Alternative Fan ~ original poster wmax351

[johnny]

From the list at IBMWR.org, with a few annotations from me (wmax351).

Bosch fan for K radiator fan
Date: 6/23/2004 2:54 PM
From: Eamon Stanley <flopthree@hotmail.com>
Bosch part # 0 130 007 027, available from a good auto electric store under that number. 55-80$ list( I was low), and I got one for 55$. Used in earler 911's as the A/C condenser fan motor, seen discounted on the net to the mid-50's. The Porsche part dies in exactly the same way. According to the ETK, the same fan ass'y is used in all the k's up to the K12, so the same motor ought to work in all of them. I haven't found out yet if they're rebuildable under the Bosch part#, but I will. Also if just the brushes and bushings can be had. I'd be unshocked if VW and/or Audi use a motor from the same series (BPA) for some similar application.

[noppo]

*** UPDATE ***

For those who can't easily make it to an auto electronics shop, 0130007027 is available online at http://www.summitracing.com/
They ship worldwide, and take returns.

[wmax351]

*** UPDATE ***

For those who can't easily make it to an auto electronics shop, 0130007027 is available online at http://www.summitracing.com/
They ship worldwide, and take returns.

+1 on summit. Really good business.

[D.Bachtel]

This worked out well for me, an exact copy fit wise with stronger brush holders. Offered and received for $40.


http://www.ebay.com/itm/301683979404?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Just trying to be nice......

Don in Nipomo, California    Central Coast... SLO county  68 degrees and white puffy clouds 1987 K75C 632

[richarddacat]

*** UPDATE ***

For those who can't easily make it to an auto electronics shop, 0130007027 is available online at http://www.summitracing.com/
They ship worldwide, and take returns.

Need some reassurance, is this one of the best replacements for the K75 radiator fan. I figured this thread is a bit old that I better check. My searching the Lieberry came up with this.

Part number is still good, $60. on Summit.

[Laitch]

Need some reassurance, is this one of the best replacements for the K75 radiator fan.

This will work but replacing the entire fan and motor with a 6.5" Spal puller fan is considered a more durable choice by many. Photos in many of the threads with instruction on the procedure have corrupted photos in them.  Woodgeek here seems to have done this but he didn't explain how he secured the fan in the original bracket. Maybe you should PM him. Here is a link to the post showing the fan in his customizing thread.

Some have done what woodgeek did then riveted the fan into the bracket. Some might have used epoxy. Some have made new brackets by tracing the old and modifying the hole in one of the bracket legs.

[The Mighty Gryphon]

Personally, I would use a failed fan as a good reason to replace the whole thiing with the Spal unit.  There are two problems with the Bosch unit that don't appear to affect the Spal.

First, the brush holders melt from the ridiculous amount of heat that can build up in the fan area.  The new fan will have the same problem.

Second, the blades can slip on the motor shaft because they are just a press fit, again subject to loosening from heat softening of the plastic material in the hub the shaft is pressed into.  The older the blades get, the worse this problem will be.

I have yet to hear of a Spal replacement failing on these bikes.

[richarddacat]

I ran across this thread;


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


but I didn't find a link to the Spal fan and like you mentioned the photos are screwed by PB.

Did this fan mount in the same location as stock? The link above's picture looks to be on the front of the radiator??? Will the K75c shroud fit over this?

PM sent to woodGeek....Thx

[thecableguy]

FYI that fan from Summit is the exact Bosch replacement.  My original failed like others on here, but not until the brushes were almost gone already, the bearings got tight from disuse and over thirty years elapsed. 


I just replaced mine with that one as I didn't want to fiddle with retrofitting the Spal. This one snaps right in.  Put a bit of locktite on the fan shaft if you are worried about it slipping off.


Check back with me in 2047, I'll let you know if it lasts another thirty years...


Jim

[Laitch]

Check back with me in 2047, I'll let you know if it lasts another thirty years...

By that time, you'll need a Ouija board to get my query. :giggles

[richarddacat]

FYI that fan from Summit is the exact Bosch replacement.  My original failed like others on here, but not until the brushes were almost gone already, the bearings got tight from disuse and over thirty years elapsed. 


I just replaced mine with that one as I didn't want to fiddle with retrofitting the Spal. This one snaps right in.  Put a bit of locktite on the fan shaft if you are worried about it slipping off.


Check back with me in 2047, I'll let you know if it lasts another thirty years...


Jim

I like simple too.
Looking at all options and with riding weather here I don't like the downtime. At the time this is my only bike.

[The Mighty Gryphon]

As my feeble memory recalls, the Spal fan installation is a six step process.

First, the new Spal has it's mounting ears removed.  Cut them off and file smooth.

Second, Cut the Bosch fan from it's mounting frame.  All you want to remain is the mounting ears and the outer ring.  That is the part you'll use to mount the new Spal fan.

Third, Cut the old Bosch ring in two places at the 3 and 9 o'clock positions.  attach the two halves of the ring to the Spal fan with pop rivets.  I used three rivets for each piece.  Try to make the two gaps between the pieces of the old fan about the same. 

Fourth, Offer the new unit up to the radiator.   File the top mounting hole in the ear to line up with the hole in the radiator.

Fifth, cut the old connector off the Bosch fan.  Make sure that when the fan is connected to 12v it blows the air in the right direction(pulling air through the radiator).  When you have it right, solder the wires and insulate with shrink tubing.

Sixth, attach the new fan to the radiator and install the radiator.

As long as you have the radiator out, it's a good time to flush the inside with vinegar to remove any mineral deposits that may be in there.  I Filled mine with white vinegar and soaked it in a pan which i filled with vinegar to cover it.  I left it in the pan for a couple hours after which I flushed the dead bugs and dirt rom the fins as well as the interior passages.  It goes without saying you want to flush the fins from the back side pushing the dirt and bugs out the front.

If you need a pan, you can get disposable aluminum one cheap at the Dollar store.

[richarddacat]

And beside not being a Bosch what are the advantages of the Spal fan??

[Laitch]

And beside not being a Bosch what are the advantages of the Spal fan??

It just seems more durable to many riders. Its fan has two additional blades. Maybe it moves a little more air. Like I wrote before, you should be good-to-go with replacing the motor on the OEM fan. Ride, not ruminate is my credo.

[The Mighty Gryphon]

The Bosch fan has an additional problem related to the blades slipping on the shaft.  Besiides the slipping causing reduced airflow, the blades have been known to move forward on the shaft, contacting the radiator and causing leaks.

[Laitch]

For those who have gotten this far in the thread, here is the Spal mounting pictorial explanation.

[richarddacat]

 :clap: +1

[rbm]

Heat Management

Collected articles that includes several different suggestions for managing heat buildup on K-bikes.  Detailed instructions on Spal fan installation.
K75 / K100 Spal Fan Bracket
Outline drawing 1:1

[woodgeek]

This will work but replacing the entire fan and motor with a 6.5" Spal puller fan is considered a more durable choice by many. Photos in many of the threads with instruction on the procedure have corrupted photos in them.  Woodgeek here seems to have done this but he didn't explain how he secured the fan in the original bracket. Maybe you should PM him. Here is a link to the post showing the fan in his customizing thread.

I'm going to pull my radiator and fan assembly to take some more photographs and change the fans wiring connectors. My assembly, the Spal inside the Bosch frame, is a friction fit for now. I'm going to secure it permanently with rivets. The friction fit is probably secure enough, just not bulletproof. I'll update this post or add a new one with those photographs and descriptions. I'm also updating some of my previous posts with some more detail and photos to help future Brickers. I have a habit of being too thrifty with words.


Gryphon did an excellent job detailing the steps to modify the Spal frame. He puts my descriptions to shame. I modified the original Bosch frame by cutting through the frame at the bottom, allowing it to flex around the Spal frame. The Spal frame is larger than the inner circumference of the Bosch frame, so I also cut the Bosch frame near the upper mounting ear. I didn't cut through the upper loop of the mounting ear, just through the frame. I've attached an image to illustrate my cuts with the cuts being red lines.