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Radiator converting
Posted: February 2nd, 2008, 8:41 am
by Ported&Polished
I would like to see an indepth post reguarding radiator converting.
Posted: February 2nd, 2008, 9:11 am
by 2weelz
Times 2....
Posted: February 2nd, 2008, 9:43 am
by eyesky2002
Do I dare say 3

Posted: February 2nd, 2008, 9:45 am
by AlisoBob
For what Gen?
Posted: February 2nd, 2008, 11:37 am
by Ported&Polished
Gen 3 please.

Posted: February 2nd, 2008, 11:44 am
by teemtrubble
125 or 250?
Posted: February 2nd, 2008, 11:49 am
by AlisoBob
This is the best advise I can give..
Use CRF rad's, and convert the flow path to mimic the original CR500 flow path.
You dont have to hassle with the copper fittings, but assemble the parts as shown.
Mike uses the CRF rad's on his Gen 3 125 conversions too.
1. Highest coolant volume
2. Large hose connections
3. Same bolt pattern
4. Great cooling.
If you want to use the stock Gen 3 rads, you can use them to mimic the orginal C500 flow path as well, but I think it will run hotter than the 4 stroke units.
Posted: February 3rd, 2008, 10:44 am
by 2weelz
How about gen 2 250?
Posted: February 5th, 2008, 9:18 pm
by Ported&Polished
So which crf rads are the ones to use? 250 or 450? I want to start fresh on my build with some clean units, need to start looking now.
Posted: February 5th, 2008, 10:21 pm
by iggys-amsoil
A new set will set you back around $280. The stock CR250 gen3's work great. However the crf ones look narrower and taller more like the steelies. The CR250 can get that molded Jawbone hillclimb imprint look from your leg like mine.

Posted: February 6th, 2008, 8:29 am
by hoofarted
2weelz wrote:How about gen 2 250?
X2
Is the gen2 the same?
Posted: February 6th, 2008, 10:48 am
by ShanMan
Actually, gen. two rads work better than gen. three rads for a gen. three conversion because you do not have to modify the lower cross-over spouts...they are already pointing at each other. I believe you still may have to modify the downward spout that is feeding the waterpump however.
Posted: February 6th, 2008, 12:53 pm
by Ported&Polished
This is good stuff, thanks for the info.

Posted: February 6th, 2008, 1:24 pm
by AlisoBob
On the CRF rads, the crossover hose is pretty big, creating issues on bikes with limited space, like a gen 3.
Gen 2 Rads sound like the hot ticket!
Posted: February 7th, 2008, 7:51 am
by Ported&Polished
Here are some '01 rads. They look about perfect!


Posted: February 7th, 2008, 7:58 am
by AlisoBob
Get um!
Posted: February 7th, 2008, 12:22 pm
by eyesky2002
Looking thru the fiche, looks like the 02-04 CR250 use the same radiator, which looks similar to the 01 only a different part #. Anyone have a 02-04 CR250 rad and a 02-04 CRF 450 rad to compare mounting locations; maybe post measurements??? I already have a new CRF450 left rad that I need the outlet rotated; been shopping for a deal on the right one, but this idea may open up a whole new window for a right one that needs no modifaction.
Posted: February 28th, 2008, 2:42 am
by AUSSIECR500AF
I may as well throw my two cents in.
I have a CR500AF, CRF450 02 Setup. I bought silicon hoses from a performance car part supplier (readliy available in all countries). When I bought the bike, the main linking hose (radiator to radiator) ran straight across the cylinder, it was touching and with enough heat, would have melted causing untold damage. Using the new hoses, a standard aluminum T piece (make sure the diameter is as close as the internal diamater of the hose, a 90 degree aluminium elbow and some stainelss steel hose clamps, I have created an awesome coolant system that doesn't touch any heated parts and flows well. No additional welds, add-ons required.
I have ridden the bike in extreme temperatures and the bike has never screemed for water. It took me a good 2 hours thinking about the hose routings, 8 beers, 2 scotches, a couple of phone calls and all my questions were answered.
Sit down near you bike, visually picture what you want to see and with enough tenacity and patience, you too will make a great coolant routing system.
My rule was, keep the diameters the same, limit the internal diamater of the hoses when bending them (i acutally used a hose clamp where the hoses bent to open up the diamter to reduce the crink in the hose) and the rest will be sweet.
Comparative analysis was used to determine if the AF was running at the same temps as my steely 500 and the results speak for themself.
Its not rocket science and I can only suggest you use common sense (if you ride a 500 and live to tell the stories, you have nothing to worry about) you will be fine.
One last point, the 500 engine has a great water pump and will push the water through with ease. All you have to do is keep the internal diameters of the hoses as consistent as possible and MAKE SURE they are NOT TOUCING either the cylinder, head or Radiators.
If you wants pics of my config, let me know.
Keep the dream alive
Posted: February 28th, 2008, 7:10 am
by hoofarted
AUSSIECR500AF wrote:
If you wants pics of my config, let me know.
Keep the dream alive
Ya some pix will help visualize a little better.
Thanks!
Posted: February 28th, 2008, 7:53 am
by AlisoBob
AUSSIECR500AF wrote:It took me a good 2 hours thinking about the hose routings, 8 beers, 2 scotches,
Thats how I built my gen 4 A/F....
Allot of thinking while driving.... then building.
Get it straight in your head first!
Are you left handed , Aussie?
Posted: February 28th, 2008, 7:55 am
by teemtrubble
If you need help with GEN3 125's I can help there!
Posted: February 28th, 2008, 6:41 pm
by AUSSIECR500AF
Aliso, I am a lefty mate
Posted: February 28th, 2008, 6:43 pm
by AlisoBob
I can tell by how you operate...
Takes on to know one, I reckon...

Posted: February 28th, 2008, 7:31 pm
by AUSSIECR500AF
curious now, how do I operate?
Posted: February 28th, 2008, 7:33 pm
by AlisoBob
Visually, and logically....