K11 Owners Group

eddieshep999 · Joined: 02 Jul 2006 Posts: 5 Location: Reading UK

Anyone know if a K75S 1996 model Radiator would be a direct replacement for a K100LT 1991 model Radiator?

Or because of the larger engine size of the K100 would I need to get the same size radiator either from a K100LT or the K1100LT ?

Thanks

Eddie Sheppard

bmwmick · Posted: Sun Jul 02, 2006 8:59 pm Post subject: Re: Radiator Replacement

Flying Duck · Posted: Tue Jul 04, 2006 10:02 pm Post subject:

Merely frrom memory, I believe you'll find that the K75S radiator is slightly different from a K100. A K75RT would fit though.
_________________
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

acftfliehr · Big Brick Rider Joined: 05 Nov 2007 Posts: 62

I tried to find the topic regarding replacing the 2 row radiator that someone replaced with a 3 row radiator used on early K100's.

I have just swapped out a '85 radiator to my K1100LT with excellent results.

Fan doesn't work nearly as hard, and temps don't climb when you climb a hill in 80 degree weather at 90 MPH....

The install was dificult in that the upper radiator rail rides against the L/H frame supprt angle, fan motor rubbs the airbox and the lower cooling couple ing on the L/H front of the engine chaffs the radiator lower rail.

Added anti chaff foam to the coupling and the fan but the upper frame is still a minor problem that vibration is induced into the radiator that is normally rubbermounted..

I plan on going to a radiator shop and try to have them recore the old 2 row unit to a 3 row unit, designing it with these issues in mind.

Does any one know of a radiator shop that would be interested in doing this?

acftfliehr@yahoo.com

abreeze · Posted: Tue Dec 11, 2007 11:46 am Post subject:

counterpoint:

I replaced my k100(bigger) radiator with a new (smaller, it is the only new one you can get now) and there was no noticable temperature difference.

However when I upgraded to a new(after 93' w/ steel impeller) water pump the engine runs significantly cooler.

acftfliehr · Big Brick Rider Joined: 05 Nov 2007 Posts: 62

Would the 1994 K1100LT have the new style water pump installed at the factory?

If not, the K100 that the larger radiator was on, has this item. Hmmmm another possible cannablization....

acftfliehr · Big Brick Rider Joined: 05 Nov 2007 Posts: 62

Radiator up-date..

The 2 core radiator off my K1100 is now on the repaired '85 K100...

Now that the Bay Area Temps are going up, well what do you know, the temp continues to climb on uphill grades cranking the power up say 80 to 90 MPH.

Take a look at this link talking about the differences between the K’s cooling systems by <themason> on his posting of 25.04.08 20:59

Very interesting indeed!

http://f3.webmart.de/f.cfm?id=2385371&l=2&r=threadview&a=1&t=3313097

Flying Duck · Posted: Wed Apr 30, 2008 4:32 pm Post subject:

A K75S radiator will NOT fit a K1100.
_________________
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