eightyknots Posted July 27, 2012 Share Posted July 27, 2012 There really needs to be some balance in the Holden-vs-Ford-esque debate between Rotax and Jabiru engines. To even things out, here are some Rotax paperweights: 1 Link to comment Share on other sites More sharing options...
dazza 38 Posted July 27, 2012 Share Posted July 27, 2012 Yeah but they have made seven million engines in 350 different models.They are bound to have some bad ones. They didnt make Bultaco bike engines did they ? If they did, that would count for alot of bad engines LOL Link to comment Share on other sites More sharing options...
fly_tornado Posted July 27, 2012 Share Posted July 27, 2012 we are all going to die, lets not encourage Jabiru Link to comment Share on other sites More sharing options...
Wayne T Mathews Posted July 27, 2012 Share Posted July 27, 2012 Holden vs Ford? I don't think so... Surely it's not that close... Now Mercedes vs Morris I might entertain... 3 Link to comment Share on other sites More sharing options...
Doug Evans Posted July 27, 2012 Share Posted July 27, 2012 ford all the way for me / there is no other Link to comment Share on other sites More sharing options...
brilin_air Posted July 27, 2012 Share Posted July 27, 2012 EightyKnots... Thank you. -Linda Link to comment Share on other sites More sharing options...
Guest Howard Hughes Posted July 27, 2012 Share Posted July 27, 2012 Ford v's Holden? The Leyland P76 springs to mind, you can work out for yourself which engine I am referring to! Link to comment Share on other sites More sharing options...
bones Posted July 27, 2012 Share Posted July 27, 2012 not 1 4 stroke in pics i could see, thats like comparing diesel to petrol Link to comment Share on other sites More sharing options...
Wayne T Mathews Posted July 27, 2012 Share Posted July 27, 2012 Ford v's Holden?The Leyland P76 springs to mind, you can work out for yourself which engine I am referring to! In an effort to say something nice about the P76, I must admit that for its day, it had a good boot. 1 Link to comment Share on other sites More sharing options...
Doug Evans Posted July 27, 2012 Share Posted July 27, 2012 In an effort to say something nice about the P76, I must admit that for its day, it had a good boot. When it wastn't on firer 1 Link to comment Share on other sites More sharing options...
dazza 38 Posted July 27, 2012 Share Posted July 27, 2012 The boot for the P76 was designed around the 44 Gallon drum I think from memory. A farmer could place a 44 gallon drum in the boot.Pity the designers forgot about everything else.LOL Seriously though-apparently it was one of the first cars of that era, to have the engine designed to go under the car in a major crash. A bloke who loved them told me that. Link to comment Share on other sites More sharing options...
johnm Posted July 28, 2012 Share Posted July 28, 2012 lets be fatalistic ................ lifes a sexually transmitted terminal disease ! how and when you get to the big landing strip in the sky ................ is to a degree ......... your choice the following won't apply to most of us ?; but any coroners inquest or investigation report - concerning you - won't have any bearing on your own, one way trip, up top - however .............. for the sake of those left behind it would be good that such an investigation says ............................ (don't know how to finish that bit) 1 Link to comment Share on other sites More sharing options...
Gnarly Gnu Posted July 28, 2012 Share Posted July 28, 2012 Yes there was a Rotec engine not far from here that made a paperweight of the aircraft it was fitted to also, all it takes is for the dodgyest bit to give. Link to comment Share on other sites More sharing options...
turboplanner Posted July 28, 2012 Share Posted July 28, 2012 lets be fatalistic ................ lifes a sexually transmitted terminal disease !how and when you get to the big landing strip in the sky ................ is to a degree ......... your choice the following won't apply to most of us ?; but any coroners inquest or investigation report - concerning you - won't have any bearing on your own, one way trip, up top - however .............. for the sake of those left behind it would be good that such an investigation says ............................ (don't know how to finish that bit) Not any more if you take someone with you, or leave someone injured. If you were negligent, and there are a lot of regulations and procedures to be adhered to not to be negligent, their family will employ PL lawyers who will freeze your estate for years until suitably fair compensation is paid to the victims. It's certainly not a Holden vs Ford thing, and if someone wants to drag Rotax into it maybe they should spend some time going through the Pilot Notes like I did to see just how many Rotaxes. The issue is, if an engine, any engine fails after take off or in flight, recent records indicate that some of you are not going to come out of a forced landing. That's the serious issue that should be addressed, not avoided by starting a football-like competition. Link to comment Share on other sites More sharing options...
ahlocks Posted July 28, 2012 Share Posted July 28, 2012 ..... PL lawyers who will freeze your estate for years... No assets, no insurance, no worries then aye.... Link to comment Share on other sites More sharing options...
turboplanner Posted July 28, 2012 Share Posted July 28, 2012 In your case, you'd survive so they'd clap you in the stocks. Link to comment Share on other sites More sharing options...
ahlocks Posted July 28, 2012 Share Posted July 28, 2012 Free rations and quarters and no cash bonus for legal types is a pretty good deal really.... 1 Link to comment Share on other sites More sharing options...
turboplanner Posted July 28, 2012 Share Posted July 28, 2012 Never thought of that....a big step up for a firey. 1 Link to comment Share on other sites More sharing options...
ahlocks Posted July 28, 2012 Share Posted July 28, 2012 Never thought of that..... Every cloud has a silver lining Tubz. It's just difficult to see it while in it and trying to maintain wings level off an iPhone... Link to comment Share on other sites More sharing options...
Powerin Posted July 28, 2012 Share Posted July 28, 2012 I know this is not going to sway the protagonists either way.....but I agree it is not a Holden vs Ford thing. I don't have an axe to grind, I don't own either. I have mostly flown 912 Rotaxes in my training....but that means nothing. These Rotaxes have had plenty of maintenance issues that have grounded them, one has had a forced landing from loss of coolant. Rotaxes fail too! No arguments! But I were to make a purchasing decision both of my feet would be firmly in the Rotax camp.....IF I could afford one. You pay for the privilege. As Turbo has said, whether you look at Pilots Notes in the RAA mag, or the Airworthiness section of Flight Safety mag, Jab engines feature highly...Rotax do not. And for the same old issues. It is incorrect to say that is because there are so many more Jabs. My conservative estimate from the RAA register is that the ratio of 4 stroke Rotaxes to Jabs is 6 to 7. Worldwide Rotax is king (queen?). On top of that let's just have a look at the last few engine ADs from Rotax and Jab. From Rotax we have some potentially serious defects such as crankshaft faults. However, they were not actual faults which caused actual failures but *potential* faults found through inconsistencies in a rigorous quality control system. This suggests to me a mature product whose basic design is very sound. On the other hand Jabiru is *still* mucking around with some very basic engine parameters, such as compression ratio, to fix *actual* faults...and their fix is to change their base design by sticking some washers/shims under the cylinders? But this one seals the deal for me from the Jab AD about the new 12 point nuts/though bolts. This is a direct quote: "Normal aircraft practice is to ensure that a minimum of around 1.5 threads project through the nut, however in this case that is not necessary." So here we have Jabiru, in an attempt to fix another basic problem, advising owners fitting the 12 point nuts that it is not necessary to follow normal aircraft practice?? Sorry....this simple statement just screams out to me a company making it up as it goes along, rather than making informed engineering decisions. I really hope they get it together and produce a trustworthy powerplant for their good, solid, no-nonsense airframe. Rant over.... 5 Link to comment Share on other sites More sharing options...
coljones Posted July 28, 2012 Share Posted July 28, 2012 snip snip snip But this one seals the deal for me from the Jab AD about the new 12 point nuts/though bolts. This is a direct quote: "Normal aircraft practice is to ensure that a minimum of around 1.5 threads project through the nut, however in this case that is not necessary." So here we have Jabiru, in an attempt to fix another basic problem, advising owners fitting the 12 point nuts that it is not necessary to follow normal aircraft practice?? Sorry....this simple statement just screams out to me a company making it up as it goes along, rather than making informed engineering decisions. I really hope they get it together and produce a trustworthy powerplant for their good, solid, no-nonsense airframe. Rant over.... Begging to differ. "standard aircraft practice" should be something under continuous review as it might not be advantageous, practical or even safe as circumstances change or evolve. When doing anything new one should always consider if the rules fit the circumstances. If, after an AUTHORITATIVE review, a change to standard practices are warranted then there should be no need to continue the standard practice. I am sure that Jabiru are mindful of the limits of their insurance if they were offering poor advice or engaging in ill prepared engineering reviews. The critical aspect of bolts and nuts is the degree of thread engagement. The bit sticking out the top is redundant but serves as a visible indication of the thread engagement and to have some thread there to increase the time delay before the nut falls off after having worked its way loose due to poor installation and torquing. In the olden days, I seem to remember, virtually every nut and bolt on engine was wired up to prevent it coming loose. Some things have changed. "Testing has shown that 12-point nuts (Figure 2) can carry a slightly higher load than the original MS21042 type nuts. As they are longer they also spread the tension load over a higher number of threads on the bolt. This reduces the load concentrated on any given thread and improves the ultimate strength and fatigue life of the assembly. New case assembly hardware has been developed which uses a larger (7/16”) thread. This increases the effective diameter of the bolt and again, reduces the peak stress in the part. This improves the ultimate strength and fatigue life of the assembly." cheers. 2 Link to comment Share on other sites More sharing options...
Wayne T Mathews Posted July 28, 2012 Share Posted July 28, 2012 I know this is not going to sway the protagonists either way.....but I agree it is not a Holden vs Ford thing. I don't have an axe to grind, I don't own either. I have mostly flown 912 Rotaxes in my training....but that means nothing. These Rotaxes have had plenty of maintenance issues that have grounded them, one has had a forced landing from loss of coolant. Rotaxes fail too! No arguments!But I were to make a purchasing decision both of my feet would be firmly in the Rotax camp.....IF I could afford one. You pay for the privilege. As Turbo has said, whether you look at Pilots Notes in the RAA mag, or the Airworthiness section of Flight Safety mag, Jab engines feature highly...Rotax do not. And for the same old issues. It is incorrect to say that is because there are so many more Jabs. My conservative estimate from the RAA register is that the ratio of 4 stroke Rotaxes to Jabs is 6 to 7. Worldwide Rotax is king (queen?). On top of that let's just have a look at the last few engine ADs from Rotax and Jab. From Rotax we have some potentially serious defects such as crankshaft faults. However, they were not actual faults which caused actual failures but *potential* faults found through inconsistencies in a rigorous quality control system. This suggests to me a mature product whose basic design is very sound. On the other hand Jabiru is *still* mucking around with some very basic engine parameters, such as compression ratio, to fix *actual* faults...and their fix is to change their base design by sticking some washers/shims under the cylinders? But this one seals the deal for me from the Jab AD about the new 12 point nuts/though bolts. This is a direct quote: "Normal aircraft practice is to ensure that a minimum of around 1.5 threads project through the nut, however in this case that is not necessary." So here we have Jabiru, in an attempt to fix another basic problem, advising owners fitting the 12 point nuts that it is not necessary to follow normal aircraft practice?? Sorry....this simple statement just screams out to me a company making it up as it goes along, rather than making informed engineering decisions. I really hope they get it together and produce a trustworthy powerplant for their good, solid, no-nonsense airframe. Rant over.... Good points... Begging to differ."standard aircraft practice" should be something under continuous review as it might not be advantageous, practical or even safe as circumstances change or evolve. When doing anything new one should always consider if the rules fit the circumstances. If, after an AUTHORITATIVE review, a change to standard practices are warranted then there should be no need to continue the standard practice. I am sure that Jabiru are mindful of the limits of their insurance if they were offering poor advice or engaging in ill prepared engineering reviews. The critical aspect of bolts and nuts is the degree of thread engagement. The bit sticking out the top is redundant but serves as a visible indication of the thread engagement and to have some thread there to increase the time delay before the nut falls off after having worked its way loose due to poor installation and torquing. In the olden days, I seem to remember, virtually every nut and bolt on engine was wired up to prevent it coming loose. Some things have changed. "Testing has shown that 12-point nuts (Figure 2) can carry a slightly higher load than the original MS21042 type nuts. As they are longer they also spread the tension load over a higher number of threads on the bolt. This reduces the load concentrated on any given thread and improves the ultimate strength and fatigue life of the assembly. New case assembly hardware has been developed which uses a larger (7/16”) thread. This increases the effective diameter of the bolt and again, reduces the peak stress in the part. This improves the ultimate strength and fatigue life of the assembly." cheers. But then so are these... Bottm line IMHO? As Powerin said, "I really hope they get it together and produce a trustworthy powerplant for their good, solid, no-nonsense airframe." Link to comment Share on other sites More sharing options...
turboplanner Posted July 28, 2012 Share Posted July 28, 2012 The bit sticking out the top is redundant Firstly it's standard engineering practice, not just aircraft practice. Secondly there is a sound structural reason for this; it prevents dishing of the centre, which would adversely change the angle of the top threads, reducing their load carrying capacity by a small percentage. It could be that testing has shown the new bolts have so much over-capacity they can do without this percentage. 2 Link to comment Share on other sites More sharing options...
fatmal Posted July 28, 2012 Share Posted July 28, 2012 I've had a Rotax engine fail on me - more than once! It was an in-line twin-cylinder disk valve induction 250cc, producing approx 70bhp, so it's no wonder it melted pistons! Thankfully, it was in a motorcycle so I could just coast to a stop and wait for the crew to pick me up from the side of the racetrack. I also raced an Aprillia RSV1000, which had a Rotax-built 1,000cc V-Twin. Great motor! Reliable, fast & sounded fantastic! Nowadays, I fly behind a Rotax, and (touch-wood) have had no mechanical issues - long may it continue As for the Jab - I've never flown behind one, so I'll stay well clear of commenting! Link to comment Share on other sites More sharing options...
turboplanner Posted July 28, 2012 Share Posted July 28, 2012 If you really want to compare engines in this serious matter you need to compare the two primary engines. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now