Fuel Heater project (Kumaran)

[kumaran]

Hi guys,

For couple of days, I was working on simple method to save fuel consumption. Check the photos . On first test, I made 4 turns of copper tube onto exhaust pipe. Then fuel from tank goes to copper tube and gets heat from exhaust then goes to carburetor. Did few rounds of testing on short distance with no problem. On first day of long drive testing from home to work (43KM) I notice some jerking like insufficient fuel to carb. After adjusting tube from tank then everything goes well with 10% increase on speed on full throttle. The motorbike was tested for 2 days before made further adjustments.

Yesterday, I made 19 turns of copper tube onto exhaust. Again tested on short distance with no problem but big torque improvements. Then today while coming to work, the engine jerks and stops. After few kick start, the engine stars back and after few KM again engine jerks and stops. I have no choice but to reconnect with original fittings.

I was wondering why this happens? Am I doing correctly of missing some important item? If anybody already went through this testing before, please advice on how to overcome this problem?

[buddog]

Kumaran I suspect you are vaporizing the fuel before it gets to the carb thus a vapor lock stopping fuel flow. This used to be a common problem on old american cars where the fuel pump sat to close to the exhaust.

[Chris]

Sounds like you just need to find the "happy medium" between better performance and vaporization. If 4 turns gave an increase but 19 was too much, then perhaps try 8 for a week or two and then move up to 12.

Experimentation is all about testing things in a scientific manner, not just saying 4 worked ...let's see if 19 is better. Oh 19 has problems so we'll go back to original design. -What happened to the 4 where things were working just fine?

When you have a problem you want to go back to the last "stable" setup. If the last stable setup appeared to be 4 then you should go back to that, not all the way back to square 1.

[kumaran]

[buddog]

[kumaran]

[Palic]

[kumaran]

[buddog]

[Palic]

[kumaran]

[kumaran]

. I did this simple testing. I use fish tank oxygen pump and valve to control the torch flame.

[thirsty]

Hello,
I find this idea very interesting and I have alot to say. I did some searching for info and I think I have found some useful stuff. I have found some good stats on auto-ignition temperatures, calorific values and boiling points of various fuels.

Here are the links.




This website has lots of resources that could prove useful in other areas.

These should make it much easier to determine safe temperatures to heat the fuel to. Adding acetone and then running into a fuel heater could be dangerous because acetone has a much lower auto-ignition temperature than gasoline. I think it would be a good idea to stay under the boiling points as well; if the fuel was heated above its boiling point the expansion of the gasses in the fuel line would increase pressure drastically.

The flash points are interesting. If I am understanding correctly, the flash point for gasoline is -45 degrees F, which means that gasoline evaporates enough gas at atmospheric pressure to form a combustible mixture in the surrounding space. Does this mean that if you where to take a match or other hot flame to the surface of liquid gasoline it would ignite and continue to burn or does it mean that gasoline can form a combustible vapor over time that will ignite but not self propagate?

I also found a report done by the EPA on gas saving products. They list fuel heaters as showing some gains in efficiency.


Can anyone shed some light on in-line fuel heaters for LPG systems? The way I see it there could be good gains if you stayed under the self-ignition temperatures and wouldn't need to worry about the pressure changes at boiling point. I have heard of "Bottle warmers" being used to heat bottles of nitrous oxide (NOS) to desirable temperatures before drag racing in order to get maximum power from the added gasses.

Can someone explain how the initial temperature of a fuel changes the characteristics of its combustion and increases efficiency in an ICE? Does it lower the required energy input to get the reaction started? - (lower enthalpy in chem??).


kumaran,
In your experiment with the hot pan and gasoline, I believe that if the pan was hot enough the gasoline would have ignited, although the combustion process would not have begun until the gasoline had formed a vapor in the air. Since boiling point of gasoline ranges from 100-400 degrees F and the self-ignition temperature is 280 degrees C. If the pan was say 300 degrees C higher then couldn't it be hot enough for the gasoline to quickly form a very hot vapor and self ignite?

It would be handy to have a measure of the temperature of the fuel after the heater. I have seen digital thermometers that have a metal probe can be fit into a T section in your fuel line. Something like could work. If there is a fuel pump then an adjustable fuel pressure regulator could add more accuracy to your experimentation. If you put it before your heater you could limit the flow of fuel from the pump and use it to adjust the pressure going to the carb. If you don’t have a fuel pump then to overcome the overflow problem you probably need to lower the temperature by reducing the number of turns like the other guys have suggested.

The bubble torch sounds nice. They say it can melt zinc and aluminum. Do you have any photos of your setup? What are you using as a torch tip?


Palic,
Nice job measuring the exhaust. What section of the exhaust did you measure? How did you take your measurements?

[kumaran]

[freddyflatfoot]