I think you've managed to find the least credible sources for anything on the internet. Pre-vaporizing fuel and the classic "Brown's Gas" "HHO" myth? Just because something has a patent, does not mean it actually works.

From your first "article", this should have told you they don't know what they're talking about:

I guess we should all ditch our intercoolers and "cold air" intake systems in favor of superheated air.

What is Brown's Gas/HHO? energy from water? I dont really think thats what they are talking about.

well i guess the idea made sense to me.. maybe im understanding it wrong :scratch: im just trying to teach myself and shit, i know the internet is half nonsense anyways. Im sure those 100-200mpg stories are crap. I agree though, a couple sentences were contradictory to what they were trying to say. But I didnt take everything that they were saying in theee.. uhh, "article"? :jerkit: as fact. I mean im pretty sure they didnt use spellcheck either lol. But I kinda liked what they were saying and thought i understood it. im sure you guys can help show me what the problem is with it.

ok so my understanding of what they were saying is that the unburned gas that ends up in the exhaust, would have been utilized if it were completely vaporized and mixed with the air. And since the fuel wasn't atomized enough to burn, you get a loss of hp/mpg and poor emissions. correct so far, yes? no?
Fuel vaporizes faster when heated. So if your able to apply heat to the fuel, before it gets mixed with the intake charge, it becomes more finely atomized and ends up with a greater percentage being burned. I guess the reason they need a chamber to vape the fuel is because it needs to be at a lower pressure? or just needs the space to begin vaporizing maybe? Is there any reason why the fuel would NOT vaporize in those conditions? The problem i see with it is that I would imagine the vaporization process wouldnt be fast enough to keep up with the fuel requirements of the engine. Is there a way to partially vaporize fuel without a chamber? I guess thats where I dont see how it would work.


woah good idea! Im gonna start drawing up plans to replace my IC with a space heater, ill start a thread in the 3rd gen section. dont worry, ill give you credit.

:nod::icon_tup:

I dont think they were saying anything about air temps. The benefits of a dense intake charge dont seem to apply to fuel i guess. Air is already a gas, so if you can get it colder and more dense, you can get a larger amount of air into the combustion chamber. It sounds like they want to do the opposite to the fuel. The amount isnt an issue as long as the fuel setup is adequate. Its already a liquid, so that means its too dense. it needs to be heated so it can vaporize and mix with the air.

I guess i thought just because cold air is beneficial to a motor, that cold fuel does the same. but when you think about it, they aren't even in the same phase to start with. they each need their own conditions to properly mix, and have the most efficient/complete combustion.

So anyways thats what I thought they were saying. i guess it makes sense to me. but if someone could let me know if thats even what they were talking about or why it wouldnt work, that would be cool. Im not advertising any of this as fact. lol. I would just like to hear some opinions on it :) thanks

I bought the whitepaper myself - it is impressive.

The only thing I remember from the one engineering lecture I went to in college was that hot fuel means better efficiency, because it vaporizes better that way. So apparently they even coat the valves with a material that causes the gas to vaporize when it flows past them. IIRC.

Heating fuel for a race car makes sense because it cools the intake charge, since fuel economy is not an issue.

Honda and McLaren in late 1980s were 'managing' their fuel and intake air temperatures to make the best of the situation at hand.

Going to run out of fuel at this Grand Prix? Preheat fuel, bypass intercooler to maintain air temps around 80degC, tune leaner and whola, we have more power available from our given volume of fuel and win 15/16 races in the season.

Reducing the power by 10%, whilst reducing the fuel usage by 15% sometimes allows you to win 15 out of 16 race meetings(when the rules are stupid and its a fuel economy run not a race).

It is true that fuel doesn't vaporize as well when the engine is not yet up to operating temperature but I'm sure you know that. That's why you have a choke on a carb or you inject additional fuel on conventional EFI systems.

You have to think about it this way: if the fuel and combustion chamber are too cold, you get droplets sticking to the manifolds and you have higher HC emissions. This creates a problem during the cold start phase of the EPA FTP (Federal Test Procedure) 75 emissions certification test. That's why warming the engine up quickly is important.

If the fuel is too hot, you have excess evaporative emissions, which then causes a problem during the hot start portion of the EPA FTP 75 emissions certification test. That's why you have returnless fuel systems, side feed injectors, fuel pump control modules, charcoal canisters, and other systems to reduce fuel vapors. On old engines you can actually get vapor look due to too much vaporization. It's all about keeping everything within an optimal range.

https://www.rx7club.com/attachment.p...1&d=1312294184

Here is an emissions chart from a prototype Ford Ecoboost engine performing the FTP 75:

https://www.rx7club.com/attachment.p...1&d=1312294417

You can see that most of the emissions occur when the engine (and fuel) are cold or when it is heatsoaked.

Oh yeah i remember hearing about vapor lock now, wiki says older engines had this problem because the fuel pump was usually located higher than the fuel tank, and wouldnt be able to supply the carb with enough liquid fuel to keep the float bowl from draining. But in-tank pumps dont have the problem.


I tried to find out why it would be a problem and found a simple explanation of how the emissions system usually deals with fuel vapors.

"Fuel vapor is normally created in the fuel tank as a result of evaporation.It is then transferred to the EVAP system charcoal canister when tank vapor pressures become excessive.When operating conditions can tolerate additional enrichment,these stored fuel vapors are purged into the intake manifold and added to the incoming air/fuel mixture. "

Why would a car fail if the extra vapor was getting past the emissions system and being burned? Does the vapor make the car run too rich?

I'm not exactly sure how it creates more actual tailpipe emissions. Maybe the vapors just get sucked through the engine and don't always burn completely, causing higher HC emissions. We can only assume that evaporative emissions must be pretty damn important for emissions certification or the OEM's wouldn't spend so much time and money developing emissions controls. Did you know that the Prius has a collapsing/flexible "bladder" gas tank to reduce evaporative emissions?

While that's an interesting race tactic, for the purposes of the average person with their street car, no one is bypassing their intercooler in the name of slightly better fuel economy. 80C IATs? No thanks.

The problem I have with the statement I quoted above is that it claims that cold air will reduce power via a lack of fuel atomization. That's why you let the engine warm up, and why there are intake temperature sensors to allow the ECU to make fuel delivery corrections. Talk of power loss from cold winter air is ignoring the more important variable: cold air is more dense. Pack in more air, add more fuel, get more power.

Yes, there is an effect on cold start emissions. However, I don't think you'll find anyone on this forum that is concerned that the cold start emissions of their engine.

I for one, did not. Now I can add that to the long list of reasons I would never own one:

#109 - colostomy bag for a fuel tank

I cant really find anything that explains it fully either. HC and CO are both a result of incomplete combustion, but i think its those big droplets that accumulate on the chamber walls that produce the hc's and co.

A few years ago my auto teacher showed our class how a fine mist of fuel is more efficient, he had a coffee can with two holes punched on each side. and the lid was just resting over the top. in one hole was a bbq lighter and the other he sprayed gasoline into with a spray bottle. when the nozzle was set to "spray" the lid blew right off. when the nozzle was on "stream" nothing happened. I know im going over a 7th grade auto lesson but what im getting at is how the stream of fuel probably only caught a slight flame, but didnt burn quick enough. so like a regular engine, all that excess fuel has got no way out besides the exhaust and out into the atmosphere. thats where the emissions come from.

so if the fuel vapor does go through the combustion chamber, it will be some of the first fuel that gets burned. because it has the most surface area for the oxygen to come in contact with. the fuel that is more dense takes longer to burn. so what these dudes http://vfis.us/ are saying, is that if all the fuel that entered the chamber were to be vaporized already, it would blow the lid off the coffee can even higher than the squirt bottle did. er.. fuel injector!

You guys know i was kidding about the space heater thing right?! haha I agree with you 88. im not sure what jobro was saying about bypassing the intercooler? but pre heating the fuel though makes sense to me.

the way i see it, cold/dense air is only 1 part of the equation. vaporized fuel would more readily mix with the air and since the mixture is so fine, it would have a much more complete combustion. i never said heating the air is a good idea, but there was that statement in the link i posted that sorta made it sound that way.
If you could look past that poorly worded sentence, and let me know what your thoughts are on heating fuel i would like to hear them!