R1100/R1150 Hot running

[japachap]

Hi chaps!

Ive got a home workshop project underway at the moment and Im wondering how many of you riding the R1100/50 models (Im leaning more to the RT and RS versions, but would consider the other variants aswell) have ever had the bike overheat? Im not talking critical overheating, to the point where something breaks of springs a leak of boiling oil, but more where the temperature guage has risen quickly above normal due to riding in hot weather/heavy traffic/slow riding/ offroading/ sudden deceleration from highway speeds to standstill etc, etc?

 

Its just pie-in-the-sky right now, but Im interested to see if anyone has ever been bothered by this problem and with for example the BMW RT-P fan being so expensive, if anyone would consider fitting a cheap aftermarket alternative if one were available?

 

Just an idea. Thanks for your input!

 

Oh- the poll, just tick the box for 'YES', otherwise leave it blank for 'NO'

[japachap]

Cheers to the sixteen(?) of you who did the poll! In all honesty, I really didnt design it very well. After two months scanning the net and a few days in my garage I have this wee beastie-

Sadly its not that powerful

(josstick test...)

 

But Ive just found a US supplier for some seriously more powerful fans, and a neater design, so watch this space...

[Woodie]

Way overkill, but neat to see!

 

[AndyS]

Cheers to the sixteen(?) of you who did the poll! ...

 

I wonder if the reason you got so few polsters is because it is totally un-necessary.

If the bike didn't have a temp gauge you wouldn't even consider all this work.

The bike copes pretty well without it. If it was stationary and running, then it may well be another issue. But then again the fairing sharks fin and assosiated plastic would probably melt/catch fire first.

 

Andy

[Technologist]

What's the CFM on each Fan? Are they 80mm Fans?

 

These fans have 84CFM each and are double Ball bearing fans with Great Reviews.

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16811999612 $11.99 each.

Way cheaper then spending $260 for the Stock setup.

 

All the Police R1150RTP's have them and I like mine. I can sit in 110F desert heat to charge the battery without overheating.

[Trullion]

+1 on what AndyS has said; my 850GS has no RID, no ABS, no floating disks and no problems. Ignorance is bliss.............

 

I doubt that here in the UK the engine is ever likely to overheat unless left idling too long, though global warming might eventually change this.

 

Ride safely

[Joe Frickin' Friday]

 

I just wanted to say that it's pretty cool to see you've found a way to incorporate a beer can into the project.

 

[Dave39]

Only had a problem once when caught in heavy downtown stop-and-go traffic on a hot 100+ degree summer day. I try to stay way clear of traffic jams whenever possible so wouldn't bother with any kind of add-on.

[AndyS]

...... I can sit in 110F desert heat to charge the battery without overheating.

 

I doubt it! Why do you want to sit still and charge the battery?

moreover, I bet your plastic around the exhaust would fail.

Mind you, if you increase the flow rate a bit more, you could use it as a performance aid.Suck yourself forward a little faster:-)

Andy

[Clive Liddell]

In any case that is "only" the oil that is being cooled what about the lack of airflow over all the cylinder fins and the bottom of the engine.

[japachap]

:rofl: :rofl:

Awwwww, man!

Isnt it amazing how jaut a few pics can really stir up a response!

 

Y'know, its true that its a lot of effort to go to for something that typically only happens maybe once or twice a year. The problem is more that when I get an idea, I like to take it to its conclusion.

Questions-

Why is there a temerature guage if its to be ignored?

Why did BMW think it necessary to design an item for the police?

Why did only Joe make the important observation that Beer was involved?

 

Some answers-

Thats three 80*80*25mm fans, producing a maximum 31.5CFM each and a maximum pressure of 2.83mmH2O. The set-up is just too wide to mount easily. Three 60mm or better yet three 70mm fans would fit the 214mm wide cooler better, but Im currently looking at two 102CFM 80mm fans which would give (hopefully) an thru-flow of air at about 20km/h (12mph)- thats comparable to a small car radiator fan (eg Spal, at 5.5inch diameter and 248CFM gives about the same air speed per unit area). Pricewise- its about 32euro (dollar???) for the two units, plus some ally bracketry.

 

Look, Im just bored, ok?!

[T__]

japachap, one thing to keep in mind..

 

In the auto industry we have found that while lots of fan area increases the radiator air flow at “O” mph or low vehicle speeds it can actually reduce the air flow through the radiator at higher speeds.. In some cases we get better high speed air flow with the fan(s) turned off.. Better flow yet with the fans removed..

 

Your fan rack design has a lot of surface area located in the air stream (large motor bodies & lots of fan blades).. Be sure you are not hindering high speed cooling at the cost of low speed cooling as the engine is doing more work at high speed..

 

 

Twisty

 

[japachap]

Spotted that one, Twisty1. The first design didnt seem to make much difference on the daily commute, but you are right, anything placed before or after the cooler will restrict the airflow. What I also look at is that the cooler itself really restricts the airflow as the filling is quite tightly spaced. Incidentally, why does no-one ever worry about airflow when they fit a cooler-guard on a GS for example? Maybe cooling at speed is more dependant on the engine finning than the oil cooler...?

Theres also the thought that the gaping front of the RT fairing around the forks channels a massive ammount of air up past the headstock, and I wonder just how much back-pressure (if any) this builds behind the cooler at speed...

Too technical?

[Technologist]

...... I can sit in 110F desert heat to charge the battery without overheating.

 

I doubt it! Why do you want to sit still and charge the battery?

moreover, I bet your plastic around the exhaust would fail.

Mind you, if you increase the flow rate a bit more, you could use it as a performance aid.Suck yourself forward a little faster:-)

Andy

 

You just pointed out another reason for a Fan. To keep the exhaust from changing colors and keeping the plastic from melting.

 

 

Mine is a Police Bike used on a Movie set in the Desert. Also the fan cools the bike and exhaust keeping the plastic from overheating. My exhaust looks much better then the none fan cooled bikes most likely from the fan cooling when needed.

 

The bike is from the Indio Police and the fan is a necessity in that heat. When police pull over someone they might sit the bike for hours with Strobes and radio's running. They need to recharge the batteries on those calls when needed.

 

The Fan is a BMW factory part for the Police versions. So yes even BMW feels the need for them. Why else would they install them from the factory?

[Technologist]

:rofl: :rofl:

Awwwww, man!

Isnt it amazing how jaut a few pics can really stir up a response!

 

Y'know, its true that its a lot of effort to go to for something that typically only happens maybe once or twice a year. The problem is more that when I get an idea, I like to take it to its conclusion.

Questions-

Why is there a temerature guage if its to be ignored?

Why did BMW think it necessary to design an item for the police?

Why did only Joe make the important observation that Beer was involved?

 

Some answers-

Thats three 80*80*25mm fans, producing a maximum 31.5CFM each and a maximum pressure of 2.83mmH2O. The set-up is just too wide to mount easily. Three 60mm or better yet three 70mm fans would fit the 214mm wide cooler better, but Im currently looking at two 102CFM 80mm fans which would give (hopefully) an thru-flow of air at about 20km/h (12mph)- thats comparable to a small car radiator fan (eg Spal, at 5.5inch diameter and 248CFM gives about the same air speed per unit area). Pricewise- its about 32euro (dollar???) for the two units, plus some ally bracketry.

 

Look, Im just bored, ok?!

 

I think I calculated last week that three 80mm 84CFM fans would give about a 14.7? or 15mph air flow. So our numbers are pretty much the same. I don't know why people are giving you a hard time when it's a useful item depending on your location. Some people don't like splitting lanes to cool a bike and this is a good safety device for traffic jams in hot weather.

[David R]

I would turn the bike off when I could. It seems to cool down fast. I don't get in 100* traffic jams.

 

The hottest I have it was 6 bars (one over normal) Idling around a tourist town in first or second gear.

 

Would these fans impede air flow when running it hard at high speeds?

 

David

[Technologist]

I would turn the bike off when I could. It seems to cool down fast. I don't get in 100* traffic jams.

 

The hottest I have it was 6 bars (one over normal) Idling around a tourist town in first or second gear.

 

Would these fans impede air flow when running it hard at high speeds?

 

David

 

The BMW bike gets massive cooling at high speeds as most of the resistance above 20-30 mph is air resistance. Pushing a Bike at top speed is like having a monster 100+HP fan hitting the bike. Overheating really is only a problem at very low speeds like 0-20 mph with an air cooled bike with no air flow. Or crawling up a steep mountain in first gear doubled up.

 

[japachap]

Cheers Techno!

At risk of stirring the fire further, it does seem odd that some owners will go to massive lenths to fit all manner of styling products to their bikes (c'mon- how many fit oil cooler guards, but pass on headlamp protectors, if the goal is truely to protect fragile and expensive components from stone chips?) with no real benefit , but something a bit technical and dirt cheap with the potential to help in extreme circumstances seems to set alarm bells ringing. What surprises me most is I could understand it if I was on a German website where the Germans have stricter anti-tamper laws, but gawd, the US is the home of customising and clever/odd tweaks.

Oh, and Ive had my temp bars up to the red before now, decelerating to standstill from motorway speeds and being stuck in slow-crawling traffic. In some situations you just cant switch off!

A further thought is that even a household cooling fan is useful when, for example, performing throttle bodiy/injector balancing in a garage (door open, obviously!), so its all useful...

[japachap]

In any case that is "only" the oil that is being cooled what about the lack of airflow over all the cylinder fins and the bottom of the engine.

Isnt that why they're called 'oilheads'? Cooler oil will help dissipate heat throughout the whole engine, but you are right, the finning on the engine is a crucial factor once on the move..

[jblaze5779]

I actually got to the very top of the temp gauge twice this past summer. I was stuck in traffic and it was broiling hot out 100+. I ended up being forced to drive down the shoulders of I-35 and 75 in Dallas to avoid ruining my bike.

 

I was thinking some auxiliary cooling would be good for bike located in hot areas. I was also thinking, like others, that a fan setup would probably block air at higher speeds.

[David R]

I can tell the thermostat doesn't open till the 5th bar. I left for work when it was 44*f. I didn't have any heat at the ducts until I was at the next town 15 miles away. 50 to 60mph most of the way. The bike cools fine the way it is for my type of riding.

 

I like the fans and execution. I like the beer can too.

 

David

[Technologist]

I actually got to the very top of the temp gauge twice this past summer. I was stuck in traffic and it was broiling hot out 100+. I ended up being forced to drive down the shoulders of I-35 and 75 in Dallas to avoid ruining my bike.

 

I was thinking some auxiliary cooling would be good for bike located in hot areas. I was also thinking, like others, that a fan setup would probably block air at higher speeds.

 

The oil cooler has tight spacing on the fins. You will see that the air is restricted by the fins causing a large pressure drop. The Three fan setup in the picture won't restrict the airflow much at all compared the to stock BMW Fan on the Police model.

 

You will notice that the fans blades have more air surface gaps and less pressure drop then the fins on the cooler. The fans are brushless and will spin at higher speeds without power, further reducing air resistance.

 

Once you reach about 20-30mph the oil cooler is only a small portion of the engine cooling. Many air cooled engines don't even have oil coolers.

 

The net effect is minimal at operating speeds and the fans will help you when needed.

 

The only problems are that his fans just need higher CFM and higher RPM motors allowing them to move more air and to handle higher speeds without damage. Like traveling at 130mph for a few miles. As long as his fans are brushless and double ball bearing high RPM fans they would be an asset in cooling and not a hinderance.

 

Again look at the top pictures and notice the air gaps in the oil cooler and the giant gaps in the fans. You will see air flow will not be impeded much as the blades will spin at higher speeds even without power. The stock BMW fan has much more restriction and works great but costs $260+

[japachap]

Well, I think Ive narrowed it down to a suitable unit.

I think maybe Technologist will have the most interest in this...

 

Explanations-

Cooler area 0.017548 sq.m (8.2*21.4cm)

Fan cm2- Assuming all fans draw air through a square area with side length equal to the fan diameter. (It just simplifies calculations a little)

Fan CFM- cubic feet/minute. Maximum airflow through the fan. Think of it as like maximum speed/BHP on your bike.

Fan units- how many can easily be fitted behind the RT oil cooler. With the right design, more than one unit would allow partial redundancy if one fan fails.

KPH/MPH- rough calculation of maximum possible (though unlikely!) average airflow speed through the cooler allowing for x number fan units operating at full CFM

Mass -weight per unit

SUMg- weight of x units in configuration

Amps- max current draw per unit

SUMA- obvious

Watts- nice comparison- compare total wattage of assembly to a 60W headlamp bulb, or a 21W tail-lamp bulb for example (puts things in perspective)

Noise dB(A)- manufactureres quoted noise ratings per fan unit. Everyone uses dB(A) as its the oldest weighted convention and supposed to most accurately reflect the sensitivity of the human ear. Sadly, it doesnt, and tends to hugely undervalue low frequency noise which is less likely to cause hearing damage in the short term, but is more likely to increase driver fatigue. dB ratings are only useful if qualified by the distance of the metering device from the sound source. Most manufacturers quote dB(A) at a one-metre distance.

SUMdB(A)- total noise from x number of units. Bit tricky to explain, but two units producing 60dB each, produce 63dB together- 3dB equals a doubling of noise. Further than that its all hazy...

Pressure- maximum pressure at zero airflow- how hard the fan sucks. Think of it as torque- the more torque, the faster you reach top speed, or the better you can pull up hill...

Cooling factor- this is just for fun. I was impressed by the original Bi-Sonic fan I tried and decided to use its calculated airflow (6.45KPH) as the benchmark. Thus, 12.9KPH is double 6.45 and hence the cooling factor is 2.

 

About the fans-

Bi-Sonic- original 60mm fan. Ultralight and quiet. Surprising airflow for such a tiny unit.

C/Master- fairly average computer case-cooling fan. Really quiet. Higher CFM than Bi-Sonic, but didnt take into account the greater fan area. Net result (although my MK1 used three fans) for two fans- less efficient than three Bi-sonic!

SPAL- Random automotive unit, hopefully of about similar size and power to the BM RT-P fan, as used for small radiators: to give an idea of desired output. The CFM seems massive, but is also spread over a much greater fan area. Incidentally, the bigger the fan, the slower it is likely to spin and the less likely it is to maintain either a high CFM OR a high static Pressure. 23kph and 30mmH2O give a reasonable benckmark to aim for from a cheap unit. The SPAL is also waterproof to IP68.

Delta IP55- The most readily available water-resistant fan I found online. Higher output units are available, but these three units alone pull 40watts of power, are the second noisiest configuration here and give only a medium performance. My idea for the design was that it would be removed during winter/wet months. theres also the school of thought that its unlikely to get very wet behind the cooler; in operation, it spins so fast that water will be flung off anyway, and there are no brushes/contacts which could easily corrode and cause failure.

Delta PFR- a monster! two units wayyy outperform the SPAL,but weigh in a bit heavier. Operates at 9000rpm- past your engines redline!!! The most powerful configuration here, but also the noisiest. See Delta Fans on you-tube for typical 'screamers' from circa 2000-1. Got me worried about noise. Two thoughts- 60dB is equivalent to loudish normal speech at 1m- 63dB is two people having a loud discussion 1m away... the cooler sits inside the fairing, so sound is likely to be dampened and the rider has a helmet (at least in the EU) anyway. Draws a whopping 66watts- thats an extra headlamp bulb!

 

Delta FFB- Total noise in the region of 4 people talking simultaneously (girls night out!), not too high a power consumption, pressure ratings similar to the SPAL and still reasonable maximum airflow speed. Doesnt tip the scales too high and gives almost three times the 'Cooling Factor' of the Bi-Sonic setup.

 

I compared the CFM/mmH20 charts for the Delta PFB, FFB and the A100 and A101 versions of the Spal today, with the SPAL units normalised to the Deltas 64cm2 area (ie 283CFM over 196cm2 is roughly three imaginary fans of 64cm2 area apiece, each producing 90 to 110CFM (SPAL quotes at 13V operating voltage. Thus, the comparison per unit area of airflow is easier. The FFB sits comfortably between the two SPAL variants.

 

Reckon I'll be putting in an order for the FFB shortly...

 

Hope its of interest!

[japachap]

So, I might just have the solution-

 

A few things happened in this story recently. I had to have the headlamp cowling off for another electrical problem, which gave me access to the oilcooler. There are substancial mounting flanges to either side of the cooler casing where the 1150 RTP fan would be bolted. I figured I may as well use them too as anyone wanting to fit such a device would probably prefer the 'designed-in' mountings. I was also chatting to the local BM tekkie, who is really helpful and he showed me the 1100 setup. I never realised the 11 already has ducting from the cooler to the vents under the mirors. He slated the working of the thermostatic control though- 'In summer, you dont want the extra heat by your hands, and in winter it never get hot enough to open the ducts when you want it..'

I thought it might be cool to remove the valve mechanisms and replace them with fan units, utilising the existing ducting.. However, on the 1150, I have two ear-splitting Bosch horns which are mounted in the subframe-loops where the ducting would have run...

 

Theres an engineering design adage that often get forgotten- "Keep it simple, stupid!"

 

With that in mind, some careful measuring and a further 4 hours playing in the garage, may I present- DESIGN 2!

 

 

Nifty... and surprisingly not that loud at 60dBA/fan. Its almost unnoticeable over the engine noise and on its own could easilly be 2-4 times as loud. I'll even go as far as to say its as far from being irritating as I could possibly imagine...

 

Performance. Well, Im currently busy with silicone sealant trying to create a closer fit to the cooler, without actually sticking them together, but theres already a superb blast of hot air. I was initially concerned that this partly gets vented under the tank and hence by the electronics and battery, but I figure a warm air current is better than a hot, still environment...

I'll let the 'Joss-stick test' photos speak for themselves. Taken in a draught-free garage (obviously without the engine running!)

 

 

And a couple of pics of the mounting behind the cooler-

 

Shame its no longer the weather to really test its effectiveness...

Im now looking at power supply and switching options...

 

Afterthought- if it wasnt for the two horns, there'd be space for three fans on the same mounting bracket...

[japachap]

Afterthought- if it wasnt for the two horns, there'd be space for three fans on the same mounting bracket...

 

Looking at it again, three fans with this mounting plate probably wouldnt interfere with the horn positioning.

 

Also done some quick figures for the 'open area' of each fan- outer diameter less motor diameter- comes to about 36cm2 (6cm*6cm)/6.25 sq inch(?), which is not far off the ducting size the 1100RT uses. In theory then, the un-powered airflow will be no worse than the 1100RT with its ducting. It may even be better...!

[NonComp]

Doesn't this setup actually obstruct natural airflow through the cooler at speed? Are those fans waterproof? They look a lot like computer cooling gear.

[japachap]

Hey Glen,

 

I think the answer is in the rest of the thread!

 

The fans do obstruct airflow at speed, compared to a cooler with no fans.

However, compared to a 1100RT cooler with its thermostatically-controlled warm air ducting to the vents under the mirrors, its about the same...

A three-fan set-up would improve this, but most of the cooling at speed is directly from airflow over the cylinders and through the fairing. Then theres the extra cost of a third fan...

Its difficult to be precise without a lot of expensive lab testing. In practise I dont think it makes much difference. The fans could be run continuously with the ignition on. They are rated normally to something like 30 or 50,000 hours operation. Even at 30,000 hours- thats the equivalent of at leat 90,000miles riding! I wouldnt expect them to last that long obviously,and I would realistically expect the fans to be removed from the bike before the winter and nasty road salt comes into play...

 

Waterproof? No.

Waterproof fans to IP66 (IIRC..) are significantly dearer, heavier, have lower flow capacity and much higher current drain. We're talking the difference about a three-fold increase in wattage just to get the same airflow. They are also very difficult to find to purchase- a part of my thinking was that the components have to be 'easilly' available- even these fans took me nearly two months to find a supplier...

The gap between the rotor/motor andd the drive plate is about 2-3mm (1/8inch) so water could fasibly get in. However, its a brushless motor, meaning there are no moving/electrical contacts to corrode. The drive electronics seem to have a thin waxy sort of plastic coating, but an occasional light spray of WDF would probably be enough protection.

There wont be much water comming through the cooler itself and the fans are relatively well-protected inside the fairing, under the headlamp. In operation, I envisage the 7500rpm propellors and high airflow to practically disallow any water time to collect in the fan electronics themselves. Theres also the point that its very warm so close to the cooler, so any moisture should dry almost instantly! Ive also mounted the fans with the opening for the wiring at the bottom, as opposed to the side (you'll notice the sticker on the back of the fans appears sideways on...).

I wouldnt pressure wash them! I am planning on running them on my bike this winter for some severe testing...

 

Computer fans? No, not really.

Most computer fans kick out to about 30CFM and run at 18dB noise. Thses run at 102CFM and 60dB noise apiece. Too noisy for most users to consider in their home computer. More people are considering higher output fans, but have to place the computer in another room, or add sound insulation.

After two months searching, I have only found one computer components supplier which sell high-performance fans (at least in Holland) and those were only to about 60CFM.

Ultra-high fan speeds are mainly used in OE/server or military applications where CFM far outweighs dB in the design considerations.

These fans are not easy to come by for the general public, you really have to know where to look...

 

Incidentally, the optimum design of three 70mm fans for the RT cooler was scuppered by the 70mm fans (they are produced!) being rarer than rocking horse shit, generally only for OE supply, and too expensive to be considered for a 'budget' design.

 

I hope that answers your questions Glen.

 

Will try to make a vid sometime and get some winter testing done...

[NonComp]

The thing about water and electrical gear, is that water gets into to absolutely everything -- and stays there. I recently had my ST1300 pulled apart and in the process, noticed that the stock Honda wiring harness for the heated grips had a "waterproof" inline fuse holder mounted upside down. I opened it and found the fuse had been immersed (for some time) in water that had corroded the contacts. The fuse holder was buried inside the plastics, right next to the left-hand cylinder heads (lots of heat).

 

In reality, one rain storm at highway speeds will tell the story. If you really want to know, set it up, get it running, get the garden hose out, set it to a gentle spray and point it directly into the opening.

 

My oil coolers are outboard on the 1100 roadster, so I don't have airflow issues with plastic. And since I don't have a temp guage, I don't worry about it.

[japachap]

I take your point Glen! Luckilly you dont 'have to worry about it' on the Roadster. Similarly, the RS, S and GS probably dont suffer with it either- though if anyone has on these bikes Id be interested to hear! And a big part of it is psychological- if you are sitting in traffic, or filtering on a hot day it can be quite stressful (especially if fully-loaded and with a pillion- off on holidys) and to see the temperature guage going skywards, whether it indicates real trouble or not, just adds to the worry-load!

 

For me, the thought of being able to throw a switch, or know that there is something cheap but reliable working away, to reduce that stress factor is the whole resaon I started playing with this idea...

 

And I totally know what you mean about waterproof connectors. They typically arent... But, if water does get in due to exterenal air pressure/spray etc, then there is nothing in the 'sealed' connector to push it back out again. You are probably better off with a non-sealed connector than one which leaks a bit!

 

Its been interesting watching the poll results change slowly as this thread has developed- the more likely it is that something cheap can be made, the more people are interested...

 

Ive got a wiring kit now, so will be fitting the fans in the next week or so...

[NonComp]

My guess would be that the most vulnerable point will be the fan motor shafts. Water will get into the fan bearings. The fans will get sticky (not start up unless there is some airflow through to assist by pre-spinning them) and eventually seize. You may get some warning as the bearings may get noisy first.

 

The fans will most likely seize after a period of inactivity, such as storing the bike for the winter.

 

Remember that the original BMW design for these oil coolers was to cool the oil at normal road speeds, not when the bike is standing still. So if the fans seize or are not operated all the time (or on a thermostat) then the resulting airflow will be greatly reduced, when compared to the original design.

 

Yes, the engine has cooling fins. But BMW added the oil coolers to provide supplemental cooling while the bike is being driven.

[japachap]

The fans will most likely seize after a period of inactivity, such as storing the bike for the winter.

 

Some of us ride in the winter...

 

Theres also the issue of maintenance...

 

I digress...

[japachap]

All the Police R1150RTP's have them and I like mine. I can sit in 110F desert heat to charge the battery without overheating.

Technologist- I almost forgot to ask- do your fans run all the time, or is there some sort of thermostatic control on the RTP? Do you know where the wiring runs to- ie where the fans is connected to the bikes loom?

 

Im leaning towards 'always on' at the moment...

 

[NonComp]

Some of us ride in the winter... Theres also the issue of maintenance...

Since you ride in the Netherlands in the winter, you are probably dealing with salt and water... I guess yearly fan replacement would work...

[smiller]

Way overkill, but neat to see!

That's kind of where I am. It seems that only about 10% of respondents in the poll have ever experienced any concerns or even occasional overheating, and occasionally running hot won't hurt these engines at all. It doesn't get a whole lot hotter than Texas in the summer and I have rarely felt the need for supplemental cooling (for the bike that is, I could sure use some...)

 

This thread contains a lot of good info and is appreciated, and if you regularly commute in Phoenix or Las Vegas in summer (ouch) then such a mod might come in handy, but it seems like the application might be rather limited for most of us. Just letting the bike run hot once in a while won't hurt anything, and fans are just one more thing to fail.

[japachap]

Ultimately, Im doing this because I find it interesting and beats sitting in front of the TV with a beer every evening. Im hoping something useful may come out of it, but if not- what the hell.

I appreciate constructive comments and bearing in mind about 9 out of 30-something people who filled the poll in said they might consider a cheap fan mod, Im happy to share my findings/ideas/creations to a point.

 

Im getting a little pissed that the naysayers seem to be those riders who havent experienced hot running of even ride the bikes that it occurs on. And Ive never got pissed about comments on a forum before...

Anyway, Ive found another forum where a guy with a 1200RT has similar problems, so Im looking in there for a bit.

 

Will look back here soon...

 

Be good!

[smiller]

No offense meant and no one is trying to say nay. The kicking around of many points of view is characteristic of these threads, no disrespect intended.

[japachap]

No worries, Smiller!

Im maybe a bit touchy as Im dead tired from work and this is the first time in a very long while Ive adopted a 'pet project' (the last was building a chain maille vest!...) that Ive really ploughed a lot of hours into. Of course all points of view are appreciated- I just prefer those that sound a little 'positiver'

[NonComp]

Im maybe a bit touchy as Im dead tired from work and this is the first time in a very long while Ive adopted a 'pet project' (the last was building a chain maille vest!...) that Ive really ploughed a lot of hours into. Of course all points of view are appreciated- I just prefer those that sound a little 'positiver'

OK, something positive for you: I doubt that your modification will do your bike any harm. Good luck.

 

P.S. 102F in stop and go traffic this summer - no problems.

[jblaze5779]

I tried a mini mod like this on my bike. I hooked a vantec tornado fan up to the back of the oil cooler and wired it to a dash switch. I haven't ridden in weather hot enough to try it yet but I hope it'll keep me from having to drive along the shoulder next summer.

[japachap]

Was that just the one Tornado, Jblaze, do you remember the CFM, and what did it cost you?

 

My two 102CFM cost me E31.56, plus E18 carriage, plus E9.50 import duty= E59 = $87USD. They do kick arse though...

[FatBaxter]

Wouldn't it be simpler to just mount the fans at the other end of the ductwork -- just behind the hot air exit grills in the fairing, below the handgrips?

[japachap]

Wouldn't it be simpler to just mount the fans at the other end of the ductwork -- just behind the hot air exit grills in the fairing, below the handgrips?

 

Spot on Baxter!

 

The moment I saw the ducting on the R1100RT I thought-'that would be useful', but the 1150 doesnt have the ducting. BM dropped it as, to quote my local head technician- 'it only gives you hot air in the summer, and doesnt work in the winter'. Ive also looked at the cost of fitting the ducting aftermarket and the BM prices are almost double that of just fitting the OE RT-P fan, so cost-wise its a non-starter for 1150s.

 

I do really like the idea of ducting hot air away from the front of the engine, but Im also of the thought that a warm airflow around/through the front of the fairing and over the cylinders is better than no airflow at all... The air will never be as hot as the cooler or the cylinders so will always do some (albeit small) cooling work...

[japachap]

So after several weekends in the garage creating an accessory wiring loom, the fans are installed

 

For a bit of fun and for you entertainment/education/riddicule I made a video of the story... a first for me...

 

and I know I cant present for toffee...

 

 

Enjoy!

[ianboydsnr]

So after several weekends in the garage creating an accessory wiring loom, the fans are installed

 

For a bit of fun and for you entertainment/education/riddicule I made a video of the story... a first for me...

 

and I know I cant present for toffee...

 

 

Enjoy!

 

nice video

[japachap]

Thanks, Ianboydsnr!

It was a lot of fun to make, but seems to have killed the thread...

Hey-ho, Im happy at least!

[ratfink]

I enjoyed your video and sent a link to a friend who blistered the fairing on his RT. He was stuck in downtown traffic on a hot day while a marathon was in progress.

 

In 5years and 20k miles the only time the fan on my RT-P has activated is when I intentionally ran the temp up to test it, doesn't even come on till 8 bars on the temp gauge.

 

I've seen several standard RT's with blistered fairing bits near the exhaust headers. I haven't seen such blistering on RT-P's I've

looked at, even though It is common for them to idle stationary for long periods of time. My conclusion; the fans carry enough heat away from the engine to help reduce exhaust temperatures enough to prevent fairing damage.

 

The fan is seldom needed in cooler climates but sure is nice to know it is there. I've overheated other air cooled bikes in heavy traffic and it is a PITA.

[NonComp]

I think that it is very unlikely that the fan could do anything to prevent blistering of the fairing. The exhaust temperature will remain constant and the headers themselves are not cooled by the oil cooling circuit. That cools the exhaust port area of the heads.

[ratfink]

The heat is produced in the combustion chamber and on a stionary idling bike most of the heat is going out the exhaust.

 

If the oil cooler is suddenly rejecting heat by virtue of the fan,

thermodynamics dictate that heat will be drawn to the cooler. With the fan running on my RT-P the heat rejection at the cooler

is pretty significant, for the sake of argument lets say 15% of the total combustion heat is now being rejected at the cooler instead of virtually none without the fan.

 

The heat of cumbustion is constant, now 15% is being rejected elswhere. That heat has to come from somewhere. Wouldn't it result in lower exhaust temps? Wouldn't heat rejection through the cooler result in proportionally less heat going out the exhaust?

[NonComp]

Ratfink, the heat is pulled from the cylinder head by the oil cooler, not from the exhaust gases. The exhaust gases exit via the valve and enter the header. If your theory was correct, then the oil cooler would be reducing the combustion temperature.

[ratfink]

It's not based on theory it's based on laws. The laws of thermodynamics and the law of conservation of energy. The only sources of heat are combustion and to a lesser extent, heat of compression (maybe some friction). If some of the heat is rejected at the cooler it has to reduce the heat exiting through the exhaust.

 

Admittedly some heat is rejected through the cooling fins etc. but on a stationary bike it is minimal. The heat exiting the cooler is mostly heat of combustion.