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Davegess
| | Posted on Sunday, October 29, 2006 - 12:20 am: | 
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Air cooled engines can have a significant advantage when it comes to emissions. The vast majoriuty of emissions happen in the first few minutes BEFORE the engine reaches operating temperature. Most AC engines warm up quickly because they have much less mass to warm. They are our of the overly rich high pollution period much faster than the liquid cooled engine.
Liquid cooling can be used to make an engine quieter but so can other things. I doubt that noise will be the death of the XB engine nor will pollution. |
Rocketman
| | Posted on Sunday, October 29, 2006 - 04:50 am: |
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It's this simple. If you want to make power with an air cooled V twin like Buell do you need
large displacement
suitable size intake
suitable size exhaust
Somewhere along the line all three add up to noise pollution.
The solutions are power sapping for the majority. That is my point.
Rocket |
Jlnance
| | Posted on Sunday, October 29, 2006 - 05:57 am: |
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Yes you would think so.
But I watched the XBRRs run at Daytona, and they are very very quit. |
Blake
| | Posted on Sunday, October 29, 2006 - 06:29 am: |
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Sean,
Noise is not pollution on account of it disappears leaving behind no ill effect. Noise is just noise.
We are talking about actual air pollution. Try to keep up. |
Rocketman
| | Posted on Sunday, October 29, 2006 - 07:28 am: |
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I'm talking the bigger picture, which is how will Buell comply with ever more stringent regulations being introduced.
Air pollution is perhaps the least of Buells problems in this regard.
Instead Buells task is to try and keep their trademark designs whilst making their bikes quieter.
This affects Buell in three major areas.
1.
The mechanical noise of a large displacement air cooled V twin with chain drive primary inside a separate housing and gear driven cams likewise, will necessitate the use of ever increasing additions of bodywork and various noise deflecting / silencing attributes.
(Witness the fella in another thread who's experienced difficulty in removing a rear spark plug. Much more of a task for a home mechanic. Much more of a cost down the dealership.)
The necessity for cooling fans to keep engine temp's down. Oil cooler to keep oil temp's down, etc etc etc.
2.
Intake noise to feed two large capacity cylinders requires large air box and large intakes. This limits / predicts certain design parameters.
3.
Exhausting a large capacity twin cylinder requires a sizable muffler with suitable baffling. Ever quieter silencing will sap power.
Further ahead than air pollution then?
Rocket |
Buellshyter
| | Posted on Sunday, October 29, 2006 - 08:23 am: |
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Warr's HD XbRR isn't quiet at all with that new pipe on it. |
Ceejay
| | Posted on Sunday, October 29, 2006 - 10:58 am: |
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The reason buell's fit under the new regs is because they are air cooled-thus run a bit hotter and burn a bit more completely the NOX that many of the water cooled folks need to add a cat for to get rid of. Rocket has a point being that the more stuff you add to the mix the less efficient the motor becomes, but if buell isn't looking to increase the displacement most of those things don't come into play because they are already proven to work. And for the most part wouldn't the customers that were looking for higher performance be changing out pipes, intake and possibly even body work anyway? Street bikes vs. Race bikes.... |
Rocketman
| | Posted on Sunday, October 29, 2006 - 11:14 am: |
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That's exactly the point. Aftermarket is the answer to performance enhancements, for now. Who knows what the reg's will allow us the consumer to change in years to come. And who knows which direction Buell will go when the time is right for a new Buell platform. I think that was part of Matt's point earlier with regard to future regulation and change.
Maybe we'll get a Nicky Hayden special commemorative edition Buell, lol.
Rocket |
Blake
| | Posted on Sunday, October 29, 2006 - 11:27 am: |
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What makes you think that noise regulations will be getting any more strict? They won't be as far as I know. They are already extremely strict. It is a non-issue.
One one hand you say that a chain is noise, then on the other imply that a gear driven assembly is noisy. Which is it?
I think the Buell OEM mufflers are probably some of the best performing sport bike mufflers in the industry.
I suspect that quelling primary drive and cam box noise if needed would be a fairly simple matter. The technique was first developed as far as I know to help certain aircraft structures survive horrendously intense acoustic environments. Picture the elevators of a fighter jet at full afterburn.
Most recently the automotive industry has made use of the technology. Some of them even tout it in advertisements as if they invented the idea.
What is it?
A thin layer of tough adhesive sandwiched between whatever metal alloy or composite skin/structure requires acoustic damping. |
Blake
| | Posted on Sunday, October 29, 2006 - 11:53 am: |
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Ceejay,
Low revving, long stroke, lower compression engines do not produce the copious amount of NOx that high revving, short stroke, higher compression engines do. |
Ceejay
| | Posted on Sunday, October 29, 2006 - 02:56 pm: |
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Blake-care to let me know as to why? I was always under the assumption that higher comp usually meant better efficiency, thus a better burn and possibly to some extent lesser emmisions. Usually the cat is put in just to increase exhaust gases and help the Pt convert NO3 to NO2(I'm not sure if this is right)
Basically I thought that the air cooled ran a bit hotter-I think I remember someone telling me that thier harley ran hot/lean from the factory just to help combat EPA regs, than the water cooled thus the need for a water cooled having a cat.
I know rather simplistic view, but I can't see why there would be a huge difference in emmisions produced unless it is solely because of the longer stroke pulling in more air to allow for a more complete burn. This as apposed to the high revving 4's using a more deisel like charge- e.g. rich- using the higher compression to get less than optimum fuel mixture to burn.
Sorry for trying to get a lesson but my company hasn't ponied up for more schooling yet.... |
Teeps
| | Posted on Sunday, October 29, 2006 - 04:06 pm: |
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Ceejay Posted on Sunday, October 29, 2006
The reason buell's fit under the new regs is because they are air cooled-thus run a bit hotter and burn a bit more completely the NOX that many of the water cooled folks need to add a cat for to get rid of.
<snip>
Ah... no.
http://www.epa.gov/air/urbanair/nox/what.html
NOx can also be reduced by using E.G.R.
Excerpt from the link below:
Contrary to what you'd think, it has a cooling effect on combustion temperatures that helps reduce the formation of oxides of nitrogen.
http://autorepair.about.com/library/glossary/bldef -176.htm |
Anonymous
| | Posted on Sunday, October 29, 2006 - 04:08 pm: |
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There are many reasons for thesae motors being so clean burning and fuel efficient, most too complex for discussion here. But here's a piece of food for thought. Long stroke=longer burn time=less emissions. |
Jlnance
| | Posted on Sunday, October 29, 2006 - 08:00 pm: |
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Ceejay - I'll hazard a guess. I'm not an engine designer, but am fairly comfortable with chemistry and thermodynamics. So I might even be right. 
The higher compression leads to more efficient engines, other things being equal, because less of the heat from the combustion process is blown out the exhaust. It isn't related in any significant way to the percentage of the fuel that is actually burned.
High compression engines operate with a higher peak temprature. This leads to the formation of NOx.
The high RPMs do not allow as much time for combustion, leading to HC products not being consumed.
The average (not the peak) cylinder temp of the air cooled engine may be higher. This leads to better combustion and less HC products.
Perhaps Blake can tell me if I'm right |
Ceejay
| | Posted on Sunday, October 29, 2006 - 10:31 pm: |
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The egr's usually come into play at idle and cold running-where an engine is usually running the poorest in regards to fuel economy. I can understand the reason for cooling the combustion chamber, but in the case of the catylitic converter it is after the EGR, head pipes, and oxygen sensor. At least it used to be, I don't know about the newer(2000 up) cars/trucks/bikes. It seems like they were designed as an afterthought or last ditch effort...Which makes it pretty cool about buell's as they don't need one due to proper engine design.
Looks like I may have answered my own question... |
Trojan
| | Posted on Monday, October 30, 2006 - 04:38 am: |
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What makes you think that noise regulations will be getting any more strict? They won't be as far as I know. They are already extremely strict. It is a non-issue.
Noise is a huge issue over here in Europe Blake, and I suspect that it will be in the US before too long. Why do you think that the Screamin' Eagle exhausts and race kit pipes have been discontinued?
We have 'drive by' noise testing over here in Europe for new models, as well as other strict criteria for mechanical noise etc.
There are,as you say, many ways to combat noise, from simple 'masking' to computer generated 'noise cancelling' software and speakers. Why aren't the manufacturers following this route I wonder? I saw a demonstration some years ago that featured a TVR sports car running a completely open exhaust pipe and noise cancelling equipment and it was eerily quiet and very strange.
It seems to me that a lot of the Auto industry don't want to 'solve' noise and pollution problems, just stick a band aid on them and hope that the problem will go away, hence catalyitic convertors and the like. |
Rocketman
| | Posted on Monday, October 30, 2006 - 05:23 am: |
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Ill attempt to upload a word document here that might be of interest to you Blake.
<!-attachment-!> <!-/attachment-!>
Rocket
Sorry but the file is too big.
(Message edited by rocketman on October 30, 2006) |
Blake
| | Posted on Monday, October 30, 2006 - 02:11 pm: |
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Ceejay,
Higher compression ratios within a reasonable range produce more power, not better efficiency. Racing machines run high CR's; fuel efficient vehicles run moderate CR's.
My understanding is that the lean mixtures of modern engines coupled with higher compression ratios and the resulting higher heat of combustion produce larger quantities of NOx compared to lower compression engines. It is just the result of the imperfect chemistry happening inside the engine. In a perfect world all the fuel would burn and the only products of combustion would be carbon dioxide, water and nitrogen. The nitrogen is a bystander; it enters as the main constituent of air. Under intense heat of combustion it can combine with oxygen. Then you get smog.
I'm no expert in chemistry or thermodynamics. But the above is my understanding. Maybe an expert in the field will chime in too confirm or clarify the above.
Matt,
I stand by my statement above that "What makes you think that noise regulations will be getting any more strict? They won't be as far as I know. They are already extremely strict. It is a non-issue."
Noise is a HUGE issue here too and our laws and regulations reflect that. We like you and the rest of the developed world have strict noise testing for new vehicles to ensure they meet our regulations.
My point is that the current regulations are already so strict that tire noise is the predominant noise emitted from most any motor vehicle these days.
Off road performance accessories have been taken of the shelf because they were being employed on street machines and they never ever met noise emissions regulations. The regulations have not become more rigorous.
There is no evidence that I know of suggesting that noise regulations will become more rigorous here insofar as engine and mechanical noise are concerned.
The tire companies and road builders are the next logical target. Ever notice how tire noise on concrete road surfaces is much louder than for a nice asphalt surface? Dito for some configurations of tire tread versus some others too.
Sean,
Email it to me? |
Ceejay
| | Posted on Monday, October 30, 2006 - 03:02 pm: |
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I know I don't like noisy tires-insert favorite burnout pic here
Blake funny thing is I have a degree in Biology/chemistry-give me a question about the human/animal combustion process and I would well do better, but the things that seem to be happening inside that chamber can get pretty baffling... |
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