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New Jabiru Engine


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There is a new Jabiru engine on the horizon or rather a major update to the current series. It will feature cast alloy cylinders instead of the machined steel cylinders. There is no steel liner, instead it will have Nikasil lined bores. The cylinders are interchangeable with each other, unlike the current production and the thru-bolts are extended to retain the heads as well. (Four head bolts instead of six.) The new incarnation runs much cooler than the previous models. The heads and even the tappet cover are cast alloy! It may even weigh less than previous models.

 

 

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Pressure castings?

Ozzie, not being an expert on castings, I wouldn't know. Suffice to say they looked very neat, the spacing of the fins a bit wider than the current machined ones.

 

 

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Good to see Jabiru still investing in local manufacturing. Nikasil should be an improvement, and stop the rusting bores problem (I have to remember to run my engine on a weak 2-stroke mix before a long period of inactivity).

 

Tough stuff, that Nicasil. When my wife's 1978 Guzzi was assembled they couldn't even get within the incredibly sloppy tolerances typical of Italian manufacturing at the time. The crank had so much movement the rings somehow chewed out the top of the Nicasil bores. When my engineer tried to bore out the barrels to insert iron liners, all his best cutting gear was wrecked.

 

 

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When my engineer tried to bore out the barrels to insert iron liners, all his best cutting gear was wrecked.

Yes, I believe that they need a diamond hone to get the final bore dimensions!

 

 

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Double Dutch to me. Talk maths or C++ programming :drool:and I might have a chance...

basically the old jabiru engine was written on fortran. new one is using a rotax 912 technology from the 90's

 

 

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There is a new Jabiru engine on the horizon or rather a major update to the current series. It will feature cast alloy cylinders instead of the machined steel cylinders. There is no steel liner, instead it will have Nikasil lined bores. The cylinders are interchangeable with each other, unlike the current production and the thru-bolts are extended to retain the heads as well. (Four head bolts instead of six.) The new incarnation runs much cooler than the previous models. The heads and even the tappet cover are cast alloy! It may even weigh less than previous models.

Sounds good but will there be any improvements with the Carburation that you know of ?

 

Alan.

 

 

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Sounds good but will there be any improvements with the Carburation that you know of ?Alan.

Alan, I don't know if there is any improvements with the carby. Regards, Bob

 

 

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What's wrong with the carby?No problems here

Phil

Hi Phil, nothing wrong with the carby, I was merely asking if there were any improvements.

 

Better more even fuel distribution to all cylinders is one.

 

Alan.

 

 

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Hi Phil, nothing wrong with the carby, I was merely asking if there were any improvements.Better more even fuel distribution to all cylinders is one.

Alan.

just wodering myself. I did post sometime ago that perhaps they could move to direct injection to allay cold stating but since I got the idle jet drilled out starting has been perfect on cold days

 

Temp O K so I am very happy chappie now

 

cheers

 

phil

 

 

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Achieving even fuel distribution will always be a problem, unless you inject ( the motor). One way of improving it would be to use a supercharger downstream of the carb with a small boost. This works particularly well with radial engines where fuel distribution is a real problem. Once the cooling problems are fixed the mixture is not quite as critical, anyhow, and the engine becomes capable of delivering more power. Nev

 

 

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I would'nt get too excited fellas . Jabiru are currently doing tests on some engine mods but at this stage only have 20 hours on the engine . My guess is that any new engine will be many months , or even years away .

 

Bob

 

 

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I would'nt get too excited fellas . Jabiru are currently doing tests on some engine mods but at this stage only have 20 hours on the engine . My guess is that any new engine will be many months , or even years away .Bob

Hi Biggles Bob, I even offered to put some hours on it for them, if they'd pay for the fuel!016_ecstatic.gif.156a811a440b493b0c2bea54e43be5cc.gif

 

 

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I would'nt get too excited fellas . Jabiru are currently doing tests on some engine mods but at this stage only have 20 hours on the engine . My guess is that any new engine will be many months , or even years away .Bob

Then we will have to import them from Jabiru South Africa.

 

Alan.

 

 

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Unfortunately the amount of Local Manufacturing has dropped dramatically here with this engine. Cast Barrels and Heads all coming from Overseas. Only very minor work required by CAMIT. The Water Cooled Heads being offered on the market by other manufactures won't fit onto the new cast Barrels (Nikasil Bore). Only downside of the new cast head and Barrel design is that you have to remove the Inlet/Exhaust pipes to tighten the lower head bolt. As RKW says the heads are now tensioned directly to the through bolts, not the barrels. Early pull through tests on the engine hot and cold are extremely positive. No more loss of compression or tightness from distorted barrels when hot. Very good compression of all 4 cylinders with very positive kickbacks after each pull through of every cylinder. Definately a much better seal between the bores and rings. Still a lot more testing to be done before being released as a factory option. But will definately be an improvement if it all gets the tick of approval for certification. wonder what the cost will be to convert to the new barrels and heads. At this stage on the 4 cylinder has been built.

 

JabSP6

 

 

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Hi Biggles Bob, I even offered to put some hours on it for them, if they'd pay for the fuel!016_ecstatic.gif.156a811a440b493b0c2bea54e43be5cc.gif

Gidday RKW . O.K. if you ar 80 kg or less, as its only in the J120 at this stage 051_crying.gif.fe5d15edcc60afab3cc76b2638e7acf3.gif

 

 

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Gidday RKW . O.K. if you ar 80 kg or less, as its only in the J120 at this stage 051_crying.gif.fe5d15edcc60afab3cc76b2638e7acf3.gif

Well I'll just have to go on a diet! But not till after Christmas!!!! I've just helped the boss make the Christmas pudding. I licked the bowl and spoons, so I can't legally fly for eight hours! poke_tongue_out.gif.5a7d1a1d57bd049bd5fb0f49bf1777a8.gif

Merry Christmas everyone.

 

 

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