RKW Posted December 21, 2011 Posted December 21, 2011 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. 2
RKW Posted December 21, 2011 Author Posted December 21, 2011 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.
Old Koreelah Posted December 21, 2011 Posted December 21, 2011 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.
J170 Owner Posted December 21, 2011 Posted December 21, 2011 Double Dutch to me. Talk maths or C++ programming :drool:and I might have a chance...
RKW Posted December 21, 2011 Author Posted December 21, 2011 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!
Litespeed Posted December 21, 2011 Posted December 21, 2011 Sounds much better to me. I had a nikasil lined BMW R100CS. 220,000kms and still sweet.
fly_tornado Posted December 21, 2011 Posted December 21, 2011 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 1
J170 Owner Posted December 21, 2011 Posted December 21, 2011 basically the old jabiru engine was written on fortran. new one is using a rotax 912 technology from the 90's Right, all falls into place....
Guernsey Posted December 22, 2011 Posted December 22, 2011 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.
RKW Posted December 22, 2011 Author Posted December 22, 2011 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
Jabiru Phil Posted December 22, 2011 Posted December 22, 2011 What's wrong with the carby? No problems here Phil
Guernsey Posted December 22, 2011 Posted December 22, 2011 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.
Jabiru Phil Posted December 22, 2011 Posted December 22, 2011 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
facthunter Posted December 23, 2011 Posted December 23, 2011 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
biggles Posted December 23, 2011 Posted December 23, 2011 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
Litespeed Posted December 23, 2011 Posted December 23, 2011 How about some direct injection? (post moderated - Admin) 1
RKW Posted December 23, 2011 Author Posted December 23, 2011 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!
Guernsey Posted December 23, 2011 Posted December 23, 2011 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.
JabSP6 Posted December 23, 2011 Posted December 23, 2011 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 1
biggles Posted December 24, 2011 Posted December 24, 2011 Hi Biggles Bob, I even offered to put some hours on it for them, if they'd pay for the fuel! Gidday RKW . O.K. if you ar 80 kg or less, as its only in the J120 at this stage
RKW Posted December 24, 2011 Author Posted December 24, 2011 Gidday RKW . O.K. if you ar 80 kg or less, as its only in the J120 at this stage 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! Merry Christmas everyone. 1
Tomo Posted December 24, 2011 Posted December 24, 2011 I'm only 70 kgs.Alan. Well I'm 56kg... And a J120 fan... so....
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