[JES_VFR]

I was, we hit 85 here this week and the VFR started getting mighty toasty in stop and go traffic. I have bitched before about the stupidity of Honda's puller fan design on the left side rad.

For me the scenario is something like this.
If I'm cruising around at more than 20 mph, my water temp is 195 or less.
As soon as I get into stop and go driving, the temperature will begin to creep up. It will go up pretty darn fast if I'm stuck behind one of the city buses or next to delivery truck where you can just feel the heat pouring off the other vehicle.
Now once it hits 225 the fan switches on and the fun begins. The temperature does not go down, instead it will continue to creep up, In fact just the other day it went all the way to 230 before the light changed and I turned onto a side street so I could get out of traffic and move some air through. As soon as I get moving more than 25 mph and can keep moving that fast, the temp will come down. I have repeatedly checked that the fan is turning at full speed and even stopped to feel the heat being blown out the front of the bike.

So while I was on lunch Thursday, I wandered back into the Honda parts aisle to the section where we have cooling fans. I had a halfhearted hope that I could score a replacement fan for a vtr1000f. I was basing this choice on several facts. One the fans share the same locking nut on the shaft, they were specified as the same diameter, the motors are supposedly the same size and spin in the same direction.
Well we had one and since it was just sitting there on the shelf I bought it to put my own eyeball on the problem.

I had nothing really important that I could do anything with this afternoon,.. So I broke out the tools to see how hard could it be?

Well here are the pictures.

Here is the original stock Honda fan with the locknut removed from the shaft.

DSCN1189.jpg

Here are the two blades side by side with the motor above

DSCN1188.jpg

Here is the VTR fan blade slid on the shaft waiting for me to smear some paste locktite on the shaft threads

DSCN1190.jpg

And another shot of the new fan inside the shroud and the old blade next to it. You can clearly see here that the VTR fan blades move the air in the opposite direction of the VFR fan.
DSCN1191.jpg

On pair of photos with the Honda packaging in the background so you can see and get the part number.
DSCN1193.jpg


DSCN1192.jpg

I yanked out the pair system while I was in there and installed the block off plates from our own Toro1. I don't know about the rest of you, but the inside of the covers and the hoses was coated with a black oily film. I bet that was not good for power or emissions either!

Anyway I put it all back together, then started the bike and pretty much just let it sit until it was warm enough to engage the fan. Even in the still air of the garage, the 225 temp immediately started to drop and in minutes it cooled off enough that the fan switched back off. Yeah the heat blowing back from the left side was noticeable, but it was not excessive nor did it last very long.
I let it cycle like that a couple of times while I did things like lube the chain, adjust the throttle cable, inspect the welds on the sideracks, etc. After three more cycles, I shut it off and declared it a sound victory.

IMO, this is how Honda should have done it all along.

[Chev]

Sounds like you may have a winner. Let us know if you experiance in traffic is similar.

[toddulu]

Let me preface this by saying that i'm not the most mechanical guy in the world, but...

Would it be possible to just take the OEM fan off and flip it 180 degrees so the fan blades are pointing the other direction rather than having to buy the vtx part? I've read lots of other threads and lots of people think it's counter productive to suck the air in the opposite direction of what is natural. I've been having MAJOR overheating issues and am looking for ideas on anything...

[jeremy556]

Perhaps you had some other underlying problem that it would not drop from 225+ degrees? In routine 110 degree ambient temperatures mine would kick the fan on at 220 and would drop to 200 or at least stay between 210 and 220.

[spud786]

I have no problem with the vfr cooling system , if bike goes over 220 fan comes on sends it back to 200 no issue completely stock


223/224 degrees is the max i ever see in the 37,000 mile I've owned it

[AussieinUSA]

toddulu, on Apr 20 2008, 10:44 PM, said:

Let me preface this by saying that i'm not the most mechanical guy in the world, but...

Would it be possible to just take the OEM fan off and flip it 180 degrees so the fan blades are pointing the other direction rather than having to buy the vtx part? I've been having MAJOR overheating issues and am looking for ideas on anything...

Todd, this is something i've got experience with, I reversed polarity and flipped the blade on the right hand side of my RC51. It defineatly helped with the 51 but they are known to run hot, real hot in our climate. I had to drill out the backside of the blade alittle to make it work but that was the extent of it, oh I added some spacers also. Have you thought of removeing the V-cowl also as this allows more airflow over the cyclinders. In your case i'm not sure i'd do this as the VFR isn't typically a real hot runner, your problem is somewhere else although doing this shouldn't hurt even if the problems found. I took pics whilst doing it on the RC so I know what I did, real easy actually and if ya want to do it let me know, maybe I could help ya when I get back.

[JES_VFR]

toddulu, on Apr 20 2008, 09:44 PM, said:

Let me preface this by saying that i'm not the most mechanical guy in the world, but...

Would it be possible to just take the OEM fan off and flip it 180 degrees so the fan blades are pointing the other direction rather than having to buy the vtx part? I've read lots of other threads and lots of people think it's counter productive to suck the air in the opposite direction of what is natural. I've been having MAJOR overheating issues and am looking for ideas on anything...

If you mean flip the entire fan (motor and blade), I cannot see how that could be done. The space is at a premium in there and you would probably have to fabricate a new mount and shroud. Plus the motor would be very close to rad, which could cause all sorts of issues.

I suppose that you could just try reversing the fan motors direction by changing the polarity of the wiring, but that seemed like a lot of work to get a very inefficient fan.

besides by the time you pull the fan out and design a different solution, you could have installed the <$30USD fan blade could be installed and the bike buttoned. Back up.

All I know is that my fan comes on between 224 and 225, just as it always has since new.
I don't think that 225 vs 220 should make a whole lot of difference, and I don't know which way the VTEC fans 'attempt' to move the air.

I do know that I have heard this from other VFR owners in this area, and the only solution before this was "get moving ASAP". I know of one rider in my area that has scrapped the factory fan all together and he just takes his chances in traffic (of course he will also illegally lane split to keep moving).

I'll keep an eye on this for the next few days, and report my findings.

This post has been edited by JES_VFR: 20 April 2008 - 10:32 PM

[spud786]

Yeh I dont know why some have more heating issues, I know the last guy was running watter wetter without antifreeze , and it says very clearly on the bottle does not significantly increase waters boiling point which is 212 degrees.

being the vfrs normal operating range is higher than that , I definitely see an issue developing

[JES_VFR]

Well I hopped onto the online fiche and looked at the VTEC's fan.
It also is a puller or sucker fan blade. So it also sucks the heat from the radiator back into the rest of the bike.

It also looks like the VTR fan blade will fit on the Fan motor of the VTEC's but only a side by side comparison would tell.

So VTEC owner's if you are running hot in traffic, you might want to give it a try.

[bear22099]

spud786, on Apr 20 2008, 10:35 PM, said:

Yeh I dont know why some have more heating issues, I know the last guy was running watter wetter without antifreeze , and it says very clearly on the bottle does not significantly increase waters boiling point which is 212 degrees.

being the vfrs normal operating range is higher than that , I definitely see an issue developing

The rad cap will raise the boiling point for you. 4 degrees for each pound of pressure. That means at sea level (since water boils at 212 at sea level), a 15 pound cap will raise the boiling point to 272 degrees. Note that in Denver, water boils at 202 degrees on an average day.

[JES_VFR]

There are all sorts of ways to raise the boiling temp of the coolant, but that doesn't solve the issue of running hot and eventually overheating.

There are coolants that can get way up past 300F without boiling, but that is not okay for a bike's engine.

That is why I'm investigating the cooling air flow and a fan blade to change it from the original plan.

By the way, the GL1800 have a similar "backwards" flowing fan and their owners all complained to Mother Honda about it. The GL1800's would overheat in parades and traffic.
Honda did something to resolve this but I don't remember what it was (except that it was not to change the fan design).

So the rc51, the VFR and GL1800's have these draw in fan designs and they also have low speed cooling issues.
coincidence???
You tell me.

Today was cooler than last week and I did not encounter much creeping traffic, so I cannot offer much useful test data. All I can say is that when I stopped the bike after commuting home and the temp rose to 224, the fan kicked in and the temp very quickly (compared to other times) started to come back down.

[combine pilot]

Last summer I added a switch to the fan on my 01. So now I can turn the fan on before the temp gets to high in stop and go traffic. This winter I checked into my heating issues more and found the thermostat stuck part way open. (inherent problem with bikes listed)
The thermostat being stuck part way open does a few things:
1. The bike doesn't warm up very quick.

2. Once warmed up it won't hold temp at proper level for the fuel injection while moving (depending on how far open it is stuck and how cold out it is.)

3. If it is stuck open it warms the water in the rads so when the themostat is supposed to open and get cool water from the rad it gets pre heated water. And the temp just keeps climbing.

4. If you can cool the water in the rad before the thermostat opens you cool the motor down faster.


Therfore I like the idea of an override switch to get the process going before the temp gets to high in stop and go traffic.
It seems to work for me.
I do not wish to offend just hope this helps you and others.
Very interested in the outcome.
Keep us posted.

[xenocide]

combine pilot, on Apr 22 2008, 10:06 AM, said:

I checked into my heating issues more and found the thermostat stuck part way open. (inherent problem with bikes listed)

Thanks combine! My bike takes a long time to warm up but does hit 165 and stay around there but also doesn't seem to come down from 225 fast when idling w/ the fan on either. I initially thought the thermostat was messed up but as the weather got warmer the bike warmed up slightly faster but not as fast as a car normally does so I wasn't sure. Also my initial mileage was in the mid 30s which I HOPE is a problem with the thermostat. Combing this with your advice above gives me the idea that like yours my thermostat is stuck partly open . I wonder if I were to grab the upper radiator hose before the bike hit 165 and it was warm that might confirm it?

[Auspañol]

Well I would beg to differ with my compatriot AussieinUSA, and would dare to state that the VFR is a known hot-running bike. Everyone I know over here who has one, or knows someone who has one, says they boil your eggs in no time...

I find that if I'm not circulating above 80 km/h both my 5th and 6th gen will heat up to the max and enter into the cycle of tripping the fan at around 106ºC, cooling her down to 96ºC and heating back up.... and so on ad libitum

I agree, the design of the fan is flawed... to pull or suck air inward through the rad toward the motor is based on the idea that the air entering would be cooler than the air around the motor if the fan were to blow air through the radiator from the inside out... BUT, this is only valid if the bike is stationary and the ambient temp is relatively low. Here in the sunny 40ºC south-of-Spain summers this does not apply so much. Also, I don't tend to spend much stationary time on a running bike... only when stopped at the lights. If I do venture into city traffic, I am usually moving at some speed, albeit low... so if the fan kicks in, it's fighting against the natural air flow due to the movement of the bike and it's effect is probably neutralized to a high degree... or at least not taken advantage of to it's maximum potential.

Also... heat is the arch-enemy of our electrical systems and the number of R/R which die in the arse over here in summer is mind-boggling. Some spare parts outlets have realized this and stock up on more R/Rs over summer than usual... my dying R/R experience occurred after a stifflingly hot afternoon running around town on the 5th gen...

I have many a time wanted to reverse the polarity on the fans of both my bikes... but am unsure as to whether this would be agreeable for the motor, the fan's motor I mean... not the bike's. Using blades that run in the opposite direction sounds like a winner... it can't be all that bad the short periods you're stopped and it's blowing hotter air off the engine than ambient through the rad... and when you're at anything over 0km/h it must enhance the natural airflow in through the front of the bike... being able to manually switch the fan on could be a great plus in combination with the reversed helix... hmmmm, I reckon I'll have to try that for this summer... just have to keep in mind to turn the fan off when it's not needed and always before turning off the bike so it's not on when I want to start up the bike... although you'd hear it-... noisy bugger.

So the part number in the photo is for the reversed helix right?? Off the VTR??

I'd also live to whack another fan on the RHS rad, but the engine's eccentrically placed and there's no room for one the same size... a couple of PC fans fit on the outside in the gap in the fairing but I doubt they have enough pull... guy I know stuck two on there, claims it makes a difference... but he has the OEM fan switched and so it's hard to say where the blame lies... there's just enough room for a PC fan on the inside front-bottom corner of the RHS rad, but same difference I reckon.

This post has been edited by Auspañol: 22 April 2008 - 01:57 PM

[AussieinUSA]

Auspañol, on Apr 22 2008, 01:50 PM, said:

Well I would beg to differ with my compatriot AussieinUSA, and would dare to state that the VFR is a known hot-running bike. Everyone I know over here who has one, or knows someone who has one, says they boil your eggs in no time...

Ok, i'll give you that but I was comparing to my 51 (SP2), now theres a bike thats really known to run hot and in my case in summer always above 230f, my polarity/blade switch defineately helped. I hear ya though brother, Viffers can get toasty

[Darth Bling]

JES_VFR, on Apr 20 2008, 06:38 PM, said:

I was, we hit 85 here this week and the VFR started getting mighty toasty in stop and go traffic. I have bitched before about the stupidity of Honda's puller fan design on the left side rad....


DSCN1192.jpg

...IMO, this is how Honda should have done it all along.

Excellent post Jes. I'm going to have to have to perform this swap myself.


I've found that the VFR's cooling system works very well when you're stopped. But, if you're riding around between 10-20 mph, the radiator fan loses all of its efficiency since it has to push against the wind. But, once you get up to highway speeds, the wind easily overpowers the fan and the bike cools down.

When I was in Billings, MT last summer, I was putting around town at about 15 mph. It was about 95°F out and I was currently running water with waterwetter (good stuff!). Well, my bike overheated, bad. I was seeing temperatures over 250°F and my VFR was puking radiator fluid everywhere. When I got on the interstate to head back to my hotel room, the temperature of the bike was hovering around 238°F as I was running an easy 85 mph. I refilled the bike later than night after it cooled down and i had lost 1/2 of my radiator fluid. There were a bunch of Goldwings there too and their bike's have the same stupid radiator setup that the VFR has too, and they were all having overheating problems just like me. Stupid Honda....

[Auspañol]

AussieinUSA, on Apr 22 2008, 09:37 PM, said:

Auspañol, on Apr 22 2008, 01:50 PM, said:

Well I would beg to differ with my compatriot AussieinUSA, and would dare to state that the VFR is a known hot-running bike. Everyone I know over here who has one, or knows someone who has one, says they boil your eggs in no time...

Ok, i'll give you that but I was comparing to my 51 (SP2), now theres a bike thats really known to run hot and in my case in summer always above 230f, my polarity/blade switch defineately helped. I hear ya though brother, Viffers can get toasty

Correction: my highly esteemed compatriot AussieinUSA...

[JES_VFR]

Auspañol, on Apr 22 2008, 01:50 PM, said:

So the part number in the photo is for the reversed helix right?? Off the VTR??

That is the correct part number for a US market VTR1000f.

The new fan is louder when running than the old one. I don't know if that is because its moving the air out or if the blades just are a different design.

Did get into a little bit of traffic tonight coming home (I was kind of stuck in the right lane with a rear tire going down from a nail )!!!! Anyway at about the third light behind the morons who have nowhere better to drive their smoking hulks of 1960's GM crap, I hear the fan kick on.
The temp was 224 flicking to 225, where it sat for a minute, then it started to go down. A couple of minutes later, the temp is hovering at 219 and the light changes, as soon as I get moving, I'm clear of the GM heatmobile and the temp drops to 200, then 196.
Before it would have climbed to 230 and hung there for a couple of miles.

[AussieinUSA]

Auspañol, on Apr 22 2008, 02:40 PM, said:

AussieinUSA, on Apr 22 2008, 09:37 PM, said:

Auspañol, on Apr 22 2008, 01:50 PM, said:

Well I would beg to differ with my compatriot AussieinUSA, and would dare to state that the VFR is a known hot-running bike. Everyone I know over here who has one, or knows someone who has one, says they boil your eggs in no time...

Ok, i'll give you that but I was comparing to my 51 (SP2), now theres a bike thats really known to run hot and in my case in summer always above 230f, my polarity/blade switch defineately helped. I hear ya though brother, Viffers can get toasty

Correction: my highly esteemed compatriot AussieinUSA...

well thank you my Spanish speaking compadre'

[AB-Oz]

I would suggest that a lot (but not all) of the "my VFR runs hot" babble that goes on is because we have a digital temperature readout instead of a dial. Now we are more conscious of the numbers instead of the hand on a dial hovering around about there somewhere

[toddulu]

AussieinUSA, on Apr 22 2008, 06:31 PM, said:

Auspañol, on Apr 22 2008, 02:40 PM, said:

AussieinUSA, on Apr 22 2008, 09:37 PM, said:

Auspañol, on Apr 22 2008, 01:50 PM, said:

Well I would beg to differ with my compatriot AussieinUSA, and would dare to state that the VFR is a known hot-running bike. Everyone I know over here who has one, or knows someone who has one, says they boil your eggs in no time...

Ok, i'll give you that but I was comparing to my 51 (SP2), now theres a bike thats really known to run hot and in my case in summer always above 230f, my polarity/blade switch defineately helped. I hear ya though brother, Viffers can get toasty

Correction: my highly esteemed compatriot AussieinUSA...

well thank you my Spanish speaking compadre'

How does spanish sound with an Aussie accent???

[Nicole]

spud786, on Apr 20 2008, 10:53 PM, said:

I have no problem with the vfr cooling system , if bike goes over 220 fan comes on sends it back to 200 no issue completely stock


223/224 degrees is the max i ever see in the 37,000 mile I've owned it

+1 Mine's never approached 230 either.. Even when it's mid-high 90's out.

[y2kvfr]

Darth Bling, on Apr 22 2008, 03:38 PM, said:

JES_VFR, on Apr 20 2008, 06:38 PM, said:

I was, we hit 85 here this week and the VFR started getting mighty toasty in stop and go traffic. I have bitched before about the stupidity of Honda's puller fan design on the left side rad....


DSCN1192.jpg

...IMO, this is how Honda should have done it all along.

Excellent post Jes. I'm going to have to have to perform this swap myself.


I've found that the VFR's cooling system works very well when you're stopped. But, if you're riding around between 10-20 mph, the radiator fan loses all of its efficiency since it has to push against the wind. But, once you get up to highway speeds, the wind easily overpowers the fan and the bike cools down.

Although I've never had my '00 puke all over the place, I do think the design is flawed. I see the same results as Darth for speeds below 30mph. The temp keeps rising unless I either STOP or wick it up to 45+.

John --- definitely keep us posted. I think it may be a winner of a swap!

-t

[phaedrusman]

I don't know. I'm thinking there is something else at play here. I've sat in traffic (Warner Robins, GA...one of the worst traffic problems for a small city that I've ever seen) with ambient temps over 100F several times and never a problem. Temp hits 220, fan kicks on, hauls temp down to 212, fan kicks off. Repeat.
As for the design on the cooling system, really it makes sense to me. When the fan is running while the bike is moving, air is still dumping over the right side rad. I've made use of that very fact while my t-stat was messed up and ambient was too cool. I put a chunk of a license plate (what can I say, it was laying around and was a dead perfect fit) over the right side rad. Blocked enough air flow to keep the bike a bit warmer so I didn't have to run in a lower gear constantly, and I still didn't have to worry about overheating because the fan on the left rad.
Perhaps you guys are having issues with the right side radiator? Also, if you guys have changed your coolant, what did you use for a water source? Make sure you use distilled water. Pure H2O. Tap water and the like still have trace amounts of God knows what else in them...causing deposits and corrosion on the inside of the cooling system (and water jackets of the engine), decreasing the efficency of said cooling system.
Personally I would have tried just switching the polarity of the fan. I haven't looked at the wiring, but ASSume it is just 2 wires. I'm pretty sure it is a DC motor. It doesn't really care too much which way its spinning. Now, granted the fan blades may not be the most optimal shape for pushing air, but hey, you get what you pay for.

Just my $.02.

[Tightwad]

Here is an interesting option I came up with. This would allow control of the fan when the fan switch is NOT activated by the Temp getting to 220. It would provide a safeguard against forgetting to turn your fan on.

[combine pilot]

I don't read shematics well so this is not a knock Tightwad. Just simpfied.
I set up my switch as a closed ground (-) SoThe fan is switched on as a ground loop so no positive wire is required.My fan is swiched on manualy and or by the thermo couple.
This way I can't forget to turn it on. It also shuts off with the key if left on.
David

[Tightwad]

combine pilot, on Apr 23 2008, 11:05 AM, said:

I don't read shematics well so this is not a knock Tightwad. Just simpfied.
I set up my switch as a closed ground (-) SoThe fan is switched on as a ground loop so no positive wire is required.My fan is swiched on manualy and or by the thermo couple.
This way I can't forget to turn it on. It also shuts off with the key if left on.
David

yeah, your way probably works better.....this is what I get for overthinking it. Piggyback onto the black wire, connect to switch, connect switch to ground. Power is switched with the key.

[fastrc46]

AB-Oz, on Apr 22 2008, 10:23 PM, said:

I would suggest that a lot (but not all) of the "my VFR runs hot" babble that goes on is because we have a digital temperature readout instead of a dial. Now we are more conscious of the numbers instead of the hand on a dial hovering around about there somewhere

I too agree with this. I also wonder how close the calibration of the gage is to correct. We all know the speedos are notoriously off. I would submitt that the temp gages are off a bit also.

My 98 never sees the temps mentioned here. I put a Scotts Performance oil filter on a few years back and it droped the temp. about 10 degrees. The filter has much more flow than a paper element filter. So it's like water and oil cooled.

[crepitus]

AussieinUSA, on Apr 20 2008, 09:56 PM, said:

toddulu, on Apr 20 2008, 10:44 PM, said:

Let me preface this by saying that i'm not the most mechanical guy in the world, but...

Would it be possible to just take the OEM fan off and flip it 180 degrees so the fan blades are pointing the other direction rather than having to buy the vtx part? I've been having MAJOR overheating issues and am looking for ideas on anything...

Todd, this is something i've got experience with, I reversed polarity and flipped the blade on the right hand side of my RC51. It defineatly helped with the 51 but they are known to run hot, real hot in our climate. I had to drill out the backside of the blade alittle to make it work but that was the extent of it, oh I added some spacers also. Have you thought of removeing the V-cowl also as this allows more airflow over the cyclinders. In your case i'm not sure i'd do this as the VFR isn't typically a real hot runner, your problem is somewhere else although doing this shouldn't hurt even if the problems found. I took pics whilst doing it on the RC so I know what I did, real easy actually and if ya want to do it let me know, maybe I could help ya when I get back.

When I bought my RC51 the previous owner had removed the left side fan due to what he said was both fans pulling air into the engine area just made hot air build up in there. In the year and a half I've had it I have never replaced it and the temp never goes above 220. The right side fan seems to be enough. I have the fan and have thought about reversing it and placing it back on the bike but it really isn't necessary.

[AussieinUSA]

crepitus, on Apr 23 2008, 12:59 PM, said:

When I bought my RC51 the previous owner had removed the left side fan due to what he said was both fans pulling air into the engine area just made hot air build up in there. In the year and a half I've had it I have never replaced it and the temp never goes above 220. The right side fan seems to be enough. I have the fan and have thought about reversing it and placing it back on the bike but it really isn't necessary.

I tried this first and it worked great, actually better than what I ended up doing..................when moving. At stop and go and in slow moving traffic though it was a different story, the bikes temp rose incredibly quick to #'s that scared me so I wound up reversing polarity and blade which gave me the best results overall. I've read many posts where people said you only needed to change polarity and that would do the trick, well I tried this initially and found that that idea did absolutuley nothing. Whats happens is the blade now spins opposite so it should be pushing not pulling which it does except the pitch and direction of the blade are now wrong, the air ends up not only not pushing but also not sucking, it sorta does nothing at all. I tested this off the bike so I could really see what was happening, maybe on the bike it'd be different but i'm not sure how in stop and go traffic. Taking the fan out altogether, (left side) along with the plastic deflector was absolutely the best whilst moving, all sorts of air can hit the front cyclinder and escape through the left rad at speed. Just my findings and also on a 51, not tested on a VFR.
Also....I'm in an incredibly hot climate, on average 72 days over 100f, (last year we had over 90 days) so this is a brutal test for these machines

Todd, Spanglish is what I believe we're talkin here although he kicks my ass in both languages

This post has been edited by AussieinUSA: 23 April 2008 - 01:35 PM