Engine Cooling Perfection Achieved
Race Director
Joined: Feb 1999
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From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Nice work Photovette. I am very intrigued by the Mark VIII fan setup and you guys have done nice work documenting the work and results. Thanks for posting the pics. Those will come in handy oneday. 
Melting Slicks
Joined: Feb 2003
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St. Jude Donor '03,'11
i don't get why everyone thinks the electric fans are the *****. I don't like the whole concept that they won't come on until the rad hits 160/180 or whatever. Whatever thermal reserve you would have had is lost.
With a mechanical fan the air is pulled thru all the time keeping the radiator as cool as possible at all times allowing considerable thermal reserve capacity that will be needed for WOT operational bursts.
I'm of the opinion that fans need to run all the time with these cars because of the small frontal area. A negative pressure area sure helps things when at highway speeds.
With your system you will probably never see any deficiencies because it is more than anyone needs for cruising around. But when really running hard for long periods you could see some temp spikes. My sysem with a 2 row 1.25" tube aluminum radiator and mechanical fan i have been unable to exceed 190 at Mosport which has big straighaways. You won't see higher duty than that other than maybe towing a trailer in the mountains.
With a mechanical fan the air is pulled thru all the time keeping the radiator as cool as possible at all times allowing considerable thermal reserve capacity that will be needed for WOT operational bursts.
I'm of the opinion that fans need to run all the time with these cars because of the small frontal area. A negative pressure area sure helps things when at highway speeds.
With your system you will probably never see any deficiencies because it is more than anyone needs for cruising around. But when really running hard for long periods you could see some temp spikes. My sysem with a 2 row 1.25" tube aluminum radiator and mechanical fan i have been unable to exceed 190 at Mosport which has big straighaways. You won't see higher duty than that other than maybe towing a trailer in the mountains.
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Sometimes it's needed. I have a long water pump being installed along with the new belt system, and you cannot use a mechanical fan.
I got the car with a mechanical fan installed, and everything was working properly. The car would exceed over 200 F at idle, and anything over 50 MPH. I installed an electric and I had 190 from idle all the way up to extended periods at 70 MPH. I had to switch back to mechanical when the fan I was using burned up two SI alts in a row.
I'm going back to electric, but this time with a better charging system, and a better controller.
Melting Slicks
Joined: Jun 2003
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From: Niles, MI
Melting Slicks
Joined: Oct 2004
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From: Knoxville Tennessee
It seems that the car manufacturers went exclusively to electric fans so that cars will warm up sooner. Using computer controllers and relays the temps are better maintained with less spikes in temps than conventional systems. Also saves a few horses as well. Engine driven fans are not as efficient at low speed/low engine rpm conditions; exactly when they need to be most efficient. My C3 runs cooler at 100 MPH than at 20 MPH because the fan is bearly turning at 20 MPH. Electric fans aren't controlled by engine rpm and can better maintain constant temps. at any speed. I installed an auxillary 12 inch electric fan to help cool the system in stop and go traffic. At highway speeds with a properly maintained system, you don't need any fan; which is why the engine driven fan has a clutch that disengages it at highway speeds.
Bernie
Bernie
Melting Slicks
Joined: Jun 2003
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From: Niles, MI
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Team Owner
Joined: Aug 2006
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From: Columbia Missouri
Nah, that was my fault for not researching what those alts were really capable of. One of them was an SI that was upgraded to 135 amp. It burned faster than the stock SI that was already on the car.
Team Owner
Joined: Oct 2004
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From: Springfield MO
St. Jude Donor '07
As far as I know 200 F is considered normal operating temperature.
That's exactly what I'm talking about. By the time you switch alternators and buy a controller and all the other stuff you need you will have a ton of money and effort tied up in something that IMHO gives you very little in return. Same goes for serpentine belt systems IMHO. But its your money and time, if its something you want to do its cool.
That's exactly what I'm talking about. By the time you switch alternators and buy a controller and all the other stuff you need you will have a ton of money and effort tied up in something that IMHO gives you very little in return. Same goes for serpentine belt systems IMHO. But its your money and time, if its something you want to do its cool.
Team Owner
Joined: Aug 2006
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From: Columbia Missouri
Say you're stuck in traffic on a moderately hot day. Just sitting there idling. How high will the temp get? Do you rev the motor to get the temp down while you wait?
Drifting
Joined: Jun 2004
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From: staten island ny
As far as I know 200 F is considered normal operating temperature.
That's exactly what I'm talking about. By the time you switch alternators and buy a controller and all the other stuff you need you will have a ton of money and effort tied up in something that IMHO gives you very little in return. Same goes for serpentine belt systems IMHO. But its your money and time, if its something you want to do its cool.
That's exactly what I'm talking about. By the time you switch alternators and buy a controller and all the other stuff you need you will have a ton of money and effort tied up in something that IMHO gives you very little in return. Same goes for serpentine belt systems IMHO. But its your money and time, if its something you want to do its cool.
ESU
Melting Slicks
Joined: Feb 2003
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St. Jude Donor '03,'11
If you have that problem then you have a bad fan clutch. An engine driven fan has a lot more capablity than any electric fan. Idle may be the only condition where an electric fan wins.
Its like trying to supercharge you engine with an electric fan, just can't get there playing with 12v.
Wait till those used fans crap the bed when you're in traffic. Probably safer with dual fans if you're going electric.
Last edited by turtlevette; Feb 6, 2007 at 10:07 PM.
Team Owner
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From: Springfield MO
St. Jude Donor '07
Team Owner
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From: Columbia Missouri
Melting Slicks
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St. Jude Donor '03,'11
The clutch thermostat spring makes it stiffer as temp increases.
I tried the electric fan thing back in the 80's and had electrical problems, thermostat switch problems yada yada yada.
Mechanical fan is simple and trouble free.
Team Owner
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From: Springfield MO
St. Jude Donor '07
it doesn't disengage but it slips more at higher rpm. The heavy duty clutch is stiffer across the rpm range and it will move some serious air.
The clutch thermostat spring makes it stiffer as temp increases.
I tried the electric fan thing back in the 80's and had electrical problems, thermostat switch problems yada yada yada.
Mechanical fan is simple and trouble free.
The clutch thermostat spring makes it stiffer as temp increases.
I tried the electric fan thing back in the 80's and had electrical problems, thermostat switch problems yada yada yada.
Mechanical fan is simple and trouble free.
Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Melting Slicks
Joined: Feb 2003
Posts: 3,053
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St. Jude Donor '03,'11
Yep,
I give, all the new cars use them so its probably the way to go. My car has never cooled correctly at highway speeds so i'm staying with the mechanical until like you say i put an engine in that doesn't facilitate a mech fan.