Going to be doing an electric fan on the ZJ to help with stationary cooling. Looking at a Flex-a-lite Black Magic 180 which is their reco for the truck. 3300 CFM single fan unit.
I've never done an aftermarket fan before. Is it worth the extra $120 to upgrade to the soft start, variable speed controller over the standard on/off at a temp units? Both have provision for ac relay and override switches
Also, with a 195 tstat, at what temp would you turn on the fan?
I have had problems with those fans. if they get too hot the plastic housing/shroud that they set in will warp. I never understood this because they’re sitting against a rather warm radiator. Ever since then I’ve always pulled fans with the shroud from cars in the junkyard. By far the best I found where the fans out of Ford Taurus with the bigger V6.
In reply to dean1484 :
You and everyone else. They're getting hard to come by and are only marginal for the V8 in the ZJ anyway. Any better aftermarket options? Remember the 3300cfm number...
I have a Black Magic fan on my RX7 and it has an adjustable Tstat that came with it. I have been very happy with it. I have it set to come on around 190. It is a track only car so doesn't see any sitting in traffic so setting the run setpoint temp may be different. Mine typically just runs if I have to sit in line waiting to go out on track and then again for a minute or so when I get back to the paddock after I have shut the engine off.
I tried a single 16", 2800cfm electric to cool my 351 Cleveland in my 1969 Cougar. It wasn't capable of maintaining temps in traffic when ambient temps were in the mid-80's. I replaced that with a Derale 16833 fan shroud combo rated at 3750 cfm and that one has done the trick. I also installed an Autocool Guy PWM fan controller as the fans at full rip are LOUD. The controller uses radiator outlet temp to turn on the fans and ramps them up instead of just turning them on full blast. I've been able to maintain temps in all kinds of conditions up to 95F ambient parked and idling in full sun. I can also turn both fans on full speed with a toggle switch and that dropped my temps by 30F in a matter of minutes while in cruise traffic creeping along in first gear with mid-80's ambient temps. My fuel injection system can show temps and I monitor them all the time.
As an alternative to the Taurus fans, it was suggested to me to consider a Contour/Mystique/Cougar V6 replacement fan which sell for about $100 online. Other fans which the internet seems to like were Mark VIII and the previously mentioned Taurus. Some other OEM replacement fans I considered were from an Impala/Grand Prix with the 5.3 V8, a CTS-V fan or a new Mustang V8 fan. My though process was largest engine creating the most heat requires the most cfm.
In reply to wawazat :
ooh, good call on that Derale part number. I hadn't found that power pack series with the aluminum shroud. I like that a lot better, but i was hoping for something quieter than the mechanical fan. That may be what pushes me to the PWM type variable controller, just trying to keep noise down. I like the look of the Autocoolguy controllers too, none of the major market PWMs I've looked at had confidence-inspiring reviews. I assume you're running the 85 amp unit?
In reply to ultraclyde :
The Derale dual fan systems come in a variety of sizes. Measure carefully before you buy as I found out when I screwed up and bought the wrong size that Derale won't sell you just the shroud itself. I had painted mine before fitting it so no returns. I cut and modified it to fit and it's working fine. Check dims and water pump clearance as they can get a bit deep. Summit sells on ebay so when one of the 20% off everything specials tey run at times popped up I bought it. Free shipping at that price point and I had it within two days.
I ran across the AutoCool Guy when poking around on some hot rod forums and it had good reviews unlike every other PWM controller I saw. I'm using the NB-100. I got quick response to my questions and it arrived quickly after I ordered it. It's not water proof so keep a that in mind when you plan your install. Its also pretty big so I mounted mine in the trunk. The heavy gauge wires from the fan negative connection took some time and money to run. There is another highly regarded PWM controller from Delta Current Control, but customer service seems to be their biggest downfall from what I saw.
You can set up all the control you want with two relays. Have both relays power the fan on the high side. On one relay, ground the low side through the sensor and supply it with switched power. On the other relay, ground the low side to the frame and supply the low side with a jumper off the A/C clutch wire. $20. That way you have redundant relays and it will come on when it gets hot or the AC is on.
Keep the sensor kick-on temp about 5-10 degrees warmer than the stat. That way it's only kicking on if the factory cooling isn't cutting the mustard.
Suggestion... get the fan and zip tie it in place without wiring it and take a 20 mile highway trip. In rare situations, a pusher fan will block more airflow at higher speeds than it flows when it's on. Its not common, but I would hate for you to spend all the time installing it and wiring it only to find out that the truck has trouble cooling on the highway.
In reply to Curtis :
ehhh...I don't think 2 relays is going to get me variable speeds on the fans automatically slaved to the engine temp like the pulse width modulated controllers we're talking about. And these are puller fans that will completely replace the factory cooling.
wawazat - wow, they're that big? I hate not being water proof in a 4x4 application.... Have to think about the implications on that.
The Dorman 620-101 is a direct replacement for the Mark V111 and can be had new for $80-$100 bucks.
In reply to ultraclyde :
For a ZJ, do a Taurus / Mark VIII fan or find a used 5.9 fan (basically the same thing). I've got an extra 5.9 fan shroud / blade (needs a new motor) around somewhere if I can find a way to ship it. They move a lot of air and they're 2 speed, so there's less need for a variable controller.
As far as temps, for a 195 t-stat, I'd say on somewhere around 210 - 215 and off 5 degrees lower. If it's 2 speed, turn the high speed on around 220 - 225.
Do be aware, ZJs don't have great engine bay airflow, so you may find yourself fighting airflow and cooling issues above 50 mph with the electric fan.
Interesting options. I have no problem venting the hood in addition to the electric fan.
ultraclyde said:In reply to Curtis :
ehhh...I don't think 2 relays is going to get me variable speeds on the fans automatically slaved to the engine temp like the pulse width modulated controllers we're talking about. And these are puller fans that will completely replace the factory cooling.
wawazat - wow, they're that big? I hate not being water proof in a 4x4 application.... Have to think about the implications on that.
Good call on the puller. I thought we were talking about supplemental fans
In that case, strike what I said. Might be worth the coin to get a good controller.
ultraclyde said:Interesting options. I have no problem venting the hood in addition to the electric fan.
Check out a set of 5.9L hood vents or a set of aftermarket hood vents. They really let out a ton of hot air. Jeep put the 5.9 vents on the lower outer hood lines but i have seen a few that place them up top. The good thing about the jeep louvers is the rain catch pans that are installed with them. You dont have to worry about water intrustion.
In reply to kevinatfms :
The drip trays block 90% of the air flow through the vents, unfortunately. I cut the drip trays out on mine and the vents let out a lot more air now. And no issues with stuff getting wet (the driver's side just drips onto the airbox lid anyway).
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