Jabiru engines on the brink ??

[gyroo]

Gee Mad Muz Thanks for reposting the link I posted on page 1 of this thread. Duh.

[MadMuz]

Here is a link to Rotec..... wow, they seem awesomeEdit: So you did Mark, sorry about that ... I wondered where I had found it

[birdy]

I reckon it"s blindingly obvious why Jabs burn out their exhaust valves and deform their heads.Ex valves can burn even in new petrol engines that show no sign of heat problems.Incorrect geometary of intake will create lean mixs on sum cylinders.These pots will continuously burn the ex valves, no matter how much cooling it has.

[WEST OZ FLYER]

Ross, that ul engine you posted has the same mounting bolt pattern as the Jabiru engine although slightly heavier. I was told that if the registration number has an E in front the 24 means that it can"t be used at a flight school, aero club etc ( hire and reward ) and you could do what ever you wanted to it as it was now experimental. Put in a proper engine and would have a decent airplane.

[tonydenton]

I agree russ, I have friends that have a jab and never had a problem. not even a tiny fault. they have been around Australia and all.

[Russell]

Many owners have no problems at all, many have lots of problems.The " regulations" make it near on impossible to make changes no matter how better that change has proven to be.Guys that build from kits, can make changes, prove them, but factory built machines are hamstrung by regs.Heat control is the prime factor to most problems. There are mechanical issues as well, but heat is the killer.Maybe, just maybe, with casa threatening jab, finally jab will be forced to address issues, if they do, then jabs will be brilliant, as a flying machine they are faultless. Mine 100kts true cruise, 15L per hr.........not badStill love them gyros tho, really do. .......one of each is the ultimate indulgence.

[RossM]

Another air cooled engine.Don"t forget, I know nothing about engines.http://www.corvusaero.com.au/UL-Powe...power.com/they recommend CHT and EGT sensors, CHT on every cylinder, and a lot of warnings about never exceeding max temp.

[gyroo]

That"s true, Birdy, they are neatly machined. But, as a matter of common sense the dramatic reduction in cylinder fin cooling area the further out you go has always mystified me (see Picture 1 for the Jab setup). If you look at WWII engines from 60 and 70 years ago, as a matter of routine the designers and builders of air cooled engines gave them enormous amounts of cooling fin area right AT the head (see Picture 2 showing the cylinders of a Pratt and Whitney R2800 - an 80 year old design).

[birdy]

The machining of the engine is so neat I would"nt mind having a clean engine mounted on a frame in my house as a piece of art. Dam shame. Aint that the truth. If its profesionaly finnished, polished, has pretty paint or stupid bells n wisls, fair chance all its good for is a wall ornament.

[mad max]

I helped o"l mate oil change his 4 cyl. Jab. 7 yrs. back (Jab. engine in a light wing) He"d just flown from Townsville to Tennant Creek. He fired it up and it went good. Stopped it and started it again and it locked up while cranking. A gudgeon pin had slipped out. Circlip grove was too shallow. The machining of the engine is so neat I would"nt mind having a clean engine mounted on a frame in my house as a piece of art. Dam shame. :"(

[danny]

I"m Just adding my bit.

[Russell]

Yea tony, heard from a lot of folks, the Camit group are good people. They have quietly been doing a lot of R&D all funded by themselves. At the minute they are progressing with " certification" of THEIR engine, I would expect the bills are mounting, heard goss that just getting through the cert thing alone is around $300k.....so I would now expect that proceeding further may be restricted by funds. It"s a real shame, as reports say their engine has addressed the problems in the current jab engines. I have a view that jab may be making things awkward for Camit as well. Will be interesting just where all this ends up, I believe there is over 4000 jab powered aircraft out there, most aware of Camits endeavours, and all 4000 waiting to retrofit Camit mods, and/or....buying a Camit engine. Would be nice to see certain folks, rethink their strategy and embrace Camits engineering, but i won"t be holding my breath.......pity.

[gyroo]

Hi all,the other comment that I"ll make is that we all probably know that it takes an enormous amount of money, time and effort to get any product into the marketplace.After having done all that, manufacturers are often especially reluctant to implement substantial changes to their product out of fear that courts will identify any such change as a tacit admission that the initial product was defective in some way.The way car manufacturers have largely sidestepped this issue is by regularly introducing newer models where their launches can be associated with lots of hoopla, where the obvious cosmetic changes are accentuated and hyped, but where even very substantial (even critical) engineering mods can sometimes be buried deep inside and not mentioned so as to NOT highlight the shortcomings of the earlier models! Sneaky. There"s a whole sub-species of bottom-dwelling corporate lawyers who make careers out of devising such devious smoke and mirrors strategies. With aircraft, unfortunately, because designs like Jabirus have been put forward for "certification", it makes it very much harder for an aircraft manufacturer to steadily introduce newer models with substantial modifications.As a lawyer myself I can"t see any easy pathway out of this situation for Jab, other than the current proprietors winding up and transferring the operation over to a fresh legal entity (a new Company, with genuinely changed ownership), and that would be the "relief" the engine manufacturers probably need who would then presumably be free to use Rotec as an approved sub-contractor in the engine manufacturing phase, or to go it alone with their own mods they"ve been tinkering with.Mark R

[gyroo]

Hi Tony - from what I can see I think the word "burned" is appropriate, but I don"t mean that financially - I mean exhaust overheating problems with the air cooled head.Check out this link:

[tonydenton]

I don"t think " could persue " is in their language skills from what I"ve heard. there are lots of people getting burned at the moment and for a while. I"m happy to say the owners of the engine building factory are very good friends of mine and an absolutely lovely couple to know . PERSONALLY THEY HAVE MY FULL RESPECT . they are well respected in town by everyone too that they know and deal with. remembering they have to build to "contracted engine design and specifications".