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Hootowl
| | Posted on Monday, July 01, 2002 - 11:19 am: | 
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It is possible to overcool an engine. Higher HP engines make more heat, that's a given, so you need more fin area to cool it. No problem, add more fins. What happens when you're riding your bike in 35 degree weather? Will it ever warm up? You have to consider both extremes of the temperature range. Water cooled bikes don't have this limitation. Too cold out? Don't let water through the thermostat. There are advantages to water cooling as well as air cooling. Where do you want to make the trade? |
Aaron
| | Posted on Monday, July 01, 2002 - 11:28 am: |
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Hoot: not much of the motor sticks out of the fairing. But they open up the area in front of the cyls to allow cool air in. The BMW design is actually claimed to be "oil-cooled" and not air-cooled.
I'm all for a 2-stroke! Even water cooled ... the simplification of the motor (no valvetrain) more than offsets the coolant and pump and radiator. Valvetrains suck. |
Hootowl
| | Posted on Monday, July 01, 2002 - 11:36 am: |
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Even so, the heads on the beemer are hanging out in the breeze. (Which has always bothered me. I'd hate to damage a head from a low speed dump.) YES a street legal 2-stroke would be the shiznit. Direct injection is the way to go there. Yamaha has been using it in their PWC's for a couple of years now. I have to wonder how long it would live though. Can you get 100K miles out of a 2-stroke? (bearing lubricaion) I really have no idea. The only 2-stroke I own is attached to a weed eater. |
Davegess
| | Posted on Monday, July 01, 2002 - 11:37 am: |
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This month's American Rider magazine ha a great article on the Nova, H-D's liquid cooled V-4 that never made production. Photos of a very late prototype from the harley archives plus lots of details of the bike. HD owns some interesting liquid cooling patents from that project. Of course the patens have to be nearing the end of there life, perhaps they will want to use them before others can?
Dave |
Sarodude
| | Posted on Monday, July 01, 2002 - 11:41 am: |
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Aaron-
Man, I'm SO with you on the 2 stroke thing... Devastatingly simple mechanics... Maddeningly complex tuning... 2 strokes make power purely by retarded coincidence... Pure love...
-Saro |
X1glider
| | Posted on Monday, July 01, 2002 - 12:10 pm: |
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Yes, valvetrains suck. I'm still waiting for my dream to come true...solenoid actuated valves that are controlled by computer. Just imagine a virtual cam that varies timing, lift and duration for any situation to realize some serious HP and a truly flat torque curve. There would also be fewer parts to maintain or go bad, lubricate, elimination of mechanical noise, less weight and a more compact engine. Best of all, we can finally sqeeze in 4 or more valves/cylinder. The auto industry has played with the idea for years. I'm not sure if they've given up or forgotten about it though. The problem they had in those days was lack of computer power and the longevity of the solenoids. Up to 5000 cycles/minute and excessive heat destroyed them. I believe they were still using valve spring returns. In the age we live in, I'm sure there's something out there that can handle the task. The computer is no longer an issue at least.
2 stroke? I think the EPA is dead set on eliminating them, even from weed eaters. (2006 in CA and 2008 everywhere else).
Separate crank journals for a Buell? Please do. I don't think the potato, potato sound belongs here.
Water cooled? Please don't. There is absolutely no need for it. I've seen 350+ HP VW Beetles buzzing around the Cali coast.
Like Aaron say's. You gotta think outside the box. It's time to reinvent, rather than refine. |
Eeeeek
| | Posted on Monday, July 01, 2002 - 12:14 pm: |
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AIR COOLED AIRPLANES: WHooohoo! Someothing I know about!
Hootowl, ducting (cowls) allows for propper airflow over the engines in airplanes, not the speed they are going.
Fact: If you pull the cowl off of your average air cooled airplane, it will over heat. Even with that great big "fan" on the front and air flowing by at 100+ knots.
What does this mean? Well, it's not where you hang the parts, it's how you direct the air over the parts. Of course, this has no impact on a stationary vehicle unless you employ fans or some other method of keeping the air flowin.
Follow up fact: My TLR has dual fans on the upper radiator. They are thermostatically controlled and I have yet to see them come on. I talked to other TLR owners and apparently they don't kick on until the temp reads 225 degrees. The most I've seen in 220.
Vik |
José_Quiñones
| | Posted on Monday, July 01, 2002 - 12:34 pm: |
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The Firebolt is already air/OIL cooled........
The Victory Cruiser is air/oil cooled and uses 6 quarts of oil!!!
The Ducati 900 SuperSport is air/oil cooled and has a half fairing.
The Suzuki Bandit is air/oil cooled and makes 99-100 hp in stock trim with a 1200 cc engine. So 100 EPA sound/emmission legal horsepower with an air/oil-cooled engine is possible. But it's an inline 4 DOHC design, which most people here would not prefer.
The Suzuki Katana 600 & 750 are air/oil Cooled and have full fairings.
Fairings and air/oil cooling are compatible as long as you have ducting/fans to direct the airflow when the bike is stopped or going slowly.
It's much easier to hide ducting and fans behind a fairing, than trying to make them look good in a "naked" bike. Unless they're chrome or carbon fiber......
Quote:Okay, so they're not real light or powerful. But it shows that air cooling can be made to work.
Well, that's the crux of the problem, isn't it?
We want 100+ HP in a lightweight, EPA Sound/Emmisions legal Air Cooled V-Twin small enough to fit inside an XB frame.
Easier said than done, or it would have been done by now. In two weeks maybe? |
José_Quiñones
| | Posted on Monday, July 01, 2002 - 12:36 pm: |
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From the Erik Buell Interview at gazette9.com
Quote:g9: Did you consider water-cooling the Blast engine?
Yeah. Absolutely. We considered it. But at the core physics level, it doesn't make as much sense. Because when you want to get rid of heat...the bigger the difference in temperature between two things, the faster the transfer of heat. Say you've got an engine that's gonna run at 180 degrees Centigrade, and you're running 100 degree water, you only have an 80 degree "delta t" (difference in temp) to get rid of heat. So you're gonna have to circulate tons of water past it to get that transition. Then when you've got that water heated up, now you take it out, you stick it in a radiator, and you expose it to 25 degree air. Again you don't have any delta t. Well if you run that 25 degree air right past your 180 degree cylinder, you're gonna get rid of more heat.
You know, during WW II they were building a lot of tank engines. They had battles going on in the desert. And they had water-cooling versus air-cooling back then. And they dropped all water-cooleds. Because you cannot get rid of the heat. They all went to air-cooled engines - the U.S., the Germans, everybody. An air-cooled engine gets rid of heat better when the temperature's high - a lot better. It's actually why the Volkswagen...became such a successful product - that, and the Citroen 2CV. That was air-cooled. That was the first car to cross the Sahara Desert - cause it was air-cooled! Nothing had ever been able to make it before.
Now, like you ran into, probably your timing's a little off or something like that, you get detonation. It's not an air-cooled situation, it's a matter of the timing's wrong. But you'd probably get that in your water-cooled and just wouldn't've heard it because of the water jacket....
The only thing we can't compete with as well is sound deadening - but man, from every other standpoint there's an advantage.
So we really couldn't find a reason to make it water-cooled. Everything said, make it air-cooled. Now, maybe under optimum situations, you design an engine for racing, to work at a certain temperature, to get the peak efficiency out of it, yeah...but for all-around-use engines? Air-cooleds are wonderful.
g9: Won't water-cooling and fuel injection eventually be needed to meet emissions limits?
The air-cooled engine seems to be fine. Again, the emissions tests are a true measure of what everyday life is like, the way the governments have set them up, so they measure start-up and all these kind of things...to get the vaporization of fuel to get clean burn, you need a warm combustion chamber. Particularly in cold start...we were gonna build a bike that people were gonna use for transportation, for jumping around the city. We expect a lot of short trips, and in fact most motorcycle use is for a lot of short trips. Air-cooled engines heat up almost instantly. Whereas in a water-cooled engine you've got to heat all that water up before the temperature stabilizes. The big deal is, the fuel dumps into the cylinder, is it truly vaporized yet or not - and oh by the way, I've got a choke on, so I'm dumping in extra fuel. An air-cooled motor just kills water-cooleds in the first bag of the three-bag test. The first bag is the start-up bag.
That bike right there, the Blast...our average emissions, and I'm just taking an average number - if you just take hydrocarbons, CO (carbon monoxide), and NOx (nitrogen oxides), the three key ingredients, averaged together, we're under 30% of the California standard. Less than 30%.
We'll probably do water-cooling, cause some customers want it, and there may be some advantages; but, to have to do it across the board? It's gonna be a long time before that has to happen.
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Hootowl
| | Posted on Monday, July 01, 2002 - 12:44 pm: |
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Eeeeek,
My point was that an airplane spends very little of its time stopped in traffic. (i.e. waiting on the ramp to take off.) It's pretty much always moving. I am familiar enough with airplanes to know that. Although the jets I worked on for 12 years in the Navy certainly had different cooling requirements than your average Cessna.
I have a fan on my X1. I have to sit in traffic for about 15 minutes on a hot day before it comes on. I'd call that an effective cooling system.
Was "propper" a pun? |
Eeeeek
| | Posted on Monday, July 01, 2002 - 01:06 pm: |
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It was now 
Airplanes spend little time stopped? Ever take off from Executive airport on a weekend? You get queued up for awhile in the 100+ degree heat
That's a joke, by the way. Even when standing still, there's good airflow over the engine via the props.
Jets are a different story.
Vik (private pilot since '94, been flying since I could reach the controlls). |
Hootowl
| | Posted on Monday, July 01, 2002 - 01:16 pm: |
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The only airplane I've ever piloted used a rather unique cooling method. The engine was kept completely outside the airframe, attached only by a tow rope. |
Jima4media
| | Posted on Monday, July 01, 2002 - 01:32 pm: |
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Would anyone here fly an airplane that had a Harley engine in it?
You come down the road and see a car fire blazing on the side. As you approach you bet what kind of a car it is. More than 50% of the time it is an air cooled VW.
I rest my case, your Honor.
Oh, and I still like air-cooled BTW, just saying they aren't perfect.
Jim
X-2.5 |
Henrik
| | Posted on Monday, July 01, 2002 - 01:33 pm: |
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>>If they have to stop for traffic, they have bigger problems than their engine overheating.<<
Hootowl; Very funny 
Henrik |
Jima4media
| | Posted on Monday, July 01, 2002 - 01:36 pm: |
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Now on the other side of the arguement, how about that 992cc air/oil cooled Ducati Multistrada?
90HP at the rear wheel ain't bad for a stock bike.
Jim |
Sarodude
| | Posted on Monday, July 01, 2002 - 01:39 pm: |
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VW fires are attributeable mostly to volks not knowing how to deal with their fuel system and to the marvelous magnesium cases in some of those cars.
-Saro |
Elvis
| | Posted on Monday, July 01, 2002 - 01:47 pm: |
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I think we need to consider the context when interpreting the g9 interview. That was an interview regarding the Blast, so Erik was focusing his answer on why he built the Blast the way he did. He was clearly justifying the air-cooled blast as something other than the cheapest, simplest solution. I'm sure his marketing hat was telling him to put a spin that indicated this was the route he chose to go rather than the route that was most economically feasable. Within the interview, he said the following:
Quote:Now, maybe under optimum situations, you design an engine for racing, to work at a certain temperature, to get the peak efficiency out of it, yeah...but for all-around-use engines? Air-cooleds are wonderful.
This quote tells me that Erik feels water-cooling is best, but you can still do some neat things with air-cooleds.
I'm not about to jump into the trap of debating this. I have enough faith in Erik's judgement to believe that if he, in his heart, believes in air cooling, we will see excellent air cooled engines from him in the future. If, on the other hand, his heart leans toward water cooling, we will see a water cooled engine and I highly doubt it will be the VRSC.
I tend to think the interview represents some carefully chosen words from a very smart man who is trying to sell the air-cooled engines that he is currently able to offer, but I don't see the depth of conviction that tells me he, in his heart, wouldn't like something a little better.
Again, I don't want to get into this debate, but it seems to me that even the air-cooled camp is basically saying: "Sure air-cooled is only 80% as good as water-cooled as a general rule, but Erik is smart enough to make it better." If we accept that as true, wouldn't we really rather see Erik start with water-cooled and make that even better still?
Does anyone have any quotes on the topic that are less than two years old? |
Jima4media
| | Posted on Monday, July 01, 2002 - 01:57 pm: |
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I've got it! A Turbo Lycoming flat six powered motorcycle with variable prop! Short microprocessor controlled winglets to keep you on the ground
See if any cars or deer are going to mess with you then. |
Hootowl
| | Posted on Monday, July 01, 2002 - 02:05 pm: |
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So there I was, flying along on my bike, when suddenly... |
Jima4media
| | Posted on Monday, July 01, 2002 - 02:39 pm: |
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...I had a lap full of venison sausage.
Exactly! |
Eeeeek
| | Posted on Monday, July 01, 2002 - 03:00 pm: |
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If Harley made airplanes, I'd never step out from under the cover of a bunker.
Vik |
Aaron
| | Posted on Monday, July 01, 2002 - 03:26 pm: |
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It never ceases to amaze me the way 2 different people can read the same quote and see totally different things. I don't interpret his quote that way at all. This is a guy who's always looking for a way to do it differently. He never follows the herd. You really think he secretly wants to do it the same way as everyone else?
I bet he'd *really* like to do another 2-stroke! |
Davegess
| | Posted on Monday, July 01, 2002 - 03:59 pm: |
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Eeeek, I have seen a BMW club t-shirt that had a drawing of an airplane with vtwin motors and a line that said something like "If harley made airplanes would you ride in one"
Of course it had a BMW airplane on the back. |
Elvis
| | Posted on Monday, July 01, 2002 - 04:10 pm: |
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Aaron,
I don't think he's being secretive at all, I think he's laying it out there and he ends the interview by saying he will do water cooled bikes.
To paraphrase what he says throughout the interview: Most people think engines have to be water-cooled, but air-cooled engines have many advantages that people don't think of. They work great in hot weather, they work great for a commutor bike like the blast particularly when you consider it will be used for short trips. For a high performance bike such as a race bike, I would use water cooling, but air cooling is great for general purpose bikes. Eventually we'll offer both, but it will be a long time before we completely phase out air-cooled engines.
Nowhere in the article does he say he prefers air-cooled bikes for high performance. The real question becomes: Does he intend to manufacture high performance bikes or general purpose bikes? Based on his own words, he will use water-cooling for high performance bikes and air cooling for general purpose bikes.
It seems a strange position to say that using the same basic engine that every American motorcycle manufacturer has used for the past (what, 50 years) is being different while trying something new would be following the herd.
Can't water-cooling be part of his creative new engine? I don't mean to question you're sanity, but implying that going from air-cooled to water cooled is equivilant to going from four stroke to two stroke is a bit wacky. |
Aaron
| | Posted on Monday, July 01, 2002 - 04:24 pm: |
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Elvis, you planted a whole bunch of words in my mouth that I didn't say. Particularly that last line. WTF?
I thought that his remark about doing water-cooled eventually was only because some customers want it. I mean, that is what he said. |
Elvis
| | Posted on Monday, July 01, 2002 - 04:43 pm: |
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Aaron,
I'm sorry if I mis-interpreted what you said. I thought the whole point was about his comments on air vs. water cooling. When you threw out the comment about two strokes I thought you were saying that it was as likely he would go to a 2 stroke as a water cooled engine.
Let me know what else I planted and I will explain and/or apologize, but I'm afraid you haven't conviced me he didn't say what he said.
Quote:So we really couldn't find a reason to make it water-cooled. Everything said, make it air-cooled. Now, maybe under optimum situations, you design an engine for racing, to work at a certain temperature, to get the peak efficiency out of it, yeah...but for all-around-use engines? Air-cooleds are wonderful.
Seems clear enough to me. |
Phillyblast
| | Posted on Monday, July 01, 2002 - 04:51 pm: |
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Elvis,
I would consider a Buell first and foremost an "all-around-use" bike, by extension any motor for a Buell street bike an "all-around-use" engine. My interpretation of EB's comments are for a controlled, specifically optimized situation, e.g. racing, watercooled is the way to go, but for an everyday driver, a street bike, air-cooled has distinct advantages.
Obviously, I'm biased. My bike is a daily driver, and I don't want to sacrifice streetability in favor of a high peak hp #. But I want a high performance "all-around-use" bike, one I can take out on the weekends to a track day with a reasonable certainty that when I get passed by everyone and their sister, it's me, not the bike, slowing me down. Air cooled works for that, and quite well. |
Elvis
| | Posted on Monday, July 01, 2002 - 05:02 pm: |
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Phillyblast,
I agree 100% |
Aaron
| | Posted on Monday, July 01, 2002 - 05:17 pm: |
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No, I don't think there's a snowball's chance in hell he'll give us a 2-stroke, that's wishful thinking on my part. I think that'd be great, but no, I don't think it's likely. That'd be a big R&D effort.
My point is that he has a history of thinking way outside the box, looking for different ways to do things, proving to the world that there's more than one way to skin the cat.
I think it'd be great if the next motor reflects some of that philosophy. I think the world of motorcycling would truly lose something if Buells became just like every other bike.
But, I also realize that's just me, there's a large contingent that would like to see Buell going head to head with the furrin' bikes on their turf.
Like I said, it'd be cool if they could do both, make us all happy. |
Jim_M
| | Posted on Monday, July 01, 2002 - 05:22 pm: |
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HD will be the ones to go after the "furrin" bikes...this I believe. Buell will keep thinking outside the box, I believe this too.
But, will HD's actions have any adverse reprocussions on Buell? This is what I wonder... |
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