Fuel & Air Cooling Box
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mckutzy
Well-known member
OP----Pulling A FreeRunner....
Going All Bob....
An inside joke....
Going All Bob....
An inside joke....
Poboy kartman
Senior Moments Member
ezcome-ezgo
G'me sumthin to write on
Can't be PAFR if it does what it's supposed to. Can't be GAB if it's finished.
They'll evaporate just fine, that's not an issue, but by doing so, they swallow a lot of the combustion energy maybe more than you gain from cooling the air/fuel mix.
but let's ask the physics nerd shall we??
Attention math ahead!
Let's do some basics first..
One Joule is the amount of energy to increase the temperature of one gram of water by ~ 0.239 Kelvin
since the Kelvin scale equals the ever so convenient Celsius scale
in which water boils at 100°C and average ambient temperature in spring is about 20°C
We need to increase by round about 80K
for simplicity let's assume our water droplet has a weight of 0.01 gram
(mid sized droplet)
to evaporate said 0.01g water droplet we need to add ~3.4 Joule of energy
A Joule can also be written as a Watt second..
In which case and under the [false] assumption that a single combustion would take a second it'd literally "evaporate" 3.4 Watts
which doesn't sound like much, but the actual combustion doesn't take nearly as long..
in fact @ 3000 rpms you'll have 50 revolutions per second,
so a combustion cycle alone is about 1/100th of a second only.
(the combustion itself is even short.. but let's just stick with nice numbers
)So in order to heat up our small droplet in 1/100th of a second we need to feed 340 Watts of energy (heat) in!
A Honda GX200 (6.5hp 4.8kW) @3000 rpm produces roughly 4kW
end of science...
And with that evaporating the droplets alone will
swallow 8.5% of the motor power.
True, the droplets can be smaller, but 20°C (68F) isn't that cold..
and the colder the water, the more energy you'll need to boil away the water
and even if the expanding water vapor is able to regain 80% of that loss (which I doubt)
you still loose 1.7% of motor power because of the water
'sid
PS: I hope you're not referring to MW50 cooling from WWII, since again that'd be a very different animal
Poboy kartman
Senior Moments Member
They'll evaporate just fine, that's not an issue, but by doing so, they swallow a lot of the combustion energy maybe more than you gain from cooling the air/fuel mix.
but let's ask the physics nerd shall we??
Attention math ahead!
Let's do some basics first..
One Joule is the amount of energy to increase the temperature of one gram of water by ~ 0.239 Kelvin
since the Kelvin scale equals the ever so convenient Celsius scale
in which water boils at 100°C and average ambient temperature in spring is about 20°C
We need to increase by round about 80K
for simplicity let's assume our water droplet has a weight of 0.01 gram
(mid sized droplet)
to evaporate said 0.01g water droplet we need to add ~3.4 Joule of energy
A Joule can also be written as a Watt second..
In which case and under the [false] assumption that a single combustion would take a second it'd literally "evaporate" 3.4 Watts
which doesn't sound like much, but the actual combustion doesn't take nearly as long..
in fact @ 3000 rpms you'll have 50 revolutions per second,
so a combustion cycle alone is about 1/100th of a second only.
(the combustion itself is even short.. but let's just stick with nice numbers
So in order to heat up our small droplet in 1/100th of a second we need to feed 340 Watts of energy (heat) in!
A Honda GX200 (6.5hp 4.8kW) @3000 rpm produces roughly 4kW
end of science...
And with that evaporating the droplets alone will
swallow 8.5% of the motor power.
True, the droplets can be smaller, but 20°C (68F) isn't that cold..
and the colder the water, the more energy you'll need to boil away the water
and even if the expanding water vapor is able to regain 80% of that loss (which I doubt)
you still loose 1.7% of motor power because of the water
'sid
See...it's all about condensation and the energy it takes to absorb it!
Soooo....if Alex could condense his posts....it would take less energy to absorb them!
(Like that's gonna happen! )
See...it's all about condensation and the energy it takes to absorb it!
Soooo....if Alex could condense his posts....it would take less energy to absorb them!
(Like that's gonna happen! )
LOOOOL... I can... c?
'sid
Denny
Canned Monster
One major concern I have is how much condensation will be created in the fuel tank. Cold fuel will act as a platform for water to condensate.
I think you would be much further ahead to build a cool can with coils of copper tubing inside. With all the alcohol in fuel these days I would be leery of even trying that. However I would consider water/methanol injection not only would you cool the fuel but the incoming air also.
My 2 cents.
Denny
I think you would be much further ahead to build a cool can with coils of copper tubing inside. With all the alcohol in fuel these days I would be leery of even trying that. However I would consider water/methanol injection not only would you cool the fuel but the incoming air also.
My 2 cents.
Denny
Poboy kartman
Senior Moments Member
My 2 cents.
Denny
Great! Just great! Now I see where your whole pledge to the "Poboy for President Fund" ACTUALLY went! !!!
chancer
ɔ ɥ ɐ u ɔ ǝ ɹ
One major concern I have is how much condensation will be created in the fuel tank. Cold fuel will act as a platform for water to condensate.
I think you would be much further ahead to build a cool can with coils of copper tubing inside. With all the alcohol in fuel these days I would be leery of even trying that. However I would consider water/methanol injection not only would you cool the fuel but the incoming air also.
My 2 cents.
Denny
But wait! You use the condensed water in the fuel to separate out the Alcohol!
Also the water will knock the carbon off the piston!
SkidooTNT
New member
To me cooling the fuel just seems like to many problems for very little reward. Both the weight of the copper coil needed and the huge potential for condensation in the carb. In a fuel injection system condensation isn't a problem.
In cooling systems big gains are in air cooing. If the air is 30 and you could get it to 10 I would think you could add a lot more fuel with out running rich. As for having problems with water droplets in the air and the energy lost your forgetting that the energy it is taking to evaporate is a waist product. This will also help keep the engine cooler.
There are drag cars out there that actually inject water into the intake manifold to cool the air. Granted those cars have turbos and are running 30lbs boost, the principle is still that same.
In cooling systems big gains are in air cooing. If the air is 30 and you could get it to 10 I would think you could add a lot more fuel with out running rich. As for having problems with water droplets in the air and the energy lost your forgetting that the energy it is taking to evaporate is a waist product. This will also help keep the engine cooler.
There are drag cars out there that actually inject water into the intake manifold to cool the air. Granted those cars have turbos and are running 30lbs boost, the principle is still that same.
chancer
ɔ ɥ ɐ u ɔ ǝ ɹ
Right. I mean your car still drives fine in Fog.
Most cars actually exhaust 10 gallons of water (in vapor form) for every 1 gallon of gas!
Most cars actually exhaust 10 gallons of water (in vapor form) for every 1 gallon of gas!
SkidooTNT
New member
Yep. Burning fossil fuels creates water vapour.
Gas is a hydrocarbon. The hydrogen molecules in gas bond with the oxygen molecules in the air to creat water during combustion. Obviously there are other by-products as well, the carbon and things like nitrogen molecules in the air have to go somewhere.
Gas is a hydrocarbon. The hydrogen molecules in gas bond with the oxygen molecules in the air to creat water during combustion. Obviously there are other by-products as well, the carbon and things like nitrogen molecules in the air have to go somewhere.
FreeRunner15
=======
Noooo. it would work for an intercooler but i dont see a need for it here.
and fuel is already cold. havent you had some drip on your hands from the carburetor?its pretty cold. unless you are trying to make your motor more fuel efficienter and run lean.
But there is a thing called "Cold Start"ing which makes a vehicle much harder to start especially on cold mornings because the gas (due to science and cold temperature) is more of a liquid and not heated up well into..a gas. I don't know if the same is applied to carb engines.
chancer
ɔ ɥ ɐ u ɔ ǝ ɹ
Its about to get real, up in here.
SkidooTNT
New member
This does apply to carbs actually more then EFI though the temps you would be lowering the air to would not make a difference in this regard, but the fuel would. The problem with cold gas is condensation in the carb. As the cold fuel sits in the bowl it will cause condensation and therefore a build up of water in the bowl. Potentally this could lead to the engine starving for fuel because it's getting water instead of gas. This isn't a problem in EFI systems because there is no where like the bowl of a carb for the gas to sit.
The cold air priciple can be very effective by simply creating deser air. Denser air means more oxygen which means you can add more fuel. So not running lean. It's more like running rich with out running rich.
Just because gas feels cold on your hand dosent mean it's cold. Your hand will feel cold because when the gas is evaporating it is is actually stealing heat from your hand in the process. Hence your hand feels cold.
Denny
Canned Monster
My 1956 terratrac bulldozer has a problem with icing of the carburetor only on hot and humid days though. Figure that one out. 
Denny
Denny
chancer
ɔ ɥ ɐ u ɔ ǝ ɹ
Thank you! Its called Evaporative Cooling. Same as any Air conditioner, Same as when you are drying off out of the Shower, Same as the reason we sweat.
I cannot believe He actually posted that! Even Him.
---------- Post added at 10:26 PM ---------- Previous post was at 10:20 PM ----------
Again Evaporative cooling. It is Hot out, the gas is expanding or Vaporizing or Evaporating, so fast it causes, the air cools and it causes, condensation. On a humid day there is more moisture in the air the condensate vapor drips and freezes!My 1956 terratrac bulldozer has a problem with icing of the carburetor only on hot and humid days though. Figure that one out.
Denny
It is a simple as any Air Conditioning system. That is why an AC unit that is low on Freon will actually ICE up.
SkidooTNT
New member
My 1956 terratrac bulldozer has a problem with icing of the carburetor only on hot and humid days though. Figure that one out.
Denny
Chancers got this one right. This is why liquid cooled snowmobiles have a rad line that runners through the throttle body to prevent freezing. Any moisture running through the constricted space of the throttle body is going to want to condence there because the fast moving air and fuel evaporating fuel has a large cooling effect. On a hot day more moisture is in the air and the fuel is evaporating faster. Both leading to ice.
chancer
ɔ ɥ ɐ u ɔ ǝ ɹ
Thanks.
Gasoline actually make a great Refrigerant. Except it is so Dangerous. LOL
I do wonder though, On the 1956 Terratrac Dozer. Would more Fuel pressure help. Is the the fuel only expanding in the Carb, and freezing. Or is there air space in the fuel line and or carb bowl allowing the Gas to prematurely vaporize.
---------- Post added at 10:44 PM ---------- Previous post was at 10:38 PM ----------
Similar issue that causes "vapor lock" on carburated engines with mechanical fuel pumps.
Gasoline actually make a great Refrigerant. Except it is so Dangerous. LOL
I do wonder though, On the 1956 Terratrac Dozer. Would more Fuel pressure help. Is the the fuel only expanding in the Carb, and freezing. Or is there air space in the fuel line and or carb bowl allowing the Gas to prematurely vaporize.
---------- Post added at 10:44 PM ---------- Previous post was at 10:38 PM ----------
Similar issue that causes "vapor lock" on carburated engines with mechanical fuel pumps.
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