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Best electric rad fan

6K views 44 replies 19 participants last post by  BogiesAnnex1 
#1 ·
What's your recommendation for an electric radiator fan for a stock 1986 chevy 350 in a 29 ford? Think best price here. I'll be replacing a 14 inch mechanical fan that doesn't like parade mode above 90 degrees.
 
#12 · (Edited)
Mechanical fans(single vs single) will almost always pull more air then electric. There are exceptions. But they are not cheap. Dollar per dollar the mechanical will keep that engine cool better while costing a very marginal hp difference.



I would play around with seeing if you can fit a 7 blade (6 if you can not fit a 7) fan from a 80's Chevy truck. The 7 will blow your hat off and you can hear it when the thing is actually turning.

The fan/clutch can be picked up at a junk yard and unless you have a electric water pump will bolt right up. The clutch can be checked for good operation with a heat light. Once again you will hear when it comes on and watch the gauge drop in "parade" traffic. A new clutch can be bought for cheap and bolted on quickly if the junk yard one is not turning on/off when it should.






But, you asked about electric fans.
I prefer to run 2 small fans vs one big fan. I have even run 3 before. The reason is that you can cover more area with 2 or 3 small circles then you can with one massive one. A shroud pulls the air towards that one fan. But by having 2 or 3 you have that blade right there already. With 2 or 3 fans you can also set them to come on at different points drawing less amperage.
Right now I have one coming on at 195 and another turning on at 210 which keeps that temp right around 215. Both fans are using independent controllers drawing 25 amps each. It is just less strain on your alternator then placing the load on it all at once.

I am cheap at heart so I tend to hit up junk yards. My favorite fans are ones without shrouds from the factory.

OK I have not taken a picture of the ones before I cut them up. All I have is a video. But what you are looking for is the factory fans that have the ring(shroud) around the fan blades. Or (my favorite and in the video) where the blade is actually curved.


The ring is good. But if you can find one with the "lip" that little lip pulls air in from around the fan itself.

Here is a ring from a lumina.
http://ecx.images-amazon.com/images/I/511vf77Qt+L._AA250_.jpg

Here is a ring from a grand prix.
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/5i4AAOSwIgNXqNZw/$_1.JPG

Here is my favorite fans. The actual blade has the ring with the lip that pulls more air around the fan blade and the picture below is almost what you will find in the junk yard. The metal piece is replaced by plastic.
http://www.wright-here.net/images/olds/electric_fan/fans-1.jpg

Electric Fan Installation

You can cut these down and melt the corners together to fit most radiators. I have laid them vertically, and horizontally(in the video) to fit them in almost anything.

The motors are tough. I have abused them through water, ice, sand, they were made to last. If they do go out they come out easily. Hey its a stock part so your not looking for a company that may have changed hands.

Here is my current project(one of 4 ongoing) just to show you the fan/blade that I am talking about more then anything.
 
#16 ·
Here's why you gotta have a fan shroud. Consider this: 16 X 16" radiator core with a 16" diameter electric fan mounted to the core with those push thru ties.

Radiator core frontal area is A rad = 16 X 16 = 256 square inches

Electric fan area is A fan = Pi X 8 X 8 = 201 square inches

That leaves 256 - 201=55 square inches of radiator core not effected by the fan

55/256= .21 or 21% of rad core not effected by the fan. That's over 1 fifth.

Obviously if you have a bigger rad core than 16 X 16" which most people do, with the 16" fan, the percentage of unaffected core area goes up dramatically.

Let's say you have a 16 X 20" rad core with the same 16" diameter electric fan.

Rad core frontal area is A rad =16 x 20 = 320 square inches

Electric fan area is still 201 square inches

That leaves 320 - 201 = 119 square inches of unaffected core area.

119/320 =.37 or 37% of rad core area unaffected by the fan. That's over one third.

It gets even worse if you have an AC condenser and a trans or engine oil cooler out front to restrict air flow. Shrouds are a must to avoid in traffic overheating. You also must have a big enough radiator to begin with. The auto manufacturers use the smallest radiator they can get away with to keep cost and weight down. Then we come along and modify the engine or put in a bigger engine and find out the hard way, the original radiator doesn't make it.
 
#18 ·
Lotta good info here but after taking measurements looks like I don't have enough room for an electric fan even if I move the radiator forward as far as I can. I'm running a 14 inch 6 blade fan now and looks like there is only room for a 15 inch fan max. Don't know if 1 inch will make much difference. Probably going to rig up a shroud.
 
#19 ·
I want to bring up something that nobody has mentioned yet.

When you are looking at good high CFM Fans you see literally nothing on the back side of the fan except 3 or 4 legs used to mount the electric motor.

On the cheaper fans you see a grille on the back consisting of rings about 1/2" spaced apart. You would not believe how much restriction that plastic grill causes. it also impedes airflow at highway speed when the fan is off. If you have a fan like that I suggest you remove those rings.

The quality electric fans shown in this thread, if you notice have open backs. Also note the OEM fans are open to the rear. If you are concerned about getting a finger in there Pant the area Red and remember to keep the Gerfingerpokin digits out of the way of the fan.

I had to bring that up. I see fans on eBay rated at some absurd CFM and when you look close they have so much restriction it is a wonder they move air at all.

That is all I got on this fan thing.:cool:
 
#24 ·
what temp thermostat are you running??
is it a quality t-stat?? like a Stant or ACDelco??

sometimes a higher temp t-stat will stay more in control/stable in traffic..
its much easyer to cool the water down to 195*, than trying to cool it to 160*..

does it cool good on the hiway now?? what temp does it run on the hiway??

looks like the only other option is a shroud,
no room for a electric fan without moving the radiator forward..
the good electric fans are usually 4" or thicker..
 
#27 ·
I'm running a 180 degree stat now. Running down the road it stays at 200 maybe 205. It's just in stop and go traffic in above 90 degree temps that it starts heading towards the 230 mark. I've got 1 inch between fan and radiator and I can only move the rad forward maybe an inch and an 1/8. Not enough room to do anything with.
 
#25 ·
I've used electric fans on quite a few of my race cars. Higher HP and therefore higher cooling needs. The Derale brand fans always performed great. Better than several other brands I tried. Moved good cfm, fairly quiet (considering), built well.


If going for one of the higher CFM systems just make sure to supply enough power as they do pull a lot of amps. Especially on start up. I've got one dual setup that pulls 30A each for a total of 60A startup needed.


Anyway, that's the brand that has satisfied all my needs for electric fans. No complaints.
 
#26 ·
X2 on Derale fans, they perform great for me too and are compact enough to fit where others don.t.
I have two much like "Bryonski" above on my 36 with stagared on temps to lesson the on demand, even then when the second fan comes it will lower the idle speed due to current load. I
Upgraded my alternator and wiring to meet the demand, so it gets a little pricey, right at $600 bucks with the fans, alternator and wiring upgrades on mine.
But they do the job well!
 
#30 ·
good deal checking the gauge..

put the thermometer in the bottom of the radiator and see if its getting a good temp drop..

if it has a good temp drop? it may be a water flow problem??

16"x18" core is not very big, so it must be thick??
how many rows of tubes?? what size tubes??
 
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