SPAL FAN replacement: Is this the one?

[The Mighty Gryphon]

Not to split hairs here, Martin, but the system is designed to activate the fan before the engine overheats. It seems to work on my moto. That's why in a fully-functioning system, the fan activates before the temperature warning light is lit. An override switch keeps the fan from cycling in hot weather or traffic operation—which can be bothersome to some riders—besides allowing the rider full control over its operation.

I like the fan's cycling; it has old world charm. Of course, I'm not riding in the desert, or heavy traffic very often.

The override switch doesn't interfere with normal fan operation. 

[Laitch]

The override switch doesn't interfere with normal fan operation.

Didn't say it did.

[bizzaro]

My coolant starts pissing before the fan comes on. The override keeps that from happening..........as long as I am paying attention to my temp guage. Thank you jjj who gifted me the guage! 

And Gryph, it doesn't seem to. One time when I wasn't paying attention to my guage, the fan came on automatically. I tapped into my blue/yellow wire at the relay to put in the over-ride.

[Martin]

I don't override the fan in winter. I only do it in summer in traffic as a precautionary measure. I know that the fan will cut in before the temperature light. But a stinking hot day in traffic I'd rather preempt the fan. As I stated in an earlier post I can experience fuel vaporization problem under those conditions, and maybe turning the fan on early will help. I know it won't hurt.
Regards Martin.

[Filmcamera]

I use my override switch the moment I drop below an average of 30 mph.  If I don't I know the temp will start to climb and I just don not like to see the needle starting to get right up there. Apart from possibly shortening the life of the fan by running it a lot I see no harm in keeping the engine temp around the mid way point rather than the 3/4+ mark.

[The Mighty Gryphon]

Didn't say it did.

 "An override switch keeps the fan from cycling in hot weather or traffic operation"

Perhaps a poor choice of words.

[Laitch]

Perhaps a poor choice of words.

Those are a good choice, Gryph, there just aren't enough of them. —when it's turned on— might have been useful in there somewhere. You can stick that wherever it's convenient. :giggles

[Lumis]

I see everyone is using 6.5 spal. I can't find 6.5 version in EU. There is one in kbikepartsholand.com, but it's twice the price for included bracket. My father works with metal and he can laser cut same bracket for free. I only find this version of spal https://www.holley.com/products/discontinued_product/parts/30100358 which is 7.5. I've measured radiator and it still fits and some space is left for mounting. Can bigger fan work, without causing any additional problems?

[stokester]

tills.de  has a nice fan kit

[Lumis]

tills.de  has a nice fan kit

I don't see point of paying +-60eur fot bracket when I can get it for free. I need just fan not kit.

[frankenduck]

You don't need a fancy bracket to install a SPAL fan. I just use a couple of small pieces of 1/8" thick aluminum bar stock.




Will a 7.5" SPAL fan work? I think so. In the picture below I copied the fan above, increased its size by 15% (the difference between 6.5 and 7.5) and then pasted that to the radiator picture above to give an idea of what a 7.5 would look like.

[Laitch]

Can bigger fan work, without causing any additional problems?

It is likely that the smallest diameter fan that would do the job satisfactorily was chosen by BMW to keep production costs down; a larger fan should be okay. The one you've chosen is for 12V systems and doesn't seem to draw excessive amps in operation so it should work well if you can anchor it securely. It could be louder when running.


Please post an explanation of how you mount it, some photos of the project, and a review of its performance.

[RetroTexan]

Will a 7.5" SPAL fan work? I think so.

Has anyone actually attempted this? When you reinstalled the radiator with the larger 7.5" SPAL fan replacement, did you run into any collision issues with the frame/hoses/other components? My fan crapped out over the weekend (melted brush arms) and I'm currently thinking of going the larger fan route since Texas summers can get pretty intense. Would like to have a bit more piece of mind knowing I have a larger fan in an environment that these weren't necessarily designed for.

[Laitch]

The 6.5 puller moves air at ≈330 cfm; the 7.5 rate is ≈440 cfm. What many riders have done is install a fan switch to run the fan when they think it's needed. It should not be run all the time. With or without the override switch, the 6.5 has gotten high marks around here and using it could lessen anxiety about fitment. Some have installed fuel coolers because hot fuel within the tank radiates excess heat onto the legs; likewise, insulating the fuel rail and the fuel return line also have been done. Insulation beneath the tank has also been improved, including deploying the legendary johnny blanket.

The guide below has a few other suggestions. Some involve both BMW and aftermarket parts that are no longer found as new stock.

[RetroTexan]

Nice resource, thanks for posting it here. It looks like the 6.5" fan BARELY fits without interacting with the frame or other components (see the required adjustment of the hose clamp at the tube above the temp switch housing). So I don't think a 7.5" fan would work in this instance. I do very much appreciate the attention to detail in creating a mounting bracket out of 1/8" sheet aluminum for the new fan attachment.

[Lumis]

Nice resource, thanks for posting it here. It looks like the 6.5" fan BARELY fits without interacting with the frame or other components (see the required adjustment of the hose clamp at the tube above the temp switch housing). So I don't think a 7.5" fan would work in this instance. I do very much appreciate the attention to detail in creating a mounting bracket out of 1/8" sheet aluminum for the new fan attachment.

you got me worried about fan not fitting.. I already got fan and spend half day designing bracket. phew what a relief when i checked. that 7.5" spal is the same size as the OEM fan.
Screenshot 2024-02-27 at 18.40.45.png (35.94 kB . 497x576 - viewed 108 times)

[The Mighty Gryphon]

Instead of spending time making a new mounting bracket, just reuse the old mount. 

It only takes the better part of 15 minutes to cut the ears off the Spal fan, remove the old fan from the mount and pop river the Spal into the old mount.  That includes ovalizing the top hole in the old mount to line up with the threaded mounting hole on the radiator.  There is a discussion on making the modification here:

http://www.motobrick.com/index.php/topic,4313.0.html

The good stuff is in post #18 by Roadbandit.

This is the neatest retrofit you can do.  I had one on a bike that was totally destroyed in a collision and the modified Spal mount and fan were still usable and are still working in another bike 6 years later.

[RetroTexan]

Sooooo Frank’s photoshop skills were pretty spot on. I ordered the 7.5” Spal fan and it covers a slightly larger area than the OEM assembly. It BARELY fits in the frame due to some of the tabs interacting with one of the radiator hoses so I’m going to trim that off, slap some foam tape in there, and pray it doesn’t rub a hole into the hose.

Does anyone know the output of the OEM fan assembly? McKenzie's claims the 7.5” puller fan chooches at 366 cfm.

https://www.mckenzies.com/products/spal-7-5-puller-fan

Here are some pics for anyone looking at upgrading to a larger fan for warmer climates.