Cooling fan direction?

[eddie cap]

Dear 5th gen. Brothers; I was told that the cooling fan on our bikes has the
capability to spin in either direction. Does anyone know for sure if that is a true statement? Also, under what conditions make it spin forward or backward ? If the fan can spin in either direction, what is the most efficient direction for the best cooling. My reason for asking the above questions is that I am thinking of turning the fan into a manual system.

[eddievalleytrailer]

My '07 fan sucks air in only. I've heard of reversing fans, but have never seen one in action.

[ZonaMan]

From what I have read about this, is that the fan turns on at 220F and sucks air in from the outside of the fairing versus sucking it up on the engine side and blowing out. This makes sense since the outside air would be cooler than the air passing by the engine. Why would you want to change what the Honda engineers developed anyway? Or make it manual for that matter?

Since it is a simple electrical fan like the one on your CPU, you could probably reverse the direction of it by simply reversing the wires.

[eddievalleytrailer]

Honda did it right. The air in the engine compartment is hot. Why would you want to pull that hot air through the radiator? The natural flow of air when at speed is to pull air from the engine compartment, but while riding there is so much of it, it doesn't really matter. When stopped or at slow speeds the fan needs to pull in nice cool air from outside. Not the preheated air from inside.
Besides, if it blew out it would go right on the rider. I would hate that!

[Spensersdad]

Originally Posted by eddie cap

... Also, under what conditions make it spin forward or backward ? If the fan can spin in either direction...

To clarify: as designed, your fan pulls air through the left radiator whenever it comes on, whether you're stopped at a light or at any speed.

I read a post here last night which implied that the fan's direction of rotation changed with respect to road speed. I think it referred to a gen. 6 bike. I don't know for sure about this as I don't own a gen. 6, but I find it verrry unlikely.

[eddievalleytrailer]

My 07 fan pulls air in only. I have paid attention and never noticed it blowing air out through the radiator.

[eddie cap]

To Zonaman and Eddie; I did not want to change the direction of the fan,however I read somewear that Honda used dual directional fans, I
cant substantiate if its fact or fiction. I agree that Honda engineered a great bike in the VFR and I really like the V-4. When you guys stated that the fan comes on @ 220 F, in my opinion thats a bit hotter than I ever want to see my engine, I know most VFR'ers have become accustomed to the bikes high temps, it makes me uncomfortable, so I wired the fan manually and now I have a choice when the fan comes on. For my first test ,I ran it during a Friday
evening rush hour. When I first got in the snarled traffic the bike was at about 185 F. I switched the fan on at that temp. and the motor never got hotter than 190F, so I believe if you start cooling the engine down at lower than 220F there is a good chance it will never get there! 220F and higher just cant be good for the engine.

[eddievalleytrailer]

I agree that 220F is hot. One of the reasons for this is to clean out the catalatic converter. When it gets hot enough, it will burn out a lot of the carbon which gathers there and stops it up. Engine heat is the only way the converter will work properly. Also hot engines run cleaner. A hot engine burns the fuel more completely. That helps Honda meet the EPA regs. I put a switch on my 83's fan, because that engine is less capable of dealing with that much heat in the top end causing gaulded cams. Honda has learned a lot since the 1st generation as far as operating temps. I hear of people getting 80-90,000 miles on these gen6 bikes with few or no problems, so I guess I'm going to trust Honda on this one. I would feel better seeing 190-200F at most, but Honda knows best (I hope).
I think the reversing fan is an urban legend or somebody's modification, and not from the factory.

[flameface]

reversing fan is so when you are stopped in traffic the fan blows in from the fairing vents, and dumps the hot air out the front, toward the front wheel and away from the rider. When in motion, the air management design of the fairing vents is to use the air flowing by the bike to pull air out the vents, so the fan runs in that direction when in motion so as to not fight the the natural air flow of the fairing vents.

"Honda Engineering...answering the questions no one is asking".

[nozzle]

This fan thread sucks.



unless you are stopped at a light, then it blows.



(is that a line behind me? ...again?)

[eddievalleytrailer]

Originally Posted by nozzle

This fan thread sucks.



unless you are stopped at a light, then it blows.



(is that a line behind me? ...again?)

AMEN BROTHER!