Fan Delete test fit

[Iforgetalot]

First day of the fan delete 'project" on my 99 540i 6spd. I am installing a Flex-a-Lite 16" S blade model 398 mounted on a Jegs aluminum shroud 25-5/8" W x 17-1/2 H x 1/2" Deep, part number, 555-52065. So far it looks like it going to fit really nice. I ordered the shroud with the intention of fitting it inside the radiator perimeter resting against the cooling fins and ducts but the one they sent is longer top to bottom with a total of about 18-3/4". At first I was having the usual reaction one gets when receiving the wrong part but since it was here I figured well lets give it a try. It turns out this size will work just as good if not better. The way it is now the shroud will rest against the top and bottom radiator tab with just about 1/8" to spare on both sides. It will be fastened using the included bolts and nuts through existing holes. The install leaves 1" between the fan and the engine so I will be installing engine and transmission mounts for peace of mind.

Some may ask why and all I can tell you is that I have replaced the fan clutch twice and both times it worked as intended. I am not worried about the fan coming apart or any unmeasurable HP gain claims. I am trying to get my car to sound like a car and not a taxiing vintage propeller airplane.

Not sure which fan controller to use. Trying to decide between these PWM models: Derale, Hayden or the Flex-a Lite. If any of you have any recommendations on a controller please let me know. I will be ordering one before Friday.

Test fit.jpg Test fit 2.jpg

[ViolinARC]

Looks sweet!! The clearance seems sketchy though. How much space between the back of the fan and the engine?

[Iforgetalot]

Looks sweet!! The clearance seems sketchy though. How much space between the back of the fan and the engine?

One inch. Can increase to 1.3/4" if I remove a plate on the back of the fan that seems to serve no purpose other than displaying the model name. I think its ok, fingers crossed.

[Chisum]

The fan clutch/fan setup does take HP. Check out this video. https://www.youtube.com/watch?v=ZXdLgaFXZzs

Chisum

[geargrinder]

Looks sweet!! The clearance seems sketchy though. How much space between the back of the fan and the engine?

Agreed. There are lower profile generic fans out there, I might look around for one of those?

Sir Forgetsalot - Clarify on the part number mixup - is the PN you mention the same that you received, aka if somebody wanted to order that would they get that? Also how are you mounting the explosion I mean expansion tank on the shroud?

I'm still running visco delete , AUX fan only, and it works great but the OEM shroud (which is pretty functionless at this point) makes it harder to deal with the blower belt tensioner and stuff... Have considered going to a different shroud to try to gain a fraction of an inch here and there... I have an M5 shroud and tank which I also wanted to try but funortunately that was a tighter fit than the 540 unit... MAYBE I could make it work but that'd only be for the benefit of using the M5 explosion tank instead, wouldn't gain me any space there.

[Mach540]

Why would you want to use an M5 exp tank?? That amber goiter really messes up a beautiful engine bay.

[Iforgetalot]

Agreed. There are lower profile generic fans out there, I might look around for one of those?

Sir Forgetsalot - Clarify on the part number mixup - is the PN you mention the same that you received, aka if somebody wanted to order that would they get that? Also how are you mounting the explosion I mean expansion tank on the shroud?

I'm still running visco delete , AUX fan only, and it works great but the OEM shroud (which is pretty functionless at this point) makes it harder to deal with the blower belt tensioner and stuff... Have considered going to a different shroud to try to gain a fraction of an inch here and there... I have an M5 shroud and tank which I also wanted to try but funortunately that was a tighter fit than the 540 unit... MAYBE I could make it work but that'd only be for the benefit of using the M5 explosion tank instead, wouldn't gain me any space there.

Gg to be honest I don't know if its a part number mixup or bad part description on their part. I ordered part # 555-52065, the box says 555-52065 but there are no numbers stamped on the shroud itself so I have no way of knowing if it is indeed the correct part. I looked in their web page for a shroud with measurements matching what I measured here at home and could not find shrouds with height of 18-3/4. So I am going to assume that if you order what I ordered you may get what I got, a shroud that has different dimension from what their webpage shows, but will fit very nicely on the outside of your radiator instead of inside the perimeter resting against the fins.

I am planning on mounting the expansion tank using the factory shroud or more accurately, part of it. The factory shroud was broken by the PO so I'm just modifying it to fit my needs. I am trying to keep at least the top cover so that it hides the radiator and snake hose while at the same time keeping the mounting area for the tank. I did some test fitting this morning and the shroud has a lot of support bits and pieces getting in the way of a tight easy fit. I am considering just cutting the tank mount and riveting it to the shroud. For future maintenance the shroud would have to come out with the tank mount which does not seem to be a big deal, in theory.

I made some more room for the fan and now feel a lot better about spacing issues. See pic.
Attachment 605495


I also notched and bent the top and bottom corners to give a better seal around the radiator.
Attachment 605496

Will update some more tomorrow, my garage gets really hot, really fast. Not my dd so I'm taking it easy.

After all the test fitment I will probably use a small diameter hose to seal the ends by cutting it length wise and sliding it over the shroud's left and right edge.

[geargrinder]

Hmm. Sectioning the oe shroud and riveting just the top bit to the generic sounds like a decent approach.

[Iforgetalot]

Her is the expansion tank mounted. I used only the portion of the shroud that supports the tank and the small "tray" under it. I may clean it up a bit more but as it is now the tank is firmly mounted at the same height as factory. I use three rivets to attached it to the aluminum shroud. I'm pleased with the results. Its 100% functional and about 80% aesthetically pleasing. I wanted to keep the part of the shroud that covers the top of the radiator but it was broken where it attaches to the drivers side and it just wouldn't fit right so for now this is it. On the other side of the shroud I am going to mount the controller, I just have to decide which one to get.

Expansion tank mounted.jpg

[geargrinder]

Cool. Very interested. Maybe I should do this. So if it wasn't for your shroud having issues, you'd have retained the whole top rail for cosmetics, yes?

[philly98540]

Interesting and different approach. I like it. What is the gap between the shroud and rad fins? Looks about an inch. Should be enough for air flow on perimeter zones.

[Iforgetalot]

Cool. Very interested. Maybe I should do this. So if it wasn't for your shroud having issues, you'd have retained the whole top rail for cosmetics, yes?

Yes I would have liked to keep the top of the shroud so that at a glance it looks stock and clean. The way it is now you can tell there is something "missing". I also removed and replaced the shroud with the tank holder in place a cpuple of times and it is surprisingly easy. I think it beats removing visco fan and shroud for extra space when needed.

Interesting and different approach. I like it. What is the gap between the shroud and rad fins? Looks about an inch. Should be enough for air flow on perimeter zones.

The shroud is listed as being 1/2" deep. Looks like it's more, maybe by 1/8 or so. I do believe it will draw air from the entire surface, maybe not as much around the edges but still better that slapping it against the fins like I've seen around in some cars. The fan cutout on the shroud is exactly 16", the fan I ordered is about 1/8" sorter on width, leaving a small gap left and right of it. I am going to seal that gap with some well placed sealant so as to minimize the areas where air can bypass the radiator.

[Iforgetalot]

Update:

Took the 540i for a 400 mile two day round trip. I think I can safely say that the electric fan is doing its job very well. I drove it harder that I normally do and I saw no evidence of temp creeping up. The hottest it got was at 109 during slow stop and go traffic. I believe we can call this fan delete a success, at least for normal street driving.

Just for future searchers, here is the thread that talks about the controller I ended up using.

https://www.bimmerforums.com/forum/s...ature-settings

Final controller install
Fan controller_2.jpg

40 AMP Fuse
Fan controller fuse.jpg

[douglawrence42]

I’m considering this. Any updates? Still happy with it?


Sent from my iPhone using Tapatalk

[Iforgetalot]

So far so good. No regrets. No overheating issues of any kind. If I were to buy another 540i, I would do the same.