Cold Gas
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From: Calgary
Originally Posted by slalom44,Oct 4 2007, 04:14 PM
The benefit of cooling the gas is insignificant to the benefit to cooling the air intake. Here's why:
Gasoline is a liquid. The specific heat of gasoline is relatively low - about half of the specific heat of water. That means that cooling a gallon of gas requires half as much energy removal as a gallon of water.
But gasoline combusts as a gas, not a liquid. To get the vaporized gas one degree colder, you would have to reduce the temperature of liquid gasoline by over 200 degrees!
On top of that, Air is only 21% oxygen. Almost one fifth of the air is Nitrogen, which doesn't burn. That means that you would have to cool the gasoline vapor five times as much to get the same effect as cooling the air.
Gasoline is a liquid. The specific heat of gasoline is relatively low - about half of the specific heat of water. That means that cooling a gallon of gas requires half as much energy removal as a gallon of water.
But gasoline combusts as a gas, not a liquid. To get the vaporized gas one degree colder, you would have to reduce the temperature of liquid gasoline by over 200 degrees!
On top of that, Air is only 21% oxygen. Almost one fifth of the air is Nitrogen, which doesn't burn. That means that you would have to cool the gasoline vapor five times as much to get the same effect as cooling the air.
Now I'll start work on my Nitrogen air filter so I don't have any of that pesky non-combustible air entering my engine.
Sooooo you're saying a little ice pack on a fuel rail, or cooling element in the tank wouldn't drop the temp 200 degrees? I'm sure you're right. The problem as well is, even if you could super-cool the gasoline, there is too much water in the crappy gas available, and you'd pontentially have freezing in the lines. On the other hand, if you used freezing to seperate the water from the gas I would think you're creating a better fuel! We should all go home and throw some gerry cans in the freezer.
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From: Bay Area, CA
Originally Posted by slalom44,Oct 4 2007, 03:14 PM
On top of that, Air is only 21% oxygen. Almost one fifth of the air is Nitrogen, which doesn't burn. That means that you would have to cool the gasoline vapor five times as much to get the same effect as cooling the air.
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From: CT
A couple of things popped into my head...
The density of air changes somewhat dramatically with temperature, since it is a gas. Gasoline density is nearly constant in comparison.
Another benefit of colder air over gas is that it takes up a much larger volumetric percentage of the mixture entering the cylinder.
There is also little time for the fuel to cool the air charge. This is because the fuel injectors are located so close to the cylinders.
Cooling of the gas would richen the fuel mixture, although insignificantly. If no extra air is added, this extra fuel will go to waste out of the tailpipe. Also, a richer air/fuel ratio will produce less power than a lean mixture to some extent.
The density of air changes somewhat dramatically with temperature, since it is a gas. Gasoline density is nearly constant in comparison.
Another benefit of colder air over gas is that it takes up a much larger volumetric percentage of the mixture entering the cylinder.
There is also little time for the fuel to cool the air charge. This is because the fuel injectors are located so close to the cylinders.
Cooling of the gas would richen the fuel mixture, although insignificantly. If no extra air is added, this extra fuel will go to waste out of the tailpipe. Also, a richer air/fuel ratio will produce less power than a lean mixture to some extent.
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From: Bellingham, WA
What goes into the cylinder a mixture of air and gas. A mixture of air and cold gas is cooler than a mixture of air and warm gas. A cool mixture is more dense than a warm mixture. A cylinder full of cool, dense mixture has more molecules of oxygen and of hydrocarbons in it than one full of warm, less-dense mixture.
Those extra molecules release extra power.
Those extra molecules release extra power.
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From: Hawaii
The flashpoint is still the same no matter what the temp of the fuel is before detonation. Some race cars might have something to cool the fuel to help stablelize it, and help avoid early detonation.
I think the flashpoint of Gasoline is around -40'
I think the flashpoint of Gasoline is around -40'
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From: Covington WA, USA
Originally Posted by rocrfella,Oct 4 2007, 02:40 PM
I was thinking of the opposite. I think we should heat it up so it burns better.
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From: Jacksonville, Florida
don't forget that the pressurization of fuel prior to it being sprayed into the combustion chamber will heat it up some as well. Also, gasses can generally be cooled much faster than liquids.
cool air is still better bang for the buck, literally.
When the fuel is aerosolized into the combustion chamber its going to have a lot more surface area present that will be exposed to the air, cooling the air would have a higher impact and be more efficient than cooling the fuel.
Interesting idea, but as for power I would think the gains would be almost negligible for the energy invested.
cool air is still better bang for the buck, literally.
When the fuel is aerosolized into the combustion chamber its going to have a lot more surface area present that will be exposed to the air, cooling the air would have a higher impact and be more efficient than cooling the fuel.
Interesting idea, but as for power I would think the gains would be almost negligible for the energy invested.
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From: Dry Branch
These things have been around forever, but they are for CARBURATED cars. Not recommended for cars with fuel injection.
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Originally Posted by RED MX5,Oct 5 2007, 04:46 AM
These things have been around forever, but they are for CARBURATED cars. Not recommended for cars with fuel injection.
.....I'm old 
