Jump to content

Cooling Fan Set up on an 08 CRF450R..???

Recommended Posts

Ok..so before I start, I've been searching this out for a little while now.. I've read a few threads where guys have hooked up computer type fans via cordless drill bat and etc.. but really haven't found any completed threads/projects where a fan has been added and what not...


Details: I currently have an 08 CRF450R. I recently purchased a TrailTech 70W weighted Fly Wheel (13 oz over stock) and Stator kit. My stock radiators are in "Ok" shape I guess.

End Goal - I'll eventually end up with some sort of Headlight set up (Factory X or 6" light bar..) and an LED Tail/Brake light. I will be doing mostly woods riding..some fast aggressive, but some tight technical as well - I just want to be proactive on keeping the bike cool as there are lots of threads out there about 450R's overheating in the woods if your going slow or sitting still for a short period of time.

450X Radiators? - My first thought was to get a left hand side 450x radiator with a factory type fan set up - But I couldn't find any concrete info if the "X" radiators will fit on the "R" bikes - If someone could confirm or deny this that would be great - also any year compatibility ?

Chinese/Aftermarket Radiators - I've used these in the past with great success - and they seem to be "Stronger" than the factory ones to some degree and offer a claimed "40%" greater capacity - But still need to get air flow across the radiators.

Higher Pressure Radiator caps / Alternative Liquid solutions - While I understand the concept of keeping your radiators from Boiling over - I'm not sure I would want to go this route as you are actually running the engine at a higher Temp... even though it's not actually "Boiling Over" - I will say having an overflow reservoir is a great idea and I'm going to incorporate this as well - more so in a "Worst case" type thing.. ?

Aftermarket Fans - looks like there are a few reasonable ones out there, but one that keeps popping up is the SPAL 4" fan,.. I guess the trick would be finding a suitable way to mount it (I just can't bring my self to use Zip ties! :naughty: ) Trail tech has a nice kit but it looks like its set up for an "X", using the factory mounting tabs and also the temp sensor port.


Right now I'm leaning towards a SPAL 4" fan and some sort of radiator "Fin" mounted temp sensor as well as a bar mounted manual switch (Just in case) .... the trick would be mounting it "professionally" as I mentioned before.

If the X Radiators will mount up with no issues, then that would a nice option - Maybe a used right hand side w/ factory fan,.. or a Tusk right side radiator (It has the fan mounting brackets) ... who knows,.. just pondering away.. :(







Share this post

Link to post
Share on other sites

A higher rated cap wont keep it cooler, it just prevents you from blowing off the coolant. Granted, the coolant doesn't work well when it's in the dirt, but, putting a 1.6 BAR cap on just raises the boil over point.

The big Chinese radiators work pretty damn good. One guy I know, he's a vet guy, not super fast, but he just rides tracks and his bike never warms up entirely. He'll pull off and its like 160F, which isn't hot enough. Should be 180-190.

The 70w stator is all fine and good if it's rectified and regulated, you can run the fans directly off it. No battery needed. And what's wrong with zip tys on the fans? As long as you've got firm foam pads between the fan body and the radiator fins, you wont have a problem.

Share this post

Link to post
Share on other sites

Thanks for the reply Shawn!

On the Rad. caps I thought I read where Honda recommended a 1.4 as the highest.(?) Either way, I'd rather just keep it cool to begin with using oversized Rad's and a Fan.

The 70W "Kit" I have from Trailtech has everything included in regards to Battery Pack, Stator, Flywheel, Rectifier/regulator. So I think I'll be good there.



Share this post

Link to post
Share on other sites

I tried a 120mm computer fan but when I put on my WC rad braces I had to take it of.  An 80mm fan will work and there is rough service ones, low amp draw. Remember its volume you want, not pressure.  Use 8 zip ties like radiator "pull strips" used on transmission coolers to mount it up.  Thin, cheap, and easy to mount. 


To power it, screw all that battery mumbo crap. Get one of those dc to dc converters(fleabay) with multi level inputs 16/24/36/40v input and they out put 12v continuous.  Tap into the stator output...thinking blue wire(17v @ idle and a tad over 22v revved)..cant remember now.  The dc to dc converter is tiny and you can cut a short piece of inner tube and stuff it inside, zip tie both ends nice and tight and hide it in your air box.  Grommets and whatever to be creative.   Basically an isolated zener diode setup but its epoxy potted and prewired so super easy. With capacitance it doesnt load up the stator and sap power/current fed to the CDI. 

Edited by KeyKeeper

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with: