I have been researching off and on for the last couple of months of how to get my VFR to run cooler in stop and go traffic. The highest it reach was 239F on the gauge cluster.
I have found a couple of options in the forum,
1. run a reverse fan blade from an RC51
2. install a higher CFM SPAL fan, although I couldnt figure out what size fan to run
3. Install slight larger radiators from a 6th gen
4. Install a custom front mount radiator from a Suzuki TL1000R
Right now I am like options 2, as I have run spal fans in the past without any issues on both bikes and cars. Or maybe a combination of option 2 and 3. Does anyone know what size fan would fit, a spal 5.5" or so? Also any input on any of the other options is very much appreciated.
The spal fan as far as I understand, has been done along with a lot of other things. Bottom line, with out a lot of redoing and fitment issues none are much help by the sounds of it. just don't go slow. but something tells me it wasn't a big enough deal for Honda to re do this. but ah, they did on the 8th gen didn't they.
I've been riding an F6B around all week. It's got side rads and fans that pull from the side and push the air out the front. Exactly like the 5th Gen, except for the second fan. Biggest difference is an analog temp gauge. I bet if your bike was showing the needle near the top of the "normal" range you wouldn't give it second thought, but seeing that exact readout on the display makes us focus on the temp.
I've been riding an F6B around all week. It's got side rads and fans that pull from the side and push the air out the front. Exactly like the 5th Gen, except for the second fan. Biggest difference is an analog temp gauge. I bet if your bike was showing the needle near the top of the "normal" range you wouldn't give it second thought, but seeing that exact readout on the display makes us focus on the temp.
while that may be true, 239 degrees F is hot for any gas engine.
Nothing will stop the 5th gen running hot in traffic.
Some things help, but only mrginally.
I have the 6th gen right side radiator, and the fan overide switch.
Left side radiator is doable, but not without lots of mods.
TLR radiator, I can't see how you could get it to fit.
Same for right side radiator fan, not easy.
My opinion is best bang for buck was the overide switch.
I will try reverse fan blade if I find one, but not expecting much.
Last time I swapped with my mates CBR1100XX on a hot day, his bike was running just as hot as mine.
Installation of a fan override switch solved most of my cooling issues. It takes some presence of mind to be on top of it but if I am it prevents things from getting out of hand.
Cogswell Installation of a fan override switch solved most of my cooling issues. It takes some presence of mind to be on top of it but if I am it prevents things from getting out of hand.
Yes the owner's manual states 122C as a maximum (252F) beyond which serious engine damage can occur.
Just a question (maybe a dumb one) regarding changing the airflow direction, why is a reverse blade required. Surely the fan is powered by a DC motor, and reversing the rotation would be as easy as swapping the polarity of the wires?
Terry Surely the fan is powered by a DC motor, and reversing the rotation would be as easy as swapping the polarity of the wires?
Yes but dc motors could be designed to rotate in one direction (better) than in reverse. This was discussed on another thread, but i can't find it now. I don't know if it was a bearing related issue, that could end on blades hitting the radiator or what, but there was a reason to swap blades instead of reversing the polarity
The reason not to simply reverse DC polarity and thus reverse the direction of rotation of a fan blade is actually an aerodynamic one. The most important feature of most motorcycles' fanblades is their airfoil shape - the curve of the blade from leading edge to trailing edge. This curve achieves greater flow at a given rotation speed through Bernoulli effect. 'Lift' occurs with low pressure on the convex side of the blade and high pressure on the concave side. Rotating the fan in the opposite direction would actually reverse this gain in flow - even less lift than flat blades would be generated. Flat blades would function in a more Newtonian manner, like paddles rather than wings.
It's not directly related to flow, but it is interesting to note that the angle of attack also varies from the hub to the outer 'tip' of the blades. This is because the blade's linear speed is slower at the hub. The blades have greater pitch or angle of attack at the hub than they do at the outer end of the blade in order for the entire fan to flow air at nearly the same rate across its area.
A 1998 VFR800 is 19 years old now. Wondering about the condition of the water pump impeller? Any loss in efficiency at the water pump would be a problem in the overall heat-rejection equation. How quickly and how often each little molecule of coolant circulates through the engine and then through the cooling system make a big difference.
I bought the spal 5.2" pusher fan from amazon. I am going to give my radiators a thorough cleaning and install the new fan. If that doesnt work, then I will look into replacing the water pump. As a last resort I will retrofit a front mount radiator.
Don't want to hijack This Thread but can anyone give me some pointers on what type of coolant is best. I have always used the Honda product but I know there are other aftermarket versions out there that are supposedly better at controlling Heat.
In fact the best coolant is the cheapest: distilled water. Problem is: it boils at 100° and 1 atm and does not protect against rust. Any combination of this and ethylenglycol will improve boiling point (and freezing point) and prevent rusting with some additives.
You don't want it to get so high it's flashing. That is a critical warning. I believe the bike shuts down over 125°C but cannot confirm that is true.
I think you just confirmed my RR issue theory. After my battery dying on me (I fixed my overheating issue at the same time as adding a usb/12v charger). Each time my bike died I had been in stop and go.
After getting a boost I had ridden straight to my mechanic, the we're running some charging tests and at best I was getting 12.3v, after the bike was running a while the charging dropped to 12v flat or less even at 4000rpm. I noticed we were hitting the 106C mark.
I had initially blamed the problem on the charger, not thinking that I had in fact added two electrical components at the same time, as I was also introducing working fans to the mix.
I have a new RR coming and I'm hoping the stator isn't trashed, but I will be preparing myself for that job.
I'm hoping the part is in for Monday or me and my wife's motorcycle tour will have to become a really long car ride.
EDIT: I can confirm that the bike does not shut down at 125C
When I first got the bike it had hit 139 before I realized it was flashing and red (was my very first ride since September er of last year and I was riding it out of downtown Toronto focusing on not dying).
Traffic was stop and go and I started just shutting the bike down myself.
I only ever had it start flashing twice since and shut it down whenever I could when stuck in stop and go traffic.
Since making sure my coolant was filled and air free the bike barely ever crests over 100 and usually in the 80-90 range. Thankfully I don't think I've done any damage. When I first realized that I had hit 139 in Toronto it was when I was very close to leaving downtown and was running at higher speeds which brought the Temps down pretty quickly.
interceptor69Don't want to hijack This Thread but can anyone give me some pointers on what type of coolant is best. I have always used the Honda product but I know there are other aftermarket versions out there that are supposedly better at controlling Heat.
Sent from my SM-G920V using Tapatalk
I read a lot about avoiding coolants with silicant in them.
interceptor69Don't want to hijack This Thread but can anyone give me some pointers on what type of coolant is best. I have always used the Honda product but I know there are other aftermarket versions out there that are supposedly better at controlling Heat.
This coolant is the best I've found by a long shot.
Superballs I think you just confirmed my RR issue theory. After my battery dying on me (I fixed my overheating issue at the same time as adding a usb/12v charger). Each time my bike died I had been in stop and go.
After getting a boost I had ridden straight to my mechanic, the we're running some charging tests and at best I was getting 12.3v, after the bike was running a while the charging dropped to 12v flat or less even at 4000rpm. I noticed we were hitting the 106C mark.
I had initially blamed the problem on the charger, not thinking that I had in fact added two electrical components at the same time, as I was also introducing working fans to the mix.
I have a new RR coming and I'm hoping the stator isn't trashed, but I will be preparing myself for that job.
I'm hoping the part is in for Monday or me and my wife's motorcycle tour will have to become a really long car ride.
EDIT: I can confirm that the bike does not shut down at 125C
When I first got the bike it had hit 139 before I realized it was flashing and red (was my very first ride since September er of last year and I was riding it out of downtown Toronto focusing on not dying).
Traffic was stop and go and I started just shutting the bike down myself.
I only ever had it start flashing twice since and shut it down whenever I could when stuck in stop and go traffic.
Since making sure my coolant was filled and air free the bike barely ever crests over 100 and usually in the 80-90 range. Thankfully I don't think I've done any damage. When I first realized that I had hit 139 in Toronto it was when I was very close to leaving downtown and was running at higher speeds which brought the Temps down pretty quickly.
Incessant fan functioning and a poor battery, r/r, or stator will see the bike die relatively quickly. The straw breaking the camel's back.
Sounds more like the stator to me as you are undercharging. The r/r when malfunctioning usually means overcharging. Not necessarily though. You might be lucky. Could also be the connector between the two is burnt out creating resistance.
Incessant fan functioning and a poor battery, r/r, or stator will see the bike die relatively quickly. The straw breaking the camel's back.
Sounds more like the stator to me as you are undercharging. The r/r when malfunctioning usually means overcharging. Not necessarily though. You might be lucky. Could also be the connector between the two is burnt out creating resistance.
I'm praying it's the RR right now. At this exact time I can get one or the other done. The stator I will likely have to bite the bullet and find time to do it myself the RR I may have to as well.
Incessant fan functioning and a poor battery, r/r, or stator will see the bike die relatively quickly. The straw breaking the camel's back.
Sounds more like the stator to me as you are undercharging. The r/r when malfunctioning usually means overcharging. Not necessarily though. You might be lucky. Could also be the connector between the two is burnt out creating resistance.
Confirmed the stator is toast. Having that replaced. Looks like the bike trip became a car trip, but we will still be camping wherever.
On the bright side, there really isn't much else wrong with the bike, so it should be all maintenance and wear parts from here on.
I finally got a chance to do a 40 mile ride today on the new radiators and wow do they work!! It was only 59 F outside, and the bike while moving would only get to about 172. When stopped it would rise into the 190s. As soon as I started moving it would drop down again. I wasnt able to get it hot enough to test the new SPAL fan.
If I could find a set that didnt leak at the weld, I would say this is a great pair of radiators.
fonque I finally got a chance to do a 40 mile ride today on the new radiators and wow do they work!! It was only 59 F outside, and the bike while moving would only get to about 172. When stopped it would rise into the 190s. As soon as I started moving it would drop down again. I wasnt able to get it hot enough to test the new SPAL fan. If I could find a set that didnt leak at the weld, I would say this is a great pair of radiators.
[image: emoji4.png] Im glad that it worked but that jb weld makes me be scared about the future of that bike ? I would rather look for a good tig weld in a short time... I know that jb weld is like a miracle, but a leak on a pressurized radiator fixed with jbweld from the outside wont last forever... Good luck and keep us updated!
I finally got a chance to do a 40 mile ride today on the new radiators and wow do they work!! It was only 59 F outside, and the bike while moving would only get to about 172. When stopped it would rise into the 190s. As soon as I started moving it would drop down again. I wasnt able to get it hot enough to test the new SPAL fan.
If I could find a set that didnt leak at the weld, I would say this is a great pair of radiators.
Does it also feel less hot when you ride? I'm a new owner...only have mine for a few weeks. It's a great bike but damn if the heat isn't making me second guess getting it. Coming from an SV650, it feels like I'm riding a furnace.
This is the best part, since installing the new radiators and spal fan my legs are significantly cooler!
I think this is due to running a pusher fan instead of a puller. I think with a puller fan the air has no where to go but to your crotch.
I've had a chance to ride in the mid 80s, and the bike just touched 221 in stop and go traffic. Temps we're pretty steady between 210 and 221 in heavy traffic.
This is the best part, since installing the new radiators and spal fan my legs are significantly cooler!
I think this is due to running a pusher fan instead of a puller. I think with a puller fan the air has no where to go but to your crotch.
I've had a chance to ride in the mid 80s, and the bike just touched 221 in stop and go traffic. Temps we're pretty steady between 210 and 221 in heavy traffic.
Awesome, I might just try replacing my fans and see if that helps. At least for now I'll be able to ride longer through winder than I could on my SV :)
Has anyone tried cutting vents in the narrow strip of lower fairing facing your shins? It seems to me the fairing traps heat in the engine bay and vents might let it flow backwards, albeit onto your legs.
Stray
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