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Opinions on an addition of a helper electric fan

Posted By: MidPenMopar

Opinions on an addition of a helper electric fan - 04/08/13 07:48 PM

One of the things I have been waiting to do is I want to install is a helper electric fan on my roadrunner's 383. normally I don't have any issues when driving but the engine will start to overheat if I am sitting in traffic on a hot day for any more than a few minutes.

I have asked a lot of my local car club folks and I get the range of replies from "Its the best thing they did to help cooling" or "If you need one your have other problems you should address first as the stock radiator should be sufficent". Then the debate over puller or pusher fans come into play as well.

So far I have had the stock 22 inch recently radiator flushed out and cleaned. I am running straight distilled water and some soluble oil as an additive. I also installed a higher output water pump and am running a stock clutch fan.


So I was thinking of just adding a front pusher fan that I can operate when only needed via a switch but I wanted to get some opinions from people that have done this before to what really works best.

Thank you
Stu
Posted By: cjskotni

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:00 PM

I will take a crack at this one. :-)

I would think a big block car should have a 26" radiator and not a 22" which would be correct for SB or /6. This would be the first thing I would upgrade to address your cooling issue.

I have heard mostly negative things about using pusher fans from "they do little to nothing" to "they hurt cooling". I have heard some say they can actually obstruct airflow through the radiator when you are cruising because they sit in front of it. At idle, it might help some, but I would not pursue this course of action. In addition, you will most likely have to upgrade the charging system to handle the extra current draw since you will want to run that fan @ idle where your alternator output is at its lowest.

Also, make sure your fan shoud is well-fitted (better have one). If I were you, I'd see about going to the larger radiator first. I think a 22" radiator with a BB is a little tiny.
Posted By: Exit1965

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:03 PM

Hi Stu. For the idling in traffic problem.. I installed 2 small Spal pusher fans. 8 or 9 inches..for ATVs. They sit at the bottom of the radiator opening basically behind the bumper. So they do not restrict airflow through the grill. I rarely need them but when they are on it will start dropping the water temp no problem. I run them with manual switches. At the top they are connected using those plastic screws that have a plastic nut on the other side of the radiator. The bottom are held on with zip ties to small holes I drilled in the body.
Posted By: MidPenMopar

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:10 PM

Quote:

I think a 22" radiator with a BB is a little tiny.



Yep that is the factory radiator that Mother Mopar felt was good enough for my 383 for some reason though.
Posted By: RapidRobert

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:10 PM

Quote:

normally I don't have any issues when driving but the engine will start to overheat if I am sitting in traffic on a hot day for any more than a few minutes.

If it recovers when you get moving that tells me that you need more airflow or water flow (or both) & more likely to need airflow. A smaller WP pulley will speedup the fan & the WP & will give you room to run a larger crank pulley which will speed em up even further plus a side bennie of speeding up the alt (always needed). Alot of times just flushing a rad wont clear the cores much (rodding is good but dangerous on weak tubes) but if it recovers quickly when you get moving then you are good there. I'm assuming your fan depth is good & you're running a shroud. Is the front grill unobstructed? An anticav plate on the pump would be good. . I've never ran an electric fan in addition to a regular fan so no opinion if it would help but I'd think that it would if it didn't obstruct much. Just an electric fan by itself is inadequate from what I've gleaned on here about em.
Posted By: rapom

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:20 PM

I used this one on my 68 charger because I had the exact overheating problem at idle plus my A/C would stop blowing cold at idle. Installing this fan solved both issues.

http://www.the-fan-man.com/shop/size-pus...316f4ddd4b70a22

But you may have to upgrade your alt.

I have it wired to come on automatically with the a/c or if the temp goes over 175.
Posted By: 70Duster440

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:30 PM

Fan shroud? That can make all the difference. I cooled my 440 with a 22" 3 row, shroud, and solid fan.
Posted By: MidPenMopar

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:46 PM

Quote:

Fan shroud? That can make all the difference. I cooled my 440 with a 22" 3 row, shroud, and solid fan.



Yep i have a nice factory shroud and the fan is about 2 inches away from it.

Attached picture 7659720-Roadrunenrbackfromtheshop2013035.JPG
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:56 PM

Quote:

...

So far I have had the stock 22 inch recently radiator flushed out and cleaned. I am running straight distilled water and some soluble oil as an additive. I also installed a higher output water pump and am running a stock clutch fan.

...



Do you have a stock fan shroud on it?

Could also have to do with the carb tune and timing curve/events of the motor.
Posted By: RapidRobert

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:58 PM

I believe you want the fan to be ~2/3 of the way into the shroud. Can someone clarify
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 08:59 PM

Quote:

Quote:

Fan shroud? That can make all the difference. I cooled my 440 with a 22" 3 row, shroud, and solid fan.



Yep i have a nice factory shroud and the fan is about 2 inches away from it.



What is the amound the fan is sunk into the fan shroud opening? Like 50/50 in and out. Or something else?

What is the minimum gap between the fan tip and shroud edge? Probably not 100% perfect consistant gap all the way around and that's fine.
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:01 PM

Quote:

I believe you want the fan to be ~2/3 of the way into the shroud. Can someone clarify



50/50. Half in and half out.
Posted By: 62maxwgn

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:07 PM

Straight water is not the best coolant !
Posted By: cjskotni

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:09 PM

Quote:

Straight water is not the best coolant !



Straight water will transfer heat better than anti-freeze or the water/anti-freeze mix.

However, your boiling point is not going to be near as high as with coolant added so always a danger of boiling the coolant which could blow a hose!
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:13 PM

Quote:

Straight water is not the best coolant !



It removes heat better than anti freeze.

It's not the best resistance to freezing for sure though.

http://www.turbomagazine.com/features/0703_turp_cooling_system_additives/viewall.html

Attached picture 7659764-TurboMagazineCoolingResults.jpg
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:27 PM

Quote:

Quote:

Straight water is not the best coolant !



Straight water will transfer heat better than anti-freeze or the water/anti-freeze mix.

However, your boiling point is not going to be near as high as with coolant added so always a danger of boiling the coolant which could blow a hose!



50/50 Antifreeze mix only raises the boiling point about 11-12 degrees F.

A 15 lbs radiator pressure cap raises the boiling point another 45 F.



The much more important value in the cooling system is what’s called the Specific Heat Capacity. The heat capacity is basically how much heat energy the coolant can carry out of the engine and to the radiator.

Posted By: dOrk !

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:33 PM

On a bone-stocker that is not going to be RPMed a lot .... a shroud WITH one of those OEM big-bladed flex-fans works well ....

Pusher fans are not worth a HOOT ..
Posted By: RapidRobert

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:38 PM

OT, On the (warm weather only) stock car: straight water & a can of water pump lube & antirust & some water wetter or several drops of dish soap
Posted By: MidPenMopar

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:46 PM

Quote:

Quote:

I believe you want the fan to be ~2/3 of the way into the shroud. Can someone clarify



50/50. Half in and half out.



So is that the definate answer for fan placement as i have always wondered what was the best. I thought as close to the radiator as possible, but it seems not.
Posted By: therocks

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:49 PM

My 65 440 that built large runs a stock never touched rad.Its a C body 22 with factory shroud.I run a SS 18 inch flex fan.Never overheats even at the track and idling in the 90s.When I street drive in the 80s,90s it still never goes over 190.My kids 62 300 built 413 also runs a 22 factory.It runs like mine never over 190.His was recored to a 4 row about 12 years ago.Rocky
Posted By: west

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:51 PM

I would go to a larger rad. as suggested. It is the easiest and prob. least expensive route. The high volume pump probably isn't helping either. It can actually push the water through the rad. too quickly not giving it time to cool.
Posted By: Challenger 1

Re: Opinions on an addition of a helper electric fan - 04/08/13 09:57 PM

First thing I would do is jet it up 1 or 2 steps and make sure it has enough timing at idle. Cost nothing!!

All stock cooling here Stu And I have been in some really hot places with no overheating at idle.

I'm starting to see a glimpse of your tune up from here Stu? Burning off the coating on your headers said something to me also?
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:00 PM

Quote:

Quote:

Quote:

I believe you want the fan to be ~2/3 of the way into the shroud. Can someone clarify



50/50. Half in and half out.



So is that the definate answer for fan placement as i have always wondered what was the best. I thought as close to the radiator as possible, but it seems not.



Yes, half in and half out of the opening edge of the fan shroud opening. That came from an engineer at a radiator manufacturer.

Also the diameter of the opening should be 10% the diameter of the fan.
Posted By: MidPenMopar

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:04 PM

Quote:

My 65 440 that built large runs a stock never touched rad.Its a C body 22 with factory shroud.



I am sure i have some other issue as i have had this problem since i got the car 12 years ago, but i was hoping to get a sort of cheap quick fix untill i rebuild the engine in the winter. So that was why i was thinking of an external fan.

I saw how well it worked with one of my friends did that with a $150 pusher fan on her 350 V-8 camaro and it did the trick for her when she was up ar Hot August Nights on a 100 degree day in a parade.
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:07 PM

Quote:

First thing I would do is jet it up 1 or 2 steps and make sure it has enough timing at idle. Cost nothing!!

All stock cooling here Stu And I have been in some really hot places with no overheating at idle.

I'm starting to see a glimpse of your tune up from here Stu? Burning off the coating on your headers said something to me also?



I'm thinking Stu might me getting hot in heavy gridlocked San Francisco metropolitan traffic.

So that's like driving for 1/2 hour plus then coming to a complete stop and for over 3 minutes moving at a walking pace at best in gear with an automatic.
Posted By: MidPenMopar

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:10 PM

Quote:


I'm starting to see a glimpse of your tune up from here Stu? Burning off the coating on your headers said something to me also?



Yep i am going to do that and richen up the fuel mixture this week to see what that does if anything. The problem is around here it never gets hot enough to test if that helps at all. So i have to wait untill i go somewhere warmer in the summer to see any results and i did not want to find out when i get stuck.
Posted By: RapidRobert

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:17 PM

Quote:

Also the diameter of the opening should be 10% the diameter of the fan.

Do you mean if it's a 12" dia fan then the fan tip(s) to shroud clearance should be 1.2"?
Posted By: autoxcuda

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:20 PM

Quote:

Quote:

Also the diameter of the opening should be 10% the diameter of the fan.

Do you mean if it's a 12" dia fan then the fan tip(s) to shroud clearance should be 1.2"?



1/2 of that number to get the difference in radius. Clearance would be .6" on each side from tip to opening edge in that case.
Posted By: RapidRobert

Re: Opinions on an addition of a helper electric fan - 04/08/13 10:23 PM

Forgot about the dia/radius difference . Got it & thank you & for the 50/50 info also
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