| Author | Message | ||
     Jmartz |
We need more power, that's a fact. Problem is, we will have to give up some the low end torque we so dearly love. I like this design but have given up on it for the sake a bit more top end. | ||
| Brucelee |
How does the VROD design inform this discussion? It has a little of all of these tidbits (if I understand its design); 45 degree VTWIN with water cooling and multi valves. It is my understanding it spins faster and makes more HP and torque than our 1200 XB motor. Is that true and if so, it would seem that solves the problem. AM I off base here? | ||
| Bomber |
I believe the guy that made those Fuell 4-valve heads passed away last year . . .. never saw a dyno sheet either, but the bling factor was certainly there . . . .. . 4 valves CAN let a valve train operate faster, but I have a feeling that we could upgrade the valve train significantly without really affecting the redline of the engine as a whole | ||
| Brucelee |
The VR1000 Superbike race engine provided the cornerstone for development of the new Harley-Davidson engine, called the “Revolution.” The Revolution engine is still a v-twin … that’s where the similarities with the old OHV v-twin end. The new engine is an 1130cc 60º v-twin sporting 4 valves/cylinder, dual overhead cams, liquid cooling, and fuel injection. It revs to 9,000 rpm and produces 115 hp. Not bad … not bad at all! | ||
| Brucelee |
The dyno really showed the V-RODs power. The stock V-ROD produced 98 hp. The addition of the Screamin’ Eagle pipes and the requisite changes upped that to 108 hp. Not quite up to my V-MAX’s 115 hp, but an excellent showing. The OHV engined Harleys usually put out around 65 hp in stock form. | ||
| Lightisright |
It really comes down to max piston speeds and sideloading that limit rpm. Sure, you're not going to get 10,000rpm out of that pushrod design but I've put together a short list of various bikes and their max piston speeds at redline (or what I could surmise as redline from various articles). 4500 feet per minute has been sort of the holy grail of F1 and racing bike engines for years. Look at the new R1!! SV 650 4519 fpm @ 11,000rpm 999 4583 fpm @ 11,000rpm R1 4835fpm @ 13,750rpm R6 4526fpm @ 15,500rpm XB9 3906fpm @ 7500rpm XB12 4320fpm @ 6800rpm XB12 4447fpm @ 7000rpm XB12 4754fpm @ 7500rpm I think you can see that raising the XB12's rpm to 7500 falls pretty much outside of reasonable even compared to the screaming new R1. And this does not take into account side loading resulting from connecting rod length (a hard number to come by). Hope this is readable. B | ||
| M1combat |
"Also, rod length does not affect piston speed, stroke does." Correct, but rod length DOES affect side loading, which increases exponentially with more RPM's. Lightisright- Hmmm, I guess I really should have done the math sooner... You are correct, 4754 FPM is a bit high. I think however that saying that 4500FPM has been the "holy grail" of F1 and race bikes may be a bit much... I have heard that 4500FPM has been widely used as the reliable street number... | ||
| Sarodude |
I have a suggestion: I've been on a number of motorsports oriented sites and this insane HP / Torque thread always pops up. I have a solution: www.HorsepowerVsTorque.com The domain is free for the registering. Someone go buy the domain name and host a site and let's stop flogging this long dead horse. Anyone wanna do ContactPatch.com? You have to buy it from these guys. -Saro | ||
| M1combat |
You should see the last one we had a few months back  . | ||
| Gonen60 |
Someone go buy the domain name and host a site and let's stop flogging this long dead horse. I don't see where this is a dead horse issue. I for one am just asking questions to try and learn a little more about the mechanics of my bikes motor. I can say, If the HP doesn't start rising, I can't see how in two years Buell will keep selling more and more bikes each year. Sure next year the XB12 will not change much, most likely. Thats ok, the new 12s engine will still be sort of new. Come 2006 without a bunp in HP What will be the selling point. Every other company bumps there HP every couple of years at least. I'm just trying to determine 1 can they (more HP) with the same V Twin Motor? 2 will they and how much? 3 whats taking so long? I think everyone here would like there XBs to be a bit more competitve with the Japanese SportBikes Performance is the name of the game for all of Us. | ||
| Steve_a |
Generally, power is proportional to piston area, given equal piston speeds. The 12 makes more power than the 9 because it peaks at a higher piston speed, pretty close to a limit for a streetbike with high-mileage durability in mind. The valvetrain is actually more capable than the crank/piston in this particular case, as valve float doesn't occur to beyond 8000 rpm. Improved flow and more compression and improvements to intake and exhaust can yield somewhat more power than a current 12 makes, but big improvements require more revs and more piston area -- and that almost certainly requires rejuggling the bore/stroke ratio, as on Buell race engines. | ||
| M1combat |
I think they'll bore it and put a bit of work into the heads. Maybe slightly different cams for 2006. Got me though. You can certainly get more power out of the engine even at 1203cc's. I think it'll be headwork and cams if they don't bore it for 2006. | ||
| Darthane |
Gonen60 - Buell hasn't significantly increased HP since the intorduction of the S1WL - yet their sales have increased year after year. They do NOT need to up HP incrementally every year to sell bikes. The Japanese makers have no choice - their bikes are all the same! People who buy Buells do not do it for the HP. If they did they're not right in the head. That said, pretty much all of us like to do things that increase power on our bikes, but I personally think that that is less questing after some magic HP number as it simply is that the average Buell owner likes to tinker more than the average rice-rocket-rider. Face it, 90% (if not more) of the rice rocket riders out there slap a pipe on their bikes and that's it. Then they ride them 2,000 miles a year. We've got Buellers that are messing with the electrical systems on their bikes in order to get rid of the muffler actuator. Other guys played around with their velocity stacks. How many crotch rocket owners do you know that are truly that interested in how their bike works and just plain messing around with it? | ||
| Dyna |
Face it, 90% (if not more) of the rice rocket riders out there slap a pipe on their bikes and that's it. Then they ride them 2,000 miles a year. Bryan, dont even go there. We have read from many many new posters just on this site alone who have picked up an S1 or an S3 & it has super low miles. The Buell riders arent putting on any more miles than the other sportbike owners are. yet their sales have increased year after year Sales have actually flattened out & are dropping. Results were posted a couple months back. I do agree that Buell is going to have to come out with something thats going to knock everyones socks off in order to stay competitive. And coming out with just another rehash of the same ole present V-twin isnt going to be enough. | ||
| Doughnut |
I have dealt with a few people who have bad mouthed my S2 for it's "weak" motor. I simple twist the throttle and pretend that I can't hear them.  | ||
| Gonen60 |
Face it, 90% (if not more) of the rice rocket riders out there slap a pipe on their bikes and that's it. That is true!, but when you Buy a street legal "Race" bike what else do you need to do? | ||
| Gonen60 |
I do agree that Buell is going to have to come out with something thats going to knock everyones socks off in order to stay competitive. And coming out with just another rehash of the same ole present V-twin isnt going to be enough. Right Dyna, lets just hope the Buell HQ can read the writing on the wall! | ||
| Blake |
Johncr250, Liquid does not automatically in all cases cool better than air. If the bucket of water was at 212o would you still want it thrown on you to extinguish a flame? That analogy is invalid anyway since air in that case is acting as fuel and the water is acting as extinguisher. Putting out a flame is not about cooling as much as it is about denying oxygen to the combustibles. The beauty of air cooled engines is their simplicity. Cooling effectiveness for both convection and radiation heat transfer each improve as temperature differential (difference in temperature between coolant and heated item) increases. So as the engine becomes hotter, the cooling system gains effectiveness. What do you suppose is used to cool the liquid?  Liquid cooling does have its significant advantages too (noise attenuation). But on a street bike and considering simplicity and ease of maintenance the ducted forced-air-cooled engine wins hands down. An air cooled engine just looks a whole hell of a lot better too, and that is very important to many motorcycle enthusiasts. It is to me. Aside from SteveA's much appreciated input. I'd add that the XB9 goes to 7,500 rpm, so the valve train is likely good for near 8,000. The XB12 has the same valvetrain...  Static, The Buell XB models utilize forced air cooling. It does not "seem to skip a step" it absolutely does skip a step compared to liquid cooled engines. Like their air cooled cousins, liquid cooled engines also suffer significant ambient induced fluctuations in their operating temperatures. Liquid cooled engines also have surfaces exposed to ambient conditions do they not? What medium is used to cool the liquid in a liquid cooled engine, even on a hot day in the desert? Apparently the air is quite adept at removing heat from a relatively cool liquid since it is air that is removing the exact same amount of heat from the liquid that the liquid is removing from the hot aluminum engine. Does the liquid provide a uniform coolant temperature to all portions of the engine or does it continue to get hotter as it travels through the engine? Imagine how effective the air might be in removing heat directly from a hot aluminum fin? Which provides a better more efficient path for heat to escape... solid aluminum, or solid aluminum and water? What is the ratio of convective surface area for an air-cooled cylinder versus one of similar size that is liquid cooled? What material conducts the heat away from the combustion chamber in an air-cooled engine? Is it a good/efficient conductor of heat? Controlling air cooling of an engine is not "difficult" as you claim. It's been done for years in civilain and military vehicles. The variation in temperature for a motorcyle engine is not extreme, a 130oF design range in ambient air temperature is probably generous. The highest performance engines in the world are air cooled. You know the ones you might find on an F22. You think water is more controllable? If it is ducted and forced among/between passages, it is controllable. So is air. The HUGE advantage of air cooling is that you will NEVER run out of coolant. A liquid cooled engine overheats, and they DO overheat... the coolant goes away in a hurry, the engine melts. An air cooled engine gets hot, the limitless supply of cool air becomes even more effective, the engine continues to run just fine. Water alone does not transfer heat more rapidly, it all depends on operating temperatures, convection surfaces, and flow rates. You'll be hard pressed to prove that "water at a temp between 180 to 195 will actually transfer heat away from the combustion chamber more rapidly (than ambient air)." You'll be glad to know that your Buell model was rigorously tested to confirm its continuous operation in the most tortuous high heat counditions imagineable, far more tortuous than you are likely to encounter even riding in/around Tempe. Unibear12R nailed it. If liquid cooling is so great and superiour, why do most all the liquid cooled bikes need catalytic converters and air injection to meet emissions specs? Hoot, Generally speaking, four valves means smaller valves which means less valve mass and thus less spring pressure required to return the valve to the seat, thus higher revs can be achieved before onset of valve float where in a two valve head, the spring pressure required becomes prohibitive. JM nailed it too. Quitter! You were supposed to build your short stroke big bore Buell! Brucelee, The VRod engine is a 60 degree V-Twin with offset crank pins. Lightisright, Check out the new Kawi ZX10R and the Duc 749R and 999R. M1, "rod length DOES affect side loading, which increases exponentially with more RPM's." Piston to cylinder side loading due to rod inertial loads is small compared to the kick load during the power stroke. Or are you just talking about the lateral bending loading on the rod itself. If so, never mind. You are 100% correct. ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) Dyna, "Another rehash of the same ole present V-Twin isn't going to be enough." Kinda like how Japan Inc releases yet another tired old rehash of the same old present IL4, year, after year, after year... The XB12s on average are putting down significantly more and broader power than any previous Buell. The specs are not that different, but the real world rear wheel performance is significantly improved. Think back to 1994 when the 1203cc S2 was putting out what, 65 rwhp? The current crop of XB12 models are putting out 90+ rwhp, a mere 38.5% improvement in engine performance. That ladies and gentlemen is FRIGGIN HUGE!!! Are todays 600cc IL4's putting out that much more power than their predessessors were ten years ago? I think not. Imagine what the next ten years might hold for the 45 degree air cooled American twin. I'm enthusiastic for such a future at Buell. But that's just me, I like to focus on the positive rather than whine and berate and focus on the negative. (HINT!) Please forgive spelling errors. Time to hang up. | ||
| Roc |
Expensive gas makes the air cooled Buells look that much better. | ||
| Rocketman |
Blake, please don't turn this thread into a science lesson LOL Darth, People who buy Buells do not do it for the HP. Well if that were true what was all that increased HP bragging stuff when the Thunder Storm S1WL's were launched? Pricked my ears up - I bought one. If they did they're not right in the head. Ah yes too true, too bloody true LOL. That said, pretty much all of us like to do things that increase power on our bikes, but I personally think that that is less questing after some magic HP number as it simply is that the average Buell owner likes to tinker more than the average rice-rocket-rider. I can't agree with that over this side of the pond. The tuning business is massive over here. Every year MCN UK fills the Alexander Palace with it's 10 day Road and Racing Show and the amount of exhibitors specializing in tuning mostly Japanese bikes are doing a roaring trade, mostly selling to members of the public, not racers. Sure lots of the stuff is cosmetic but lots of increase performance stuff is sold too. The Japanese bike riders over here look for HP just as much as the average Buell HP junkie might, I assure you. Common place are big bore and turbo applications when you attend any 'run whatya brung' drag meetings. They're the ones were you turn up on your streetbike and 'race' on the day against the clock allegedly, thus not requiring a race license. Very popular over here since Superbike magazine launched a competition to find the fastest streetbike in the UK about 20 years ago. Incidentally, Max Power magazine did similar for four wheelers too. Both very popular activities over here every year. The four wheeled boys look for more HP too. It's a British thing  Rocket | ||
| Darthane |
Ahh, Rocket - that's why I specifically mentioned the S1WL. As for the tinkering thing - yes, European (from what I hear) and Japanese (from what I've seen) riders are much more likely to tinker than the average American rider. What was the increase in riders in the last 5 years in America? It suddenly became 'cool' to ride, but that carries a lot of growing pains with it, including more tickets, accidents, and a lower percentage of riders that know or care what makes their bikes tick. That is true!, but when you Buy a street legal "Race" bike what else do you need to do? <~~Gonen60 Ahh, but that's not all they can do to increase performance, it's just that they're not interested enough in pursuing other avenues. I'll got back to riding my horribly under-powered 35HP more fun than all hell Blast now. | ||
| Dyna |
Blake I hear ya & really Im not bitching about the present motors power output. Its a fun ride, but I truly hope they will see the light & offer the Revo powered bike alongside their current offerings. Build that bike & I guarantee sales will see a huge increase....well so long as the price doesnt jump to some crazy assed $15,000-16,000 range. | ||
| Jmartz |
Blake, H20 does have more heat capacity than air and is able to modulate the head temperature within a narrower range. Heat exchange to the air in the atmosphere is done in a more efficient part. Graves always complained that during a race the constant wacking of the motor raised the average temp enough to loose him 10% power. Consider a red hot piece of iron. In air it cools a lot more slowly than if dipped in water. I have begun looking into building the motor again. I had not done it because S&S had told me they could not supply me with 3.5 stroke flywheels. This was because they have never modernized their castings to include monolithic shafts. The nuts that hold the shafts interfere with the connecting rods. I recently discovered that this is only true if you use the 1.5 crankpin. Since I plan to use Ti rods the 1.25 pin should be plenty strong, especially since this is not going to be drag motor, which is what S&S seems to design for. | ||
| Gonen60 |
Again, I am very Happy with My XB9, But that is not to say I would not be even more smiley if I could buy a 125hP XB. Maybe it's as simple as Harley Davidson has said "No production Buell can out Muscle the top HD Bike" Who knows? As far as Japan releasing the same old I4 every year I do not see that happening. I see the bikes getting better and stronger every year. 2003 GSX-R1000, 2004 ZX10, 2003 6RR etc.. Yes the XB12 bumped up 10 or so HP, just wondering why it's not more, and can't wait to see what the future holds. I would like to see Buell produce a full fairing sport bike, built around the XBs frame and ergos, with 120 HP...If the price was right, they would sell great. from posting and reading on other boards, such as "sportbikes.net" so many riders would buy a Buell if not for the HP figures. the problems the pre-XBs had still carry over, all though not justified. It seems the Buell name still goes hand and hand with quirky-ness for some strange reason. being different has it's rewards and pitfalls | ||
| Al_lighton |
Blake is pretty much spot on on this. Water cooling, air cooling, phooey, it's ALL air cooling. AIR is the ultimate sink for the heat in all the cases. You need to move as much heat out of the engine system to the ambient air as being generated inside the system, or the temperature goes up until you do. Equilibrium WILL be reached, and equilibrium doesn't care if it has to melt your engine, or turn it off, to do it. For a given power output, and assuming that there isn't a drastic change in the efficiency of the system (large gains in internal combustion efficiency are hard to come by, and our V-twins are plenty efficient as measured by your fuel mileage), the only way you keep internal temperatures down is to increase how much heat (energy) is transferred from the engine system to the ambient. There are only two practical ways to do this: by increasing either the flow rate at the engine system/ambient interface (either go really fast or use a FAN), or by increasing the ambient wetted area. This is the ONLY reason why liquid cooling is used: to move heat concentrated in little volumes into large amounts of external ambient wetted interface area. Beyond a certain "power density", the physics of conduction cooling prevent it from being practical, given the thermal properties and limitations of the materials in question. Liquid cooling can be made to work by increasing flow rates (and therefore heat transfer rates) and minimizing the conduction distances the heat needs to travel before transferring to the liquid medium. IF you took a hot rodded sporty engine (with standard fin configuration) that produced 130HP continuous output and a liquid cooled bike with 130HP continuous output, you could make the liquid cooled 130HP bike more reliable because you can control heat flow to the radiator, the radiator area, and boundary conditions more easily for the liquid cooled bike. Increased temp=increased failure rate, plain and simple, and a sporty engine doesn't have a large enough conduction path to a large enough wetted surface area to support a continuous 130HP for a very long time. But that isn't to say that someone couldn't do some clever fin designs and forced air convection system that could perform as well as the liquid cooled system at that output level. But at 100HP, the limits of conduction physics for the given materials is NOT exceeded. Therefore, given a proper design, there is no reason to employ liquid cooling if an adequate conduction cooling path is used. The decreases in reliability due to temperature doesn't justify the reliability cost and complexity of the water pumping systems. Note that I didn't say you can't build a 130RWHP air cooled sporty powered bike. I just said the physics demand that it WILL be less reliable if held at that power output for sustained periods, unless more exotic higher temperature capable materials are used. This is the difference between a race motor and a street motor. I have determined for myself that 100RWHP is actually sufficient for 99% of my STREET motorcycling needs, therefore, I prefer the simplicity of air cooling. If I wanted (needed) 130 or more continuous HP, liquid cooling would be necessary. Heat Transfer was my specialty before management and the current gig. Al | ||
| Johncr250 |
Blake, You bring up some very good points that i hadn`t thought about. | ||
| Sarodude |
Blake- Unless Buell & Harley start building some fugly ducting around their air cooled motors, they would certainly seem to fluctuate WAAAAAAAY more than water cooled mills (temperature wise). Unmolested VW air cooling systems were marvelous. Not only were they 'forced air' but they also had a thermostat and little shutters to keep temps in an optimal range. VERY quick warm ups. Unfortunately, most people defeated those systems 'cause they didn't know how to deal with 'em - but that's another story. Point is that your statement regarding liquid cooled engines being subject to the same ambient induced fluctuations doesn't jive. None of our household's 4 air cooled, pushrod, American motors has a thermostat and ducting to control temps. Even on the XBs, the front jug is just hangin in the breeze. I don't know of any street water cooling systems that don't utilize thermostats for controlling water flow and some other thermostat mechanism for controlling fans. Please note - I'm not trying to knock what we have. I just don't buy your statement as is. -Saro | ||
| Hootowl |
Blake, "Hoot, Generally speaking, four valves means smaller valves which means less valve mass and thus less spring pressure required to return the valve to the seat, thus higher revs can be achieved before onset of valve float where in a two valve head, the spring pressure required becomes prohibitive." I understand, but the valves in our Buells work just fine up to redline. The redline in the case of the Buell engine is defined by piston speed, not the valvetrain. | ||
| Jmartz |
Al, your eloquence is golden | ||
| Blake |
Dyna, How do you suppose BMC could accommodate a sudden massive jump in their production? |
