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OB Dual electric fans mounting options

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Old 08-22-2011 | 01:10 PM
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Default OB Dual electric fans mounting options

My belt driven fan clutch won't hold the silicon lubricant so I am installing the dual fan set up from a Mercury Mystique using the Torque Flow fan controller from AutoZone.

In researching mounting options many have used the plastic rods that insert through the shroud and radiator core pulling the fan shroud up tight against the radiator face.

I have read some concerns online about potential long term damage to the radiator from the through the radiator plastic rods wearing holes on the water carrying tubes of the radiator.

The fan shroud sits inside the face of the radiator and thus shroud and fan assembly weight actually rests on the lower lip of the radiator and supported by plastic rods. Rods would appear to only hold the fan assembly against the radiator.

Anyone using an alternate attachment process?
Old 08-22-2011 | 01:12 PM
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i have ruined plenty of rads with the plastic thru radiator push things.... bend up some nice metal brackets that can hold the fans.
Old 08-22-2011 | 07:56 PM
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PM sent. Joe.
Old 08-22-2011 | 09:02 PM
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I'm currently doing the same and have bought the plastic rod mounting kit. I haven't fit the Contour shroud up to the face of the radiator yet. Can you use the stock Contour/Mystic shroud attachment points?
Old 08-22-2011 | 09:42 PM
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I built a frame in alloy L angle - mostly 1" x 1" or similar. Top and bottom rails bolt to the original shroud mounts . By cutting some of one leg off at the corners I locked the side rails to top/bottom with epxoy and 2 pop rivets - the epoxy stops the rivets working. I have the top & bottom rails with the horizontal side inwards (of the frame), vertical outwards, verticals the same way. This enabled me to pop rivet the plastic shroud of the double 11" SPAL fans to the frame. The frame mounts towards the (car's) left side, as the top hose on the right makes fitting a bit tight - had to relieve part of the frame to clear the tranny cooler lines also, but it slides down vertically into place pretty easily.
Note that there are differences between early and late radiator cores - my original rad had a core that ran right back close to the edge of its bottom frame, but the late (S4 anyway) cores are at least 10+mm forward of the frame edge. The point of this note is that if you build a fan assembly to fit an early core, it will be back and clear of a late core, and the later cores are also vertically deeper.
I got an old damaged top shroud half, repaired the fitting area, cut away some of the sides, and it now bolts on to the top mounting points and fits the air ducts as original, so unless you look behind the rad it all looks original. Removed the original AC front fan. I ran the original AC fan power to the left hand fan, ran a separate fused line from the hot point to a relay to drive the RH fan, which relay is triggered off the LH fan power. Holds the temp just below the second white line in ambient of ~100F with AC on. Since I have just fixed a flaky earth on the dash, maybe the temp readings will change a bit....
Hope that makes some sense....
jp 83 Euro S AT 53k.
Old 08-22-2011 | 11:35 PM
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Originally Posted by atb
I'm currently doing the same and have bought the plastic rod mounting kit. I haven't fit the Contour shroud up to the face of the radiator yet. Can you use the stock Contour/Mystic shroud attachment points?
I cut the supports off so the shroud would fit inside the lip of the radiator. Not really any evident place to use those as is for securing the fans to the car.

I used some rubber door edge guard strip from Pep Boys around the edge of the shroud to avoid the edge of the hard plastic shroud from contacting the radiator surface.

Think I will look at attaching some brackets to hold the fan in place versus the plastic mounting rods through the radiator.
Old 08-23-2011 | 08:27 AM
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https://rennlist.com/forums/928-foru...dual+fan+setup

should get you all you need to know.

is a very well written thread with lots of pictures
Old 08-23-2011 | 09:41 AM
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Originally Posted by he_mech_usmc
https://rennlist.com/forums/928-foru...dual+fan+setup

should get you all you need to know.

is a very well written thread with lots of pictures
That is a great thread. I had read and participated in earlier. Challenge is he used the nylon rods which have raised concerns about long term damage to the radiator. My radiator looks different. I will post some photos tonight.
Old 08-23-2011 | 11:00 PM
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I have a Behr radiator with the oil cooler fittings (not used). Not sure if this is the original radiator. It has a 3/4 inch lip around the edges that the fan shroud fits into nicely. I added some foam padding strips to the bottom radiator lip and some door edge rubber guards to the raw edge of the fan shroud to help avoid chaffing against the radiator surface.

I am thinging about resting the fan shroud on the inside lip of the bottom edge of the radiator and using the upper air tube scoop attachinging points to mount some metal straps to secure the top edge of the shroud.

I am concerned about the wieght of the fans being born by the bottom rail of the radiator. Any thoughts?
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Old 08-23-2011 | 11:16 PM
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That lip between the core and the rear adge of the bottom strap tells me its a late radiator - is your hood a little hard to latch fully? Mine is since I put in a replacement rad like yours - they are a bit deeper, different no of tube rows vertically and horizontally.
I would add a bracket at the top to spread the weight between top and bottom straps myself.
Hope the fans do the job for you, its a cheap way to do it. Looks like it wouldnt be hard to add a couple of blow-open flaps like the SPALs and others have.
jp 83 EuroS AT 53k
Old 08-23-2011 | 11:23 PM
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plenty of options for pre-fabbed brackets too, in lieu of the nylon/plastic:
http://www.summitracing.com/search/D...s/?Ns=Rank|Asc
Old 08-23-2011 | 11:34 PM
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Originally Posted by jpitman2
That lip between the core and the rear adge of the bottom strap tells me its a late radiator - is your hood a little hard to latch fully? Mine is since I put in a replacement rad like yours - they are a bit deeper, different no of tube rows vertically and horizontally.
I would add a bracket at the top to spread the weight between top and bottom straps myself.
Thanks JP. No issues with hood closure. I will definitely look at rigging some straps to hold the top side of the fan in place and take some of the load.
Old 08-24-2011 | 01:21 AM
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we just used a large puller fan on the inside of the radiator. if you have the AC fan, as well, you can wire it up to come on when the puller is set to come on, usually with the temp sensor at the bottom of the radiator.

mk
Old 08-24-2011 | 08:41 AM
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Originally Posted by mark kibort
we just used a large puller fan on the inside of the radiator. if you have the AC fan, as well, you can wire it up to come on when the puller is set to come on, usually with the temp sensor at the bottom of the radiator.

mk
Thanks Mark. I am wiring up to a Torqflo fan controller (autozone). It has its own relay and fuse. I am tapping into the ignition wire signal to the front fan for the on/off signal to the fan controller and then will use its own thermostadt to control fan turn on tem.
Old 08-24-2011 | 02:40 PM
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It really is amazing what a close fit these fans are on the 928.
The plastic ears on the side have since been removed, but they did not interfere with the fit at all.
Check it out:



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