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old man emu

Running on the smell of an oily rag

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Came across an interesting topic for conversation while surfing the 'Net - Can you run an petrol engine on fuel vapour and use miserly amounts of fuel to go great distances?

 

The basic concept here is that using the vacuum created in the intake stroke of an engine, air is bubbled through a tank of the usual fuel the engine runs on. The fuel/air vapour then enters the engine through the throat of the original carburetor, with the throttle butterfly controlling the volume of the mixture entering the engine, thereby controlling the revs.

 

This video shows that an engine will run using this set up, but it raises many questions about its practicality.

 

 

The first thing to consider about the experimental conditions here is that the engine was set running at constant revs. That does not happen in any sort of practical powerplant use. Revs range from idle to maximum safe, depending on the requirement at the time.

 

Also, to get the engine started, the air/fuel mixture had to be adjustable.

 

These are two things that got me thinking about the experiment, and I haven't mentioned fuel economy.

 

I invite you to watch the video and apply your knowledge of fuel management to form an opinion whether this process is practical for normally aspirated 4-Stroke engines powering either aircraft or ground vehicles.

 

 

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Interesting, won't happen in an aero application, was looked at a million years ago in the auto field, how many vapour powered engines do you see these days? Theirs your answer! Besides the oil Co's are very powerful & corrupt, they would spend zillions on squashing such an idea, EP is slow to develope, think about that and why? I worked 13 yrs for MOA, trust me the Oil Co's are cunning!

 

 

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Yes it’s running. But at what fuel air mix? In an air cooled engine your fuel is doing more - much more - than just producing the explosive mix ... just how hot it’s all getting would be on wig my first thoughts.

 

If you want really good fuel economy I’d say modern automotive have it pretty much figured out - an O2 sensor and a computer controlling the fuel injection on a water cooled engine is pretty hard to better when set up for the duty cycle of the engine.

 

Our problem is the unaccepting nature of aircraft owners in experimental or ultralight to accept that engines can stop so adding electronics into the aircraft mix comes at fugging huge cost eg 912 injection.

 

 

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The Pogue 200mpg carburettor lives again!! 003_cheezy_grin.gif.a3ff7382d559df9a047d5e265974e5f3.gif

 

Charles Pogue's 1929 Imperial

 

Sorry OME, the burning of vaporised fuel in an engine has never proved to be a workable, commercial concept - for multiple reasons.

 

One, it is barely controllable. Two, the excessively-lean burn with its high combustion temperatures, will destroy the engine. Three, vapourised fuel explodes, it doesn't burn, thus we have detonation which causes engine damage.

 

 

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"If you want really good fuel economy I’d say modern automotive have it pretty much figured out"

 

Way back in the sixties, We were trying to better 30 MPG (10 Lp100 Kmes).

 

My 4 litre V6 Pajero gets the same12 L p Kms as my 2.8 litre 4 pot turbo diesel Delica, Not great economy for a modern engine!.

 

spacesailor

 

 

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Yes it’s running. But at what fuel air mix? In an air cooled engine your fuel is doing more - much more - than just producing the explosive mix ... just how hot it’s all getting would be on wig my first thoughts.If you want really good fuel economy I’d say modern automotive have it pretty much figured out - an O2 sensor and a computer controlling the fuel injection on a water cooled engine is pretty hard to better when set up for the duty cycle of the engine.

 

Our problem is the unaccepting nature of aircraft owners in experimental or ultralight to accept that engines can stop so adding electronics into the aircraft mix comes at fugging huge cost eg 912 injection.

True in many ways. The OTTO designed engines can't be improved outside of being more efficient, the technology has come to an end. EP is pretty useless in its current form, diesels are a dead end (otherwise Mooney would be King)

 

 

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Hey! I know that this idea can't produce a much reduced fuel consumption figure, but you blokes have missed the point of the challenge.

 

Putting aside the idea of "nasty oil companies smothering ideas that would reduce consumption, try coming up with the real reasons why this process is impractical.

 

I challenge you to apply your knowledge of aircraft fuel systems and fuel management to say why you can't reduce fuel consumption this way.

 

 

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Hey! I know that this idea can't produce a much reduced fuel consumption figure, but you blokes have missed the point of the challenge.Putting aside the idea of "nasty oil companies smothering ideas that would reduce consumption, try coming up with the real reasons why this process is impractical.

 

I challenge you to apply your knowledge of aircraft fuel systems and fuel management to say why you can't reduce fuel consumption this way.

Consumption will be reduced because you will crash at the end of the runway as the engine fails ;-P

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Hey! I know that this idea can't produce a much reduced fuel consumption figure, but you blokes have missed the point of the challenge.Putting aside the idea of "nasty oil companies smothering ideas that would reduce consumption, try coming up with the real reasons why this process is impractical.

 

I challenge you to apply your knowledge of aircraft fuel systems and fuel management to say why you can't reduce fuel consumption this way.

We don't need to, the fact that such designs aren't currently operational in today's advanced computer world says it all!.,

 

 

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We don't need to, the fact that such designs aren't currently operational in today's advanced computer world says it all!.,

The purpose of the thread is for people to rack their brains for the reasons it won't work. It's a learning or refreshing exercise.

 

 

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Consumption will be reduced because you will crash at the end of the runway as the engine fails ;-P

Yep. That's probably correct BUT back that conclusion with a considered argument!

 

 

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Yep. That's probably correct BUT back that conclusion with a considered argument!

UMmm. Ok

As you increase the power required in the takeoff the ability to created sufficient evaporated fuel in s setup like this will in almost certainty rapidly lean the mix so even if you get enough adequate mix in the engine to get rev rise and power to accelerate the lean mix will be overheating and melting your valve seats and piston crowns ... and the end of the runways about as far as you’ll get.

 

I might have a slight advantage over a few pilots here as I’ve lived and worked on engines all my life and have held an unlimited L2 for coming up 25 years.

 

 

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Thanks [email protected][/uSER] That is the sort of answer that I was looking for.

 

REASON 1: Fuel/Air mixture becomes chemically incorrect as throttle butterfly opens on the 'request for more engine revs'.

 

REBUTTAL: If you watch the video, the bloke adjusts the fuel/air mixture with a valve BEFORE the mixture reaches the carburetor, and the engine revs are controlled by the throttle butterfly. This seems to replicate the mixture/throttle combination already used in aircraft.

 

Keep thinking.

 

 

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Because fuel contains a certain amount of energy, and you can't get more energy than that what's in it. ICEs are quite inefficient, but changing how you deliver the fuel is not going to make that big a difference. Basically a certain amount of fuel will make a certain amount of power. End of story.

 

 

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"If you want really good fuel economy I’d say modern automotive have it pretty much figured out"Way back in the sixties, We were trying to better 30 MPG (10 Lp100 Kmes).

My 4 litre V6 Pajero gets the same12 L p Kms as my 2.8 litre 4 pot turbo diesel Delica, Not great economy for a modern engine!.

 

spacesailor

Hardly good examples of aerodynamic efficiency. Remember, drag increases at the square of your velocity. To double your speed you need to use four times as much energy. Both of the vehicles you mention have hideous drag coefficients (depending on the model), so I wouldn't go blaming on on the engine for the fact that you a trying to push a brick along at highway speed, and use most of you energy moving air out of the way. Also, both a heavy, and lot of energy is required to just to get them moving.

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The engine uses vapourised fuel whichever way it is fed. Liquid petrol does not burn. Yes I can prove that. The carburettor vapourises the fuel, by breaking it into tiny globules in the air stream, as does fuel injection. Bubbling the air through the fuel will result in vastly different air fuel ratios. These ratios would be decided by the ambient air temp and pressure. Just imagine trying to get a good fuel air mix with ambient air temp being a few degrees below freezing, then get the same mix at 35 deg C. Won't happen.

 

Our aircraft engines rely on getting the correct air fuel ratio to make them work properly, but consider the case of a diesel, or more correctly compression ignition engine. They generally run on full throttle, which is really no throttle and power is controlled by the amount of fuel injected.

 

 

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CAN

 

"Because fuel contains a certain amount of energy, and you can't get more energy than that what's in it"

 

Lace it with oxygen, & it gets a much bigger bang, how-ever it'll take the head clean off very quickly.

 

RON 180 perhaps?

 

I heard a English "Commer" two-stroke diesel was run on OLD 130ron avgas in the fifties, did what they wanted.

 

Big SHAME on Chrysler motors for dumping what is a world beater engine, "the highest power density and best high speed diesel engines in the world during that era in the form of the Rootes TS3 and TS4"

 

And these motor's are still running in original form, in Argentina's fishing fleet.

 

spacesailor

 

 

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Because fuel contains a certain amount of energy, and you can't get more energy than that what's in it. ICEs are quite inefficient, but changing how you deliver the fuel is not going to make that big a difference. Basically a certain amount of fuel will make a certain amount of power. End of story.

Give the man a seegar!.

 

 

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O M E

 

What no cigar for me!.

 

We all know Turbo-charging improves the power output of Any normal aspirated engine, & increasing the volatility of fuel will do the same, or why bother with the RON system of fuels.

 

And the Roots motor used the same amount of fuel to move two pistons at the same time.

 

spacesailor

 

 

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Spacesailor, I don't know how the Argies keep their TS3's running - unless they are making parts for them - because there are no new parts to be had anywhere in the world for TS3's. This stops a lot of planned TS3 restorations.

 

As someone who drove a TS3-powered Commer truck from Geelong to Norseman in 1995 - I can assure you - despite already being deaf - I lost at least another 30% of my hearing, just driving that screaming, gutless pile of crap!!

 

They might have been alright in the days when no-one cared about noise, no-one cared about smoke emissions, no-one cared about fuel consumption - and no-one cared about the poor buggers who had to fix them!!

 

The opposed-piston design still does have some followers, and the Achate engine company claims they have one auto-manufacturer on board who is going to put an Achates-design, opposed piston engine, into production this year!

 

At Least One Automaker Plans to Produce an Opposed-Piston Engine - Motor Trend

 

 

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Known universally in Australia as Commer Knockers for very obvious reasons

 

 

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I wonder how this would compare to fuel injection, I'm guessing a lot more effecient

With the advent of common rail fuel injection we can do magic things like electronically programming 8 separate injections during the firing phase for reasons of power/economy/emission.

It would be hard to match that now.

 

 

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O M E What no cigar for me!.spacesailor

You can have a cigarello. I did specify a normally aspirated engine, so turbo and superchargers are excluded from the discussion.

 

Besides, with the demise of high performance piston engines in aircraft due to the uptake of turbine engines, the need for fuels with Octane Numbers above 100 exists in only a very few, sports vehicle engines, so the production of that sort of fuel is bespoke.

 

 

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Came across an interesting topic for conversation while surfing the 'Net - Can you run an petrol engine on fuel vapour and use miserly amounts of fuel to go great distances?The basic concept here is that using the vacuum created in the intake stroke of an engine, air is bubbled through a tank of the usual fuel the engine runs on. The fuel/air vapour then enters the engine through the throat of the original carburetor, with the throttle butterfly controlling the volume of the mixture entering the engine, thereby controlling the revs.

 

This video shows that an engine will run using this set up, but it raises many questions about its practicality.

 

OME, some of the responders to your post consider the idea a little old fashioned, but we must all please have a little respect :

 

1903 Wright Engine .... yes they used it.

 

 

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