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Author Topic:   Electric fan
bigcityracer
Member
posted March 25, 2004 04:12 PM
3/8 dirt track. Can an electric fan keep the car cool enough?? I have set back the engine and now I would like to eliminate the fan..


racer17j
Member
posted March 25, 2004 04:23 PM
yes it can kkep it cool if you have a big enough one you also will have to run an alternator whick along with the weight of the fan adds front end weight so kinda weigh the options i guess


Special Ed
Member
posted March 25, 2004 04:26 PM
JUST SET MOTOR BACK AND THE RADIATOR IS ALONG WAYS AWAY FROM THE FAN. I RAN ELECTRIC FAN ON MY MINI STOCK AND NO ALT FOR 2WKS AT A TIME, WITH NO CHARGE.
WHAT CFM WOULD BE RECOMENDED.
THANKS


racer17j
Member
posted March 25, 2004 07:42 PM
just get a fan spacer and a good shroud will take care of the distance or just move the radiator back aways never hurts to move that weight back 3-4 inches also helps keep it out of harms way a little better. no matter how good a battery you have your gonna use alot more juice to pull a fan thats probably twice as big and to turn over your motor takes alot more juice along with the hei. you'll notice on here alot of guys stress that tou need 13+ volts to run a stock hei at it's peak a battery only puts out 12-13 max then you start pulling a fan off that and your gonna have troubles keeping it to par


bigcityracer
Member
posted March 25, 2004 09:11 PM
Hey thanks 17j never new the part about all the juicy required for HEI. Thanks I will run the alt. Still pondering the electric fan idea. I like the idea of no fan to give horses back to the engine.


Raz_900
Member
posted March 25, 2004 11:11 PM
The problem you'll run into is heat soak and not having space for a big enough fan(s). You'll need at least 4000 cfm and the best 16"-18" units aren't quite 3000 in puller mode. So you could use dual fans, http://www.flex-a-lite.com/auto/html/27inch-electric.html, or put a 16" puller on all the time and say a 12" pusher on a thermostatic switch to kick on during cautions.

Most fans pull 15-30 amps so you definitely need that alternator. Permacool, Spal and Flex-a-lite are good manufacturers to check into for electric fans.

Pickel
Member
posted March 26, 2004 07:11 AM
I ran twin electric fans on my street stock and worked well...It was a 355 11 to 1 sportsmen 2 heads and 2bbl..cept the car about 190-200 all nite.. the alt was ran off the rearend so the weight is in the back...


bigcityracer
Member
posted March 26, 2004 07:22 AM
Pickel!!!! How due you run an alt off the rearend??


WesternAuto17
Member
posted March 26, 2004 07:46 AM
I have experimented with electric fans and this is what I learned. If electric fans are set up properly, they only need to be on when the car is stitting still and maybe under cautions.

What you have to do is build an "air box" between the front of the radiator and the grill opening of the car. To get ideas on how to do this, look at a stock Monte Carlo SS from the eighties. I use a Performance Bodies early style Monte Carlo nose with a second grill cut beneath the "stock" opening.

The "air box" has to have as few holes as possible so that as much of the air entering the grill as possible, is forced through the radiator. This forced air at race speed is more than any fan, mechanical or electric, could ever hope to pull through the radiator. If the "air box" is built right, you can shut the fans off during races. I built my box out of roll plastic, its can hard to work with, but in the event of a hard front hit, the plastic will break before its tears up the radiator.

In order to keep it cool at idle, you still have to build a shroud on the back of the radiator. I made mine of 1" square aluminum tubing and sheetmetal. Again, the only holes that can be in the shroud are the holes for the fans or they will not pull air through the radiator. The fans I used are (2) 11" Speedwaymotors fans with an aluminum Howe 19"x26" radiator. If you really want to get fancy, you can a thermostat to automatically work the fans.

Electric fans are a lot of work, but I think its worth it to loose the mechanical fan. At 6500rpm, the less things spinning on the front of the motor, the better. Along those lines, I run an alternator regardless of what fan set up I'm using, but thats another debate.

bigcityracer
Member
posted March 26, 2004 08:08 AM
WEWSTERNAUTO17 Thanks for the info, my Corolla mini stock has that design in front of the radiator. But I never thought about doing it to the street stock. That's why we ask questions. It's to easy to over look simple thinks with so much going on.


WesternAuto17
Member
posted March 26, 2004 09:36 AM
This is how NASCAR type stock cars and real street cars are set up. I've even seen street cars with plastic doors that are pushed open (by air) when the car is moving, but close at idle. That might be a little overkill for a street stock.

Electric fans work great when set up right, but don't work at all when they're just slapped onto the back of a radiator.

I kind of wonder if they really provide any great benefit over a mechanical fan, but I bought the fans and was determined to make them work. I talked to a drag racer once and he told me that he gained .2ths in the quarter mile with a 406 by removing the mechanical fan and installing electrics. I'm just a humble circle racer, but even I know that 2 tenths is a lot in drag racing.

Pickel
Member
posted March 27, 2004 07:42 AM
I made a bracket to bolt it to my 9 inch and welded a pully behind the yoke.. as soon as I get it hucked up I will try to get some pics..


fastow
Member
posted March 27, 2004 08:40 AM
FASTOW any other info on the rad & shroud? Looked at Griffin's web site could not find it.


racer17j
Member
posted March 27, 2004 10:00 AM
if you read his post it says right there it's the weight not the robbing of power then and if you throw a belt on it your not gonna lose your power steering and fan in the process


UNVRNO
Member
posted March 27, 2004 12:02 PM
If you set your motor back, go ahead and set your radiator back also. I do not recommend electric fans.


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