K11 Owners Group

Gary Bennett · Posted: Thu Oct 09, 2008 9:42 am Post subject: Radiator Fan

Does anybody know how many AMPS the BMW Radiator Fan draws?
_________________
Gary
'94 K1100RS

RobWheatley · Posted: Fri Oct 10, 2008 5:49 am Post subject:

Have a look in your manual and the fuse will give you a pretty good idea of the rating, not sure at the moment and dont have mine to hand, will look later when i get home and post the answer if someone doesn't tell you before.
Rob
_________________
1999 K1100LTIC Smooth and Quiet Smile

Cruise, BFD & HID
1996 K1100RS. dead but not forgotten.

bmwmick · Posted: Thu Oct 16, 2008 12:31 pm Post subject: Re: Radiator Fan

Gary Bennett · Posted: Fri Oct 17, 2008 2:29 am Post subject:

Thanks Mick,

I'm installing a new aftermarket 200mm, low profile, brushless fan with far superior volume of air that it will shift and I needed to know what amps it draws to decide if it could run off the bikes fan relay. It can as the new fan only draws 3.5A.

I am also fitting a thermo switch which has an adjustable setting for the cut in temperature, which will allow me to dial in a lower temperature for the fan to cut in. This switch will work in parrarel to the existing BMW setup, so if my new thermo switch fails, I will have the BMW setup as a backup.

The above is stage 2 and 3 of my three stage "FIX THE HEAT" drama. Stage 1 was the fitting of the 3 core radiator. Once completed over next 2 to 3 weeks, I am positive that I won't have fried gonads anymore and I will have the engine running at a stable temperature in the hot Australian summer months. I will take photos as usual and post them when completed.
_________________
Gary
'94 K1100RS

Frank · Posted: Sat Oct 18, 2008 5:58 pm Post subject:

G'day Garry

Let me know how you go with the radiator conversion as I would like to do the same myself.

My LT runs hot in traffic especially in summer down here on the Gold Coast.

Also where did you pick up the 3 core rad from ?

Keep us all posted please.

Thanks Beemered

_________________
Ride safe

Frank
Gold Coast Australia

BMW 1997 K1100LT - White

Ulysses Member 33144
StruggleTown Tourers

RAL88 · Posted: Sat Oct 18, 2008 10:08 pm Post subject:

Hi Gary,

When I was putting in my 3 core I tried to find a brushless that was not outragiously priced. What did you end up getting and where? Also how are you looking at attaching it to the radiator?

Thanks,

Rich
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

Gary Bennett · Posted: Sun Oct 19, 2008 9:02 am Post subject:

Frank,

I've already done the radiator conversion about two years ago. I tried to buy a new radiator (K100) but they don't make them anymore, so I bought a second hand one from the BM Shop. There was a noticable improvement with the bike running at a temperature similar to the K100. Because the fan cuts in so much later than a K100, it still allows the bike to get too hot in stop start traffic. The mods I am doing in a couple of weeks will address that problem. BM Shop in Brisbane has plenty of K100 radiators, so too do a lot of the Sydney Wreckers.

Rich,

I got a fan off ebay (as advised by another Aussie on this Forum), it was $49 including delivery. The thermatic switch, which will allow me to have the fan cutting in a lot sooner was purchased off ebay also, but is redilly available from any auto parts store. The fan will be attached using the attachments supplied which go through the radiator. The fan that I am installing is the same as the one in this link

http://cgi.ebay.com.au/7-INCH-LOW-PROFILE-HIGH-PERFORMANCE-THERMO-FAN_W0QQitemZ120319886332QQcmdZViewItem?hash=item120319886332&_trkparms=39%3A1%7C66%3A2%7C65%3A1%7C240%3A1318&_trksid=p3911.c0.m14

They made a typo with the CFM it moves. It is the same fan that is for sale on the following US site.

www.siliconeintakes.com
_________________
Gary
'94 K1100RS

RAL88 · Posted: Sun Oct 19, 2008 9:11 am Post subject:

Hey Gary,

This is one that I checked with along with derale fans and zirgo fans and they said that it was not a brushless fan. Maybe I was misinformed but the prices indicate that they are not brushless. Brushless motors are much more expensive.

Rich
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

RobWheatley · Posted: Sun Oct 19, 2008 3:10 pm Post subject:

IIRC brushless fans cannot be reversed by changing polarity, Computer fans are brushless and they will only work connected one way.
Not 100% sure though
Rob
_________________
1999 K1100LTIC Smooth and Quiet Smile

Cruise, BFD & HID
1996 K1100RS. dead but not forgotten.

RAL88 · Posted: Sun Oct 19, 2008 3:39 pm Post subject:

I have brushless motors in my RC motorcycle and my RC helicopter and by switching two of the three wires you can get it to run in reverse. I had to do this on the motorcycle because I changed the mounting direction. I am not sure what IIRC motors are or if that is what I have.

Rich
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

RobWheatley · Posted: Sun Oct 19, 2008 4:10 pm Post subject:

IIRC = If I Remember Correctly, sorry used a quick way of putting it. Laughing

_________________
1999 K1100LTIC Smooth and Quiet Smile

Cruise, BFD & HID
1996 K1100RS. dead but not forgotten.

Gary Bennett · Posted: Mon Oct 20, 2008 8:57 am Post subject:

Sorry guys, I was under the impression that it was brushless and that it said so in one of the 2 sites above... but it clearly doesn't. With the Fan motor being so flat and no access to change brushes, I didn't even give it a thought that wasn't brushless. I can't see any reason why brushless should be more expensive.

Brushes or not, it's appeal to me was the low profile and CFM it can move. The factory fan on my bike is 14 years old and still going well, if I can get 7 years out of this new fan, I will be happy.
_________________
Gary
'94 K1100RS

lrome48 · Posted: Mon Oct 20, 2008 10:01 am Post subject:

Gary Bennett · Posted: Sun Nov 09, 2008 9:35 am Post subject:

Stage 2 and 3 of my three stage "FIX THE HEAT" drama have been completed. Stage 1 was the fitting of a K100 radiator, completed two years ago.

The new fan didn't fit straight in and needed some minor mods as detailed below.
First thing was to mark out where the old fan was located on the radiator as a guide to where to position the new fan.

I found that all the mounting brackets on the fan were stopping the fan from fitting in between the gussett in the frame.

So I cut them off.
I also found that the two hoses behind the radiator were hindering the fan fitting, so I trimmed a bit more plastic, there is not much chance of getting your fingers into the fan anyway (i'm flat out getting my hand in anywhere near the fan). The plastic was removed no lower than the top of the fan blades. I cut the connector for the wiring off an old BMW fan I had lying around and soldered it onto the wiring harness of the new fan.

I used the fixing straps that came with the fan, which are similar to a cable tie, except instead of being flat, they are round and the don't lock back into themselves like a cable tie, instead they have locking discs that lock on after you push the strap through the radiator (no photo, sorry).
I held the fan in place with only the top straps at first (with no locking discs), to get the right location. After 2 or 3 attempts, I finally found the right spot. The yellow arrow in the photo below, shows a bracket that I left on as it wasn't getting in the way.

I put all the straps in and pushed all the locking discs on, trimmed off the excess straps and fit the radiator back into the bike.

At this point I fed the probe for the new Thermo Switch down the hose that is closest to the Injectors, put a little bit of silicone around the capilary and pushed the hose on and did it up. The Thermo Switch came with a mounting bracket, which I mounted on the end of the radiator using the un-used threaded holes. This location allows access to the adjustor after all the Tuperware goes back on. I wired it up to earth on one side of the switch and the other side was fed back to the relay box under the tank, where I tapped it into the Blue/Yellow wire going to the Fan Relay.

I filled it all up with water and coolant and started the bike to check for leaks after it warmed up. All OK so on went the Tuperware and head out for a test ride. I stopped a few times to get the cut-in set to what I wanted.
Today (1 week later), I took the bike for a 200 km ride and the thermo fan is working just perfectly around town and it didn't come on at all out on the open road. The new fan works efficiently bringing the temp down before the Thermo Switch turns it off.
The photo below shows the range where my temp gauge sits and has done since fitting the K100 radiator. It also shows where the BMW setup previously cut the fan in at and where the new Thermo Switch cuts the fan in at now. THERES A BIG DIFFENCE.

The new Thermo Switch runs in pararell to the BMW setup and my manual override switch, so there is plenty of backup if one of them was to fail.
Basically now I just forget about it and the temp never gets any more that the thickness of the needle above that halfway mark where the Thermo Switch cuts in now.

Looking back on what I have done, I would say that Stage 1, fitting of the K100 Radiator and Stage 3, fitting of the Thermo Switch made the biggest differences. Stage 2, fitting of the different fan, didn't make a big difference. I didn't notice the temperature dropping any quicker than the original fan, however it certainly has a lot more clearance to the air box than the original and if your original fan seizes up this is a good (and cheaper) replacement.
_________________
Gary
'94 K1100RS

lrome48 · Posted: Sun Nov 09, 2008 11:43 am Post subject:

Gary,

Can you give the information on the thermo switch?

Thanks,

Larry
_________________
Larry
K75
97 K1100 LT Specialk under construction
87 SpecialK75 Carols done!
2004 K12 Special the 'Beast' delivered
K1100 Standard Custom Gone but not forgotten

Flying Duck · Posted: Sun Nov 09, 2008 12:48 pm Post subject:

I'm interested in the thermo switch too. It seems to me that that alone would make a big difference in that the bike can never get much past the middle of the temp gauge.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Jim · Posted: Sun Nov 09, 2008 12:59 pm Post subject: thermo switch

I think most of of the elctro aftermarket fans come with a thermo switch - the ones I have came with.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Flying Duck · Posted: Sun Nov 09, 2008 1:41 pm Post subject:

I'd like to experiment with just adding a thermo switch. If you can keep the temp from getting out of the middle range then I think you'd get the most bang for your buck and not have to worry about the 2 core vs. 3 core thing or swapping fans which seems like a lot of work.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

RAL88 · Posted: Sun Nov 09, 2008 3:25 pm Post subject:

Here is an adjustable thermo switch

http://www.derale.com/adjust-fan-controller.html

http://www.jegs.com/p/Perma-Cool/744387/10002/-1
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

Flying Duck · Posted: Sun Nov 09, 2008 5:41 pm Post subject:

This one looks like the ticket.

http://cgi.ebay.com/ebaymotors/_Car-Truck-Parts-Accessories__Flex-a-lite-31147-Fan-Control-Thermostatic-Adjustable_W0QQitemZ370102701489QQadiZ2865QQadnZCarQ20Q26Q20TruckQ20PartsQ20Q26Q20AccessoriesQQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item370102701489&_trksid=p4506.c0.m245&_trkparms=72%3A543%7C65%3A12%7C39%3A1%7C240%3A1318

It has a probe you stick in between the radiator fins so that sounds pretty straightforward.

Gary, you mentioned a blue yellow wire for the fan relay. I"m assuming that comes from the Moronic and triggers the fan relay, right?

2 questions:

1) Is it a positive or negative trigger to the relay?

2) Which one is the fan relay? (Location in the relay box.)
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE