deadstick Posted August 18, 2010 Share Posted August 18, 2010 Has anyone heard of a new engine that Jab is currently developing? I was told yesterday by an ex Jab technician that they are working on one.. Fuel injection? surely! Link to comment Share on other sites More sharing options...
Tomo Posted August 18, 2010 Share Posted August 18, 2010 Wouldn't surprise me. Fuel injection is relatively easy to set up, and effective. Link to comment Share on other sites More sharing options...
Tomo Posted August 18, 2010 Share Posted August 18, 2010 hmm theres nothing on their website about the 8 cyl yet.... could be it? The 8 cyl isn't being produced anymore. They had to much trouble with fuel distribution, and thermal heating. Something like that. Link to comment Share on other sites More sharing options...
Guest 4aplat Posted August 18, 2010 Share Posted August 18, 2010 hmm theres nothing on their website about the 8 cyl yet.... could be it? there is nothing on their web site nothing new till the begining of the year Link to comment Share on other sites More sharing options...
Guest basscheffers Posted August 19, 2010 Share Posted August 19, 2010 You are surprised about the Jabiru website being out of date an innacurate? Gotta wonder how much (especially) international business they lose by presenting themselves as amateurs. 8 Cylinder: goodbye and good riddance. What were they sniffing when they thought that up? I very much doubt that even if they got it to work it would have been cheaper to buy and maintain (double the cylinders!) than a same-power Aerosport Power IO-360. I don't even understand what they need 6 cyclinders for 120HP... Would be good if they come up with a better new engine, fuel injection is a good thing. Now add some electronic ignition too, please! Link to comment Share on other sites More sharing options...
motzartmerv Posted August 19, 2010 Share Posted August 19, 2010 (cough) they should just develop new engine mounts.....to fit say......i dunno, a ROTAX?? Link to comment Share on other sites More sharing options...
Guest basscheffers Posted August 19, 2010 Share Posted August 19, 2010 Haha, yes. The said they got into the engine business because nothing suitable was available. Don't think they must have looked very hard... This summer at Moonta, saw my favourite J170 ***EVER***!!!! It was a homebuilt and he put in a 912ULS! :D Link to comment Share on other sites More sharing options...
facthunter Posted August 19, 2010 Share Posted August 19, 2010 Replacement Motor? Jabiru's idea was for everything to be simple. The Rotax has , 2 TWO ?? Carbs and NO fuel injection. All the trouble getting the carbs balanced. and spring loaded to open. Have to hold the throttle closed half the time. Hate it. There goes the cheap plane concept. The rotax is certainly expensive to buy and for parts. Fortunately it doesn't need them very often. We need other engine options. Nev Link to comment Share on other sites More sharing options...
Ultralights Posted August 19, 2010 Share Posted August 19, 2010 i think the Jabiru has 1 major flaw thats holding it back from being a great engine, the carby position, which creates intake manifolds of differing lengths, resulting in different mixtures reaching different cylinders. the cylinder closest to the carby get a nice rich mixture, and run cool, whereas the front cylinders have a leaner mixture, resulting in higher temps, if the carby was centred under the engine, im sure this would eliminate 99% of their problems, then again, i believe the secret to rotax reliability is the water cooled heads., which results in minimal discrepancies between cylinder head temps. Link to comment Share on other sites More sharing options...
Guest basscheffers Posted August 19, 2010 Share Posted August 19, 2010 How much is a Jab 2200? and a 912? Is there really a big difference? Obviously, if Jab make them, they get profit from the engine and the airframe, which can be passed on as savings for the package. I'd pay extra for a Jab with Rotax, so why not have it as option? Judging by maintenance issues and frequent failures, I don't know why anyone would pay double for a "real aero engine" Jabiru compared to an AeroVee. I am not sure why spring loaded to open is a bad thing; I'd rather run full throttle for a while if the cable breaks to give me a chance to find somewhere to put it down rather than being forced to put it right there and then. What do you mean with: "Have to hold the throttle closed half the time"? I know the engineer that works on mine regularly balances the carbies, but I never heard him complain that it is hard to do or takes very long. Link to comment Share on other sites More sharing options...
Tomo Posted August 19, 2010 Share Posted August 19, 2010 Hehe, don't you love engine politics... Gotta look on the bright side, it keeps us in biz! Jabs are easy to work on, cheap, quick for parts, and simple. And there is 15 gazilion out there. Rotax are more idiot proof than Jabs. (no offense intended) Rotax are only 4 cylinder split carbs. (problems solved with that one) Link to comment Share on other sites More sharing options...
facthunter Posted August 19, 2010 Share Posted August 19, 2010 Engine comment. Bass. not disputing the idea of spring loading the throttles to open but getting the engine to a positive slow idle with TWO carbs spring loaded to open and the whole mechanism done with cables is not satisfactory as there is too much flexing and distortion in the system. Hence my statement about having to hold the throttle closed, firmly to get the low idle. if you are doing a minimum power approach. Balancing the carbs is fiddly and not a very safe practice with the engine running. If they are not set correctly they do run pretty rough at times. Ultralights, there is no reason that the heads of a 912 would run at the same temp. ALL the heads have a cooling plumbing layout there they originate at a point and end up at a similar point. ie they are in parallel. There is NO guarantee that the flow rates are the same through each one. Also the way the carbs are set-up (ie uneven pulsing) it is most likely that some cylinders are breathing better than others and that the mixtures vary also. The Rotax certainly does not suffer from some of the overheating that is apparent in many Jab motors in normal circumstances. The liquid cooling is an added complication however. Nev Link to comment Share on other sites More sharing options...
Guest basscheffers Posted August 19, 2010 Share Posted August 19, 2010 Nev, I have never had an issue with this, which may be because the SportStar uses a vernier throttle. Link to comment Share on other sites More sharing options...
facthunter Posted August 19, 2010 Share Posted August 19, 2010 Vernier Throttle. Yes that is the way to overcome it. Engineer it properly. Nev Link to comment Share on other sites More sharing options...
dazza 38 Posted August 19, 2010 Share Posted August 19, 2010 (cough) they should just develop new engine mounts.....to fit say......i dunno, a ROTAX?? :big_grin: Link to comment Share on other sites More sharing options...
Guest burbles1 Posted August 19, 2010 Share Posted August 19, 2010 UL260 aero engine Pretty interesting to read about a new fuel-injected engine in development: Description Apparently South Africa (and NZ) is/will be supplying this as an option for the Bantam B22. Link to comment Share on other sites More sharing options...
Tomo Posted August 19, 2010 Share Posted August 19, 2010 Pretty interesting to read about a new fuel-injected engine in development:Description Apparently South Africa (and NZ) is/will be supplying this as an option for the Bantam B22. Had a quick squiz at that engine, It's been very nicely done. Impressed. Fuel injection is the way to go. Though some will argue it is relying on electronics a bit much. Link to comment Share on other sites More sharing options...
Sloper Posted August 19, 2010 Share Posted August 19, 2010 Though some will argue it is relying on electronics a bit much. Cant be any worse, opps did l say that. :):) regards Bruce Link to comment Share on other sites More sharing options...
Tomo Posted August 19, 2010 Share Posted August 19, 2010 Cant be any worse, opps did l say that. :):) Fuel injection is one way to effectively control what is happening. Each injector gets told when and how much to inject by the computer. So you get very good distribution to whatever cylinder needs it. You are relying on a computer though which sensors airflow, exhausts, pressures etc... (depending on the type) Of course there are plenty of different types of fuel injection systems. Link to comment Share on other sites More sharing options...
Sloper Posted August 19, 2010 Share Posted August 19, 2010 l agree totaly, fuel injection is the way to go, really not fussed if it mechanical or electronic but l prefer electronic. regards Bruce Link to comment Share on other sites More sharing options...
eightyknots Posted August 19, 2010 Share Posted August 19, 2010 1I know the engineer that works on mine regularly balances the carbies, but I never heard him complain that it is hard to do or takes very long. Hi bass (and to all those Rotax owners out there): how regularly do you have to balance the Rotax carbies? Link to comment Share on other sites More sharing options...
Guest watto Posted August 19, 2010 Share Posted August 19, 2010 I am told Jabiru have been flight testing a throttle body type injection system, not sure if that was on the 2200 or 3300 but would presume 3300 for testing purposes. Link to comment Share on other sites More sharing options...
XAIRVTW Posted August 19, 2010 Share Posted August 19, 2010 New Jab 2200 $14500 + $1500 for installation package, Rotax 912 $21000 Didnt ask about the installation package for the rotax as I fell off my chair & the phone come out of the socket. Link to comment Share on other sites More sharing options...
Guest watto Posted August 19, 2010 Share Posted August 19, 2010 New Jab 2200 $14500 + $1500 for installation package, Rotax 912 $21000 Didnt ask about the installation package for the rotax as I fell off my chair & the phone come out of the socket. Abou 18K for the 3300, not to bad really, but both manufacturers make a great engine and realistically the Rotax should be more expensive as the engine has a lot more moving parts and parts in general, 2 different systems! one simple air cooled, one more complex liquid cooled, one cheaper to make and maintain than the other which is indicitive of the purchase and manufacturing price. The good thing is everybody gets to choose what suits them and that is the way they go, does not make one better than the other, just two alternatives. Link to comment Share on other sites More sharing options...
Guest Crezzi Posted August 19, 2010 Share Posted August 19, 2010 Hi bass (and to all those Rotax owners out there): how regularly do you have to balance the Rotax carbies? Checking the balance is part of the 100 hourly - doesn't always need adjusting though. Cheers John Link to comment Share on other sites More sharing options...
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