how i did it (Fuel heater)

[Project84]

copper will carry the heat much better

[slurp812]

Originally Posted by Roadking41a

Does copper have to be used? How about steel fuel line?

Of course steel would work! Copper is just really good with heat exchange, and he did solder it to help with that. Cant really solder steel. you could wrap the whole thing with insulation to help. We will see how high gas prices go. If they go up enough, I may be adventurous to try something like this.

[ShadowWorks]

Copper is not that expensive in the UK? you can use the plumbers kind, it bends and flares, it is a softer type, they have other kindwith 10% nickel and is much tougher.

I like this idea. it has merit, it may not double the mileage but if it gives a 2% increase that would be an extra 2 miles for ever hundred, push a car 2 miles and tell me how easy it is

Remember it's the cumulative affect of all these small mods that add up, each mod on its own is weak but combined with others the effects will reach your wallet.

[ShadowWorks]

Originally Posted by quadancer@bellsouth.net

I think I'll skip the fuel heater idea - Not worth the risk from what I've seen here.

I think its worth a try, you are resourceful enough to make your own benching rack with 4x4 and metal pegs you could do this fuel heater with ease

Tell you what I will make my own squat rack and you make the fuel heater

[collegekid01]

If I were to do it again, which I'm not, I would have make it out of soft copper tubing and wrapped it around the radiator like the one in that patent. It would only cost like... 25 bucks then. Mine was really expensive because it was made from brass fittings, but I went with that idea because I'd seen more heaters like that and I didn't know how to do all that flaring and what not to make the soft copper connect to the fuel line properly. I think someone else should give this a try especialy if they have some of the parts lying around the house or garage.

[R.I.D.E.]

Originally Posted by severach

I tried fuel heat and took it off. While it might have worked as a standalone mod my other mods were already way ahead. Highway mileage went down and city mileage went up. Knock was crazy. The average was the same. After I watched fuel heat fail to improve mileage I came up with reasons why fuel heating is generally ineffective and undesirable.

1. There is 15x the mass of air as there is fuel which means that heating the air will be approximately 15x more effective than heating the fuel. The fuel system has been tested with 140*F air temps and less which is attainable with a WAI/HAI. The higher the temperature of the air fuel the more likely it will knock. Got gauge?

2. The only free and easily obtainable fuel temperature is 200*F from the water. The fuel system has not been tested with 200*F fuel. Proper handling of fuel at such temperatures might require a temperature sensor for the fuel, ECM reprogramming, better injectors, and intake redesign. A properly designed system would vary the fuel temperature according to the engine demands. A heater we make is lucky to do anything good under any condition.

3. Heat accelerates deformation of o-rings. Viton o-rings are used on the manifold end of the injector because they resist heat deformation so well but other o-ring materials do not. At 200*F o-rings not normally in heated areas will deform and leak. At 200*F the chemicals in the gasoline will get more aggressive. Fuel is heated by the intake valve which is cooled by the fuel. All your gains will be lost by leaking and parts replacement. I hope you didn't think that heating the fuel was fire and forget.

Many mods only work because they upset the balance of the system and the system isn't balanced. If the system is badly balanced by the factory then there could be some value in putting in something that is questionable. If something is broken, fix it. That's why it might work for your "f this forum" Stealth but noone else.

Excellent post;

What is especially significant is the part about the relative mass of the air versus the fuel, a testament to Warm Air Induction, since the heat content of the air represents about 93% of the total heat content of the air and fuel inducted into the engine.

Most, if not all, EFI systems are supply and return types, with a lot of fuel moving through the system. Think gallons per minute.

The fuel passing through the proposed heater design would only have fractions of a second of time to absorb the heat from the cooling system. The same fuel also absorbs heat from the engine compartment anyway.

I have measured tank temperatures with a lazer digital thermometer while doing some testing and watched tank temps go from 80 to 95 degrees in a very short period of time.

That being said, I can guarantee you the idea is valid. A patent itself does not guarantee validity, it only states the idea is novel and original, even though it probably is not.

You can bet the farm at freezing temperatures your engine will run more efficiently if the fuel and air are above 100 degrees when they are mixed prior to combustion, especially compared to the same fuel and air at freezing temperatures. In fact in the old carburator days, the difference was driveability versus stalling hesitation and serious unburned hydrocarbons out the tailpipe.

If you have an old carbed engine with the manifold heat (thermostatically controlled with a bimetallic spring), just disable the WAI an see what happens.
Its easy to check this system, just place your hand on the air filter housing. If the WAI is working the housing will be almost too hot to keep your hand on it for long,

While fuel injection made the necessity of preheating the air no longer essential, the fact remains that atomization of the fuel will always be better when both fuel and air are at higher temperatures.

How high?

Hard question to answer precisely because there is no real way to make a blank statement that applies to every car regardless of the differences. Extreemely high fuel temperatures are definitely dangerous. Think high pressure vapors in an almost empty tank, plastic tanks that are not designed for high temperatures. Removing the fuel cap and having a blast of hot fuel vapor in your face. Overwhelming the vapor recovery system, due to hot fuel.

I don't see that as an issue with heat transfer from the cooling system. I aslo don't see the heat transfer making a big difference in the fuel temperature.

I do see a system that preheats the fuel and air as a real benefit in extreemely cold conditions.

Any FI system, and for that fact any car designed to be used in the US will have the ability to operate properly in expected temperature extreemes of -40 to 140 degrees farenheit. Properly designed systems will have some reserve capacity, so lets assume the vehicle would still operate at temperatures of -60 to 150 farenheit.

Beyond that you are playing with fire, and no one can predict the consequences or every potential scenario as far as what could happen, or the effect on longevity of your car.

regards
gary

[severach]

Originally Posted by R.I.D.E.

since the heat content of the air represents about 93% of the total heat content of the air and fuel inducted into the engine

Not only that but when the charge is compressed into a very small space it no longer matters whether the heat came from the air or the fuel.

The fuel passing through the proposed heater design would only have fractions of a second of time to absorb the heat from the cooling system. The same fuel also absorbs heat from the engine compartment anyway.

The degree to which it is heated depends on how effective the heat exchanger is. I used a 10 plate which had no problem producing 200*F fuel "at any delivery or pressure". While fuel may transfer heat slowly it also doesn't take much heat to get it warm.

There's too much flow for the fuel to absorb much heat without a heater. I've felt the bottom of the injector in the winter and it is stone cold. The first serious heat the fuel sees is the hot valve which I think provides as much heat as any heater I could install.

You can bet the farm at freezing temperatures your engine will run more efficiently if the fuel and air are above 100 degrees when they are mixed prior to combustion

No need to bet. I verify it continually. As winter turned to spring I watched my mileage increase with IAT. As the spring temps varied from hot to cold I constructed my WAI to see if I could artificially combat the mileage reduction. I found the mileage was determined entirely by the artificially raised IAT and not the actual outside air temp which determines fuel temp and air resistance.

Even more interesting, the mileage improves by 10's of degrees Fahrenheit. 60-69 produces almost exactly the same mileage but 69-71 produces a noticeable bump. That means the fuel maps are programmed in 10 degree increments for computer memory convenience and the warmer fuel maps are more efficient than the colder ones. That tells me that the computer knows that cold fuel vaporizes less and wastes more fuel to keep the engine running well.

So far as I can tell the reasons commonly provided for mileage reduction in the winter are all invalid. The least lame reason they give is that cold air is more dense leading to more air resistance. Definitely wrong since my mileage always increases when I drop altitude from a cool 950 feet to a warm sea level and the power increase from the increased air density from altitude reduction is much more than the increased air density in the winter. Heat and vaporization seems to explain it all. I'll soon have a Scangauge down by the sea to verify it more accurately.

The strangest thing is that some vehicles already implement some form of WAI and they don't see a winter summer mileage difference. I know about the few non American cars that do it but there seems an entire class of American vehicles that have WAI, or at least I have two for two in my yard: trucks.

A 10 plate heat exchanger is $40 from eBay. The necessary fittings are at Menards or Parker and cost about $20 more. $25 for soft copper doesn't seem very cost effective to me.

[mini-e]

I posted this a while ago- these guys have spent a bunch of money and heat the fuel and the air going into late model engines. They have spent 6 figures, have a dyno in their lab, are engineers, and are seeing 30% increase in millage with a ford f150 v-8. In the diagram of the system not attached to the online version of the story, the fuel passed through a tightly temperature regulated heat exchanger.

http://www.oregonlive.com/business/o...740.xml&coll=7

[theholycow]

Originally Posted by mini-e

They have spent 6 figures, have a dyno in their lab, are engineers, and are seeing 30% increase in millage

Anyone who only gets 30% increase after spending 6 figures doesn't earn much of my confidence.

[dosco]

Originally Posted by severach

I found the mileage was determined entirely by the artificially raised IAT and not the actual outside air temp which determines fuel temp and air resistance.

So far as I can tell the reasons commonly provided for mileage reduction in the winter are all invalid. The least lame reason they give is that cold air is more dense leading to more air resistance. Definitely wrong since my mileage always increases when I drop altitude from a cool 950 feet to a warm sea level and the power increase from the increased air density from altitude reduction is much more than the increased air density in the winter. Heat and vaporization seems to explain it all. I'll soon have a Scangauge down by the sea to verify it more accurately.

Interesting observation. When you climb in altitude the density and temperature are both reduced at the same time. At a constant altitude, density would increase as temperature decreases.

How does your engine measure mass flow?

A broader question is this: how are fuel maps created? Wouldn't the setup of the map depend on the sensing system?

Lastly, how does the lambda sensor play into all of this?