Electric fan?
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Electric fan?
Hey i have a non turbo 89 gtu...and im wondering if i could get a ford taurs fan to fit my car...i hear there pretty small fans....i want one for my car....what else would i need besides the fan...????
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With the old clutch fan on, and a new radiator shroud, I can sit behind the car and feel hot *wind* at idle... Love it. good way to heat the garage duringwinter too,... (lest the exhaust)
#4
Electric fans draw quite a lot of current. Most pull surges of 35A or more to start up, then run at 8A-10A. This puts extra load on the alternator. Ever pedaled a bicycle with a generator powered light? If so, then you will know that as the electrical load on a generator/alternator increases, the generator/alternator becomes harder to turn. Suddenly, all that "free" HP you just freed up is once again being used. This time, though, it is being used to turn the alternator.
That paragraph is absolutely untrue. The alternator is no harder to turn under load than it is with no load. I have no idea where this info came from, but it isn't accurate. This post isn't meant to put down aaron, but just to state that you shouldn't believe everything you read.
-Joe
#5
Re: Electric fan?
Originally posted by Douglass
Hey i have a non turbo 89 gtu...and im wondering if i could get a ford taurs fan to fit my car...i hear there pretty small fans....i want one for my car....what else would i need besides the fan...????
Hey i have a non turbo 89 gtu...and im wondering if i could get a ford taurs fan to fit my car...i hear there pretty small fans....i want one for my car....what else would i need besides the fan...????
#6
Re: Electric fan?
Also, whoever did that website should seriously consider changing the colors. That is absolutely horendous and hard to read.
Last edited by Crionics; 05-04-04 at 09:21 AM.
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#14
zoom zoom go boom
I put an electric fan on cause I dont trust the stock fan. Noone can tell you the CFM rating. And I havent seen a lick of problems with my electric. I can turn the car off, leave the key in accesory and have the fan on to help cool the motor. Horsepower gains if any are going to be so minimal that you couldnt tell unless you had a dyno. But I think its a modification worth doing. In my opinion if clutch fans are so good then why do new cars come with electric fans?
#16
Originally posted by ForsakenRX7
I put an electric fan on cause I dont trust the stock fan. Noone can tell you the CFM rating. And I havent seen a lick of problems with my electric. I can turn the car off, leave the key in accesory and have the fan on to help cool the motor. Horsepower gains if any are going to be so minimal that you couldnt tell unless you had a dyno. But I think its a modification worth doing. In my opinion if clutch fans are so good then why do new cars come with electric fans?
I put an electric fan on cause I dont trust the stock fan. Noone can tell you the CFM rating. And I havent seen a lick of problems with my electric. I can turn the car off, leave the key in accesory and have the fan on to help cool the motor. Horsepower gains if any are going to be so minimal that you couldnt tell unless you had a dyno. But I think its a modification worth doing. In my opinion if clutch fans are so good then why do new cars come with electric fans?
-Joe
#17
I wish I was driving!
Speaking of myths...
"As the engine heats up, so does the clutch as hot air from the rad flows over it. The fluid thickens up, engaging the clutch and turning the fan at engine speed up to about 2000 RPM."
What fluid thickens as it gets hotter? This would indicate that its molecules are moving slower, which disobey the laws of kinetic energy.
"The '86-'88 alternator is rated at 70A, and the 89+ unit is rated at 90A."
The S5 alt is rated at 80 amps, not 90 amps.
"The electric fan introduces many more failure points: fuse, all wiring connections, physical failure of the fan, failure of the motor, failure of the thermostat. "
1. Fuses don't just fail. If a fuse pops, there is too much current being drawn through the fuse, either via a short, poor installation, or too small of a fuse.
2. Physical failure of the fan? Gimme a break. Are blades going to come shooting off? is it going to rattle loose and become unbolted?
3. Failure of the thermostat? Umm, electric fans should retain use of the thermostat. No added failure modes here.
4. Wiring? Properly routed and installed, this is not a reasonable failure mode.
The only failure modes of an electric fan are the motor failing and the thermal switch failing (which is very common with some brands).
If we are going to mention all of the failure modes for the electric fan, let's not be biased here. The stock e-fan, along the same lines, can:
- belt slippage/ belt breakage. Very common when the air pump is not installed.
- Thermal clutch fail (common)
- physical failure (yeah right, but if it get's listed for an e-fan, fair is fair)
- Improper installation (again, yeah right, but if it get's listed for an e-fan)
- thermostat (listed for e-fan...)
As well, many new cars are using e-fans because...
1. They are FWD and the crankshaft sits perpendicular to the radiator.
2. Space constrictions do not all the fitting of a large standard fan.
"As the engine heats up, so does the clutch as hot air from the rad flows over it. The fluid thickens up, engaging the clutch and turning the fan at engine speed up to about 2000 RPM."
What fluid thickens as it gets hotter? This would indicate that its molecules are moving slower, which disobey the laws of kinetic energy.
"The '86-'88 alternator is rated at 70A, and the 89+ unit is rated at 90A."
The S5 alt is rated at 80 amps, not 90 amps.
"The electric fan introduces many more failure points: fuse, all wiring connections, physical failure of the fan, failure of the motor, failure of the thermostat. "
1. Fuses don't just fail. If a fuse pops, there is too much current being drawn through the fuse, either via a short, poor installation, or too small of a fuse.
2. Physical failure of the fan? Gimme a break. Are blades going to come shooting off? is it going to rattle loose and become unbolted?
3. Failure of the thermostat? Umm, electric fans should retain use of the thermostat. No added failure modes here.
4. Wiring? Properly routed and installed, this is not a reasonable failure mode.
The only failure modes of an electric fan are the motor failing and the thermal switch failing (which is very common with some brands).
If we are going to mention all of the failure modes for the electric fan, let's not be biased here. The stock e-fan, along the same lines, can:
- belt slippage/ belt breakage. Very common when the air pump is not installed.
- Thermal clutch fail (common)
- physical failure (yeah right, but if it get's listed for an e-fan, fair is fair)
- Improper installation (again, yeah right, but if it get's listed for an e-fan)
- thermostat (listed for e-fan...)
As well, many new cars are using e-fans because...
1. They are FWD and the crankshaft sits perpendicular to the radiator.
2. Space constrictions do not all the fitting of a large standard fan.
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1) Aaroncake probably has an EE and the various certs that go with it. the highschooler's that don't know what an EE is... need not critisize him here.
2) Viscous type clutch fans use a fluid that THICKENS as it gets hotter. Any ME will be able to list of LONG list of synthetic and natural liquids that hold this property true. Again... most highschooler's won't know what an ME is, or know that there are fluids that thicken as they get hotter. Thermalfluid dynamics, k thanks.
That said, I thought RX7s had a thermalstatic fan anyway? Thermalstatic uses a spring instead of fluid, and is more on/off, than slip/noslip.
EDIT: Heres what I was looking for: http://www.haydenauto.com/f_clutch.html
2) Viscous type clutch fans use a fluid that THICKENS as it gets hotter. Any ME will be able to list of LONG list of synthetic and natural liquids that hold this property true. Again... most highschooler's won't know what an ME is, or know that there are fluids that thicken as they get hotter. Thermalfluid dynamics, k thanks.
That said, I thought RX7s had a thermalstatic fan anyway? Thermalstatic uses a spring instead of fluid, and is more on/off, than slip/noslip.
EDIT: Heres what I was looking for: http://www.haydenauto.com/f_clutch.html
#20
I wish I was driving!
Originally posted by Rob500
"What fluid thickens as it gets hotter?"
20-50w Oil.
Rob
"What fluid thickens as it gets hotter?"
20-50w Oil.
Rob
#21
I wish I was driving!
Originally posted by Kenteth
1) Aaroncake probably has an EE and the various certs that go with it. the highschooler's that don't know what an EE is... need not critisize him here.
2) Viscous type clutch fans use a fluid that THICKENS as it gets hotter. Any ME will be able to list of LONG list of synthetic and natural liquids that hold this property true. Again... most highschooler's won't know what an ME is, or know that there are fluids that thicken as they get hotter. Thermalfluid dynamics, k thanks.
That said, I thought RX7s had a thermalstatic fan anyway? Thermalstatic uses a spring instead of fluid, and is more on/off, than slip/noslip.
EDIT: Heres what I was looking for: http://www.haydenauto.com/f_clutch.html
1) Aaroncake probably has an EE and the various certs that go with it. the highschooler's that don't know what an EE is... need not critisize him here.
2) Viscous type clutch fans use a fluid that THICKENS as it gets hotter. Any ME will be able to list of LONG list of synthetic and natural liquids that hold this property true. Again... most highschooler's won't know what an ME is, or know that there are fluids that thicken as they get hotter. Thermalfluid dynamics, k thanks.
That said, I thought RX7s had a thermalstatic fan anyway? Thermalstatic uses a spring instead of fluid, and is more on/off, than slip/noslip.
EDIT: Heres what I was looking for: http://www.haydenauto.com/f_clutch.html
#22
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[QUOTE]Originally posted by scathcart
[B]Speaking of myths...
"As the engine heats up, so does the clutch as hot air from the rad flows over it. The fluid thickens up, engaging the clutch and turning the fan at engine speed up to about 2000 RPM."
What fluid thickens as it gets hotter? This would indicate that its molecules are moving slower, which disobey the laws of kinetic energy."
Well, despite what many people think, the fluid doesnt thicken as it heats up, even howstuffworks.com gets this wrong, equating it to a viscous LSD (as many people tend to do as well), which works on a differnt pricipal, the shearing action betweent he plates of each wheel which "streches out" polymers suspended in the fluid causing it to thicken. Note that this does not involve heat to thicken the fluid. Viscous LSD fluids however are resistant to thinning out as they heat up, much like multi grade oil, however they do not thicken with heat.
A Viscous clutch uses a thermaly controled valve and a thick fluid to control its speed, the hotter it gets the more the valve either opens or closes (depending on design) to let less fluid bypass the clutch mechanism.
http://yarchive.net/car/fan_clutch.html
http://www.designnews.com/index.asp?...CA117022&cfd=1
"An early approach to reducing the load on diesel engine fans was the application of a viscous fan drive, a technology in use on many automobiles today. Essentially a fluid-coupled device that operates much like a variable torque converter, it consists of a hydraulic turbine with silicone fluid that operates through centrifugal force. A valve, which is controlled by a bi-metallic element that senses the temperature of air passing through the radiator, controls the amount of fluid-coupling slippage. The less slip, the more efficient the clutch, and the higher the fan speed. "
http://www.machinedesign.com/ASP/str...tedArticle.asp
[B]Speaking of myths...
"As the engine heats up, so does the clutch as hot air from the rad flows over it. The fluid thickens up, engaging the clutch and turning the fan at engine speed up to about 2000 RPM."
What fluid thickens as it gets hotter? This would indicate that its molecules are moving slower, which disobey the laws of kinetic energy."
Well, despite what many people think, the fluid doesnt thicken as it heats up, even howstuffworks.com gets this wrong, equating it to a viscous LSD (as many people tend to do as well), which works on a differnt pricipal, the shearing action betweent he plates of each wheel which "streches out" polymers suspended in the fluid causing it to thicken. Note that this does not involve heat to thicken the fluid. Viscous LSD fluids however are resistant to thinning out as they heat up, much like multi grade oil, however they do not thicken with heat.
A Viscous clutch uses a thermaly controled valve and a thick fluid to control its speed, the hotter it gets the more the valve either opens or closes (depending on design) to let less fluid bypass the clutch mechanism.
http://yarchive.net/car/fan_clutch.html
http://www.designnews.com/index.asp?...CA117022&cfd=1
"An early approach to reducing the load on diesel engine fans was the application of a viscous fan drive, a technology in use on many automobiles today. Essentially a fluid-coupled device that operates much like a variable torque converter, it consists of a hydraulic turbine with silicone fluid that operates through centrifugal force. A valve, which is controlled by a bi-metallic element that senses the temperature of air passing through the radiator, controls the amount of fluid-coupling slippage. The less slip, the more efficient the clutch, and the higher the fan speed. "
http://www.machinedesign.com/ASP/str...tedArticle.asp
#23
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2nd year ME :-) ( i know,.. thats not much beter than any other science /math major at this point...) But Scathcart is right and you guys are wrong.
20w50 does not mean i thickes with heat, it means it is resitant to thinning
20 means at pour temp it has the viscosity of a 20 weight oil: W mean the oil is rated at the boiling temperature of water: 50 means at the boiling temp of water its viscosity is equivelent to that of a straight 50 weight oil at 100 C
note that this is still thinner then the 20 weight rating at pour temp!
20w50 does not mean i thickes with heat, it means it is resitant to thinning
20 means at pour temp it has the viscosity of a 20 weight oil: W mean the oil is rated at the boiling temperature of water: 50 means at the boiling temp of water its viscosity is equivelent to that of a straight 50 weight oil at 100 C
note that this is still thinner then the 20 weight rating at pour temp!
#24
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Originally posted by scathcart
Heading into fourth year mechanical Engineering, FYI.
Heading into fourth year mechanical Engineering, FYI.
#25
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Originally posted by OverDriven
it states that the electric fan may over-cool the engine. It then goes on to say "They provide inferior cooling to the stock fan" at the end.
it states that the electric fan may over-cool the engine. It then goes on to say "They provide inferior cooling to the stock fan" at the end.
The alternator is no harder to turn under load than it is with no load.
Originally posted by ForsakenRX7
I put an electric fan on cause I dont trust the stock fan. Noone can tell you the CFM rating.
I put an electric fan on cause I dont trust the stock fan. Noone can tell you the CFM rating.
In my opinion if clutch fans are so good then why do new cars come with electric fans?
Originally posted by scathcart
Physical failure of the fan? Gimme a break. Are blades going to come shooting off? is it going to rattle loose and become unbolted?
Physical failure of the fan? Gimme a break. Are blades going to come shooting off? is it going to rattle loose and become unbolted?
Failure of the thermostat? Umm, electric fans should retain use of the thermostat. No added failure modes here.
C'mon Sean, you're just splitting hairs here. You know what Aaron's getting at. Nowhere does he say e-fans are crap, just that there are a lot of people who believe a lot of crap about them (see above). A properly selected and installed e-fan can work fine, but the actual gains in performance and cooling are practically zero.
Last edited by NZConvertible; 05-04-04 at 04:02 PM.