Id rather spend the £5,000 prize money subsidising the Rally, so we get the chance to see what everyone else has been doing again and learn from our mates.
With regard to VWs, what about the AeroV engine from Sonex, that is supposed to be very good and available as a kit- couldnt tell you if its the right way round though.
There are other VW derivatives like Limbach to look at too.
The people who build the Funk series of aircraft (which for some reason have never caught on over here but very popular elsewhere) had a converted Smart car engine flyin gin one of their FK9s, dont know how succesful that was.
However before we go too far down this route, look at all the people who have wasted a lot of time installing converted car engines in aircraft without success. Surely there have been loads of them and very few succeeded. The VW is the only one ever used in numbers. Corvairs seem to have a limited popularity and seem to be good. But most others have dissapeared. There were loads of Subaru Europas ten years ago, I wonder if many are left, or all converted to Rotax. Bigger Subarus in RVs and Glastars got popular with some people, but I understand there have been lots of problems, maybe not with the engine but with the installation.
If you want to be a test pilot great, but if you want to fly, surely 99% of the time you will save money by using what is available and proven now!
Not very spirit of homebuilding I must admit!
But if you want to research on something, then as Simon says electric is surely the way to go.
A VW for the 21st Century
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Bill McCarthy
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The Smart car conversion that Nigel mentioned (http://www.ecofly.de/english.htm) is a neat looking package, but costs 13500 euros (plus)...
I think that the problem with all these automotive-based motors is that you start out with a cheap(ish) engine with all mod cons, but by the time it's been fettled for aircraft use it costs as much as a Rotax...that said, the French Toyota conversion mentioned in the mag (http://ecoyota.neuf.fr/produit.html) is a more reasonable 8500 euro. (The Toyota engine is supposed to be one of the lightest of its type around, and three-cylinder engines make a great sound!)
I think that the problem with all these automotive-based motors is that you start out with a cheap(ish) engine with all mod cons, but by the time it's been fettled for aircraft use it costs as much as a Rotax...that said, the French Toyota conversion mentioned in the mag (http://ecoyota.neuf.fr/produit.html) is a more reasonable 8500 euro. (The Toyota engine is supposed to be one of the lightest of its type around, and three-cylinder engines make a great sound!)
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cardiffrob
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cardiffrob
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Found another one, although not the one I was thinking of.
http://www.homebuilt-aviation.com/components.htm
http://www.homebuilt-aviation.com/components.htm
Rob Thomas
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Brian Hope
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I think the VW connection has gone completely off the intended track of this thread, and certainly Graham's intention with his letter. There is nothing wrong with the Veedub and it will certainly go on powering homebuilts for many more years, but an alternative to the Rotax 912 it certainly is not, and nor will it ever be. The VW was mentioned because it is an example of the philosophy of a readily available and affordable automotive engine that can be converted with parts available from a number of suppliers, or from parts made by the builder from plans. The competition concept mentioned by Graham, is for a modern engine to be able to be converted by the homebuilder from plans or pre-made conversion components in the same way, the resultant conversion being competitive with the 912 engine on weight, efficiency and power output for significantly less money.
Whether we like it or not, in ten years time (or less) fuel prices are going to be prohibitively expensive and the conventional large capacity aero engines will be an unattractive proposition for most of us. Smaller, lighter airframes with more efficient engines will be the norm, and let's face it that is what is already happening in Europe where fuel prices have traditionally been significantly higher than in the US. For the foreseeable future the 912 will be the engine around which most of these new airframes will be designed, but the cost of a firewall forward 912 package is already prohibitive for many potential LAA builders. We need a home buildable and affordable alternative to keep the dream alive for those of us who cannot afford the commercial package. If the dream dies because members just cannot see that it will ever be affordable, then as an Association we will suffer because disenchanted members will drift away.
The ethos of the LAA is affordable flying, I can see no better way of demonstrating our commitment to that then encouraging an affordable engine for the future.
Whether we like it or not, in ten years time (or less) fuel prices are going to be prohibitively expensive and the conventional large capacity aero engines will be an unattractive proposition for most of us. Smaller, lighter airframes with more efficient engines will be the norm, and let's face it that is what is already happening in Europe where fuel prices have traditionally been significantly higher than in the US. For the foreseeable future the 912 will be the engine around which most of these new airframes will be designed, but the cost of a firewall forward 912 package is already prohibitive for many potential LAA builders. We need a home buildable and affordable alternative to keep the dream alive for those of us who cannot afford the commercial package. If the dream dies because members just cannot see that it will ever be affordable, then as an Association we will suffer because disenchanted members will drift away.
The ethos of the LAA is affordable flying, I can see no better way of demonstrating our commitment to that then encouraging an affordable engine for the future.
Brian et al,
I just got in and have been reading this thread which has quickly grown.
The problem with the VW is always going to be its abiltiy to dissipate the wasted energy of combustion which limits its continuous output. Bob Hoover covers this well in his many articles. That also makes the installation of the engines at least as important as the detail of the engine itself and is something that needs to be borne in mind.
The ability to deliver a sustained power level is a key difference between auto and aircraft engines. Car engines are rarely expected to run for long periods near their potential maximum power whereas aircraft engines are designed to do just that.
I read Graham's original letter as suggesting the investigation of alternatives to the VW based upon vehicle (car, jetski, boat etc) engines. However it is interesting to note that the various contributors have already pointed out information relevant to the VW that was unknown to me and others here.
However, the reason that I got interested was that a competition of this nature (irrespective of any prize that may be offered) creates an opportunity for some of our more innovative members to work within a framework defined by our Engineering team to develop an acceptable and economical solution with a potentially comparable constant power output to the Rotax.
Given that effective and technically acceptable alternatives might be developed the issues of manufacturing parts becomes secondary and frankly, given the availability of access to some very capable CNC machines that just a little research yields, is relatively easily solved.
regards
I just got in and have been reading this thread which has quickly grown.
The problem with the VW is always going to be its abiltiy to dissipate the wasted energy of combustion which limits its continuous output. Bob Hoover covers this well in his many articles. That also makes the installation of the engines at least as important as the detail of the engine itself and is something that needs to be borne in mind.
The ability to deliver a sustained power level is a key difference between auto and aircraft engines. Car engines are rarely expected to run for long periods near their potential maximum power whereas aircraft engines are designed to do just that.
I read Graham's original letter as suggesting the investigation of alternatives to the VW based upon vehicle (car, jetski, boat etc) engines. However it is interesting to note that the various contributors have already pointed out information relevant to the VW that was unknown to me and others here.
However, the reason that I got interested was that a competition of this nature (irrespective of any prize that may be offered) creates an opportunity for some of our more innovative members to work within a framework defined by our Engineering team to develop an acceptable and economical solution with a potentially comparable constant power output to the Rotax.
Given that effective and technically acceptable alternatives might be developed the issues of manufacturing parts becomes secondary and frankly, given the availability of access to some very capable CNC machines that just a little research yields, is relatively easily solved.
regards
Last edited by ColinC on Mon Oct 05, 2009 10:38 pm, edited 3 times in total.
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Colin Cheese
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Graham Clark
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912 Replacement
Brian's interpretation of my letter published in the October edition of Light Aviation is spot-on. I believe that a competition would attract interest and original ideas not only from members of our Association, but also from university engineering students and maybe even professional designers.
Our sport/hobby is a niche market activity. Peugeot/Citroen make 5,000 diesel engines a DAY! Lord knows how many petrol engines!
The ONLY way we in sport flying will be able to get efficient, modern engines at an affordable price is via the use of the mass production systems now in use in the automotive industry. The investment required to produce a modern piston engine is colossal. We can never match that.
We can either bite the financial bullet of paying high prices for niche market products (Rotax, Lycoming, Continental), OR take advantage of the investment made by the automotive manufacturers. That is the only realistic route to getting the costs of engines down in our niche market.
Not Invented Here? Then it is up to us to invent it. The history of aviation has an honourable track record of advances triggered by competition: Bleriot, Lindbergh, Rutan to name but three.
They and many others did not know that it 'can't be done.' That's why we need a competition with a juicy reward.
Graham Clark
Our sport/hobby is a niche market activity. Peugeot/Citroen make 5,000 diesel engines a DAY! Lord knows how many petrol engines!
The ONLY way we in sport flying will be able to get efficient, modern engines at an affordable price is via the use of the mass production systems now in use in the automotive industry. The investment required to produce a modern piston engine is colossal. We can never match that.
We can either bite the financial bullet of paying high prices for niche market products (Rotax, Lycoming, Continental), OR take advantage of the investment made by the automotive manufacturers. That is the only realistic route to getting the costs of engines down in our niche market.
Not Invented Here? Then it is up to us to invent it. The history of aviation has an honourable track record of advances triggered by competition: Bleriot, Lindbergh, Rutan to name but three.
They and many others did not know that it 'can't be done.' That's why we need a competition with a juicy reward.
Graham Clark
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Bill Scott
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I think there are two markets to serve:
1. As discussed, an affordable alternative to the Rotax 912
2. A light 4stroke replacement for the 50/65hp Rotax 2strokes.
I have a Rans S6 powered by a Rotax 503 50hp 2stroke. It is a great engine but will not last forever. My airframe is excellent and just recently re-skinned. At some point I'm likely to have to rebuild or replace the engine and that would seem a good time to go for a 4stroke.
The present choice is between three engines Rotax 912 / Jabiru 2200 / HKS 700.
None are particularly cheap if bought new.
I'm picturing a japanese aircooled motorcycle engine as being a candidate, perhaps the Suzuki mentioned in the latest mag?
In a past life I enjoyed playing in the mud with LandRovers. There were many after market conversion kits to fit decent diesel angines. If they can do it...... The trick is to identify an angine that has been produced in large numbers and is available at sensible price. Some costs could be recovered by selling the rmaining vehicle components.
There is an environmental justification also, as 2strokes are going to be demonised at some point.
1. As discussed, an affordable alternative to the Rotax 912
2. A light 4stroke replacement for the 50/65hp Rotax 2strokes.
I have a Rans S6 powered by a Rotax 503 50hp 2stroke. It is a great engine but will not last forever. My airframe is excellent and just recently re-skinned. At some point I'm likely to have to rebuild or replace the engine and that would seem a good time to go for a 4stroke.
The present choice is between three engines Rotax 912 / Jabiru 2200 / HKS 700.
None are particularly cheap if bought new.
I'm picturing a japanese aircooled motorcycle engine as being a candidate, perhaps the Suzuki mentioned in the latest mag?
In a past life I enjoyed playing in the mud with LandRovers. There were many after market conversion kits to fit decent diesel angines. If they can do it...... The trick is to identify an angine that has been produced in large numbers and is available at sensible price. Some costs could be recovered by selling the rmaining vehicle components.
There is an environmental justification also, as 2strokes are going to be demonised at some point.
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Bill McCarthy
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Anybody know if hydraulic motor drive has been tried. A small engine with direct drive to a hydraulic pump, then the output from that used to drive a prop through a hydraulic motor. There are some fancy hydraulic motors with swash plates that can be used to reverse the prop for "air braking" on landing. Some of these motors are only the size of a bean can and can chuck out a hefty bit of torque. Just thinking out loud - must go and investigate further !
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Nick Allen
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Bill, I've spent far too much time over the last year researching the hydraulic idea -- I reckoned that any loss in the drive would be compensated for by the improved streamlining: as you say, some of these motors are very small, and the freedom to separate completely the main power source from the prop drive unit offers some interesting possibilities.
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cardiffrob
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Sorry if I created a bit of thread drift by not getting the whole point of the 'competition'(I haven't had my magazine yet)
Maybe it would be a good idea to follow something like the Webster Whirlwind concept by merely adapting a suitable brand new crankcase/crank and utilising know pots/heads like Ron has done. A 5-cyl Whirlwind with Japanesey pots/heads with all the fancy alternator and electronics bolted on.
IIRC, Ron was talking about a crankcase/crank kit being in the order of £1000.
Ron. Where are you?
Maybe it would be a good idea to follow something like the Webster Whirlwind concept by merely adapting a suitable brand new crankcase/crank and utilising know pots/heads like Ron has done. A 5-cyl Whirlwind with Japanesey pots/heads with all the fancy alternator and electronics bolted on.
IIRC, Ron was talking about a crankcase/crank kit being in the order of £1000.
Ron. Where are you?
Rob Thomas
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