fuel vapour injection system

[some_other_dave]

I applaud you wanting to experiment. Please make sure that you carefully account for things that could affect your fuel economy in your experiment. If nothing else, make sure you do a lot of repeat testing with and without your modification. (See the post on "A/B/A Testing" on one of the other forums around here for some examples of how to do that.)

If you are merely looking at this technology to see if it does or does not work with your own eyes, then bravo to you. If you are looking to actually save gas, I would encourage you to look elsewhere for results. (How you drive generally has many times more effect on your fuel economy than anything you can do to your vehicle mechanically.)

The theory that the vapor systems work on is flawed. More than 99% of the fuel that goes into the engine is actually burned; it does not go through the engine unchanged. Even if changing the fuel into vapor helps it burn more completely, you're talking about less than 1% possible improvement.

Regardless of if it works or not, if you do implement it, please let us know the results. I'm pretty sure the results will be "no improvement" or "worse in some way", but you may find something that everyone else has missed. (Except people trying to make a buck selling such systems, of course.)

-soD

[iveyjh]

Originally Posted by holzhoechi

thanks some_other_dave for your post. I am indeed not from Bukarest/Bucharest/Bucuresti.
I am from Switzerland but working and living in Romania.
And my native language is also not english. So much to the "nuances"!!

I like to install/test a fuel vapour system on a car with my funds and resources available.

I have seen another very interesting example:
https://www.google.com/patents/US486...hVmgXIKHRZ0CN4

As I see it. It works by transforming heat from the engine coolant system and/or exhaust gases to the fuel mixture/vapourized fuel.

That's a good one, don't let these guy's discourage you

[oil pan 4]

Some of us already have that.
Its called fuel injection with lean burn and warm air intake.

[elhigh]

I think it's great you want to make a car do better than its original manufacturer specified.

That said, I want to caution you against a few things.

I noticed back near the beginning of the thread "wickydude" posted a link to someone claiming 400+mpg. That sticks in my head, and let me explain why:

I don't believe it is mathematically possible.

I don't have the numbers right here in front of me, and frankly these kind of discussions don't ever encourage me to go find them because it always devolves into a pie fight. But I will lay these facts out:

The maximum heat efficiency of a good automotive engine is about 37%. Diesels are a bit better. If you put 100 BTU worth of heat energy into an engine in the form of fuel, the very best you can get out of it will be 37 BTU worth of work. That's it. No exceptions.

Even if you approach the theoretical maximum for a heat engine, about 58%, (still trying to remember where I saw that for reference) it's still not going to get you close to 400mpg, and I don't think 400mpg is even possible. That would require an energy consumption of less than 90 watt-hours per mile, less energy than is actually consumed in moving the air out of the way of the car.

I have seen only a couple of vehicles even approach that at anything like road-legal speeds, and they were ultra-tiny, ultra-streamlined electric vehicles which enjoyed ridiculously good motive efficiencies compared to a gas engined car. 90 watt-hours per mile, but only in a vehicle that would make a coffin feel roomy and luxurious. Those things could manage the feat because they weren't moving much air aside and weren't moving it very far. The displaced masses and the magnitude of displacement were minute compared to even a compact car.

Do you see my point? It is a violation of physics. You are asking it to put out more work than it has energy to perform.

[holzhoechi]

Hi elhigh
Thanks very much for infos. From the physical standpoint I agree with you.

I just want to say it is possible to run an engine on fuel vapours only. According United States Patent 4862859 stated earlier in this thread and in many other.
In this patent they have increased the mpg to about 48 on a 125 cubic inches engine (2 Liter engine). And that was even in the 90s.

I think that is amazing!!

Why we don't have such a car available now?
I better do not ask that question, that would probably go to far.

If no company is willing to build such a car, I want to build one.
Unfortunately its not that easy.
You can see a lot of youtube videos about fuel vapour.
Most of them are wishful thinking they would have more fuel economy.

None of the infos I have, I could say "YES, that I like to have installed on my car".

Most of us know that the technology is ready to jump in when no oil is available anymore.

I am just fed up paying so much for the gasoline/diesel, when I see a car can run with a lot less.
Sorry but that has to be said.

[UFO]

Originally Posted by holzhoechi

Hi elhigh
Thanks very much for infos. From the physical standpoint I agree with you.

I just want to say it is possible to run an engine on fuel vapours only. According United States Patent 4862859 stated earlier in this thread and in many other.
In this patent they have increased the mpg to about 48 on a 125 cubic inches engine (2 Liter engine). And that was even in the 90s.

I think that is amazing!!

Why we don't have such a car available now?
I better do not ask that question, that would probably go to far.

If no company is willing to build such a car, I want to build one.
Unfortunately its not that easy.
You can see a lot of youtube videos about fuel vapour.
Most of them are wishful thinking they would have more fuel economy.

None of the infos I have, I could say "YES, that I like to have installed on my car".

Most of us know that the technology is ready to jump in when no oil is available anymore.

I am just fed up paying so much for the gasoline/diesel, when I see a car can run with a lot less.
Sorry but that has to be said.

Gasoline engines already run on "fuel vapour", the liquid must evaporate before it oxidizes. You seem to have no idea how combustion works, so how do you know these ridiculous mpg claims are true?

[RustyLugNut]

Originally Posted by UFO

Gasoline engines already run on "fuel vapour", the liquid must evaporate before it oxidizes. You seem to have no idea how combustion works, so how do you know these ridiculous mpg claims are true?

The ridiculous claims aside, there is merit to hot vapor engines though the gains to be found are only in the percentage range and not in orders of magnitude.

Be careful when you put down some person's knowledge base, especially when it is in an area outside your expertise.

[UFO]

Originally Posted by RustyLugNut

The ridiculous claims aside, there is merit to hot vapor engines though the gains to be found are only in the percentage range and not in orders of magnitude.

Be careful when you put down some person's knowledge base, especially when it is in an area outside your expertise.

I only said what I said because there seems to be tacit credence give to these claims. And that's also why I said "seems" because there is no technical discussion presented to demonstrate the apparent lack of understanding.

[RustyLugNut]

Originally Posted by UFO

I only said what I said because there seems to be tacit credence give to these claims. And that's also why I said "seems" because there is no technical discussion presented to demonstrate the apparent lack of understanding.

The OP asked an honest question. He was not trolling or selling. You and others have jumped on the "I know more than you, so there". A few have been courteous and provided good discussion that the OP seems to have digested.

holzhoechi, the useful posts pretty much sketch it out - you cannot double or quadruple your mileage via simple vaporization of the gasoline. However, "hot air engines", if properly implemented, can help close the thermal efficiency gap between diesels and gasoline spark ignition engines. Problematically, the subject is highly specialized and involved. Consequently, the application is just as involved. Proof of that is seen in the work of pfgpro and iveyjh and others on this forum. Their "high enthalpy engines" do work but with considerably more effort and skill than simply putting a bubbler bottle in the intake of your engine.

I repeat what others have said about seeking economy for economical reasons - look to driving techniques and aero improvements before fooling with engine operations. But, if you want to go down the rabbit hole, you are welcome to experiment with us in the world of engine mods.

[pgfpro]

Originally Posted by RustyLugNut

The OP asked an honest question. He was not trolling or selling. You and others have jumped on the "I know more than you, so there". A few have been courteous and provided good discussion that the OP seems to have digested.

holzhoechi, the useful posts pretty much sketch it out - you cannot double or quadruple your mileage via simple vaporization of the gasoline. However, "hot air engines", if properly implemented, can help close the thermal efficiency gap between diesels and gasoline spark ignition engines. Problematically, the subject is highly specialized and involved. Consequently, the application is just as involved. Proof of that is seen in the work of pfgpro and iveyjh and others on this forum. Their "high enthalpy engines" do work but with considerably more effort and skill than simply putting a bubbler bottle in the intake of your engine.

I repeat what others have said about seeking economy for economical reasons - look to driving techniques and aero improvements before fooling with engine operations. But, if you want to go down the rabbit hole, you are welcome to experiment with us in the world of engine mods.

On my setup I was running a waste solvent system that was heated with coolant and exhaust heat. Then it mixed with compressed turbo air that was above 200*F. At that point the waste solvent was in vapor form and directed about 3" from intake valves. I seen around a 5% increase in fuel mileage. I never tested it with pump fuel but did a evaporation test, pump fuel verses waste solvent and the results were the waste solvent evaporation rate was twice as fast as the pump fuel. I think todays pump fuel has a much stricter VOC requirement and evaporates at a much slower rate then yesterday fuels.

With this said I will say please be careful when building a fuel vapor injection system. While testing this Summer I had a over lean condition from my lean burn system while tuning. The fuel vapor system was enable and I had a intake back fire that caused a explosion and took out my secondary fuel line. After this happen I removed the fuel vapor system and made a promise to myself never to go there again. The likelihood of a intake back fire is very high when running a fuel vapor system. This can kill you and anyone near the vehicle. So be very Careful!!!!!