| Author | Message | ||
     Davo |
I finally tested the fan on/ key on temperature. It was 428 F! That explains why folks that have race kits with richer mixtures, additional scoops, removed right covers and/or super duper oil have had less fan on time. This thing is designed to get HOT and then bring the temp back to Earth in order to save Earth AND make lots of Ponies!! Its not a bad thing but this discovery by this old school wrench has really prompted me to re-examine the thermodynamics of motorcycle engines and some of my old fashioned Prejudices against heat. | ||
| Jlnance |
Neat (I was going to say cool, but it didn't really fit  .) How did you measure it? | ||
| Stevem123 |
It is true that this engine likes it when at full operating temp but you have to remember that this setting is because the sensor is at the top center of the rear head. This design makes it a good indicator for how well the fuel injection system is working and I believe the ECM also uses this data along with other data from the OČ sensor and the IAT sensor to adjust the A/F ratio. I know that is a simplistic way of looking at it but it does work pretty good. How did you measure the temperature to verify it? I have toyed with making a colored LED bargraph display to watch the signal from the OČ sensor. This would show a direct correlation of the air-fuel ratio as you're running down the road. Just one of those many yet to do projects I have in mind for the fun of it. BC Steve | ||
| Davo |
I went for a hard ride and the fan came on just as I entered the driveway so I quickly pulled into the shop and hooked up to the VDSTS and the ET was just over 420 F less than 1 minute after the fan started. I have also found that if the fan turns on while I am on the highway and the head is at 428 F there is very little chance of pre-igniton during hard acceleration, but if the fan comes on at idle or in traffic there is some pre-igniton under hard acceleration because not only is the head hot but the cylinders are hot too due to the lack of air flow across them. The fan does not pull significant air around the cylinders, just the heads. At that temperature asbestos juice would pre-ignite! | ||
| Davo |
Srevem123 How about a meter that would scale from 5 to 0 volts? Which would translate 14 F to 572 F . The fan cuts on at about 0.4 volts and cuts off at around 0.75 volts. Those numbers are not exact but they are very close. I will do the math and verify. | ||
| Davo |
The manual indicates that these voltage readings are +/- 20% correct. I am very interested in obtaining o device to monitor the ET. I am going to go out on a limb and speculate that bikes that run without the fan constantly running are actually running hotter than bikes that have a fan running much of the time. I know it sounds crazy but I am going to follow up with some fan research. | ||
| 44mag |
I pulled into the driveway after a hard ride and my temp was ~ 390F. The fan was on and it had been on for a while. I am planning on strapping my laptop to my seat and logging the temp data for a long ride this weekend. Assuming that the vibration does not ruin the bearings on my hard drive, I will post the plots. | ||
| 44mag |
I wonder if the right side air scoop makes the fan come on less often simply because it blows air on the cylinder head temperature sensor. If so, it might prevent the fan from coming on when required and cause the engine to run hot. It would be interesting to log the cylinder head temp data for a long ride before and after the right side air scoop is installed. You would also need to monitor the oil temp to see if the engine actually gets hotter with the right side air scoop installed. | ||
| Davo |
That is what I was leading up to. If the fan does not come on you could be running right at 420 F and you would think that you were running cool. If you had the scoop on and the bike heats to 428 F and then tripped the fan then you might be doing most of your running in the 380's and 390's. The point is that simply because the fan is not running it doesn't mean your bike runs cooler. It just means it doesn't get hot enough to be regulated by the fan. I am eager to read 44mag's results. | ||
| Brucelee |
From what I understand the sensor is IN THE HEAD, not on top or outside it. IF that is true, the sensor is measuring head temps. Moreover, if the fan's job is to draw air over the head when needed, how is that different from what the scoop does. Lastly, on my bike which has the scoop, the fan will come on IF the riding dictates, ie, slow hot traffic etc. I think you are barking up the wrong tree here guys, the scoop works. It APPEARS to me that there is a right side air scoop on the RR. What does that suggest? They NEED MORE AIR BACK THERE. | ||
| Davo |
There is no argument yet, as to which route is best and there has never been any question that the ET was actually a HT. The point of my post was to examine the purpose and parameters of the different components of the cooling system before I start altering and/or removing them. Is there any statements in my previous post that you think are in accurate or unfounded? | ||
| Brucelee |
No, just adding thoughts to the equation. Thanks! | ||
| 44mag |
I would like to see the data. Why didn't the Buell engineers add a scoop on the right side? It seems like plenty of engineering went into the bike. A right side scoop would not add any significant cost to the bike. So I am skeptical on the benefit of the right side air scoop. Perhaps there is an air flow issue which requires an air duct to draw air over the head from the fan at low speeds? | ||
| Davo |
or sitting still!! Also, the right side plate may keep hot air from perking of the jugs off the heads when sitting still. The left side scoop is out front picking up clean air even when sitting still. | ||
| Davo |
44mag, I might have to eat my own words. On my trip today 490 miles in the high 70's and once the fan came on it NEVER went off until I shut down. I am wondering about that right side scoop. I might try one and then clog it up and make the fan come on and then unclog it and see if the fan EVER goes off. | ||
| Brad1445 |
I have no doubt 95% of these fan threads would never have been started if the fan its self sounded like a quality product and not a metal clash heard three blocks away. Before you jump on me for not liking Buell, FYI I'm on my third x-bike and love the bikes. There is no excuse for such a poor quality fan being used its embarrassing. | ||
| Honu |
I have three X bikes now, an 03 9s , 9r, and a new 06 Uly. Here in TX when temps are 85 and above the 9's fans come on and don't shut off untill we stop riding, the wife on hers and me on mine, both engines have Syn3 oil in them. The Uly fan came on and stayed on thru a 25 mile commute from work yesterday. I might get a hand held temp sensor gun to check engine temps while riding? Any thoughts?? | ||
| Teeps |
Davo Posted on Sunday, May 28, 2006 - 10:07 pm: 44mag, I might have to eat my own words. On my trip today 490 miles in the high 70's and once the fan came on it NEVER went off until I shut down. I am wondering about that right side scoop. I might try one and then clog it up and make the fan come on and then unclog it and see if the fan EVER goes off! I find the same result regardless of riding conditions; fan comes on, does not go off until the engine is turned off... Brad1445 Posted on Monday, May 29, 2006 - 01:15 am: I have no doubt 95% of these fan threads would never have been started if the fan its self sounded like a quality product and not a metal clash heard three blocks away. There is no excuse for such a poor quality fan being used its embarrassing. Brad, There is nothing wrong with the fan itself; it's the speed at which it runs that makes it so loud. I do agree that the fan IS TOO loud. And, from the above post, seems to run too long, but then... what do I know.} Cheers, Tp | ||
| Thunderbox |
I can't believe the fan thing is such an issue. I am happy that they have a fan on the bike and I could care less if it's really audible. To move the amount of air they want to move the fan has to make noise. It's not really the fan that makes the noise it's the air coming over the head and being forced out through the rear fender. So it stays on, big deal. Could be just 10 degrees above turn on temp so that is not a big issue. I think it is just something we have to except when you buy a ULY. Never having to worry about overheating is a great trade off for the dang fan noise. I don't think any person here has ever said the bike went into missed spark mod indicating an overheat condition. So why all the worry? | ||
| Davo |
Thunderbox, Please don't think that I am complaining about the fan. I am just a tinkerer and I want to know more about the parameters and the engineering of the system. I rarely have anything long before I take it apart and try to learn more about it. Just wondering, on an average temperate day does your fan ever turn off once it starts. After a two hour ride at 78 F I pulled into the shop and let the bike idle for a minute and a half and the ET was at 372 F. I was impressed. I plan on doing a log soon. I am wondering if these guys with a right side scoop are running hotter than 372 F with similar conditions. I speculate that they are. I will get a scoop and run some tests soon, if only to have something to do. | ||
| Brad1445 |
I would pay $200 for an aftermarket fan that made no more noise than any car or other bike fan on the planet x2. | ||
| Steveford |
I put on one of Al's air scoops last night and it works as advertised; the fan only came on when I shut the bike off, just like on my old XB9. | ||
| Teeps |
Oh Boy, There's going to be a run on right side scoops... I want one too. | ||
| Davo |
I am very interested in what your running temperature is with the right side air scoop. If someone would go out for a 30 minute ride and check the ET with a VDSTS immediately after arriving back at the garage. If the ET is less than 390 on a moderately warm day (70's)I think you might have a case. If you are running hotter than 390 then the scoop is only cooling the thermostat and therefor preventing the fan from bring the temperature down to a factory predetermined optimum running temperature. (Message edited by davo on June 08, 2006) | ||
| 44mag |
One more test ... idle the bike until the fan comes on with and without the right side scoop. Then watch the temp to see if it runs hotter at idle (i.e., in traffic) with the right side scoop on. In computers, they use air ducts to concentrate the flow over the heat sink on the CPU. Without the duct, the processor overheats. The ULY design might require the ducting of air over the rear cylinder with the current design at idle. Seems like the Buell engineers would include a right side air scoop if it helped. | ||
| Stevem123 |
I'm running VDSTS on my HP Ipaq. If someone would donate me a right side air scoop in the black matte plastic that matches the stock left side, I'd gladly run some as-ridden tests and supply the results. I have my suspicions (sp? but I think you may be suprised by the results. I don't think it will really help all that much. The right side scoop will trap air between it and the front cylinder which I think will negate any real help from the addition of the right side scoop due to pre-heating the air mixing with the scoop air at the rear cylinder from the front cylinder. Sound confusing? I think adding the right side air scoop will also create a bigger scoop between the two of them where the front cylinder lives. All the air that passes over the front cylinder will now have to mix with the scoop air at the rear cylinder. It may help but it may also make the rear cylinder run hotter in slow traffic conditions. BC Steve | ||
| Chadhargis |
I asked an engineer at the factory about the right side air scoop. He said it is absolutely not needed and that the rear cylinder ran very close in temp to the front. They did duty cycle testing in Arizona and said they did not have a bike overheat, even in slow speed traffic conditions. This is not my opinion, it's directly from the mouth of the guy who was the lead engineer for the Ulysses. A pretty smart dude I would assume. Save your money folks. | ||
| Lowflyer |
Chad, This is how money is made. You fool enough people into paranoia about a particular issue and then design a product that will combat that issue (but not completely solve it since you have to be able to have a new and improved version of the product). I am working on an active vibration damper for the "wobble" issue. I hope to design a "wobbler" that senses the frequency of the inherent wobble and then emits a frequency matched wobble that is 175 degrees out of phase thus almost canceling the inherent wobble. I figure I will have five years of upgrades from there. By then, somebody will likely have some other issue I can solve.  | ||
| Brucelee |
Did you ask the genius why they have the fan if the cylinder ran the same temp as the front one? Did you ask him why the front one does not have a fan but the back one did? My HD service tech told me that the back cylinder gets so damn hot it is legend among mechanics who work on Buell. He also said that frozen studs in the back cylinder of the Buell is so common they have a special tool for removing them. The most common head repair in the HD shop, the back cylinder head on the Buell XB. Why, it gets so damn hot back there. Sorry, I have the scoop, it works. Have a nice day. | ||
| 44mag |
The front and back cylinder temperatures probably run the same because the fan comes on to cool the rear cylinder when needed. |
