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Interesting new engine


Deskpilot
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Guest High Plains Drifter

Hello Deskpilot, I'm having a read of 'Leisure Aviation' and came across an Ad for a Coax-P counter rotating propeller drive for Rotax 582. Looks like it might be some thing you are familiar with - Do you have any experience with it. HPD

 

 

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Hello Deskpilot, I'm having a read of "Leisure Aviation" and came across an Ad for a Coax-P counter rotating propeller drive for Rotax 582. Looks like it might be some thing you are familiar with - Do you have any experience with it. HPD

Hi HPD, In a word, no. I didn't get a copy of 'Leisure Aviation' so I haven't seen the article. Actually, I don't have any experience with c/r props save seeing them on RAF Shackleton's, but they make sense to me and I would like to build a scale Wyvern.

Was thereby chance, a web address for manufacturer? The only other 'possible' source was on an air boat site where they have c/r props on a v8 auto engine, a bit on the big size for aircraft use.

 

 

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I have a feeling it is a pretty safe bet this engine will not find much application in aviation. The depressing truth is that no radically new engine has ever made any significant inroads into mainstream aviation, in spite of a plethora of innovative and clever designs.

 

Notable failures are:- the Wankel Rotary engine,the Sarich Orbital Engine, most double-action diesel engines (except the Junkers 205) and the Dynacam engine.

 

For the foreseeable future small aircraft will continue to be powered by horizontally-opposed, air/fuel/oil cooled engines of the reciprocating type, larger aircraft will continue to be powered by turbo-prop or gas-turbine engines and the great majority of those gas-turbine engines will be medium to high-bypass turbofan engines, even on very small executive jets.

 

About the only glimmer of innovation on the horizon is the use of compression-ignition engines using jet fuel. We are still waiting for these to become accepted, although Thielert in particular appear to be making some progress. As for the SMA, DAIR, Wilksch and Zoche aero-diesels...well, we are still waiting! Zoche in particular appear to be little more than a long-running practical joke, and one in rather poor taste at that. No production engines and well after a decade of design and development work! One of the better examples of a "vapourware" engine!

 

It is very hard to work up any enthusiasm for radically different engine designs when the road to Hell is paved with failed examples stretching as far as the eye can see. Trying to buck the corporate muscle of Pratt & Whitney, GE, Rolls-Royce, SNECMA, Textron-Lycoming and Teledyne-Continental is a pastime with little to show and less to recommend it.

 

We are not going to see any really innovative engines in aviation whilst our fundamental orifices point towards the centre-of-mass of this - or any other - planet! We'd just better get used to it.

 

 

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Dieselten, it is just that sort of totally negative attitude (please don't call it reality) that prevents ongoing development. Those smaller companies you mentioned probably had to pull the plug because they couldn't fine open minded investors who could foresee and encourage the future development of those engines. As for the larger companies being bothered by new, small and struggling players, that's a joke. They'd probably like them to succeed so that they, in turn, can share in any new developments without having to carry the R & D costs already spent by the smaller companies.

 

Please don't take this as a personal attack, it's not. We all have our right to express an opinion, and this is mine.

 

 

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Guest High Plains Drifter

I hear there is an Australian development of an engine simular to the Junkers. Does any body know about it ? HPD

 

 

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Guest Flyer40

I'd be happy just to see aircraft engines catch up with automotive technology for fuel efficiency and reliability (ie electronic control = lower operating and maintenance costs).

 

Can I drop a hint in case there are any engine manufacturers reading this. The engine that I would like to put in my kit plane almost exists. The UL206 comes so close, but it's about 20hp short. How about a 6-cyl version, or even a Jab 3300 with FADEC?

 

I mean how can I possibly put a choke lever next to my ADS-B display or my digital transponder? I'd rather use the space for my BRS handle.:)

 

 

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Flyer I wouldnt be too hasty about electronic control, it just cuts reliability. The UL260 is limited to 20 mins or so with alternator failure and another good example is the Diamond DA-40 that crashed with double engine failure due to a bump in the power supply when they selected gear up - the ECU's momentarily stopped working.

 

Theres very little in fuel efficiency because aircraft engines only need to operate around a 10% rev range most of the time and a carb or mechanical fuel injection and fixed timing is just as good.

 

Just select the hp / weight / price combination you require and fit a solenoid to that starting enrichment control ( I must relable mine, "choke" is not what it is) that will turn a 3300 into FADEC control.

 

Ralph

 

 

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The problem is volume - not enough of it to make it viable for all but a few. Most of them had war time effort and money spent by the goverment of the day when winning was at all costs.

 

If GMH or Ford or Toyota or any other car maker made millions of aeroplane engines (for millions of planes) then you can bet they would work pretty darn well and be reasonably cheap. Thats why a basic aeroplane motor, be it Lycoming, Continental, Jabiru (relatively unsophisticated) is worth lots of dollars while a Suburu and others are much, much cheaper and much more sophisticated. (Fuel injection, DOHC, sodium valves x 16, computer managed, etc, etc).

 

Development is shared over millions of units. This is a simplistic view of the problem, but until volume increases the R&D has to be paid for with high unit prices.

 

regards

 

 

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Personally, I'd like to see a manufacturer like honda have a crack at an aero engine.

 

Formula 1, performance cars and light weight, powerfull motorcycles.

 

Can't take too much effort from a company like that?

 

 

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As Dieselten points out, another dead end

 

http://world.honda.com/news/2003/c030304.html

 

I think he's a bit harsh on Wankel Rotary's though, there have been at least 2 manufacturers that have flown certified ones - Curtis-Wright ? and Diamond/Midwest , as well as a few perenials that turn up at Oshkosh - but as you still cant buy one yet, they dont count

 

Ralph

 

 

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Flying car engines.

 

Both your posts are right on jetboy. The CONSPIRACY theory runs rampant easily I don't think it has any factual basis. GM. have built aero-engines. Ford & Packard under licence Rolls- Royce built Continental under licence (went broke, Nothing wrong with the engine) Porsch were going to build an aero-engine many years ago, (nobody would dispute their ability to build a good high performance engine, But nothing eventuated. The Bugatti aero engines were basically derived from car engines in tandem, Absolute disaster.

 

If I can liken the requirement for an aero-engine characteristics to that of a long distance road haul operation, Ie the engine is rarely backed-off. It's not just horsepower and weight. It's not that simple. If you put an F1 motor in a road train it would be lucky to get 10 miles, even though it has much more horsepower. The trick is also to get the weight down to a minimum, requiring design & testing, high cost materials & quality control, Also insurance against litigation and post-sale backing of the product). THIS IS WHAT YOU PAY FOR, NO MATTER WHO BUILDS IT. If you don't want it, don't buy it, but in these circumstances, don't expect to have it by default.

 

Just as an aside, isn't it a little sneaky to have diesel fuel usage quoted in volume (litres) when compared with avgas. If you do it on a weight/ weight comparison,(which is what a range thing would be determined on. Max AUW. being the limiting factor) there is a large difference in DENSITY ( SG.) Nev....

 

 

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Porsche did get their engine into quite a few aircraft but stopped manufacture as it obviously wasn't cost effective. Don't forget that there is more to it than getting a going engine. One of the biggest hurdles is product liability. Just think back to what that did to Cessna and Piper.

 

Jabiru are a good engine builder and their record is good. Even though a lot of people have been saying they have problems, we have a thread on this forum to report their engine problems and it has brought up very little of substance.

 

The new and exiting designs all seem to me to have very heavy lubrication requirements, and they can't seem to be able to produce more than prototype. I think the big manufucturers would snap up any good designs and produce them if they were worthwhile.

 

 

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Don't forget that there is more to it than getting a going engine. One of the biggest hurdles is product liability. Just think back to what that did to Cessna and Piper.

That's why the experimental classes are so great. No product liability and no(?) limits.

 

It lets people play with new concepts so we don't have to be stuck with expensive and archaic (albeit quite reliable) 1930's flat 4 technology....

 

My 2 cents...

 

Regards

 

Phil

 

 

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Those smaller companies you mentioned probably had to pull the plug because they couldn't fine open minded investors who could foresee and encourage the future development of those engines.

Maybe, but does anybody remember the Porsche PFM aero engine? back in the late 80's Porsche spent a fortune in R&D to develop a 6cyl 217HP aero engine, they even formed a joint venture with Mooney to build the 'Mooney Porsche'. So what happened to it? the bottom line is that those 'old' Lycomings and Continentals have an unchallenged reliability record due to being simple, low stressed, direct drive, air-cooled engines with a design honed over 75 years. THE major factor in aero engine performance is reliability, and in that respect no other piston engines have yet come close to these 'dinosaurs'. There is much to be said for 'If it ain't broken, don't mend it'.....

 

 

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browng is right on the money!

 

"Metal in the air" is what it's all about. All the factors he lists are critically important and that's why the now ancient Lycoming and Continental horizontally-opposed engines are the winners. Bear in mind an aero engine is designed to produce continuous high output power for a specific number of hours, driving the load (propeller) directly off the end of the crankshaft (although geared engines have had some notable sucess, e.g. the Merlin and Griffon) and to be as light as possible to achieve the highest power-to-weight ratio consistent with reliability and longevity.

 

I do not resile from anything in my previous post. When it comes to masses of metal turning propellers and flying through the air, the old designs are still the best designs for this specific task. This may be an unpalatable truth in this day of computer-controlled automotive engines with phenomenal reliability producing varying levels of output power and driving through gearboxes and torque-converters, but in an aircraft the application is totally different. Trying to compare an automotive engine to an aero engine is like ploughing the sea, or nailing jelly to a tree - an exercise in futility.

 

 

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Guest Flyer40

I agree with most of that diesel, except I wasn't comparing auto engines to aero engines, I was commenting on the merits of the technology and how it can be used to reduce risk and cost. I'm more risk averse than most, since that's what I do professionally.

 

That's why I like the UL260. It has the physical attributes of the traditional aero engines that you have highlighted, without the risks associated with how they are operated.

 

It's not only the hardware that gives rise to risk, it's also the human factors associated with how the engine is operated. Carburettored aero engines have killed people in ways that just don't exist with a single-lever FADEC controlled engine. They include carby icing, incorrect leaning, leaving primers unlocked, etc etc. Human error can't be eliminated through rules or training or abstract concepts such as "airmanship". Humans are fallible and will make mistakes, even the highly experienced ones. However the risk can be eliminated from the equipment through better design.

 

FADEC is well proven and significantly more reliable than older technologies, which reduces the risk of failure and eliminates several accident causal factors.

 

FADEC engines are more efficient by more accurately metering and atomising fuel and by continuously adjusting mixture. Engine life is increased by accurately controlling the temperature of each cylinder and eliminating exceeded parameters such as RPM, temperature and mixture. FADEC engines reduce cost through using less fuel, reducing maintenance requirements, and increasing engine life.

 

Real world data indicates that FADEC pays for itself quickly.

 

I've known people who would still be alive today if they had been using FADEC instead of a carby. Comparing all the risks and inefficiencies of old engines against the risk of electrical failure, which can be reduced to a trivial level through system redundancy, and the decision makes itself.

 

There’s nothing futile about FADEC aero engines. There are FADEC Continentals in operation proving this every day of the week. What I'm asking for is to have this level of safety, efficiency and economy made available to our segment of aviation sooner rather than later.

 

I’m getting impatient. I want to buy an engine soon. But I’m pedantic about safety, so I’m not inclined to buy an engine that isn’t as safe as it could be and costs more to operate and maintain than it should.

 

 

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There are FADEC Continentals in operation proving this every day of the week. What I'm asking for is to have this level of safety, efficiency and economy made available to our segment of aviation sooner rather than later.

While not disagreeing with your stated aim, there are a couple of points I feel the need to make here;

 

1. TCM Continental had huge problems getting their FADEC engines certified, they were announced in 1999 and so far I believe only two are genuinely in production, the IOF-240-B and IOF-550, and these did not make full production until late 2004, five years after they were announced.

 

2. To compare the FADEC of the UL260i to the TCM equivalent is deceptive to say the least. The UL260i uses a single automotive control unit with no redundancy, whereas the TCM engines use a quadruple redundant system consisting of two electronic control units, a duplicated engine harness, duplicated sensors, and four injector control coils. Not only are the control units duplicated, but each unit contains two fully independent microprocessor controllers and all associated components. Each of these microprocessors constitute a fully independent control channel capable of running the engine.

 

It is tempting to dismiss the chance of electronic failure as insignificant, but the long certification delays, and massive redundancy deemed necessary for the TCM FADEC engines should give pause for thought. The primary incentive for TCM to employ FADEC had little to do with operational benefits anyway, it was more to do with predicted future environmental legislation and the ultimate demise of AVGAS due to its lead content. Incidentally, the ill fated Porsche/Mooney PFM engine was also a single lever, electronically controlled unit.

 

 

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