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Now that i've been thinking better cooling; i'm curious as to which is the preferred setup to cool down the engine.

I've done tons of research on the radiator fan kits out there, Spahl, KTM, Honda etc..

But it seems that less people go with oil cooler setups. I know the JCR/Baja race guys mostly run oil coolers (though i've never seen their fans-if present).

My bike (like most) overheats when i'm moving very slowly in rough terrain.

I'm curious as to when an oil cooler is preferred over running a radiator fan kit?

I don't see any con's to either other than added weight. You can run thermostats on both systems to prevent any under-temp damage.

Let's hear it!

My opinion is if JCR is using Oil Coolers , its because they are going 50+ all the time , so they get the proper air flow to justify a oil cooler and the advantage it would gain at those speeds , personally (again MY opinion) i have found for slow hot weather riding such as found in most Single Track riding , nothing beats the Cooling Fan , though i also recommend a higher bar radiator cap to aid in keeping the bike from dumping fluid out the overflow , which can and will happen without a fan , as well as Engine Ice or some equivalent to help keep the fluid in the bike and the temps under control

Not saying the fan is THE answer , but it has worked for me and i am at 7 years on the original Piston, Rings,Clutch , riding Desert and tight single track in the heat of summer , so that says something about a motor living longer when kept cooler

I appreciate the insight Jim!

I can see how the fan would be ideal for when my bike actually does overheat (slow speed crawling). As once i'm up to speed, all is well again.

Perhaps the Baja racers go oil coolers to help cool their engines when their 5th gear pegged for a long while, at which point I can see the engine putting out some serious heat...

Yea that is the way i figure it for them , they usually sustain high speeds , so the oil would run hot , so i see the need for the oil cooler in that situation , and the airflow on the other hand would be substantial for keeping the water cool enough so they would not benefit from using a fan

But as we well know , riding slower tight trails , especially in summer heat , there is far less airflow to the radiators , hence why i opted for the fan , to me its invaluable

oil coolers are used not just for their oil cooling but also to increase oil capacity. oil burn during endurance racing is a concern so increasing the oil capacity is desirable as well as keeping the oil temperature under control.

If you are fully un-corked and jetted properly, and use a 1.6 bar radiator cap with pure engine ice, you will never over heat.

Yea when you ride California deserts at 50+ mph , not in Idaho single track you wont be going fast and you will overheat , i run Engine Ice and have a 1.6 cap and am jetted properly and my fan still kicks on several times during a ride

Now when i want to relax and take a easy ride , i go ride in the desert and my fan never kicks on

Krannie wrote:If you are fully un-corked and jetted properly, and use a 1.6 bar radiator cap with pure engine ice, you will never over heat.

How long have you been running Engine Ice? I've heard a couple of stories (yes, rumors) that it eats away your head gaskets etc...

Yes the 1.6bar cap is on the list for sure. Any specific brand to go with here?

I see a 20psi CV4 cap here on the site; isn't that 1.3 bar?

I have a 1.6 bar on both my bikes , and i am running Engine Ice as well , just this year so far , prior to that i had been running Motoul , but the bike does seem to run cooler with the Engine Ice , so i am sticking with it until/unless something goes wrong

Thanks Jim, that was the only 1.6bar I could find on the bay.

Looks like i'll be going with engine ice... Is the stuff pre-diluted?

Yes , do not add anything

You must also completely flush your system to get ALL the old stuff out , it does not mix well with coolant

Drain your system from the drain bolt at the water pump (the bolt with the washer on it at the bottom of the pump) , then tip the bike from side to side (this will get the coolant from the nooks and crannies (no relation to Krannie lol)

Then flush with clean water (preferably Distilled Water which does not corrode Aluminum like some highly mineralized tap water can) which gets all the coolant out , tip bike again , do this till the water comes out clear , then tip the bike and get all the water out

Put the Engine Ice in directly , no diluting 1 jug should fill the bike with fluid left over , put on the cap and start the bike , run it for 1 minute or less , shut it off and remove the cap , re-check the level , your done !

i'm thinking if you overheat when going slow the oil cooler will not have the necessary airflow through it to be a significant help. the fan of course creates the airflow, hence the cooling advantage. that is if the overheating is caused by slow technical or brutal trailwork.

Jim,
Are you still using the overflow return tank with the 1.6 HP cap?
Thanks-
Mike

Yes !

I would never remove the overflow tank , i have one from a 250X on my 02 450R as well

With the tank IF you overheat , that water goes in the tank , then when it cools it returns to the Radiators and you go about your merry way

Without the tank IF you overheat , the water goes on the ground , when the bike finally cools you are SCREWED because you dont have enough coolant in the radiator to keep the bike cool while you try to get back to your vehicle/camp

for those with a fan ,could you post part numbers, ease of installation ,cost and perceived benefit in cooling.? thanks in advance.