Electric Fan Conversion

[Mr Project]

Anybody out there running an electric fan for the main radiator fan on their M30/20/50?

After finding out that my third new fan clutch is bad, (just out of the warranty period) I'm finally making good on my long-running threat to convert to an electric fan.

Pics and description in the next few days as I get it put together, the fan just came in the mail today. I just wanted to see if anybody else has done this already and has any wisdom to share.

Here's the fan I bought:



16" so it fits nicely in the stock fan shroud, and moves over 2,900 CFM, so it should cool sufficiently.

[specialE34]

can't wait to see the pictures and to know the results. which model fan did you get?

[rattlehedchris]

Electric fans go out too, except when the clutch fan goes out, the fan stays on, so at least you don't overheat. Despite this, I'm going electric, too. Looks like a nice fan you're getting, too. Just keep it maintained and you'll be fine.

[E34N]

OOOOHH.. another Mr Project project..

[attack eagle]

subscribed... because it is Mr. Project.

[atl530i]

I think Permacool makes a nice kit, but you would have to retrofit everything. Then again, that is what it is all about.

[ironie]

..snip
After finding out that my third new fan clutch is bad, (just out of the warranty period) I'm finally making good on my long-running threat to convert to an electric fan. ./snip

That is pretty bad luck. I hope you have better luck with the eletric fan.
It would be intresting to see what the draw on the altenator is before and after instalation, Not that I am completely sure how to do this.
I was just thinking of you this morning and wondering how the Corviar is coming along.

[Mr Project]

Sorry, I thought I had posted a link to the fan with the picture, but I forgot.

http://store.summitracing.com/partde...5&autoview=sku

It is a Perma-Cool fan, Summit Racing part number : PRM-19115.

In this case, the fan failed and wouldn't lock, so I could have overheated. I found this out while working on the A/C. In the past it has failed by locking up, and trashing the fan, throwing blades around. I've seen other E34s and E39s where the fan blades actually went through the hood when the fan clutch seized, so I'm constantly afraid of something like that happening again. Plus I'm tired of spending $90 every year on a new fan clutch.

[5271990]

You should retro fit wing mirrors that dip when you put the car in reverse just so we can see how its done aswell

[Craig S]

Fans explode on E36s too.

How are you mounting that? I'd love to convert mine too- I really don't like water-pump mounted fans. Are you going to trigger it off the aux fan sensors?

[atl530i]

That sucks. BMWE34.net had a good write up about that. I may not be tooooooo far behind you on that.

[nrodriguez5000@]

i thought about doing this just a couple days ago and almost scooped a aux fan from a 735i from a local junkyard....prolly couldve gotten it for 20 bucks

[Herb]

Mr. Project,
I am running ONLY an electric fan on my s52 e30, it is constant on - not temp triggered. ZERO cooling problems under very hard driving. I'll find out from my shop which fan they they used on Monday. Mine is a pusher mounted where the aux. fan used to be. (No a/c on the e30)
Herbert

[Mr Project]

Thanks, Herb, I'd be interested to know what the CFM is of your fan. I'm keeping the A/C, so I'll still have the aux. fan in front, this will be on the engine side of the radiator in a puller configuration.

Ok, I had about 30 minutes yesterday to fiddle around with getting this mounted, and I got it 'roughed in' in the fan shroud.

1 - This fan has steel bracketry that is designed to allow you to mount it directly to the radiator and run big zip ties through the radiator to mount it. I really hate that kind of install, just seems cheap to me and I think it runs the risk of killing the radiator. We all know that BMW's don't need any help killing radiators. So, I decided to mount the fan by attaching it to the fan shroud. I hope the shroud is strong enough to handle this...only time will tell.

So, here are the modifications to the fan bracket:

Original:


You can see that two of the 'legs' of the fan bracket fit pretty nicely in the stock fan shroud as-is. I just drilled a couple of holes in the shroud and with some 1/4" stainless hardware, they look like they will fit just fine.


However, you can see that the stock bracket does not fit on the top section of the shroud:

Obviously you could probably solve this with some $.50 brackets from the hardware store, but I like to find excuses to use my cutoff wheel and welder.

So...here is the bracket after cutting about an inch out, straightening it out, and welding it back together:

[Mr Project]

And here's the fitment into the stock shroud:




So, I'm hoping that between ripping trim pieces for my living room and re-shingling my roof today, that I'll be able to get this put together as well (I don't call myself "Mr Project" for nothing!)

My current plan is to use the current radiator coolant temp sensor used for the aux. fan to trigger a relay that will power this fan. The 'right' solution will be to get an adjustable box with a separate sensor, since this will mean that any time the car is up to temp (170 degrees) the fan will be on. Long-term, I'd rather have the switchover temp somewhere more like 180-190 degrees, but for now it's too bloody hot here to worry about the fan running a bit more than it needs to.

[E34N]

wow.. that looks really good. OEM looking.

[attack eagle]

any chance of possibly putting a large washer under the bolt heads to spread the load out a bit more on that fan shroud, and prevent the bolt heads from eating it up? Also same on the nut side between leg and plastic?

Otherwise, very nicely done.

[Desert BMW]

I hope your fan shroud is strong enough to keep like that. Where the upper left mounting bracket is located on your fan shroud is where my fan shroud broke and a chunk is missing right there. I don't know what caused it on my fan shroud, but thats right where there is a missing chunk of plastic about 3 inches long.

[Mr Project]

Yes, AE, this is just the rough mount. I'll have rubber isolators and big washers to help the plastic survive. I hope it is strong enough as well...I know BMW and plastic don't have a good relationship.

[nrodriguez5000@]

how exaclty r ya gonan wire this in? directly to the battery with a switch? or a more complicated method?

[attack eagle]

read...

My current plan is to use the current radiator coolant temp sensor used for the aux. fan to trigger a relay that will power this fan. The 'right' solution will be to get an adjustable box with a separate sensor, since this will mean that any time the car is up to temp (170 degrees) the fan will be on. Long-term, I'd rather have the switchover temp somewhere more like 180-190 degrees, but for now it's too bloody hot here to worry about the fan running a bit more than it needs to.

[Goat128]

i think he meant where do you tap the power.. i dont think you can get power from the radiator switch...

[Analog]

I hope the shroud is strong enough to handle this...only time will tell.

Sounds dangerous. My fan shroud broke in two pieces. I wouldn't trust that. But my shroud was 13 years old...

[jel]

I just examined the fan shroud on my car & decided I wouldn't trust it to hold the fan. Please consider metal arcs or ring around the center opening & 4 legs to the shroud corner mounting bolts. I really think the BMW plastic won't long tolerate the flexing/vibration. You do great work!

[brosher]

Electric fan FTW. It takes all off 30 seconds to pull the fan on my 323. e46's with manual trans came with electric fans from the factory.