160* Thermostat?

[CandyRedRC46]

OK, so a few months ago I got a hold of a 178* fan switch. It had been sitting on my desk for a while until the other day. Being that my bike was already stripped down to instal the Motad and Two Bro's, I figured it would be a good time to do the fan switch. I'm liking the results of the exhaust a lot, but the fan switch has got me a little concerned...
The thermostat on our bikes is set at 180*... and my fan set to kick in at 178*... The bike warms up just as usual, and then the fan kicks in at around 173* give or take a few.
Now what I was hoping for, was that it would come up to 180, fan kick in and drop it to 170 and turn off. That would have been too easy... What happens is it comes up to 173 the fan comes on and it just sits there around 175 forever... The fan never turns off.
I'm thinking that thermostat is trying to warm the bike up past 180 and the fan is fighting to keep it below 178. Instead of the fan coming on and turning off, I think the thermostat is opening and closing.
The perfect answer would be a thermostat set 10 or 20 degrees lower then the fan switch, ideally a 160* thermostat... I can not find any custom thermostats for the veefer! Aftermarket yes, but they are all set at the same stock 180*...
I am not sure where to go from here. Why would they make aftermarket fan switch set lower than the thermostat if there is no custom thermostats avaliable? it never gets cold down here. I'm wondering if I can just ditch the thermostat, and let the fan switch control the operating temps?
Anyone got a solution? Don't bother with the put the stock back in replies.

[CandyRedRC46]

Here is the switch I put on:

Honda Honda VFR 800 4/5 04-05 Fan Switch UPGRADE dfygh:eBay Motors (item 250378640084 end time Jun-23-09 10:24:34 PDT)

I will try and post up some pics later on.

[bluespecv03]

A little off topic, but whats the cheapest place to get an OEM thermostat? I can't believe the price, compared to getting one for a car at AutoZone.

[15dollar]

What is the benefit of running a cooler t-stat? I've always heard that a motor is more efficient the hotter it runs.

[CandyRedRC46]

What is the benefit of running a cooler t-stat? I've always heard that a motor is more efficient the hotter it runs.

it is cleaner, the hotter it runs, to a certain extent, but not more efficient...

the idea is, if i can keep the engine operating in a cooler range. i can run it in a higher state of tune, without risking detonation. a.k.a. more timing advance, compression, etc...

also, im trying to get this sorted out before i run the battery down, or wear out the fan, alternator, wiring, fuses and such...

[CandyRedRC46]

A little off topic, but whats the cheapest place to get an OEM thermostat? I can't believe the price, compared to getting one for a car at AutoZone.

not really a concern of mine at the moment... why is yours already shot?

[15dollar]

That makes sense. What about using a manual fan switch?

[squirrelman]

The fan switch is set improperly low........... so now you want a thermosatat set too low to match???

You'll be wasting fuel cuz the sensors will send in a richer than normal mixture as it does before engine is fully warm.......
Use the stock (190) thermostat only.

[CandyRedRC46]

The fan switch is set improperly low........... so now you want a thermosatat set too low to match???

You'll be wasting fuel cuz the sensors will send in a richer than normal mixture as it does before engine is fully warm.......
Use the stock thermostat only.

"Anyone got a solution? Don't bother with the put the stock back in replies."

You have heard of a company called Dynojet, and one of their products called a "Power Commander" right?
Maybe you should sit this one out, and find some kids with first gen bikes to harass...

[NorcalBoy]

This thread is some funny shit, thanks for the laughs.

[CandyRedRC46]

well this looks promissing:

Thermostats - Motorcycle Products Ltd

Thermostat 48mm Diameter 76c - Motorcycle Products Ltd

82* C would work out to 180* F which would be the factory setting
but, 76* C comes to 169* F Which might do the trick...

does anyone know the size of our thermostats in mm?
hopefully most motorcycle thermostats are interchangable...

[BASFjon]

This thread is some funny shit, thanks for the laughs.

"Anyone got a solution? Don't bother with the put the stock back in replies."

Electronic Switches
Best I could find. I'm not claiming to be someone all-knowledgeable here, just passing some learned information, ..may have it wrong, but everything helps.

That switch should help you adjust and find what works best. I found this researching electric inline brushless water pumps to speed up water flow across the radiators, less the need for a increased flow over the fins.

Getting the Thermoswitch on and keeping heat limited at 190 is ideal. Since a 180-degree T-Stat works open more-so as the coolant heats up, I can say 190-degrees is probably safe on a factory T-Stat. Checking it in a big pot of boiling water in check with a kitchen thermometer would show you the lower and upper limits.

FYI, heat destroys oil and opens tolerances. I don't care what anyone says - that's fact. Sustained temps north of 200 degrees are just not in anyone's better interest. Oil is built to withstand Thermal Breakdown, but not built in mind to run at those temps prolonged.

...hmm...starting to think just how intensely running a VFR Hot deep cycles the battery - that is running it hot for long lengths of time. Our batteries are sealed deep-cycle and maintenance free. However every 25-30 mph stroll around a State Park deep cycles the battery if taken for a good while - based on the fan usage and lack of stator output at low rpms. I've been told a 10-minute run at speed gets the battery back to charge.

Also, just hit me, if emmisions requires hotter temps to acheive better emmissions ratings, then you would think 4th and 5th gen bikes possibly had lower fan-stat (thermoswitch) temps to where they kicked on! Might be something of interest in asking the earlier gens when they noticed their fans kicking on.

Keep me posted. If I wasn't so deeply involved in other upgrades I would be right in this with you. Just not their in the list of priorities yet.

A little off topic, but whats the cheapest place to get an OEM thermostat? I can't believe the price, compared to getting one for a car at AutoZone.

T-Stat on Bike Bandit

2: THERMOSTAT ASSY.
,AC 2AC 67188-001 Enter 0-99 $31.96

[BASFjon]

I'm wondering if I can just ditch the thermostat, and let the fan switch control the operating temps?

The T-Stat closes off the rest of the system so the motor can bleed heat into the surrounding coolant jacket - helps the motor warm up to operating temps and keeps it warm enough in colder weather. Has to be there. If it's removed it will always run cold, and that's worse then hot!

If you set the T-Stat too low, the higher heat is never given a long enough dwell time to run through the radiator to cool off - because the t-stat is wide open and flowing quickly. From what I am understanding, there is a sweet spot between the t-stat and thermoswitch, and I imagine it can only be found from trial and error.

[eddie cap]

For those of you knowledgable with over the road diesel tractors , they have two systems that work in conjunction. In front of the radiator you have a shutterstat and within the engine you have a thermostat . The shutterstat is always set at a higher temp then the thermostat. Sounds similar to the fan switch and thermostat problem that we are dealing with. I believe as most of you, that the fan switch should be set hotter than the t-stat. And yes as one of the guys said ,I believe there is a sweet spot ,probably a math formula ,that is used to attain the proper temps of the fan switch and t-stat. I just sent this data to confirm what most of you already believe. eddie

P.S- Please dont be condescending to one another, I believe we all have the intention of helping .I dont think this forum should be used to "SHOWCASE" ones
knowledge . We all had to learn,some have been involved in the sport
longer that others , respect matters!

[Action]

CandyRed
I remember Rangerscott used one designed for a Civic and ohsix9 used a tstat for a Cavalier. They didn't post details but here is a LINK if you want to take a look. One thing to look at is the stock tsat has a small plunger on the bottom that controls flow to the fast idle control. May not be a problem for you down in Key West.

Action

[CandyRedRC46]

CandyRed
I remember Rangerscott used one designed for a Civic and ohsix9 used a tstat for a Cavalier. They didn't post details but here is a LINK if you want to take a look. One thing to look at is the stock tsat has a small plunger on the bottom that controls flow to the fast idle control. May not be a problem for you down in Key West.

Action

see thats good news! because, as we all know, the civic has more aftermarket support than it knows what to do with. i can find a 160* thermostat for a civic in 5 seconds flat.
this is something i can work with

[NorcalBoy]

Although it is probably inconsequential at this point, I will submit the following information:

Most stock engined sportbikes produce maximum power between 92c (197.6f) and 96c (204.8f) coolant temp. The lower end of that window is controlled by the thermostat. The upper end is the cooling system's ability to shed heat (i.e. the fan.)

Based upon the provided information, it is best to draw your own conclusions as to the direction you should go. Right now it would appear that you are outside the temparature window for getting the most out of your engine and the list of mods in your signature. Squirrelman is correct.

[NorcalBoy]

Now that isn't very nice, is it Jon?

[BASFjon]

For those of you knowledgable with over the road diesel tractors , they have two systems that work in conjunction. In front of the radiator you have a shutterstat and within the engine you have a thermostat . The shutterstat is always set at a higher temp then the thermostat.

I take it this is an auxillary radiator, and the shutter-stat is like a heater core ball-style valve that opens this auxillary cooling circuit at higher temps to pull off the extra heat.


..I keep racking my head over this and it just makes me want to go with an electric pump, remove the t-stat, incorporate an electronic controller, and engine-ice coolant (not even mentioning the Oil Cooling Mods). I can get away with removing the t-stat because the electric pump doesn't even activate till the temps rise, and at that, it's variable to the amount of heat in the system at the sensor, not locked into the engine speed (rpm) as a factory mechanical pump is. There would also be less plumbing and heat soak to boot. Everything to the Backside of the down-hose from the Heads would be eliminated (everything behind the dashed Red Line), and there are already mounting boss(s)/points already on the motor suitable for mounting this setup - see picture below.



This would set you back about a good $400 or so to do it. Looking at it in prespective, the upside is less draw on the motor, some quicker acceleration (uncertain as to the extent), less heat soak, and better cooling management - adjustable at that - keeping the Thermoswitch pointed towards the forward black plastic lower cowl for a long screwdriver to access it and make adjustments, ..and a small improvement in low-speed cooling. The downside is total pump failure - which leaves you SOL, and it's one of those, should I have boughten two of them considerations since it's an oversees part? However the designs amoung the smaller engine electric pumps are nearly identical. Also there is more draw on the Alternator, and the EBP Pump requires 13 Volts minimum to run - which I would love to see a chart for a Stock VFR with regulated output voltage versus engine rpm (idle to at least 6,000 rpm).

I know there is someone here on this board that did an electric pump. I'll have to find him sometime soon and ask his opinions.

Now looking at the cooling circuit, you can see it is ran in a series-parallel arrangement. The Coolant Lines are split from the t-splitter at the bottom, and half the flow is proportioned to each radiator.



So the T-splitter at the bottom of the motor is a parallel supply line to both radiators (the flow direction goes from the back bottom of both radiators, across the rows, to the front tops (seen above) - feeding through the T-stat at the top junction area - mounted on top the right radiator, to the heads (E&D), through the motor, and out the left top of the motor (B&C), down to the pump inlet (A), then back to the t-spliter at the bottom side of the radiators - with a Bypass Hose to the T-Stat at (F) for when the T-Stat is closed at warmup or cooler temperatures.



And this is how this motor is designed to dissapate heat - each taking half the load. However the left one only gets the fan (in this illustration it's the radiator on the right side of the picture). Now given from what I've heard, the Fan activates at 200+ and pulls air inward...but I think this is done to push air across to the other radiator as well.

Sorry if this is a little off-topic. But it's relative and supportive information. If a simple thermoswitch and t-stat swap can remedy this, it would be awesome!!

The more and more I look at the placement and such of the design on this motor, the more and more it makes sense. It's actually designed very well. to Honda. Just at too high of a designed running temperature . Can't wait till we get this cracked and working at lower temps!!

[BASFjon]

Now that isn't very nice, is it Jon?

Nope! Just wanted to put things in perspective. I'm working, your laughing.

[Action]

Jon,

You said in your previous post "So the T-splitter at the bottom of the motor is a parallel supply line to both radiators (the flow direction goes from the back bottom of both radiators, across the rows, to the front tops (seen above) - feeding through the T-stat at the top junction area - mounted on top the right radiator...."

I think the flow is in the opsite direction.



So am I working too??? (J/K)

Action

[NorcalBoy]

Sorry to bother you hard working folks, but this has really taken off.....it's now gone from a potential $6.00 solution of a manual fan switch or a $40.00, 200 degree thermoswitch for the fan - to a complete $400.00 reengineering of the cooling system. Can't wait to see how this all ends up, good luck.

[BASFjon]

Most stock engined sportbikes produce maximum power between 92c (197.6f) and 96c (204.8f) coolant temp. The lower end of that window is controlled by the thermostat. The upper end is the cooling system's ability to shed heat (i.e. the fan.)

Interesting I didn't know that. I thought it was nearer to 185-190. I've always noticed that cars and such ran normal temps of about 180-185, and this VFR runs about 172 if it's at speed. And it runs well on this temp. In general I know that cooler temps cause poorer fuel economy.

From what I am getting here, it's in the cooling systems design to be ran at temps tipping 200 when ran hard, but with temps around 170-180 not under any agressively load.

When I get some time, I am going drain the system and refill it with engine ice, before-hand pulling the T-stat and Fan-stat, measure the temps in boiling water to get the opening and full-open readings, and then pickup an oil temp sender and digital gauge and watch what happens at low speeds. Going on about this seems to be unsupported without any solid measurements and information.

[mello dude]

This is the first time I've looked at this thread, but fan on at 178 is too low. You need to bump that up.

MD

[eddie cap]

Looking at the sketch,which I believe is from the service manual,I have to say, Action is correct. In short it appears that all the engines coolant goes through the radiator with the
radiator cap first(right side) and this radiator then transferes its coolant via two paths,one is straight back to the engine and the other path is over to the left side radiator,with fan,then down through that radiators coolant tubes and back to the engine and repeat.
In essence the right radiator is the primary,which gets 100% of the coolant and the left one is the secondary which gets only a percentage of the coolant ,seems to me the fan should be on the right side radiator,buts thats the way I see it. eddie

[BASFjon]

Jon,

I think the flow is in the opsite direction.



Action

Thanks. I'll take the hat for that one...lol

Personally I'd do a $400 redesign on this system if it meant I could go low-speed without the high temps and having to use a fan and drain the battery or cause the voltage to dip. I have an airbox cover I modified that flows air well enough to make the engine responsive down that low - it just causes a lot of heat at low-speeds. 2500 rpm at under 30 mph is the real combination that causes it.

Might not seem a concern for a lot of members here, but if you build a VFR for sport-touring and not for carving it up, you'll see what I am getting to. I think these bikes are great for building off of because they actually can make torque, have that a true sport side to them and are lightweight and fun. And parts are abudant as hell and cheap. Other then that, I would have traded up for an FJR a good while back.

[Action]

NCB
I think cold fusion and ambient temperature super conductors will figure promently in the final design.

Action

[NorcalBoy]

I deleted my last message.....pretty sure it would have lit Jon off like a roman candle. I'm done with this thread, I know what it takes to fix the problem and I've already done it. Have fun with this everybody.

[BASFjon]

Looking at the sketch,which I believe is from the service manual,I have to say, Action is correct. In short it appears that all the engines coolant goes through the radiator with the
radiator cap first(right side) and this radiator then transferes its coolant via two paths,one is straight back to the engine and the other path is over to the left side radiator,with fan,then down through that radiators coolant tubes and back to the engine and repeat.
In essence the right radiator is the primary,which gets 100% of the coolant and the left one is the secondary which gets only a percentage of the coolant, seems to me the fan should be on the right side radiator,buts thats the way I see it. eddie

You're absolutely right. Thanks for pointing that out. The Larger Hose E-16 in Illustration MCWAF3600 connects to the Bottom Neck of the T-Stat Housing at F-36 in Illustration MCWAE1600.

That doesn't make much sense to me either. You would think the secondary radiator would have more flow resistance, and not allow a chance for it to cool the system - almost acting like a helper that bleeds over. I wonder if when the pressure builds in the system from increasing the rpms, if this doesn't change - actually forcing the second radiator to flow. But low rpms - that's where is just doesn't add up. There need to be a radiator fan on that primary radiator. That just sounds like a poor design. It's no wonder why it takes so long for those temps to drop when crawling around parks.

Yeah $400 might not be a bad investment along with some replumbing and definately consulting an engineer. I would say that since I don't quite understand why they did it this way - that there is some not so obvious reasoning as to why it was engineered as they did.

Yeah I'm done here too.

[CandyRedRC46]

Although it is probably inconsequential at this point, I will submit the following information:

Most stock engined sportbikes produce maximum power between 92c (197.6f) and 96c (204.8f) coolant temp. The lower end of that window is controlled by the thermostat. The upper end is the cooling system's ability to shed heat (i.e. the fan.)

Based upon the provided information, it is best to draw your own conclusions as to the direction you should go. Right now it would appear that you are outside the temparature window for getting the most out of your engine and the list of mods in your signature. Squirrelman is correct.

im glad you are keeping such an open mind to all of this. because the way you and squirl are talking, it sounds like you believe that you were mr.honda himself...

"Most stock engined sportbikes produce maximum power between 92c (197.6f) and 96c (204.8f) coolant temp" yes this deffinetely sounds like it has some merrit behind it, but with this beeing said, how is my bike sitting at 226* plus going to be benificial??? also if you had spent more time actually reading this thread instead of just giggling to yourself you would see that i am doing this because i plan on advancing the timing a few degrees and i do not want to cause any harmful detonation.

find a fan switch that comes alive at 200* instead of 225* and i will gladly install it and toss the 178* in the trash. with the 178* fan switch being the only switch i have found alvaliable so far, this is where i am going to start my trial and error.

unlike you, i am not saying that any of this is matter of fact, i am just trying to see what works best.

.