So here's my philosophical issue for today. Since installing the Vintage Air AC system, I've noticed my temps creeping up at long stop lights (common in south FL) in addition to the idle quality starting to get lumpy, to point that I shift into neutral to have it idle smoothly again. Once moving the temps drop and all is good again until the next long light. Without the AC system, the new Cold Case radiator, original fan and new shroud were all doing a wonderful job. But I had to install that AC...so time for an electric fan, right? Right!
So I've started to shop for all the bits I need and the Taurus Fan was the first item to come in. Here's where my question comes in: the radiator width is 26" and the shroud on the truck now is also 26" wide - covers all the radiator rows. The mechanical fan is 19" in diameter and is positioned about 4 inches away from the face of the radiator. The shroud around the electric fan is only 22" wide. This means that 4" or 15% of the radiator will be unshrouded. To boot, the fan is 18" in diameter. The saving grace is that the fan sits 1.5" from the face of the radiator compared to the 4" of the mechanical fan. So I guess the point of all of this is: is the fact that 15% of the radiator will never see the air flow created by the fan anything to worry about, or is the remaining 85% of the radiator pulling in at least 2500CFM of air more than enough to compensate for this? I would think about *******izing the 2 shrouds together, but it would look like hell and I'm pretty proud of the truck with the hood open.

As always, thanks for indulging my musings.

Geoff

 

If you go with the electric fan be sure that your alternator has enough amp output. With every electrical turned on be sure the voltage stays above 12 volts. I added 2 small 8” fans in front of the condenser which might be enough to control the heat. Try to get a mechanical fan that is the same diameter as the shroud.

 

Kenny,

Thanks for your reply. Didn't think of fans just for the condenser...I may have to look into that. I do have the power all squared away already with the 130 amp 3G for the last 6 months or so.

Geoff

 

The 2 fans I installed fit between the vertical grill strut. I am not sure if there is enough room for any larger than 8”.
Each one has it’s own fuse and relay.

 

My 02 Durango has a fan out front to push air through the condenser from the factory.

My 81 with a 300 six and factory AC and shroud also creeps up at long lights. I dont worry as it is not a lot and like you as soon as I start moving it comes right down.

I would not do way with the factory set up. I read where guys replace the factory set up, no AC, and they over heat, what was so wrong with the factory set?
You say the fan is 4 inches from the radiator how far into the shroud is the fan?
How much of a gap is around the fan tips to the shroud?

The blades of the fan should be half way in the opening of the shroud if to far the fan air is bouncing back off the inside of the shroud and about a 1" gap between fan tips and shroud.
The shroud NEEDS To cover the full face of the radiator fin area or it will not pull air through the fins to cool the coolant.
The shroud should also fit tight to the radiator or air will be pulled between radiator and shroud and not through the radiator.
You can have the fan 3 feet from the radiator as long as the shroud & fan fit right.
Look at the Mounte Carlos there was like 2+ feet between fan and radiator.

Your fan is it the factory non-AC fan the truck came with?
Did the factory use a different fan, blade count & pitch, than non-AC fans?
Maybe a clutch fan for AC and non clutch for non-AC trucks?
I know for my 81 it should have a clutch fan and the blade count is more than my non-AC fan I am running but dont know on the pitch?

I would look at the fit of your shroud to the radiator and fan to shroud and fix as needed and unless the temp goes really high at lights I would not worry.
What I do worry about is the AC blowing a little warmer as there is less air flow through the condenser when stopped.
I have used foam between radiator & condenser (cant remember if I put it back after timing cover work? so the fan pulls air through both as the air could of been pulled between the 2 but it still blows warmer.
I dont know if I have room for a pusher fan or not as I have not been that worried on it blowing warm or temp creep (yet).

Keep us posted what you do
Dave ----

 

Geoff,

Taurus fan works GREAT. Hot rod friends have been using them on every car they build. HOWEVER, common issue with these beast of an electric fan.

1. Two speeds (need some wiring/device to set the two stages).
2. HIGH amp load...this will MELT a Bosch relay in 2 days of driving (actually had someone melt one on first start up...)
Option A: That means you need a SERIOUS relay ( ) And then a SECOND one for the second speed.
Option B: Use a Volvo V70 Fan relay circuit. Yes it works and was build by Ford so you are betraying the brotherhood... https://www.ebay.com/itm/31369532669...oAAOSwz7dfIwDs
Either way you need 10ga/8ga wiring and a big fuse.
3. You can mount it with those pegs that go thru your fancy new ColdCase, or will need to built a bracket to mount it. I use those pegs from Derale (Derale 13001 Plastic Rod Mounting Kit, Silver)
4. Wiring temps at two levels, and then a third lead to turn it to high speed from the compressor wire.

 

Dave:

As my truck came with AC, I have to think that the mechanical fan that is installed now is the proper type for and AC equipped truck. Like you, I subscribe to trying to make the mechanical fan work, but I fear that even though installed optimally (proper fitting shroud and modern radiator), that I am still one traffic jam away from pulling over, shutting off the truck and waiting for the traffic jam to clear. Whether global warning, excess heat from my mild engine rebuild or whatever, I think the South Florida climate is too much for the cooling system in its current form.

PCM - are you essentially saying not to sweat the 100% radiator coverage of the fan? I have a Volvo relay ordered and a BWM temp switch coming. Fabrication-wise, I can mount it to the cold case radiator, but am I not to worried by the unshrouded 2" either side of the fan? I could install rubber flaps at the Taurus fan sides that will lay against the radiator to try and seal things off, or is this not necessary.

Thanks Dave and PCM!

Geoff

 

I wouldn’t worry about it. That fan pulls so many CFM that my truck never gets over 190 with a 180 thermostat. And yes, it is 110F here. Combined with a fancy ColdCase and you won’t have an issue unless your alternator can’t keep up.

 

Before I would do anything, fill all the gaps in core support and stop hot cavitating air from recirculating into radiator. This will help at a stop. All modern vehicles do this. Belly pan.

For a high quality E fan setup, a custom shroud needs to be built to PROPERLY FIT the radiator AND the fan. I almost never see this and many report cooling issues. Don't slap a e-fan on a bare radiator, or one with a shroud that BLOCKS airflow outside of fan area.

E fans work good a stop light but no so well pulling grades or heavy loads. The Taurus E-fan would have no hope of cooling my truck. I went with a large 20" mechanical ('89 F250 w/ 460) and a customized viscus clutch, high flow thermostat. I live in AZ, A/C blows cold oat.115+