Radiator Fans and Shrouds

[tenoverthenose]

I just finished installing AC in my Wagoneer and now want to give the cooling system a bit more help. It hasn't gotten too hot yet, but I haven't pushed it too hard yet either. Currently my 258 has a mechanical fan, but it is missing the fan shroud. I'm looking at either getting a fan shroud or swapping the mechanical setup with a new electric fan.

Any solid opinions on this? Obviously the 258 can use every extra bit of power, so going with the electric has a good advantage. Either way, I'll probably add a pusher fan in front to help.

[rang-a-stang]

If you search this forum for fan conversions, there a few folks that have done threads on Electric fan conversions.

In my opinion, electric is the only way to go. You can build the whole system for well under $100 and get an OEM fan that has plenty of power and reliability for what you want to do.

In general, pushers are much less efficient than pullers. That's why 90% of OEMs put the fan inside the engine compartment (as a puller).

[tenoverthenose]

In my opinion, electric is the only way to go. You can build the whole system for well under $100 and get an OEM fan that has plenty of power and reliability for what you want to do.

Thanks, that's exactly what I'm thinking. Just to replace the mechanical fan shroud will set me back over $100, so I'm thinking of using this a a good reason to upgrade.

[Mr Carts]

I just did the Contour fan.

I am very pleased, no more watching the temp gauge rise at slow speeds.

It cost less to do the Contour fan then to buy the BJ's shroud.

http://www.rockauto.com/en/moreinfo.php?pk=365290&cc=1354395&jsn=552

[j10jim]

I just did the Contour fan.

I am very pleased, no more watching the temp gauge rise at slow speeds.

It cost less to do the Contour fan then to buy the BJ's shroud.


http://www.rockauto.com/en/moreinfo....354395&jsn=552

Have any pics? Also how hard was it to modify to work with the radiator.

[yossarian19]

I haven't gotten my project running but I too just did the contour fan.

I used a wood saw to cut the plastic tabs off the sides of the shroud.
After that, the rectangular Contour shroud fits like a glove. Seriously like it was meant to be there. You could not ask for much (anything, really) more out of a retrofit.

After that, I bent some sheet metal in my bench vise and drilled a few holes, bolted it together - and it fits like a glove.

You want to use 5" wide sheet metal and bend it at 2", this 2" leg will be where you bolt the fan shroud. That will keep it flush to the radiator.

I don't know for sure with the I6 but the V8 will give you gobs of space for it.

I bought the Contour fan new for not much money on Ebay, got some waterproof relays for darn-near-free from a newer S10 Blazer (pro tip- on the firewall, the S10s have four waterproof relays on a trick little bracket) and I'll either use an output from my EFI computer or an independent fan temp switch to turn it on. $125 tops, all in.

Engine Masters, a fun Youtube show all about engines, found that a factory fan clutch will soak up ~14 horsepower at 5,000 RPM. Let's say an electric fan uses 40 amps (it's less in real life) - 40 amps * 14.2 volts = 568 watts. Heck, say the alternator is only 50% efficient. 1136 watts, then. 746 watts per horsepower, so, when running the fans take only 1.5 horsepower at this inflated worst-case calculation. Saving 12.5 horsepower and probably 1 mpg is pretty nice! Not often you can modify something for $10 / horsepower.


EDIT: I seriously can't stress enough how easy this was. I've just about never had such a return on labor with an automotive project.

[rocklaurence]

I've done several Electric fans on different 4x4 vehicles and switched back to Mechanical. Didn't pull enough air and had grimlins

[Mr Carts]

The Contour pulls about 16 amps with both fans on.

At one point I had a 14inch Perma-cool 3000cfm fan installed but it did not work very well.

I took it off and went back to the stock fan.

The contour is a simple install.

I mounted the fan temp sensor in the output heater line (spliced in a tee fitting) as I used the Painless switch that has 1/2in threads.

Super happy with the Contour setup.

[Cecil14]

http://www.fsjnetwork.com/forum/viewtopic.php?t=5439

aa

[joe]

I'm not big on $$$ complicated electro fans. I don't even like the fan clutch doodads or worse silly plastic flex fan blades. I like rigid mount steel fans. Key is the cooling system components including fluid are in good condition. I would for sure run a shroud. Then if needed set up/space the fan so 2/3-3/4 of the blade area spread is covered by the shroud. You can buy various length alum spacers from an auto parts store. FSJ's even w/AC have been surviving for years with stock cooling systems. Since you're running a 258 It's at best and 87 or earlier. If the system hasn't been maintained appropriately over the last 30 years...most folks don't...I'd spend the money insuring the rad and block aren't full of gunk and up to spec before throwing $$$ band-aides at it. Fix the problem, not the symptom.

[Mr Carts]

A engine driven fan will not pull 3000cfm thru the radiator at idle.

I have the factory Tow package Trans cooler and the A/C condenser that completely covers the radiator.

Granted my shroud was missing so the fan was not pulling as much air thru the radiator as it should.

I installed the Contour fan to make sure at low speeds (this is when I was seeing the temps rise) that my A/C and Radiator were getting ample air pulled thru them.

In the summer I am driving out to our place in Wonder Valley (15 miles east of 29 Palm's, it gets very hot).

Today as I write this it is 115 in the shade, it was 120 last Tuesday.

I need the A/C to blast cold air are while sitting at idle while I am in the store or stopped for what ever reason.

My A/C is oversized at 22000 BTU with a 340cfm blower fan.

All of the interior air inside the Cherokee my goes thru the A/C unit every 45 seconds.

The stock fan just did not work without the shroud and I was not willing to spend the money on the BJ shroud just to pull it of and go with the Contour fan.

For me installing the Contour was the way to go.

BTW I have two heater cores installed besides the factory interior heater.

One is CJ-3 (56sq in)mounted on the driver side where the grill pie pan hole is, the other is a Ford Econoline rear heater core (80sq in) mounted under the front frame cross member.

This gives me an additional 136sq in. of cooling that goes right back into the block.

I have to block the air flow to both of them off, when it is below 70 as the engine will not warm up and the thermostat will not open.

The extra heater cores is a trick I started using years ago when I was going down Cabo for the summer.

I would spend the summers Surfing on the East Cape, I camped at Ship Wreck's.

The first summer I was there I had to drive with the heater on to keep the old IH S120 4x4 (with NO A/C) from running in the red on the temp gauge.

For the next summer I installed a Volvo 544 heater core behind the grill and from then on she ran cool every summer.

[tenoverthenose]

Thanks everyone for sharing your perspective and good information. As noted in other posts, I'm planning on driving my Wagoneer to Central America for a year, so I'm busy working out little kinks and making sure everything is reliable now while I have a garage and a parts store.

As this point, I'm planning to swap in the contour fan setup. It really sold me with the dual fans - I'm a sucker for redundancy. If one fan quits I've always got a spare to limp back with and if necessary I can always wire one up directly if I have a controller issue. Plus, removing stress from my water pump just seems like a smart move.

Also of note, the engine is in solid condition and was recently rebuilt by a reputable shop. The cooling system is otherwise working properly, it's just missing the fan shroud. Yesterday while driving in 110 heat with the AC on the temp started to climb. When I slowed down in traffic (and at stoplights) the temp started to climb fast and I had to shut off the AC.

And thanks Mr Carts for the idea about using an extra heater core. Maybe I'll plumb something like that up with a diverter hose setup where I could manually turn the extra system on or off depending on temperature.

[Cecil14]

You could always do a shutter type setup connected to a cable. Commercial vehicles have used shutters for a long time, as have diesel trains. Would be pretty simple to come up with something for a small heater core.


aa

[tenoverthenose]

Update: Yesterday I got around to installing the contour fan setup - quick and easy

For the fan mount, I trimmed all the tabs off it the fan and it slipped right up and against my radiator. In my 258 the radiator sits forward of the mounting brackets, so I was able to put screws along the sides through both the radiator brackets and fan. I should have taken pictures for clarity, but it's not going anywhere.

I wired it up pretty quickly and made sure it will activate with the AC system and it works great. It was a little over 100 here yesterday and it kept the engine nice and cool as I climbed through the mountains with the AC on. That alone is a noticeable improvement over my previous setup of a mechanical fan that was missing the shroud

Thanks again everyone for your input.