| Author | Message | ||
     Deanbush |
I am looking at ways to get the air trapped at the back of the rear cylinder moving out,because without the fan on no air actually moves from this area. The main problem is the angle of the fan directs most of the air straight-up into the bottom of the seat,also there is no outlet for the air to be released from under the seat. I have removed the brake light and rode and still no air is coming out,but when I got home and the fan came on you would be amazed at the amount of hot air coming out of the brake light hole. I was wondering if the jacked-up Euro seat,Trojan Horse, would let more air flow out.I have an XB12ss with a rightside air scoop,ceramic header and no matter how much air you cram into the rear cylinder area if it does not move out it only helps a little. I have some small 1.25" NACA DUCTS and I am looking at routing 1 per side to back of rear cylinder to push the hot air out thru the fan, or would it be better to run the fan all of the time and I do know there have been issues with the fan but what exactly,motor or bearings. Does any one have any thoughts or any have the jacked-up Euro stlye seat,I think that if we can get the hot air out from the rear cly we will all be more comfortable and can maybe get equal performance from the rear cly to match the front cyl. Thanks, Dean Bush | ||
| Jos51700 |
What Jap bike are you working on? | ||
| Hughlysses |
Dean- Some Buell riders find the heat output uncomfortable, but the engine is fine. Buell has confirmed several times on this board that the front and rear cylinder temps on these bikes are virtually identical. The tubers, which looked like they'd get much more air to the rear cylinder, actually ran much hotter on the rear cylinder. It's also been stated that the right side scoops actually screw this up- check the previous edition of Fuell. Somebody here did a detailed analysis of the fan failures on Ulys (seemed to be fairly common on the early 06's). It seemed pretty clear the problem was the operating temps were too high for the grease used which resulted in bearing failures. Fan failures seem less frequent on later bikes, so I'd bet Buell corrected the problem. | ||
| Wantxbr |
What are you trying to accomplish? Is your butt getting too hot? You trying to keep the fan from coming on? That air isn't trapped in there, it does flow. If your Butt is getting hot then put a heat shield under your seat. I made one from a welding blanket I picked up at Harbor Freight tools for around $15. Also made one for under the air box. And if your trying to keep the fan from coming on, wellll good luck. | ||
| Deanbush |
If you think that there is enough "OUTFLOW" of air from the rear cylinder and the cylinders are virtually the same temp then why is there a fan for the rear cly and no fan for the front. Also how can you explain the FACT that with the brake light assembly removed ridding on the road at up t0 80mph no air comes thru the fan from the rear cylinder.If there was "actual flow" then you would be able to feel the hot air exiting the hole left by the removed brake light assembly. The fact is the only out flow of hot air from the back of the rear cyl is when the fan is on as proven by by my previous test as described above. No I do not have a Jap bike but have owned and raced severial.I bought my 2006 XB12ss because I liked the gas mileage,I avg 63mpg cursing 75-80mphat 3500-4000rpm,I wanted a v-twin, liked the whole concept and looks and a fair price. No my butt does not get too hot but my crotch sure does and yes I have a radiant heat barrier under front of the seat and if you are in the SOUTH on 100 degree & 95% humidity days you will know what I mean.If you believe everything BUELL says,print and the fact they think you should not modify anything on YOUR motorcycle then why do they sell "performance aftermarket parts". | ||
| Iamarchangel |
Curious how you actually measured the flow while you are riding at 80mph? Lean back and put your hand over the brake light hole? You've offered no empirical info, really. In comparison, up here in the NORTH, I've spent the last two weeks holidays cruising, loved that "cursing" at about the same conditions. Everything's hot below 35mph, bit cooler when you go faster. I've not really noticed the heat concerns you're having. (Relatively new to me bike, '03 xb9r.) | ||
| Deanbush |
YEP thats exactly how I know no air is moving thru, o-yea its better if you wet your fingers before reaching back you can feel the air, well no air moving thru, once you have your fingers at the hole where the brake light was. If you do not belive me its real easy to do it yourself. Just remove the 2-screws holding the brake light on,remove the 3-wires remember where they go and you do not need to tape them up. I recommend doing this after riding motorcycle to get it up to temp so the fan come "on" then remove brakelight assembly go for a short ride somewhere close and safe and see for yourself that there is no air moving out. And when you get back home and the fan comes "on" you will "feel" the air rushing out of the brakelight assembly hole. And yes you can still feel air coming out when the fan switches from "high" speed to "slow" speed. Now if you mean hard numbers by "empirical" well basically what ever the rear fan is rated at in CFM for either speed it will be close to what is coming out of the brakelight assembly hole minus airloss because it is not a sealed system and restrictions in the airflow path from rearshock,battery,wiring,ecm,etc. | ||
| Glitch |
Remove the brake light, and put it elsewhere, install your 1.25" NACA DUCTS and be done with it. | ||
| Deanbush |
Glitch,from what I get out of your post is absolutely nothing and has no technical insight or imagination. The reason I started this thread was to get "real truthful" information,on the possiablty's and effects on engine performance and rider comfort.Things like if getting the rear cylinder cooler how will this effect the engine mapping,will it help reduce engine pinging,or could more air flowing around the rear cylinder thru the tail section help reduce aero-drag or will it create a lift effect.A little lesson IN aerodynamics DRAG is caused by the turblant air moving all around the motorcycle/rider goingdown the road and the air not being able to be smoothly put all back together again.this turbulant air creates a hole behind the motorcyclye/rider which is how another motorcycle/rider can draft.With a perfect aerodynamic shape "RAINDROP" there is "NO TURBULANCE" thus "NO DRAG".Also with a perfect aerodynamic shape there is no "HOLE CREATED" thus you cannot draft a pefect aerodynamic shape. I thougth this web site was for helping each other with problems and ideas. All the things I have said are true and all I am asking is for "TRUTHFULL INFORMATIVE AND OBJECTIVE" information | ||
| Iamarchangel |
By empirical, I meant the temperature in degrees. Me, I get paid very good money to play with metal and fire. If you can keep your hand in the air flow for more than a three count, I'd think your engine is fine. You could get a number of heat crayons and mark the area under the seat and check afterwards to see which one melted. That will give you a range of temperatures that you can discuss. You might not be comfortable, but I'm pretty sure the engine is doing fine. Still wondering about the wisdom of doing, what 80, without brake lights, and leaning back finding the hole at 80, with bare hands at 80, and assessing the temperature/air flow at 80. I was doing 80+ this morning and leaned around to check my right side blind spot, the motion caused a drift into the right lane: another learning experience. But, hey, good luck on that air movement. | ||
| Drfudd |
I have an 07 XB12Ss and the Break light hole is too small and the seat area tapers out that way, providing a restriction, just like electricity, air pressure will flow to the least restricted area, regardless of path. That is the side vents right behind your legs. In the winter time that is an excellent place to put your fingers and warm them up a little bit while riding. With the fan on the reason you feel hot air coming out the back is because the fan over powers the two side vents and forces excess air out the back. Like everyone said, Buell has done a great job equalizing the temperature from front to rear with the side scoop. The Ride Side scoop only helps at speeds, its actually a problem at low speeds(parade speeds) according to a fuell mag article. air cooled engines, like this one are designed to run at high temperatures, trying to cool it down more than what it was designed to run at just prevents peak efficiency. tubers and regular harleys have a large temperature difference from front to rear because they don't have any direct air flow, the scoop provides this on the XB's, it works rather well in this engineers opinion. | ||
| Glitch |
Glitch,from what I get out of your post is absolutely nothing and has no technical insight or imagination. To be honest, I posted that because you come off as a know-it-all with a poor attitude. I have no answers to your questions, because you've already decided that the engineers at Buell don't know what the are doing. You've already added a right side air scoop, after being offered a reason not to. Good luck with your quest to cool off an air cooled engine. | ||
| Punkid8888 |
This info sounds perfect for the "1125r motor" thread | ||
| Ft_bstrd |
Sorry Deanbush, This topic has been beaten to death. If you search for ducts, fans, heat, rear cylinder, etc. you will find mountains of experiments, testimonials, and designs. None have really done much to help the problem. You're fairly new here and probably haven't seen ALL the history of this debate/discussion. There simply isn't much appetite to rehash the old discussion. Most of the air does not get sent into the seat cavity but rather is pulled out past the rear shock and below the tail section. If you want to try to duct the air somewhere else, feel free. The marginal benefits will be minor. | ||
| Deanbush |
I appreciate everyone's feedback it is very informative. Yes I am new to this forum and no Glitch I "DO NOT KNOW EVERYTHING AND I NEVER SAID OR WROTE ANYTHING PRETENDING THAT I DID". I am only stating what I have found out for myself. As from what I have gathered from your 2 post is that you do not do any of your own work, and if the BUELL engineers built a perfect motorcycle then why the H#$# did they build the 1125r. We are all here on this forum to find solutions to problems and to "MAKE AND MODIFY OUR BUELL'S OURSELVE'S "into a better motorcycle and to make it into the motorcycle you want not just what you were "SOLD". | ||
| Mr2shim |
This thread makes baby Jesus cry. Wait, no, deanbush does.  (Message edited by mr2shim on July 13, 2008) | ||
| Iamarchangel |
I got curious about a couple of things so I did some research. I'm guessing on the type of plastic Buell uses around the seat pan area. So my info is based on that. That type of plastic melts around 410, the lower range would be in the 300s, possibly as low as 250. The top of the range is 491. These are all pretty safe ranges for an air cooled engine. Water boils at 212, paper's flash point is 451. Steel starts changing around 1200, at that temperature aluminum has already started to melt. There are no reports of melted plastic in the under seat area. Therefore, the heat is not excessive. I would say that there is no engineering concern. | ||
| Bads1 |
Straight from Erik's mouth 5 years ago at the 20th Anniversary. That fan only runs when temp get to the temp its needed. The reason the fan runs when you shut it off is that the motorcycle is no longer in motion and the fans job is to pull the heat away. It stop's any oil in the rear cylinder not to Burn or above. | ||
| Cycleaddict |
do you "lick" your fingers to get them wet while riding or do you carry a water bottle with you ? how much cooler does the motor run with the tailight removed ? ( maybe you could "drip" water onto the rear cly. to help cool it ! | ||
| Skinstains |
I have been toying with the idea of installing a small fan in both my right and left side air scoops. I would run them from a toggle or similar switch that I could turn on at will. The main reason I'm thinking of doing this is for rider comfort. I spend quite a bit of time in NYC traffic and can't always fit through the lanes to keep moving (saddlebags). I have also thought of putting a manual override switch in the existing fans circuitry. Just my .02$ | ||
| M1combat |
"Now if you mean hard numbers by "empirical" well basically what ever the rear fan is rated at in CFM for either speed it will be close to what is coming out of the brakelight assembly hole minus airloss because it is not a sealed system and restrictions in the airflow path from rearshock,battery,wiring,ecm,etc." I'm of the opinion that you should be focusing your energy more in the direction of determining the point, location and area at which you are losing air. You may also do well to take steps towards measuring the specific volume and speed of air you might be losing over time. Maybe just turn the fan 45 degrees? That's what most of us do anyway. That way the air can go through while the fan isn't spinning... as an un-spinning fan tends to stop all airflow through and/or around an area. You pose a good question. | ||
| Corporatemonkey |
Now I maybe reading this all wrong as I am quite tired, but are you saying you removed the brake light to exhaust hot air from under the seat  If so I don't understand what that would accomplish. At least on my Cityx the under seat area is basically sealed (not air tight though). The air runs from the rear cylinder through the fan, up against the seat pan where it heads 3; ways down past the shock, left and right out the side seat cavity. Buell was very ingenious in their cooling design. The rear fan only runs when necessary, as too low of temperature effects emissions. If you really overheat the motor it has a "skip spark" safety feature. It is designed to save the motor, and allow you to safely pull off the road. In my 2+ years on this board I do not ever recall anyone actually getting to the skip spark stage. This included many riders from triple degree climates. Now of course if I did read the OP all wrong, I may have just typed a whacked out response for no reason. | ||
| Darthane |
Well, plenty of us have hit spark-skip, but most of the times (my own experience included) it seems to have stemmed from some other issue, not the engine actually overheating. Myself, I trust the elves. My thigh gets too warm (on the XT), but that just proves that air is indeed escaping the pocket around the rear cylinder, and I'll be solving that with a little heat blanket. | ||
| Prof_stack |
Deanbush, your XB is fine. The fan is doing what it was made for. Summer riding can get you hot, I know. Filling up the frame with gas part way into a ride does cool things. Synthetic oil transfers heat a little better than regular oil. I suggest you relax and enjoy the ride. | ||
| Jos51700 |
"from what I get out of your post is absolutely nothing and has no technical insight or imagination" Funny, I thought the same thing about the original post. The reason no hot air comes out the brake light hole? Simple. No hot air is routed there, nor needs to be. Look at your fan in either of the two places illustrated.  The fact that you're looking at it means that there is no obstruction, thus providing an outlet for engine heat. Fact: the places illustrated are noted as low-pressure areas on most all motorcycles, and therefore create a pressure differential from the high-pressure area in the left side scoop. Air (or any fluid) flows from an area of high-pressure to low-pressure, which in this case, is across the rear cylinder. As intended, as designed. There's nothing wrong with it. There never was. Want empirical evidence? The tens-of-thousands of XB's built over the past 6 years! | ||
| Deanbush |
M1combat how did you mount the fan at 45 degrees from stock, just use 2-mounting bolts? and yes I agree when the fan is not on it blocks airflow which is my whole point. Yes a small amount heat is pulled thru the low pressure area.But the whole area behind the rear cylinder is enclosed with the only true outflow thru the fan assembly, and the fan is aimed straight up into the bottom of seat, yes if you take the seat off and look down at the fan the fan is aimed more vertical than horizontal! Correct me if I am wrong but if more air is "flowing all around the cylinder freely" does this not cool the cylinder better,lower head temp,make more power, more effecient and just over all better. Another thing I have read alot of other threads and post's and why do some of you post useless demeaning remarks and "HIDE" behind a made up name you must be the kids that THOUGHT THAT WAS BULL MILK AND A BULL TIT. Yes my REAL NAME is Dean Bush and I am Damn proud of it and at least I am MAN enough not to hide behind a make believe name and call other people stupid and walk all over their THREADS. If you do not have any useful and I mean USEFUL information then leave people alone and let the other people who truly want to help other people with IDEAS,PROBLEMS, AND QUESTIONS! | ||
| Mr2shim |
Hey, I just noticed you are from Gastonia, NC. Do you really let those loonies at Carolina touch your bike? | ||
| Glitch |
Lighten up a little Dean. | ||
| Bombardier |
Firstly - We are all friends here. Things may get a bit heated but at the end of the day we are all here for the same reason - Buells. Dean, apart from the cylinder radiating heat the exhaust header is, I believe, the main culprit in the burnt thigh issue. If you do not want to change the appearance of the bike by ceramic coating or thermo tape wrap on the header, perhaps you could just tape the area near the read cylinder but not so much that it can be seen from the outside. I live in Australia and the temperatures are quite warm here in summer (40-45 degrees C ) and have experienced the burning on the thigh. I have found that placing your leg over the holes in the plastic section under the seat tend to help as the air no longer comes out of there. By the way - capital letters, though sometimes effective in getting your point across, really do not come over very well as no one likes to be yelled at. Just a thought. Hope my suggestions help. | ||
| Wantxbr |
Heres some useful info for you. Everyone that has posted here is not hiding behind a false name, they are what's referred to as a user name. Just click on their user name and you will get detailed info on them, such as Mr2shim his name is Shimri Caldwell born in 1986 and lives in Richburg SC. He owns a 2003 XB0r Blue in color. M1combat real name Donald D. Hann born in 1977 and lives in Prescott Arizona. He owns a 2004 XB12r Black in color. Ft_bstrd had a very good idea about searching the site for the info you been requesting. Personally I wouldn't mess with the fan it's there for a reason. I've ridden in 110 degree weather in Borrego Springs Calif. without a problem. 96 degrees with 80% humidity in Solana Beach Calif without a problem. I do have an idea but didn't look into whether it would work or not, however what about using some bolt spacers under the fan to lift it off its mounting surface to allow air to pace through the sides of the fan assembly. But I think this would reduce the fans cooling efficiency. You will need longer bolts though. (Message edited by wantxbr on July 15, 2008) |
