Cooling System Fans

[c3po]

I have a small block chevy in my 1983 El Camino, many years ago I took off the mechanical fan and then put on an electric fan. The problem was that the fan's wiring was attached to the battery.
I had to buy an adapter for the battery, it was made out of brass and it kept coming loose, so I had to ditch the electric fan. I still have the electric fan in the garage, it is a Permacool electric fan rated at something like 3000 CFM, is there a way I can hook this fan up without connecting the power source to the battery, I was thinking of an on off switch.

My other option is a mechanical fan, obviously a thermal clutch is more efficient than a non thermal clutch.

Most of my driving is just cruising around, the engine normaly hits 2000 rpm's when I am going down the road, or if I hit the accelerator hard, maybe a quick jump up to 3000 rpm's.

I have read articles that flex fans eat up power, but all of the dyno tests on fans seem to be from 3500 rpm's on up. I would think that a lighter flex fan would put less stress on the water pump, even a clutch fan is spinning when not engaged or is it freewheeling.

A flex fan assembly might weigh between 1 and 2 pounds whereas a clutch fan assembly can be 7 or 8 pounds.

I have been driving around for a few years with no FAN, I was able to do this by having a 180 thermostat, but I have now put in a 195 thermostat for many reasons. With the 180 stat I could sit in traffic for a few minutes, but I do not see this happening with the 195 thermostat.

I used to have a BeCool radiator that let me get away with not having a fan, but it did not fit right, I got it cheap from a guy who was going to do a cooling system upgrade on his El Camino, but the car was wrecked before he could do this. I now have an aluminum radiator from CarQuest that seems like a nice unit.

I was told that the 195 thermostat would probably burn off any condensation in the engine better than a 180 thermostat. I do not have any A/C, so there is no condenser up front. I have been lucky that I have not gooten stuck in traffic, but I need to do something.

I have read that the Flex Fans are better today than they were years ago, whether I lean towards a flex fan should not matter much if my rpm's are well below 3000 rpm's, so if anyone has any experience with these different fans, please chime in since I have not totally made up my mind.

 

[Gary Allan]

Just get a fan controller with a relay. Easy enough to do. You can get semi fancy and get a Spal controller. There you can use the gauge output and even have two fan speeds. About $75 for the older model.

If you want to go with just a manual switch, get a properly rated relay and a couple of female spade connectors that will fit on the tabs. Run the short wires from the battery to the fan ..run lighter wire to the switch.

 

[demarpaint]

That will work well, or get a stock fan with a good clutch and call it a day. The car is a daily driver and either will serve you well.

 

[02Pilot]

I converted my BMW 2002 to a thermostatically-controlled electric last summer, finally getting rid of the unclutched direct drive mechanical fan. Huge improvement IMHO, especially as I was able to use OEM parts for the whole thing. If you have the option for a good thermo-clutched mechanical that may be the easiest, but the electric option can be set up fairly easily, even with generic components.

 

[NYEngineer]

WHERE in the world do you live that you can get by without having a fan????
On Long Island, half of your driving is sitting in traffic. That would last about seven minutes.
Ok, I have used Fex A Lite fans on many cars over the years. I've had daily driven "hotrods" with the stainless fan with the factory shroud. They pull tons of air, they've never come apart and they make a cool noise if you like that sort of thing. I keep thinking of putting one on my Yukon, but the factory thermal fan hasn't failed yet.
I'm no big proponent of electric fans on V8's, but my friend has a 91 Camaro that has absolutely no room for a decent mechanical fan. We installed some aftermarket dual electrics in it and after lots of fooling around with lesser quality controls, we finally came across Painless Wiring's fan controls and they've been in the car for about eight years.
I say if your Elky has room for a mechanical fan, go for it. You'll be fine with a Flex or a thermal clutch. Get a shroud too.

 

[eljefino]

Are you talking about side-terminal battery taps that go between the main cable and the battery? Those are kind of junky and screw up the rest of the main power feed. Get a decent sized O-terminal (like gary has pictured above) and put it either where the alternator + wire meets the starter or on the alternator output stud itself, then wire up the fan as you otherwise would have. The relay is going to be a part of this either if it has a thermoprobe or a switch inside the cab. You can do both, which is pretty cool, lots of control. Set it up so grounding the relay turns on the fan (usually the directions have you do this), then you switch to ground and have the thermoprobe's other terminal grounded... done!

Don't give up on the electric fan yet it should be lots of fun when set up right. The 180 thermostat was a bad idea as you would have a temp swing every time you got stuck in traffic a minute or two, all that thermal expansion stresses head gaskets etc.

 

[c3po]

Originally Posted By: NYEngineer
WHERE in the world do you live that you can get by without having a fan????
On Long Island, half of your driving is sitting in traffic. That would last about seven minutes.
Ok, I have used Fex A Lite fans on many cars over the years. I've had daily driven "hotrods" with the stainless fan with the factory shroud. They pull tons of air, they've never come apart and they make a cool noise if you like that sort of thing. I keep thinking of putting one on my Yukon, but the factory thermal fan hasn't failed yet.
I'm no big proponent of electric fans on V8's, but my friend has a 91 Camaro that has absolutely no room for a decent mechanical fan. We installed some aftermarket dual electrics in it and after lots of fooling around with lesser quality controls, we finally came across Painless Wiring's fan controls and they've been in the car for about eight years.
I say if your Elky has room for a mechanical fan, go for it. You'll be fine with a Flex or a thermal clutch. Get a shroud too.


I live out in the country in Maryland, and where I drive there are not many stop lights, the few a come up to I am only sitting for a minute or two.

I actually visited my cousin a few years ago in Long Island, but I did take a rental car up there. I do have the original shroud on the vehicle. I kept this on because I have read that without it on your car would run hotter, the shroud actually helps pull air in. There is no way that you can drive in Long Island without a fan, even going from Maryland to New York you can be sitting in traffic in Delaware.

I have a feeling that when I did auto-rx in the El Camino part of the reason my oil filters were loading up was because for many years I ran a 180 thermostat instead of the 195. Back in the day it was cool for us younger guys to put on a lower temp stat. of course my other friends did not keep there cars long and we did not realize that running a lower temp thermostat was just as bad for the engine as running a thicker weight oil.

 

[ted s]

unless its a race car put the stock clutch fan back on

 

[c3po]

Originally Posted By: ted s
unless its a race car put the stock clutch fan back on


I did get my hands on a clutch fan from a neighbor, but what is wrong with a flex fan on a street driven vehicle.

 

[OVERKILL]

A few things:

1. The 180 and 195 have no bearing on whether the car will overheat or not. This is entirely dictated by the cooling capacity of the system in place. This includes radiator size and airflow across said radiator.

2. The best way to wire an electric fan is with a thermal switch. There are two popular types: on/off at temp, and a variable controller.

The differences are basically:
-The on/off controller turns the fan on at a point you set. Then, when the coolant drops a predetermined number of degrees, the fan goes back off. The only disadvantage to this setup is the high current draw from the starting of the fan can be hard on low-current alternators.

-The variable controllers will slowly spin-up the fan and will only spin it as fast as necessary to bring the temp back down to the predetermined range. This makes them much easier on the charging system. They are also more money. A common supplier of these is DCC.

3. Flex fans are JUNK. As RPM increases, the blades flatten out, killing air flow. They make a lot of noise and are a lot worse than a clutch fan.


I've switched both my Lincoln and Mustang to electric fan setups. This was using the on/off style thermal controller from Flexalite, run through a relay due to the current draw of the fans in question; the controller is meant to handle fan current, but for Flexalite fans, not something the size of the Ford Mark VIII fan.

The relay is hooked to key-on power, so the fan shuts off when the car does if it happens to be on when you shut off the vehicle.

I set my on temp to be 185 degrees with a 180 T-stat. With the Mark VIII fan, that lead to about 15 to 30 seconds of fan run time.

I highly recommend this setup.

 

[c3po]

The Electric Fan that I still have only takes 9 amps too run.

I understand about the 180 or 195 thermostat having no bearing on whether the car will overheat or not. But I do believe that a lower temperature thermostat may lead to more junk not being burned off inside of the engine.

Painless Wiring sells a thermal switch kit that turns the fan on at 200 degrees and off at 180 degrees, but I have a 195 thermostat.

If I go this route I would rather put a on/off switch.

I can see the flex fans flattening out, but probably not at 1500 to 2000 rpm's. Most of my driving is cruising around and the fastest I drive this car is maybe between 50 to 55 m.p.h. and on the highway ever now and then maybe up to 60 m.p.h.

When I cruise around my town I am lucky to get the car up to 45 m.p.h., the reason I drive this slow is because we have a lot of deer in our area as well as cops with there radar guns.

 

[Gary Allan]

Brent, you should have a pipe plug that you can pull on your intake. You need to find a simple thermal switch for a early-mid 80's carb'd GM (or any other) electric fan'd engine. They didn't have computers to handle those things. A direct electric themostat ..just like on the wall in your house. You run that to the switch side of the relay ..and run the battery to the heavy contact part of the relay. If you don't have a big enough pipe plug, you can just rig a tee fitting in the bypass circuit. Same deal.

Then you can forget about it.

 

[demarpaint]

Brent, you mentioned to me a clutch fan setup your neighbor gave you. What not just use that and call it a day? In 1983, that's probably what the car came equipped with anyway. They worked just fine. Take the plastic flex fan and trash it. Besides the car has a new T-Stat and Radiator, so I would think the cooling system is in good working order. All it needs is the clutch fan, and you're GTG. JMO

 

[SHOZ]

Flex-i-lite makes a simple universal adjustable temp switch. Connect it to ground a relay to turn the fan on and off. Connect relay/fan power to a hot in run circuit, perhaps through another relay to handle the large load.

FLX-31147 is the part number.

 

[Chris142]

IMO most electric fans do not move enough air. A stock, correctly working clutch and fan will move 10,000 cfm @ 2200 rpm. Most electric fans are less than 3000cfm.

Flex fans are junk too. They are extreemly noisey and they kill fuel milage. Never put a flex fan on a vehicle used for towing. The 1st time you downshift to pull a hill the fan flattens out, moves no air and the thing overheats.

I see this every summer when somebody decides to put a flex fan or electric fans on a heavy motorhome thats towing a bunch of atv's on a trailer up Cajon pass here in Socal.

 

[eljefino]

Sounds like he only needs to get rid of as much heat as he makes idling... the ram air takes care of his moving/under load airflow. Electric fan would be ok for this. I'd go with gary's thermoswitch and add a secondary toggle. That is if you want to fiddle which I think you do... by not remaining stock.

 

[c3po]

Originally Posted By: eljefino
Sounds like he only needs to get rid of as much heat as he makes idling... the ram air takes care of his moving/under load airflow. Electric fan would be ok for this. I'd go with gary's thermoswitch and add a secondary toggle. That is if you want to fiddle which I think you do... by not remaining stock.


eljefino, is 100% correct, the only time I need the fan is if I am idling a long time in traffic.

I picked up a clutch fan from a neighbor for the meantime and I will see how this affects my mileage, I am not ruling the electric fan out, but I will probably have to say no to the flex fan.

This car is unusual in that I do not have a A/C Condenser up front, so there is unrestricted airflow coming through the radiator.

I have an Edelbrock High Flow Water Pump, and a Robertshaw High Flow Thermostat on there, and an aluminum radiator.

I also have shorty headers and a dual exhaust with high flowing Dynomax Ultra Flow SS Mufflers.

I did keep the fan shroud on the car, I still need to put the clutch fan on, but when I start the car, the temp comes up to 190 degrees or so and stays there while I am driving.

I pulled into a parking lot and it took almost 2 minutes to go from 190 degrees to about 210 degrees or so. I have gotten away with no fan because when I am sitting at a light the temp will go up a little and then the light is green and I am moving.

I have an oil pan with an extra quart of oil capacity and I have done 2 treatments of auto-rx, so I do not know if this helps keep it at temp better.

I also do not have a heater core on this car, I have a small hole drilled in the thermostat as a bypass and to relieve any air bubbles, so all of the coolant is going through the engine.

Why did I remove the heater core, I had a header bolt that broke off and I was either going to have to lift the engine out or take out the heater box. I put a plate over the opening in the firewall. Before I could not get to the back 2 spark plugs, I had to take the front tire off too get too them.

 

[Chris142]

Originally Posted By: c3po

I also do not have a heater core on this car, I have a small hole drilled in the thermostat as a bypass and to relieve any air bubbles, so all of the coolant is going through the engine.


You don't need that. The engine has a built in bypass. Thats what the small hole where the water pump bolts to is.

 

[c3po]

Originally Posted By: Chris142
Originally Posted By: c3po

I also do not have a heater core on this car, I have a small hole drilled in the thermostat as a bypass and to relieve any air bubbles, so all of the coolant is going through the engine.


You don't need that. The engine has a built in bypass. Thats what the small hole where the water pump bolts to is.


Can someone explain this, I have never heard of such a thing. The manufacture of Stewart Water Pumps said that since there water pump did not have a provision in the pump for a heater hose outlet that a small hole had to be drilled in the thermostat for a bypass.

He also went on to say that with this small hole drilled it would keep the temps in the cylinders more uniform because there would not be a constant flow of hot coolant and then cooler coolant.

 

[OVERKILL]

Originally Posted By: c3po
The Electric Fan that I still have only takes 9 amps too run.

I understand about the 180 or 195 thermostat having no bearing on whether the car will overheat or not. But I do believe that a lower temperature thermostat may lead to more junk not being burned off inside of the engine.

Painless Wiring sells a thermal switch kit that turns the fan on at 200 degrees and off at 180 degrees, but I have a 195 thermostat.

If I go this route I would rather put a on/off switch.

I can see the flex fans flattening out, but probably not at 1500 to 2000 rpm's. Most of my driving is cruising around and the fastest I drive this car is maybe between 50 to 55 m.p.h. and on the highway ever now and then maybe up to 60 m.p.h.

When I cruise around my town I am lucky to get the car up to 45 m.p.h., the reason I drive this slow is because we have a lot of deer in our area as well as cops with there radar guns.


That's a pretty mild fan. The Mark VIII fan (which will cool just about anything) draws something north of 30 amps to start the high-side. It also moves copious quantities of air.