Cooling Decisions - Need Opinions

6T5 Cbra · #1 (**permalink**) 09-30-2002, 08:37 PM

I'm looking to replace my existing radiator and fan and would like to solicit opinions. I'm running a FE390 (fairly well built) and for the most part I can keep it cool. I do run into overheating concerns on the very warm (95°+) summer days when I run into slow (or stopped) traffic. I want to eliminate the concern once and for all.

Here's what I think I've narrowed it down too. Keep in mind that I will do all necessary shrouding so that's not a concern with either setup.

Here's the radiator I'm looking at. I've compared it to radiators from Griffin and BeCool and don't see a big difference from this one other than lower cost (maybe there's more to it than what meets the eye). This one is 28" x 19" aluminum double core.

http://store.summitracing.com/partdetail.asp?part=22776

Fan Option #1 - These dual 11" fans from Spal pull 2780 cfm (combined) and will probably do the trick. It definitely has it in the "looks cool" department. Even though it comes with a shroud of it's own, I would need/want to fabricate some perimeter shrouding. One thing I did noticed about this fan is that it seems to draw a lot of amps (25-36). Does this really matter?

http://www.spal-usa.com/pdfs/11Fans.pdf

Fan Option #2 - This 16" fan from PermaCool pulls 2950 cfm and should definitely do the trick. With a little custom shrouding, I think it would look pretty good as well. The aluminum blades are stiffer and probably get a better bite, thus the higher cfm. Can't seem to find the amp draw (will have to call to find out) so that may be a concern.

http://store.summitracing.com/partdetail.asp?part=10634

I want the fans to be as effective as possible but not obnoxiously loud. Not that I could hear it over the exhaust anyway.

Anyone have experience/opinions they would like to share?

Sorry for the long post but I only want to do this once and be done with it.

Thanks,

Gene

A Snake · #2 (**permalink**) 09-30-2002, 09:45 PM

Gene,

With a very healthy 427 S/O I used a 3" thick aluminum Walker radiator, made to fit. I had a simple 16" fan, no special shrouding. I watched the temp gauge and only turned the fan on if the temp started to climb significantly. Like you, slow traffic on hot days. I didn't have problems with over heating at all.

I don't mean to be unnessecarily redundant here, but do remember that even when the gauge says 200,or even 220 you're still ok. Your cooling system is under pressure and will not boil until as high as 230-240, depending on the release pressure of your cap and what the radiator itself is built to withstand.

The big worry is getting the engine oil hot enough to "cook" it. You aren't going to do that at 200-220. Not even close.

If you're worried about boiling over, try installing a higher pressure cap. Check with the maker of your current radiator to see what it is built to withstand in the way of pressure.

Now, if you're constantly running up in the 200-220 range, even on cooler days, you probably do have an undersized radiator/fan issue.

As to shrouding, there isn't much you can do for the low speed problem, except to get a fan or fans that give you the most coverage area of the radiator's cooling fins. At higher speed, you're not having aproblem and probably won't, because the gaping hole in the nose of the car lets a LOT of air in. That said, if you install the aluminum shrouding in the nose of the car like an original has, you will assist your cooling all around. First, all of the air going in the nose is forced through the radiator. Second, engine heat is not getting to the front side of the radiator where the cool air is. Without this "nose job", at low speed, the fan will blow the air through the radiator, it will mix with engine heat and come back around for another trip thriugh the radiator.

For me, this wasn't an issue, so I never did put the aluminum in the nose. It probably won't be for you either, with the right radiator and fan combination.

BTW, I goofed more than once and let mine get up in the 240-250 range, before turning on the fan. As soon as I did though, the temp came right back down. Even on 95+ days, mine would not get over 200 with the fan running.

Dean Hornbacher · #3 (**permalink**) 09-30-2002, 10:04 PM

Take a look at Vintage Air out of Texas, They make a 18" monster 3700 cfm electric fan . I have one. I originally had a 16" Black magic fan. It did not quite get it durring the summer. Switched to the Vintage Air unit and now I can idle around in 100 deg. heat and engine temp stays at 195 deg. ( I am running 180 deg. therm). Give it a look see.....

Whaler · #4 (**permalink**) 09-30-2002, 10:14 PM

What were you presently running for a rad and fan?

Also for the others who have posted why not use a temp controller to do your fan control with a manual overide.....That way you don't have to keep your mind focused on the temp gauge let alone all the others things in busy traffic.

I have a custom 4 core brass 16x20 with a 16 inch puller on a control with bypass. I also have a high volume edelbrock water pump and Marsh underdriven pulley setup. 180 thermostat

I expect it to do the job come this summer when its on the road. Hell I don't know whats next if it didn't .......lol!!

Waterwetter??

Tim

PS Don't forget , shrouding will work against you when the car needs to have free air flow thru the rad. Shrouding at the fan it self sometimes works against you if its too restrictive. Nose shrouding in aluminum is a good idea...How does the rad sit in your car on a slant or straight up and down?

John Wais · #5 (**permalink**) 09-30-2002, 11:10 PM

Gene
See me Saturday - Mine are your first two pictures.
John W.

6T5 Cbra · #6 (**permalink**) 09-30-2002, 11:19 PM

A Snake,

I can usually keep myself out of situations that give me overheating worries. My real issue is that I'm just tired of having to even think about it. Right now I'm running a 18# cap and I feel a little hesitate to go to higher pressure. What are you running?

As far as the fans and shrouding go, greater coverage seem like a good thing. The single fan covers 201 sq in verses the dual at 190 sq in. With a little shrouding and the high fan cfm, I'm hoping to eliminate running hot for good.

Dean,

3700 cfm!!! How loud is that fan? Does this thing help your 1/4 mile times?

I sure like the sound of the 100° heat and 195° temp. What size radiator are you running?

Whaler,

Right now I'm running a 2 core Griffin radiator (25" x 19"), 180 thermostat, and unknown fan. Fan is temp controlled (on at 185°) as well as switch controlled if desired. Still creeps up in temp on hot days and slow traffic. If you take a close look at the pic of the Spal fan you can see some rubber flaps at the top of the their shrouding. These flaps actually open up when air is forced through the radiator. When the air is being drawn through by the fan, they are 'sucked' closed to force the air through the radiator. I figure I can fab something like this up on whatever shroud I use.

John,

Same radiator too?

All,

The reason I am changing the radiator is not because I think it is terribly undersized, but because (and I shutter when I say this) it's a 'cheby' inlet/outlet design. My plan is to install a stock expansion tank (exiting to passenger side) to clean things up and give it a more original look and at the same time, end the temp concerns once and for all.

Thanks for the replies guys. The help is much appreciated!

Gene

Roscoe · #7 (**permalink**) 10-01-2002, 07:44 AM

You may want to consider contacting Afco Racing. They recently made a radiator for me with AN fittings, drain, no filler for 255.00.
Very nice radiator.

If you call ask for Frank. He could probably recommend one based on your setup.
http://www.afcoracing.com/

Roscoe

wadesdad · #8 (**permalink**) 10-01-2002, 09:09 AM

Gene,

I'm using a Griffin radiator and a Summit brand 16" puller (P/N SUM-G4904). The only difference between this and a Be Cool is the outer box (BCI-75042). My friend has the Be-Cool.
I have no shrouding other than that on the fan.
The hottest I get, just off the highway at a stop light is 205 F. ANY other time I'm at 185-190.

I used the metal one as you've shown - as a pusher, without proper shrouding. I ran much hotter. The blade also flew off once!

I've seen the dual fans used also. They work fine. The SPF cars use a similar arrangement.

DAVID GAGNARD · #9 (**permalink**) 10-01-2002, 11:27 AM

Gene;

Go far the twin fan set-up. I ran the single fan,in fact the same identical one in your picture and had terrible luck with it.. I custom made two different shrouds and it did not do the job.....I'm presently using a single fan off a Caddy or Olds I go at a local body shop and I can idle in 100 degree heat for 45 to 60 minutes at 180 to 190 degrees..........

The dual fan set-up has far better shrouding than you can build and will work better IMHO.........

Actually in the course of two years I tried four different electric fans and more different shrouds till stumbling onto the Caddy fan....It is 17" with curved blades and does not pull as much amperage as I thought,very happy with the results......

David

Bish Wheeler · #10 (**permalink**) 10-07-2002, 09:48 AM

Gene,

I use the SPAL fans and they are sweet. They do, however use a lot of current as you saw. I kept burning up relays, so I went to double relays (one on each fan) and have had no more problems. They definately do the job on even the hottest days.

Bish

chopper · #11 (**permalink**) 10-07-2002, 11:43 AM

From an earlier post on the Arizona Cobras forum:

To steam or not to steam, that is the question...

This is sort of a summary of my take on the "overheating FE syndrome" and how I went about trying to resolve the problem. I ended up with a new Griffin custom-built unit, two rows of 1.5 inch tubing, 3.5 inches thick and shaped to match the height/width of the original ERA unit. Changed from antifreeze to distilled water/Water Wetter and this seems to have resolved the problem. High temps in traffic are about 208 degrees. No shroud necessary, although that was the next step if necessary. Currently running no thermometer, just a restrictor plate, but will probably drop in a 180 deg unit because I noted that the cruising temps are stabilizing at around 165 in the cooler weather. My experiences, anyway.

6T5 Cbra · #12 (**permalink**) 10-07-2002, 01:55 PM

Chopper,

I've gone ahead and ordered a Griffin radiator after several conversations them. After all was said and done, they said the 28" x 19" radiator with 1.25" tubes would work (hope they aren't wrong after reading your post). They based this on my motor (FE390 - 400-425 hp as a guess) and me using the Spal fan setup with about 85% core coverage.

Another thing they suggested was to reduce the water pump pulley size to about 70% of the crank pulley size to get more flow. Right now I am running an Edelbrock water pump so before I decide whether or not to make this 'ratio' change, I need to go through the numbers and figure out my current flow.

Right now, I'm using a 1" tube Griffin with a mediocre fan and no shrouding. With my current setup, the temp is really only a problem on hot days in traffic and/or idling too long. I would expect this new setup to perform much better. In the end, if I have to, I will shroud to 100%.

Thanks for the info, looks like I'll be pretty close.

Gene