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Reepicheep
| | Posted on Wednesday, March 29, 2006 - 12:16 pm: | 
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My M2 (which was still running perfectly when I sold it with 27k miles on it) would make its headers glow if you left it idling stationary for more then a few minutes. You only notice it when you look for it, I got myself pretty panic'd when I discovered it also.
I have not looked at my 9sx, but I bet if I left it idle for 5 minutes, was someplace where my eyes adjusted to the dark, and wheeled it in the garage and killed every light, I would see them glowing a little as well. |
Andrewc
| | Posted on Wednesday, March 29, 2006 - 01:15 pm: |
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Thank you BuellBozo. What you are saying about the high temperature makes perfect sense. I will bring that up with the tech today.
I'm fairly new to this board, but I'd like someone to let me know the last time Buellistic offered incorrect or wrong advice on a Buell technical question. When knowledgable people take the time to share their counsel, I listen the first time. My experience is that if I dont, they may not offer it the second or third time.
Too true. I've been worried about giving the impression that I'm not paying attention to certain people. I feel badly about that but it has been a confusing time for me. Not only am I discussing this issue here, but in person.
I've gotten lots of different / conflicting advice making it quite difficult to make informed decisions.
I hope nobody feels that their advice wasn't worth their effort.} |
Blake
| | Posted on Wednesday, March 29, 2006 - 02:27 pm: |
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It is a common misconception that red hot header pipes must result from a lean running condition. The hottest your header pipes will get will be due to a rich running condition where combustion is prolonged during the exhaust valve opening event.
In a high performance engine combustion continues well after the exhaust valve opening event. This is how the engine most efficiently expels exhaust gasses, by using the last bit of combustion energy to blow them out of the combustion chamber instead of relying upon the piston to push them out. An engine that is running rich will see combustion prolonged even more with the resulting flames of combustion shooting further down the exhaust header during the exhaust valve opening event.
This is entirely different than the high temperature issue that lean running causes. A lean running engine has less liquid fuel to absorb combustion chamber heat during vaporization. Thus during the compression event, the temperature of the air/fuel charge is driven dangerously high, often to the point of causing instantaneous detonation, which in turn results in even higher peak combustion chamber temperatures. But this happens well before the exhaust valve opening event. The result can be a melted aluminum piston, a.k.a. a "holed" piston. However, in this case, the one of a lean running engine, the combustion will not be prolonged, it will be abbreviated and thus the headers may not be exposed to as much intense heating.
The heat of actively combusting air/fuel is much higher than that of exhausting spent products of combustion.
Those headers are most likely getting red hot due to active ongoing combustion within them, not due to hot spent exhaust gasses.
I could be wrong. |
Hans
| | Posted on Wednesday, March 29, 2006 - 03:20 pm: |
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http://www.aero.com/publications/socal/soca1298.htm
At this link you will find:
"Exhaust systems in aircraft carry away hot gases released during combustion, reserve some heat for carburator and cabin heating, and muffle the sound of those rushing toxic gases. These systems operate red hot at temperatures of 1000 degrees fahrenheit or more."
The piston comes roughly 25% of the time in contact with hot gases. It becomes effectively cooled in the meantime by the fresh gas/air mixture. The exhaust gets only hot gases through its throat.
Hans |
Buellistic
| | Posted on Wednesday, March 29, 2006 - 05:48 pm: |
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This is not a DISCLAMER, "BUT" the XB's are run too "LEAN" which can act as a INTAKE AIR LEAK !!!
That is why "i" have not UP-DATED to an XB ...
IMO the "BRAIN BOX" should be PROGRAMED for 12 to 1 fuel/air ratio !!!
Have my TUBER(97S3T) jetted as close as
possible to this ratio and as long as "i"
stay off the throttle and pu$$y foot around "i" can get 56 MPG !!! |
Buellbozo
| | Posted on Wednesday, March 29, 2006 - 06:31 pm: |
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Blake,
"I could be wrong".
Me too. |
Buellbozo
| | Posted on Wednesday, March 29, 2006 - 08:13 pm: |
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O.K.
"...last bit of combustion to blow gases out..."
I was taught that the (relative) low pressure in the exhaust tract SUCKED gases out before the piston upstroke comes into play ,i.e. "scavenging". And no, not like scavenging applies in a 2-stroke.
Also, aircraft engines run under steady load at the leanest possible mixture shy of detonation that conditions allow. If our engines got near to that lean, we'd have no throttle response and be meltin' bits left and right.
What think ya'll???
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Jlnance
| | Posted on Wednesday, March 29, 2006 - 09:23 pm: |
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OK - I just checked my Uly. I let it idle in the garage for a few minutes, switched off the lights, killed the engine, and turned off the key. Guess what. The header glows.  |
Buellistic
| | Posted on Wednesday, March 29, 2006 - 09:27 pm: |
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"BUELLschitte", aircraft recip engines run
at a constant RPM(and have no trans. other than a verable prop.) and a short exhaust stack ...
Two-strokes run RPM pipes !!!
BUELLs(tube frames and XBs) run a tuned header/muffler set-up ...
LOUD does not mean HP/torque(ie: XBRR) ...
IMO(disclamer) !!! |
Andrewc
| | Posted on Wednesday, March 29, 2006 - 10:48 pm: |
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Jim. Thank you so much for testing your bike! I'm so glad to hear that someone with an XB12 can reproduce the glowing pipes.
I was shocked to see how bright they can appear in complete darkness yet not appear to glow in the daylight what so ever.
Would you also describe the glow as suprisingly bright?
How many miles on that Uly Jim?
Feeling better (unless both of our bikes are screwed),
Andrew |
Hans
| | Posted on Thursday, March 30, 2006 - 07:44 am: |
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That is a nice exhaust:
http://video.google.com/videoplay?docid=-236345357158387520&pl=true
Hans |
Jlnance
| | Posted on Thursday, March 30, 2006 - 08:44 am: |
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Would you also describe the glow as suprisingly bright?
Well, I was supprised to see it, so I guess it was.
It's certainly not bright enough to cast a shadow, but you can definitly see a dull red header pipe in the darkness.
I was shocked to see how bright they can appear in complete darkness yet not appear to glow in the daylight what so ever.
I was too, but I guess I shouldn't be. If you've ever taken a tour of a cave, they will often cut the lights to show you complete darkness. They they will light a match, and you can see perfectly, with shadows dancing on the walls, even in a huge cavern. But even in a dimly lit room, you would never notice the light of a single match. So your eyes are quite good at seeing in low light, but only if nothing brighter is around.
unless both of our bikes are screwed
I've got about 3k on the bike. I think they are both fine. |
Andrewc
| | Posted on Thursday, March 30, 2006 - 09:36 am: |
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I've got about 3k on the bike. I think they are both fine.
I bloddy well hope so! Mine is only 4 days old!! Like I said before though the bike appears to be running fine. I went on probably at least 500 KM of demo rides on these bikes last year, including the one that's in my garage today. I *think* if it wasn't running properly I'd notice. The engine doesn't seem to be hotter than I would expect, nor do the headers, and the fan doesn't come on more than I would normally expect either. Not like those things are the last words on the issue but honestly, I would think that if the engine was about to melt it wouldn't be running well.
What is the opinion of the group there? If one of the potential causes previously mentioned was occuring: too lean / intake leak, too rich / bad timing, would there not be other symptoms I'd be likely to notice?}} |
Andrewc
| | Posted on Thursday, March 30, 2006 - 09:46 am: |
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At any rate, I will be taking the bike in to the dealer for a look see. I asked my contact in the service dept about their experience with Buells. I was assured that they had the required Buell training and that I should feel confident about having my bike in the shop.
Moving on, the tech said that he can run an electronic diagnosis to validate timing and proper fuel mixture (should catch intake leak??). Also he said that he has a laser thermometer which he will use to test the engine and header temerature.
Can the group suggest any other tests I could ask them to do? Also what is the accepted temperature of the engine and or headers? That could be helpful. Any comments?} |
Blake
| | Posted on Thursday, March 30, 2006 - 09:59 am: |
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You will be mostly wasting your time and theirs. If the bike is running well, just ride the thing. Really.
That video link posted by Hans demonstrates why. Pretty sure they don't run F1 engines too lean.
Just ride the bike. Please. |
Djkaplan
| | Posted on Thursday, March 30, 2006 - 10:43 am: |
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This may not have anything to do with the exact subject at hand, but another thing that will cause a glowing header pipe is extremely retarded ignition timing. |
Reepicheep
| | Posted on Thursday, March 30, 2006 - 12:33 pm: |
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Very cool video Hans! Man, that thing revs up and down *quick*. |
Buellistic
| | Posted on Thursday, March 30, 2006 - 01:05 pm: |
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Hans:
Another example of "TECHNICIANS" at work !!! |
Djkaplan
| | Posted on Thursday, March 30, 2006 - 01:34 pm: |
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I've read that the titanium header pipes on F1 engines can become transparent at race speeds. |
Blake
| | Posted on Thursday, March 30, 2006 - 05:48 pm: |
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Is the guy not sticking his fingers into his ears wearing ear plugs, or is he now deaf?
That is a great video. Thanks Hans! |
Jedwele
| | Posted on Friday, March 31, 2006 - 09:12 am: |
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Hey Andrewc. I just seen this thread and had the same thing happen to me. About a year and a half ago I had just got my xb12s broken in at the 500 mile mark and took a short ride it was it was very cold in the dead of winter and was getting on it a little bit (ok a lot). It was dark out and my headers were glowing when I pulled in the driveway. But after that I had never had this happen again (havn't tried to recreate it either).I have talked to few other local buellers that have had the same thing happen ,but it was always when the bike was still almost new with very low miles and all stock(not sure why) Anyways if I was you I probably wouldn't worry about it too much |
Andrewc
| | Posted on Friday, March 31, 2006 - 09:37 am: |
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Thank you Jed. That's great information. I have a local contact with a 9R and he said that his headers don't glow at all under my conditions. However, his bike has a few seasons of riding on it.
I was really worried about it before but I've settled down on it now. I've had a few other XB12'ers confirm now.
ps. I think our definitions of "the dead of winter" are different.
Cheers |
Andrewc
| | Posted on Tuesday, April 11, 2006 - 01:54 pm: |
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Thought I would drop a line. The glowing headers subsided greatly after the break in period was over. I am nearly ready for the first service. Really liking the bike.
Thanks for all of your help. |
Hans
| | Posted on Wednesday, April 12, 2006 - 04:10 am: |
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Andrewc, Thanks for your feedback. Good to hear it.
Still the question, why it seems to happen more explicitly during the breakin period.
I know that I left the RPM`s as low as possible at short stops during that period.
I have made the observation that, during the long stop, just before the start of veteran motorcycles, the pilots did nothing else than blipping their throttles.
I considered that as being for cooling purposes: Each blip giving a big gas injection from the accelerator pump.
I have a feeling that those short blips keep the engine cooler. I would like to know, if I am right.
Hans  |
Ssavelan
| | Posted on Saturday, January 26, 2008 - 12:51 pm: |
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Thanks for everyone posting on this thread. I was worried when my 1998 thunderbolt with 13k miles on it had some bright red "is my engine going to melt" 'issues'. Good to hear that it is probably not terminal. I have been giving it about 40 miles a day and it has been ~freezing so I have been running it a little to the rich side and letting it choke plenty to get nice and warm before riding. I think that I can run it a bit leaner when the spring comes. I have only been riding a Buell for a couple of weeks and it is a lot different than the 250 Suzuki and old 750 Honda that I had. God Bless America? I too will go for a complete service and check-up in the spring and try to learn more about the bike. I am a complete newb. I couldn't even tell you what is glowing red... the start of the exhaust I would say.. you guys are calling it the header exhaust? I'm hoping to learn a lot more in the future as I try to put over 100k miles on this engine while keeping it shiny reliable and performing. BUELL!!!!! |
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