jetjr Posted December 11, 2014 Posted December 11, 2014 placing old gull wings underneath certainly stabilises temps. More resistant to changes and more even across each side. Between sides is harder, Im using a small fence to restrict air to RHS and bring temps up a bit......more trials needed but it is working I tried a inlet ramp into LHS duct, did bugger all 1
facthunter Posted December 11, 2014 Posted December 11, 2014 No-one tries (or few) angling the openings in the cowl at the front. They could account for prop rotational direction and angle of attack for low speed climb and ground operations in a T/W plane. Nev 2
kgwilson Posted December 11, 2014 Posted December 11, 2014 placing old gull wings underneath certainly stabilises temps. More resistant to changes and more even across each side.Between sides is harder, Im using a small fence to restrict air to RHS and bring temps up a bit......more trials needed but it is working I tried a inlet ramp into LHS duct, did bugger all Are you getting an even mixture to both banks? A good Cobra head setup with a directive vane at the carb air intake can make a huge difference to differing temps on either bank. Garry Morgan has done a lot of trials & testing & what he has done works a treat on all Morgans. Here are a couple of pics of my setup as advised by Garry. The vertical vane can easily be bent one way or the other to get the temps even. The large Cobra Head provides smooth airflow & the vane is vertical, top to bottom & follows the curve of the Cobra Head. The vane is just a 3" long bit of 25 thou sheet inserted in a slot on the top of the Cobra Head. I have covered the tags with some gaffer tape to seal it. It takes about 5 minutes to remove and alter the vane.
dlegg Posted December 11, 2014 Posted December 11, 2014 Sonex sell a laser cut baffle kit for the Jab at US$250. Has anyone tried this out? http://www.sonexaircraft.com/eshop/cart.php?target=product&product_id=16561&category_id=335
aj_richo Posted December 11, 2014 Posted December 11, 2014 Its about the same amount of tweaking for a custom install using the fibreglass ducts as it for the metal. I would have preferred the later fibreglass type but the cowl is pretty tight over the front cylinders and much surgery would be needed I made the aluminium ones from scratch, pretty simple fabricate Mine is well within parameters in cruise, #3 can nudge 170C with hard climbs I have an air outlet behind the sump as well as the exhaust tunnels, this keeps air flowing over the sump and minimises hot air around the carb. The oil cooler air is completely separate from cowl air flow with is own NACA inlet and outlet is controlled by a cockpit controlled flap
jetjr Posted December 11, 2014 Posted December 11, 2014 I have 2 x vanes, first one helped, second one helped less Simple to do in fibreglass Remember IF these come loose they might ruin your day, take fitment seriously Gary does good work, the cobra head looks interesting, ive head a few engine experts suggest much larger volume upstream airbox might help. Re distribution accross banks, watch out talkng cht and fuel mixtures, egt does it better. I believe every jabiru should have full monitoring of both Yes EGT are fairly even at some parts of flight, wide spread at others. Hottest cylinder swaps around too. 170 is too hot, needs to fix that
aj_richo Posted December 11, 2014 Posted December 11, 2014 170c, you need to try and get that down, it's well and truly up there! Absolutely.. in cruise its around 100-110C. The RH Sonex inlet is hard up against #1 cylinder, in fact you have to trim fins to make the cowl fit. It is not great for getting a lot of air in there and it suffers in a climb attitude... especially steep climb angles but you can't see anything over the nose either, so you tend to climb shallower and clear the nose a lot... and for the record a Camit engine would have to same problems in a Sonex cowl. And you'd have to ditch the bigger alternator 1
XAIRVTW Posted December 12, 2014 Posted December 12, 2014 The problem I have is I can't de register to 19 my 24 Jabiru 170c. I have no options. I have my engine currently in pieces after 400 hrs. I had a problem with no compression in number 2 cylinder when cold. The compression became normal once the engine was warm. My LAME tried everything to fix this issue but had no luck. 4 weeks ago I did a cross country from Gawler to Corny Point and return. On the return from Corny Point I lost oil pressure into the yellow. I diverted to a country strip near by and landed. It turned out the oil reserve was full and the engine took 300ml of oil till it was normal on the dip. I flew back to Gawler looking for paddocks all the way. I watched the gauges all the way home but everything read in the green. On landing another pilot commented that my engine smelt very hot. When the engine cooled it had no compression in any cylinders. The engine had cooked. My LAME is now having to rebuild the top end. I have totally lost all confidence in the engine now and no longer enjoy my flying waiting for it to fail. If I could I would fit anything other than a Jabiru engine. Sorry to hear about your situation hope you get back in the air soon. I dont want to sound blunt but once oil pressure was lost I would not have flown the aircraft back home regardless. Just an observation I have come across since I started test flying my aircraft was majority of pilots I spoke to who fly Jab engine, when asked what oil temp & pressure they read for my own comparison, they couldn't give me an exact figure all just said its in the green. I find that concerning as flying is not only piloting the aircraft its also engine management. 4
jetjr Posted December 13, 2014 Posted December 13, 2014 What were cht? Oil senders notoriously unreliable on many engines, Ive fitted a low pressure switch to spare oil port and red light on dash, same for oil temp If theres issues theres a second fail safe light Ive had 2 VDO senders fail in 900 hrs
facthunter Posted December 13, 2014 Posted December 13, 2014 Electric oil senders are not reliable and can leak oil. There is a range where the oil pressure is satisfactory for flight, but there is a preferred pressure. Low idle oil; pressure can be worn pump , engine bearings relief valve seat not seated properly or very hot crook oil. No compression cold and OK hot is a situation that would likely be the lifter(s) have run out of travel and the seat recession or valve stretch has caused it, or it didn't have enough in the first place.. Most alloy motors have the tappet clearance increase when hot but you can't rely on that. Your LAME should have looked harder. There is no magic out there to count on.. You shouldn't take known hazards into the air. There are already enough unknown ones for you to cope with. already. Nev 1 1
rotor Posted January 1, 2015 Posted January 1, 2015 Sorry, I haven't read all of the short stories above BUT - don't the Camit engines come out of the same factory that built the Jab motors? They look identical on the outside? Good luck!
Bruce Tuncks Posted January 23, 2015 Posted January 23, 2015 I put gull wings on the underneath after reading the Limbach article. But I did some other things at the same time... 1. Opened up the cowl front holes to match up the ram-air ducts. 2. Blocked off gaps around the ducts.. but I notice the later ducts are more refined and don't need this now. 3. Modified the flow of air from the lower cowl hole so that the flow was nearly all through the oil cooler and not just increasing the lower-cowl pressure. 4. put the then-current bigger finned heads on the rear cylinders. 5. Put CHT's on all 4 heads. My best guess is that the engine runs about 15 degrees cooler, with only a few degrees of difference between the 4 heads. Yes it would have been more scientific to do these things one at a time but I just wanted a cooler-running engine. I have never thought that these things should have been done for me by the factory. If they were, I wouldn't have been able to afford the aircraft. Right now, I'm intending to replace the existing heads with CAMIT ones because a single head-bolt has moved a bit. 1 3
jetjr Posted August 5, 2015 Posted August 5, 2015 Reviving this thread My all new CAE 3300 turned up last week, mid install now, just fiddly little stuff to complete now. Includes Inhibitor, 40A altenator, TOCA, new ducts and exhaust seals. Sure looks great and improved in so many ways. Spent time with both Ian and Rod in Bundy before. Was a pretty simple decision with limitations extended around the same time. I do respect Rod and his accomplishments, but in engines I think theres problems which will be around for a while yet. Things are pretty quiet (not surprising) at Jabiru. Rod was very open and accommodating and saw some good things being developed but a fair way off yet. Camit busy and timelines are extending to get their gear. They are still finding their feet after a tough few years. Theres a lot of politics there for sure but smoke is clearing. Theres likely to be 2 Bundy made engines for some time to come. I can run though all the changes CAE have made but the list is long. His engineering is excellent no doubt and assembly very impressive. They were making some new Jabiru engines when I was there and differences, even in assembly process, are significant. Anyway fun to be had. 1 3
Russ Posted August 5, 2015 Posted August 5, 2015 I would ( just for piece of mind ) install a camit tomorrow, but i have a 160C type cert, and it all gets just too hard.....and that pees me off.
jetjr Posted August 5, 2015 Posted August 5, 2015 Certification is still a future plan but some tough hurdles to cross before that can happen.
Jaba-who Posted August 5, 2015 Author Posted August 5, 2015 I would ( just for piece of mind ) install a camit tomorrow, but i have a 160C type cert, and it all gets just too hard.....and that pees me off. I think you should hold off on that sentiment for now. What you've said basically is that - "Jabiru have some problems" "Camit is not a Jabiru". "Therefore Camit have no problems. " " Thus I will feel safer in a Camit" The evidence does not support that at all ....... Yet. It does not contradict it either ..... Yet. Rod says Ian's changes won't fix the issues. He says his changes will. Ian says Rods changes won't fix the problems He says his changes will. When you talk to both and ask them to explain their changes and the reasons for them you come away convinced each is right - till you talk to the other and then you get sure the other is wrong and the one you just talked to is right. Rod says he has about 250 engines in the field with his changes and no problems. There are very few Camits in the field. Ian says he has made changes that will fix the problems. But he has very few runs on the board yet. I would be waiting till more numbers come in before you settle into a state of contentment behind either engine 1
Russ Posted August 5, 2015 Posted August 5, 2015 Way back when............folks sewed the seed of doubt re my hyd jab engine. Its now done 500+ hrs ( did give it a top end 100hrs ago ).....it purrs. But that "seed" lurks in my mind ( niggles away there )........i would like that GONE. If.........the "new/upgraded" jab is the answer..........i'm in, would be a straight forward change over. Early next yr, we are planned direct east to west, then coastal north, over the top, then down the coast, then NQ. Eliminating that "seed" would make the trip more enjoyable. I would like to wish on those jab bashers...........headwinds in your travels.........Grrrrrrr 3
jetjr Posted August 5, 2015 Posted August 5, 2015 Not my experience Jaba-who, speak for yourself. Decision was easy after talking to both, added to my experience with new and Jabiru rebuilt engines. There are thousands of solid lifter engines out there, Camit has improved them researching and fixing known issues....not exactly a new design. The choice is actually a Jabiru improved one or a Camit improved one. I think Camit have solutions to problems based on nearly 500hrs flying and servicing a Jab engine. Im also taking advice from Australias best Jabiru service people. I understand if you can wait, not exactly sure how you "wait" to spend money on an engine, you either need it or not. The only question is feed more into repairing old one or replacement. Based on current info Camit is way in front let alone the complete separation from the CASA limitations. You want to believe what Rod says and hopes, expect more of the same.
Jaba-who Posted August 5, 2015 Author Posted August 5, 2015 Actually I'm not giving an opinion or speaking for myself. I'm just stating the facts. It's your answer that's following an opinion. Which is fine. We all have to make decisions based on how we want to interpret the facts placed before us. I haven't at any point said jabiru or Camit were better. Rather ( as a statistician and scientist) I have put forward the statement that there is not enough scientific evidence to support the assertion that one ( either the current jabiru model or Camit) are better than the other. Primarily I was replying after Russ said that for piece of mind he would put in a Camit if he could. My response was to suggest that his piece of mind was misplaced because of the lack of evidence. You can say Camit ( or Jab have fixed the problems - but until the runs are on the board you can only say " they say they have fixed them." You might agree with them but you are only agreeing to an opinion. They aren't't fixed till they are in the field and tried out on ( vastly ) more hours than they have now and shown to be fixed. That's a scientific fact because neither engine has accrued the hours in use ( or the satisfactory tracked data) to provide statistically useful data. Rod told me that he has About 250 engines in the field and quoted some hours he thought they had done ( lots) with no problems. But I wonder where he got that number of hours as data because I have never heard of Jabiru asking owners to give jabiru company any of their data. I suspect there are two uncertainties in Rod's optimism. 1. He is making an estimate of the hours. Which may not be correct. 2. We all know many problems go unreported back to Jabiru. And since Camit have already had one forced landing a couple of months ago here in North Queensland ( albeit with a fuel injected modified engine ) they aren't entirely pristine either. Although that problem may or may not have been related to the Camit part of the power plant. So I'm not pushing either barrow. Sure I have a new jab engine which I'm happy with. Although I originally ordered a Camit ( till the tax man told me I couldn't afford it).
Russ Posted August 5, 2015 Posted August 5, 2015 And since Camit have already had one forced landing a couple of months ago here in North Queensland ( albeit with a fuel injected modified engine ) they aren't entirely pristine either. Although that problem may or may not have been related to the Camit part of the power plant. So I'm not pushing either barrow. Sure I have a new jab engine which I'm happy with. Although I originally ordered a Camit ( till the tax man told me I couldn't afford it). Fact...........the engine lost oil......why.....the non camit oil cooler hose burst. Camit rebuilt the engine at no labour cost to owner......now that's service. 1 2
Oscar Posted August 5, 2015 Posted August 5, 2015 I believe that Jaba's major point is entirely correct: until there is a decent statistical base upon which to draw conclusions - rather than opinions - then any 'argument' of difference between the two is based on emotion and personal judgement rather than fact. I reckon the fact that Jaba originally wanted to go CAMit, then found he had to go Jabiru and is happy with his decision - gives him a pretty convincing - to my mind - status to comment. It is human nature, that where we do not have the necessary skills/experience/exposure to all the relevant data, we tend to rely on the opinions of others - and those of us with a discerning nature judge the value of the opinion of others very much on our belief that they HAVE the necessary skills / experience / access to relevant data to make their opinion valid. Good managers do NOT necessarily know all the 'answers' - but generally they have the expertise to recognise the quality of the advice of others. This forum is a fine example of both ends of the spectrum and the various threads about Jabiru engines in particular has provided both excellent information and rabid postulation. Let me state - once again, though I suspect most contributors here know my position - why I have had sufficient confidence in CAMit's developments to put my own limited money, augmented by my time and effort, into building a 'CAMit' engine - albeit a rather mongrel version, using a base of a re-cycled standard 2200J that had only run test hours. Let me ALSO state for the record, yer Honour, that this engine would not exist without the generous assistance of BOTH Rod Stiff AND Ian Bent. Why this is, is another story entirely -though it goes back to the earliest days of both Jabiru and CAMit. CAMit would not have become aircraft engine manufacturers if Rod Stiff had not decided to build the Jabiru engine (the reasons for which have been exhaustively re-counted, but if anyone does NOT know it: you should read: http://www.aeromech.usyd.edu.au/AERO1400/Jabiru_Construction/jabiru.html ) Conversely, Jabiru would NOT have been as successful as if has, had CAMit not been able to provide the development of a viable manufacturing process for the 2200 and subsequent 3300 engines - which is why CAMit holds a 50% share in the Jabiru engine IP. The original 1600 engine worked - just. Make no mistake: Rod Stiff dreamed up one of the best - arguably THE best - 'ultralight' airframe to fit the regulations then in force. ( Don't judge the LSA55 by the standards of the modern 'LSA-class' under the ASTM regulations - they came later). He and Phil Ainsworth had the uncommon good sense to contract two damn fine engineers to assist them in the development of that - but it needed a better engine at the same weight as the KFM for which it had been designed to be a success. Ian Bent and CAMit made that development possible. Since those early days, over 5,000 Jabiru engines have been delivered. CAMit have manufactured them all, to Jabiru's ever-changing design requirements. The people who glue the Jabiru engine plate onto the crankcase, are CAMit employees. They do that when the engine to which they are affixing that plate has been manufactured, assembled, and test-run in a dyno to Jabiru's specification. Those engines incorporate components delivered by Jabiru to CAMit - including pistons, rings, bearing shells, valves, valve guides, seals and hydraulic lifters. The engines are assembled according to Jabiru instructions, using Jabiru-specified techniques and materials. While anyone who has had long-term experience with 'the 'Jabiru story' will have deep respect for Rod Stiff''s (and Phil Ainsworth's) achievement, I don't think anyone has ever successfully prosecuted the case that Rod is by nature consultative or amenable to advice. Certainly the two aero-engineers used in the early development of Jabiru aircraft remain friends and consultants - occasionally - to Rod, but he has in general forged his own path forward. Rod's reaction to problems with his engine(s) is to 'fix' the faulty part. Ian Bent's reaction is to research WHY the problem is occurring, and to fix the system chain that leads to the problem. I know which approach I believe to be the more fundamentally sound - and it is CAMit's. 3 2 3
jetjr Posted August 5, 2015 Posted August 5, 2015 "Good managers do NOT necessarily know all the 'answers' - but generally they have the expertise to recognise the quality of the advice of others" Very true If we had to wait for new products to develop a data package which reaches conclusion, the progress in most markets would be very slow. They are out there, GA is actually one. Costs and lack of innovation illustrate outcomes of this approach. In commercial, competitive environments, technical managers and project specifiers have to make these calls every day. You hear lots of claims and plenty of BS. Reading between the lines and assessing real product risk is a key part of the job. 2
Russ Posted August 5, 2015 Posted August 5, 2015 Oscar ol chum.........love your posts, by chance are you oscar wild jnr. Oscar senior was one hell of a writer.......and you is up there. 1 1
fly_tornado Posted August 5, 2015 Posted August 5, 2015 When Camit come out with an engine competitive with the UL power engine, in terms of performance, specifications and technology, I'll drink Oscar's kool aid. 1
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