iphone smoke/fire incidents and lots of those directly attributed to faulty 3rd party chargers and overcharging with 3rd party chargers. Ipad Charger output should be less then or equal to 5.1v 2.1A 10W Iphone charger will charge an ipad but at 5.0V 1A 5W so half the speed. Some may argue a safer option in a small aircraft. But from anecdotal evidence the use of Genuine v 3rd Party charger and the charging past 100% seem to be biggest safety issue.

 

The new alternator may or may not be better. But the real issue with ipad/iphone fires is not overcharging and not using dodgy 3rd party chargers.

 

 

[Old Koreelah]

Interesting, Camel. Now that I have my own source of AvGas, my 2200 never gets fed Mogas. I am concerned that eventually lead will build up on the valve stems, because it runs rich and cool (EGT around 800 F).

 

 

[facthunter]

I've heard of it building up on the valve seats on liquid cooled motors, ( and then a small part comes loose and causes compression loss and seat damager sometimes. They would be running much cooler than the aircooled motors (even Yours) run. Nev

 

 

[Old Koreelah]

I'm not too worried yet Nev, but I would like some indication of the hours it takes before lead build-up becomes an issue.

 

 

[Oscar]

Jabiru recomend to run their engines hard, that is cruise at 2850rpm, they say do not baby the engine. I tend to run my engine at lower revs and tend to baby it. Can't really see why the engine should be run hard and the gumming rings thing is not a good reason or using Avgas to burn lead off plugs. As using a different oil and Mogas cancel these problems. Using fuel to cool the engine does not seem to be the case either. I know someone who has run several engines to TBO, doesn't run them hard and uses non aviation oil. Any thoughts ?

Seriously - and not wishing to be in any way combative - is the 'run hard' and 'don't baby it' thing more conventional wisdom handed down from person to person than actually what Jabiru says? I can only comment from the J120 POH, because that's what I have access to, but those terms don't appear in it - and there's really nothing about engine operation that suggests it. They're both very subjective terms anyway!

 

However, here's some quotes from the 'Jaba Chat' of September 2011 that might provide a bit of perspective on what Jabiru actually are saying - and some of it is worth reading carefully, because they are fairly comprehensive explanations of a difference between 'run it hard' as most might interpret it vs. 'let it spin freely':

 

CLIMB OUT SPEEDS

 

There appears confusion on best climb out speeds. Manual specifications for best rate of climb

 

for J160 and J230 is 68 and 75 knots respectively.

 

This means this air speed will give the best chance of clearing obstacles if the need arises.

 

However the rate of climb for best engine management has been largely left to operators.

 

The quickest way between two sets of traffic lights is to floor the accelerator and race the engine

 

– but it’s not the way most of us do things because we understand that driving that way will use

 

more fuel and wear the engine out faster. Similar arguments apply to climb speeds with a Jabiru

 

Engine. The 4 cylinder engine will look after you better with better air/oil cooling if climbed around

 

80 knots while the 6 cylinder will think highly of you at a 90 knot climb or above. If flying a J430/

 

J450, climb speeds for load will differ especially according to load. Once heading to that cross

 

country destination cruise climb at elevated speeds (shallow angle of climb) contributes to good

 

engine management. At these higher speeds not only is there more air available to cool the engine

 

but the RPM is higher, allowing the engine to rev more instead of “lugging”. This significantly

 

reduces the stress on the engine and makes it less likely to suffer detonation or other

 

long-term maintenance issues.

 

 

 

OPERATING RPM

 

Historically we have always recommended that operators allow their engine to rev rather than

 

lug. Done properly this approach works very well, however in certain cases it can also be damaging

 

as it has been over-simplified and does not necessarily consider percentage power.

 

For example, consider a Jabiru J200 with a Jabiru engine, propeller and cowls. In a full power,

 

straight and level run at sea level this aircraft should reach speeds in the 130 – 140 KIAS range

 

and the engine will be revving to around 3100 – 3200RPM. In this aircraft – which is fairly sleek

 

and fitted with a well-matched propeller – cruising at 2900 rpm is fine because it will be at a relatively

 

low power setting.

 

In comparison, the same engine and propeller could be fitted to a bush plane with slats, flaperons,

 

tundra tyres and the aerodynamics of a brick. In this case the static RPM and RPM on takeoff

 

would be similar to the J200 – but flat out straight and level at sea level the aircraft won’t do

 

much more than 100 knots and the engine will be stuck at about 2900 – 3000 RPM or less. In

 

this case trying to cruise the engine at 2900 RPM would be disastrous as it would be a very high

 

percentage power setting.

 

The above examples are deliberately extreme but their message can be applied across all airframes

 

and engine models.

 

It's not like keeping a diesel engine under decent load to avoid glazing the bores! What Jabiru are saying, basically, is: let them rev decently, don't beat them to death. It's not difficult to see that this is quite different to 'use

 

them hard' - if 'use them hard' is taken by the pilot to mean 'load them up and make them work all the time at the top end of limits'. So I don't think you are 'babying' your engine, but rather using it intelligently! If it's toddling along at lower revs and the CHTs are good - then surely you're giving the engine its best chance of returning you the sort of life you expect.

 

One has to wonder - how many Jab. engines are bought to premature ends because the operators thought they were doing what Jabiru says, based on 'conventional wisdom' handed out by a mate, someone on the field etc. - rather than actually operating them according to the manufacturer's recommended techniques?