I put a flex fan on my Van... and the A/C in that also blew cold... You know, They have different styl clutch fans, The thermo one is what I would reccomend, But it isnt that hard to pick up any fan, with out a clutch, to just try it... Even youtrs, removed from the clutch, use a spacer, and hook it up direct...

Or just mount an electric one in front, on a toggle switch.. to see

 

just checked the cluch and it is turning the right way. On the flex a lite web site they say the fan should be 3/4-1 inch from the radiator is this right? My clutch sets about 3 inches from the radiator. One thing i have noticed is only about half of a fan blade sets into the fan shroud i would think the fan should set deeper in the shroud. But one thing about it the fan never makes a roaring sound and i didn't realize it until to nite. They do make spacers to move the fan deeper in the shroud wonder if i should try it? And get another fan clutch.

 

It's your fan clutch. If you don't hear the fan roar when it heat up you have the wrong clutch or a bad clutch. When my truck gets hot the fan gets loud for about 40-50 seconds and I can literally watch the temp gauge drop. Towing 8000lbs in town or in the mountians I never get above 210, normally it sits on 195-200.

Make sure you have a thermostatic clutch, not the other type. Fan clutches come in two types, thermo and percentage of slip (there is another name for those, but I can't remember it..) The best clutch to buy is a Ford Factory clutch, that's also the most expensive. I have a HD NAPA clutch in my truck, it works great.

Edit: we were posting at the same time.. Fan halfway in the shroud is perfect.

 

I agree with that... I was touching on the fan clutch difference, but I am not sure of the names either, cuz I just make sure it is the thermo one. The only thing, with out getting to technical... make sure the air has someware to go, not air pulled threw the radiator, past the fan then into an obstructtion, and boucing it back. I would say there is a happy medium some where, in reffrence to your fan, shroud, and space between your fan and radiator. SO when you have the engine at 1500 rpms, a peice of paper should stick to you radiator, in the front. If Enough air is moving by.

 

I had a 95' 302 that had a similar problem. Low miles (almost new). Took back to dealer many times. Replaced pump, fan, clutch, sender, t-stat several times, different temp t-stat, etc. blah, blah, blah. Still the same problem. Finally a mechanic drilled a 1/4" hole in the flat part of the t-stat. Problem FIXED!!! Since that has happened, I have heard about this more than once. I think some t-stats even have this "by-pass" feature built in. I even did this on a couple of other trucks myself. Always comes up to proper temp and stays ROCK steady. Try it, cheap to do and if it doesn't work, you are only out the cost of of a t-stat and gasket!! Let me know if you do and if it works for you.
Craig

 

I think you may be running too lean; with your mods(I assume you have the efi Comp cam) the motor is definitely going to throw more heat than stock, which was a lot to begin with. If you can adjust your AFR with the Anderson PMS, try running it richer, say 12.5 to 13.0, def. don't go above 13.

Just b/c optimum AFR is 14.7:1, most motors cannot run that lean, due to inefficient designs(cooling abilities, exhaust scavenging). A race motor that never has a real load put on it may be fine, but a truck motor that pulls a heavy truck plus whatever else, def. needs a richer AFR.

As an example, I have an '07 GT500 that I've bumped up to 600 rwhp, and the tune is set at 11.5 AFR. The supercharged motors in current Fords, and even adding superchargers to current fords, everyone runs richer AFR's, and it has been dyno-tested and shown that the richer AFR doesn't lose any hp. Now, naturally aspirated motors don't need to be that rich, but I've seen lots of modded ones running 12.5 to 13.5, but I've never seen them leaner.

If you can change the AFR with the PMS, it's worth a try, what have you got to lose? I would bet money on it that this is def. your main problem.

Since I did the BBK Cobra TB and port matched inlet, and custom 4" cold air, mine has been running lean, that I'm am trying some things to richen it back up. I have an SD efi, though, not the MAF, which I'm jealous, I wish I had. I know I picked big power, I would guess at least 40 rwhp, it really pulls good right to the 4200 shift point.

Once I get my lean issues sorted, I am going to run against some of my friends moderrn trucks, incl. a few diesels, to see how this old beast of mine does, and will be videoing them, and will post on Youtube. I'll make sure to post a link.

 

I think i fixed only a hot day will tell. I got me a new fan clutch today i took the old one off and did a spin test of the 2. Of corse the new is harder to spin so took both of them and stuck them in 200 degree water. the new one was hard as hell to spin like it should be the one off the truck had no change still spun with no effert. So don't use one of those Hayden clutches as they are junk. I tried to get one from ford but they had to order it so i went with a torqflo from auto zone. So far so good there is a major difference of air flow at idle to it has never moved air like that. But i will know for sure tomorrow when i put it to the test. Thanks to everone for the help

 

Your blade is positioned correctly, relative to the shroud. The flexalite site spec of 1 3/4'' is for no shoud.

 

I fixed it part of the problem was the fan clutch that either broke down really fast or never really worked. The other problem was the thermostat i put a new 180 degree stat in when i rebuilt the motor. I checked it in a pan of water with a temp gauge it starts to open at 205 and 210 it is half way open and closes at 160. I checked it about ten times this shows once again new stuff isn't always right.

 

Glad you got it resolved and nice job validating the fan clutch failure. Now get back to burning some gas...

 

Distance from the radiator is irrelevant as long as the fan blades are operating at the rear opening of the radiator shroud. You do not want the blades completely inside or outside the rear opening of the shroud. I have never seen a flex fan help a cooling issue.