4.3LXJ
08-02-2011, 09:18 PM
I have had good fans on my XJ, but in the coming weeks I am looking at the possibility of going up a 40 mile long hill and climbing 6,000 feet and flat towing a vehicle in the process with the wife with me which means the air needs to be on too. I have a good aluminum radiator but wanted to upgrade the fan so I could get more air through the radiator. I have drug this Ford Taurus fan around with me for about 7 years now and decided it was time to use it. It makes a good upgrade over the stock fan and is capable on the high speed of moving 4800 cfm if it has a good shroud. So here is how to make the shroud to fit in the space where the belt driven fan is.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_18-44-21_728.jpg
The first thing to note is that the XJ 4.0L radiator is only 11" tall and the Taurus fan is 16" in diameter. If you bolt up the fan directly to the radiator it will not pull 4800 cfm, but more like 3800 cfm. If you are a whiz with geometry you can figure it out for yourselves. So you can have some of it above the radiator or below. In my situation, I only had about 2" to play with above so I chose to put the extra 5" of fan below. This is the shape I chose to use, although you could use a more square shape if you desired. I started with a flat piece of aluminum. I have the advantage of having a shear and brake in the shop, but I have made two other shrouds with angle aluminum pop riveted. Besides, I can't bend a 19" piece of hardened aluminum in my brake. So I used some 20 gauge galvanized steel, same stuff duct work is made out of and spaced the fan out a little farther than you will be able to with a 4.0L engine.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_18-44-42_763.jpg You can see if yo look closely I pop riveted it all together, which is not hard to do if you are using sheet metal or angle aluminum. The idea is to space the fan a little back behind the radiator and duct the air so it has to go through all the fan. Here is the final shape.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_20-01-34_958.jpg
Next it was time to cut out the space for the fan blade. I don't have a compass that I can draw a 16" circle with, so I made one with a scrap piece of aluminum, a drill screw and a sharpie marker.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-04_16-00-33_29.jpg
I used a saber saw with a metal blade in it to cut on the line, but I needed a hole to start with. A step drill makes a nice large hole quickly.
Here is the finished ducting on the shroud.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_15-32-38_200.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_15-32-28_661.jpg
Notice there is quite a bit of fan on the outside edge that would not be used without the shroud. This is the most efficient area of the fan.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_20-10-33_142.jpg
Next you have to get creative according to what you have to work with. I chose to use aluminum tubing and bend it with spring benders, the type plumbers use to bend copper tubing. However I have also used angle aluminum spaced out from the shroud in other projects. I then made a mounting plate to mount the motor to and welded the bent tubing to the motor plate and shroud. What you cannot see is some rubber grommets under the plate to help keep the motor quiet. Here is the finished shroud.
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1277.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1278.jpg
Notice in the photo there is a small sheet metal hook to go on to the stock radiator shroud mount. The other side rests on the frame rail where the notch is.
Here it is mounted in the XJ
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1267.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1268.jpg
Next, you have to wire it up. I like things to operate like OEM things, and since my wife needs to be able to drive this it has to be a no brainer. So here is my wiring diagram for it.
http://i649.photobucket.com/albums/uu215/warriorsuspension/Taurusfanwiring013.jpg
Now a few words of explanation here on this diagram. First I have functional AC. So it has to work both fans when it is on. Second, the fan needs to work on low speed during normal operation and high speed with AC or when the engine is working hard for extra cooling. The other thing is that both of my fans can pull 50 amps on start up, so heavy duty 12 gage wiring and 60 amp breakers were used for both. Also, don't try to use light wiring plugs on the breakers. Get 50 amp relays and plugs that attach that are rated for that much or you will start frying wiring and it will quit on you. I have already found out the hard way with my other fan set up. So don't skimp on this part of it. My primary sensor for the Taurus fan is a Gm sensor that goes on at 200° and off at 190°. It is located in the intake manifold next to the thermostat housing which holds a 190° tstat for right now. It operates by grounding the coil on the relay. This relay powers the next relay, which if not switched on will default to the slow speed on the Taurus fan. If however the coolant going into the engine is above 185°, the middle relay will switch to the higher speed and turn on the aux fan. Between the two they will pull an amazing 7000 CFM, which Griffin Radiator assures me will handle 600 hp on the engine. If the AC compressor comes on, the wire attached to that will kick both fans on even if the engine is cold and provide enough air going through the condenser coil at idle to give the same cooling as cruising the highway thereby giving you the coldest air possible at idle in traffic or wheeling.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_18-44-21_728.jpg
The first thing to note is that the XJ 4.0L radiator is only 11" tall and the Taurus fan is 16" in diameter. If you bolt up the fan directly to the radiator it will not pull 4800 cfm, but more like 3800 cfm. If you are a whiz with geometry you can figure it out for yourselves. So you can have some of it above the radiator or below. In my situation, I only had about 2" to play with above so I chose to put the extra 5" of fan below. This is the shape I chose to use, although you could use a more square shape if you desired. I started with a flat piece of aluminum. I have the advantage of having a shear and brake in the shop, but I have made two other shrouds with angle aluminum pop riveted. Besides, I can't bend a 19" piece of hardened aluminum in my brake. So I used some 20 gauge galvanized steel, same stuff duct work is made out of and spaced the fan out a little farther than you will be able to with a 4.0L engine.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_18-44-42_763.jpg You can see if yo look closely I pop riveted it all together, which is not hard to do if you are using sheet metal or angle aluminum. The idea is to space the fan a little back behind the radiator and duct the air so it has to go through all the fan. Here is the final shape.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-03_20-01-34_958.jpg
Next it was time to cut out the space for the fan blade. I don't have a compass that I can draw a 16" circle with, so I made one with a scrap piece of aluminum, a drill screw and a sharpie marker.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-04_16-00-33_29.jpg
I used a saber saw with a metal blade in it to cut on the line, but I needed a hole to start with. A step drill makes a nice large hole quickly.
Here is the finished ducting on the shroud.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_15-32-38_200.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_15-32-28_661.jpg
Notice there is quite a bit of fan on the outside edge that would not be used without the shroud. This is the most efficient area of the fan.
http://i649.photobucket.com/albums/uu215/warriorsuspension/2011-07-05_20-10-33_142.jpg
Next you have to get creative according to what you have to work with. I chose to use aluminum tubing and bend it with spring benders, the type plumbers use to bend copper tubing. However I have also used angle aluminum spaced out from the shroud in other projects. I then made a mounting plate to mount the motor to and welded the bent tubing to the motor plate and shroud. What you cannot see is some rubber grommets under the plate to help keep the motor quiet. Here is the finished shroud.
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1277.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1278.jpg
Notice in the photo there is a small sheet metal hook to go on to the stock radiator shroud mount. The other side rests on the frame rail where the notch is.
Here it is mounted in the XJ
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1267.jpg
http://i649.photobucket.com/albums/uu215/warriorsuspension/IMG_1268.jpg
Next, you have to wire it up. I like things to operate like OEM things, and since my wife needs to be able to drive this it has to be a no brainer. So here is my wiring diagram for it.
http://i649.photobucket.com/albums/uu215/warriorsuspension/Taurusfanwiring013.jpg
Now a few words of explanation here on this diagram. First I have functional AC. So it has to work both fans when it is on. Second, the fan needs to work on low speed during normal operation and high speed with AC or when the engine is working hard for extra cooling. The other thing is that both of my fans can pull 50 amps on start up, so heavy duty 12 gage wiring and 60 amp breakers were used for both. Also, don't try to use light wiring plugs on the breakers. Get 50 amp relays and plugs that attach that are rated for that much or you will start frying wiring and it will quit on you. I have already found out the hard way with my other fan set up. So don't skimp on this part of it. My primary sensor for the Taurus fan is a Gm sensor that goes on at 200° and off at 190°. It is located in the intake manifold next to the thermostat housing which holds a 190° tstat for right now. It operates by grounding the coil on the relay. This relay powers the next relay, which if not switched on will default to the slow speed on the Taurus fan. If however the coolant going into the engine is above 185°, the middle relay will switch to the higher speed and turn on the aux fan. Between the two they will pull an amazing 7000 CFM, which Griffin Radiator assures me will handle 600 hp on the engine. If the AC compressor comes on, the wire attached to that will kick both fans on even if the engine is cold and provide enough air going through the condenser coil at idle to give the same cooling as cruising the highway thereby giving you the coldest air possible at idle in traffic or wheeling.