| Author | Message | ||
     Rocketman |
Sean, how is the torque on the MV? Well I've only ridden the 750 Brutale and the F4 1000. The Brutale is dead below 4000, though I'm told a power commander and eprom change this. Above 4000 it screams all the way to 13 or 14000. The F4 is a ballistic missile on two wheels. A Hayabusa feels torquey and has real grunt. Not sure I'd equate even that IL 4 as torquey though. At least not like my 916 for example. So the IL 4 MV's. Different feel again. The Brutale feels light and nimble and the sensation it offers is kind of like riding a tightly wound big spring when it's let go. Not that I've ridden any big springs, lol. The F4 1000 doesn't feel torquey like my 916. It feels like a relentless massive attack towards the horizon. Rocket | ||
| Starter |
I would like to see the torque curves of quite a few bikes overlaid to examine the hypothesis that twins are indeed endowed with more low down torque. | ||
| Anonymous |
Neither torque curves nor horsepower curves well describe the power delivery characteristics of motors in motorcycles. There is much more to it. | ||
| Xbullet |
the sportster engine in essence hasn't changed since 1957. it was hossed up for tubers and redesigned substantially for XB's...but then again, not really. we can nit pick at the differences between the XB motor and the old ironheads, but we're really looking at the same thing our fathers were in the 50's.... the torque-ing-est motorcycle on the face of the planet. Torque makes me happy. Torque makes me smile. That was gonna be a poem, but i couldn't make it rhyme. | ||
| Xl1200r |
the sportster engine in essence hasn't changed since 1957. I'm not sure which essence you're referring to, but the XL engine has changed plenty in 50 years. If essence means it's the same basic platform and layout, then no, it hasn't changed. But by that logic, any DOHC I4 is, in essence, the same as the very first one to ever be built. The Chevy small block served well for a simalar timespan, with displacements ranging from 262 to 400 cubic inches. While the Gen IV small block shares no parts in common with the original, it is, essentially, the same thing, only better. | ||
| Blake |
Spatten, Concerning the oil pump drive gear you have a solid point and I agree; that configuration is problematic for the Buells. Your exageration notwithstanding--I've owned three Buells and only suffered a single rockerbox leak--the rockerbox leaking problem is a thing of the past. The other issues you mention are just different not inferior at all and in all respects offer advantages over alternative configurations. Do you consider a wet sump lubrication system to be more advanced than a dry sump? Do you consider an engine that requires the addition of a heavy radiator and liquid cooling system more advanced? Do you consider an engine cooling system that responds as required very effectively cooling the cylinder heads even after engine shut-down as moe or less advanced compared to those that do not cool the cylinder heads after engine shut-down? Do you consider an engine that requires heavy catalytic converter and air injection systems in order to meet anti-pollution standards as more advanced? Do you consider an engine that provides the same power but grossly inferior fuel efficiency as more advanced? Do you consider an engine that requires periodic valve-train maintenance/adjustment more advanced? Do you consider an engine that is half the displacement yet requires twice the number of cylinders, twice the engine speed rev limit, four times the valves, and four times the throttle bodies as more advanced? I sure don't. | ||
| Blake |
I think with all else being fairly equal, the definition of "a more advanced engine" for some people will always be based upon max HP/cc. In that case a supercharged two stroke engine is likely the pinnacle of advanced engine technology and this debate can now end. | ||
| Xl1200r |
Blake, I think I'm in love...  In all seriousness, I think some people won't be happy unless they start seeing GE Turbofans strapped between the frame. But who am I kidding...60,000 lbs of thrust will only be fun for a year, then it will be time for newest engines again... | ||
| Xbullet |
Blake -- amen. Looks like they got it right in '57.  like the small block chevy (i love my 305's and 350's), the sporty engine platform has endured. and let's get real here. Harley big twins have parts that came first on a '36 knuckle that will fit an Evo and vice versa. My 83 el camino had a motor out of a 68 camaro stuffed between the fenderwells. the '57 sporty and the '07 XB may not be as closely linked as these, but there is a bloodline there that, forgive the pun, is still thicker than 60 weight. | ||
| Tpoppa |
Concerning the oil pump drive gear you have a solid point and I agree; that configuration is problematic for the Buells. OMG, on 1/29/2007 Blake actually made a negative comment about Buell. To celebrate this momentous occasion I will find a water-cooled motorcycle and poke a hole in the radiator.  | ||
| Blake |
LOL. That by far isn't the first observation I've made that was critical of Buell motorcycles. Actually the list is significant. This is a good lesson in "don't believe everything you read." At least when it comes to folks assigning behaviors to me.  You know what is really cool though? In every case so far, Buell has stepped up and produced a fix. You can safely bet that will continue. | ||
| Spatten1 |
Blake, I actually meant the tranny drive gear. Just running power off of the counter shaft eliminates the extra bearings-which happened to die on my bike. "I think with all else being fairly equal, the definition of "a more advanced engine" for some people will always be based upon max HP/cc." Actually to me it is max HP per size and weight of the engine. I agree with you that cc don't matter, but small external dimensions can aid in chassis development, and lighter is always better for a sport machine. "Do you consider a wet sump lubrication system to be more advanced than a dry sump?" Actually, yes, because I am sick of all of the leaking oil at the fittings. "Do you consider an engine that requires the addition of a heavy radiator and liquid cooling system more advanced?" No cooling fins mean weight saved. The air cooled engines we are running are heavier than more modern twins plus the coolant plus the radiator. Some of that is just dumb things like the gigantic locking plate on the engine sprocket and the giant rockers and extremely heavy lifters. "Do you consider an engine cooling system that responds as required very effectively cooling the cylinder heads even after engine shut-down as moe or less advanced compared to those that do not cool the cylinder heads after engine shut-down?" They are not as hot at shutdown if the temp is regulated with a thermostat. I've neverr heard of it as a problem, unless you do a max hp dyno run and shut it down immediatley, which is just dumb. "Do you consider an engine that requires heavy catalytic converter and air injection systems in order to meet anti-pollution standards as more advanced?" When the Buell makes competitve power and still passes emissions without those devices we can discuss it. Right now it does not even come close. "Do you consider an engine that provides the same power but grossly inferior fuel efficiency as more advanced?" My 1998 ZX9 made 140 hp and got 40mph consistently, more than my Buell does with my riding style. "Do you consider an engine that requires periodic valve-train maintenance/adjustment more advanced?" If it allows it to rev another 5k and nearly doubles the horsepower, it is a fair tradeoff, for me. "Do you consider an engine that is half the displacement yet requires twice the number of cylinders, twice the engine speed rev limit, four times the valves, and four times the throttle bodies as more advanced?" It doesn't matter to me, as long as it is reliable, powerful, light, and compact. Just read the Kevin Cameron article on the new S&S engine, it is great. S&S is addressing many of the inherent limitations in the HD engines, and they are still air-cooled. You don't need liquid cooling to update these engines, you just need the right engineers, a budget, and support from the top of the company. | ||
| Spatten1 |
Blake, I may be just being the devil's advocate a bit, but I do believe the following: Buell engines are being held back by the crank bearings and valve train. Both of which are inferior to designs of the past quarter century and keep the engine from creating much more power with great reliability. | ||
| Vanvideo |
Torque makes me happy. Torque makes me smile. Feelin' it from my Buell, Mile after mile. I completed your poem. OK, I'm no e.e.cummings. | ||
| Blake |
I'm not familiar with the Buell crank bearings being any kind of problem. I think they are better and more efficient than the plain old journal bearings most engines use. Plain old journal bearings are smaller and lighter and simpler though. Neither do I see the valve train holding back the Buell engine. The engine is limited by piston speed. The valvetrain does fine up to that limit. In my points in the prior post, I was not meaning to ask for a comparison of the existing Buell engine to another existing engine. I was meaning to evaluate the basic technology. How that technology is implemented or one what engine is another thing entirely. If you Buell isn't make better than 40 MPG, it is likely way out of tune. No way a ZX9 ridden comparably will best an acceptably tuned Buell in MPG. | ||
| Spatten1 |
Apparantly the plain bearings are necessary when rpm rises, due to large pistons in twins. The recipricating weight deforms the roller bearings at a certain rpm and recipricating mass. That is why S&S is going to the plain bearings, with their monstor motors. If you did allow higher rpms, assuming that the roller bearings are a limiting factor, then you would need to lighten up the valve train to avoid the inevitable float. Kevin Cameron (one if my heros) did a great write up on it in Cycle World. S&S is doing some serious engineering to make performance improvements without alienating their client base. They are sticking to the air cooled American twin heritage, for sure. I get good mileage at cruise, when the closed loop system is working. However, that is a minority of my riding, and I don't get very good mileage. I'm in the throttle quite a bit. That will probably change now that I'm in Colorado, and it will probably go up with a different type of riding. If the ice ever melts here I'll find out. | ||
| Spatten1 |
I forgot, S&S engineers also determined that the offset rockers flex at higher RPM, so they are going to use standard automotive stamped type, which they say perform more consistently over a bigger rev range. They are using progressive valve springs (beehive), and a few other things that have been used widely outside of HD for many years. I really believe that Buell would have opted for similar common sense upgrades done the same if HD had different priorities. | ||
| Hughlysses |
Apparantly the plain bearings are necessary when rpm rises, due to large pistons in twins. The recipricating weight deforms the roller bearings at a certain rpm and recipricating mass. That is why S&S is going to the plain bearings, with their monstor motors. Spatten1, IIRC, the Cycle World article said roller bearing cranks are pretty much a hold-over from the early days of V-twins. Roller bearings work with minimal lubrication and that's all they were able to supply back then. Plain bearings (and oiling systems) have come a LONG ways in the last ~80 years and are used almost universally in all sorts of engines. Doing away with the roller bearings and knife-and-fork connecting rods (the new S&S motor uses conventional automotive type connecting rods with split big ends) also let them go to a solid, one-piece forged crankshaft. The article said the 3-piece pressed together crank (used in HD, Buell, and clone engines) is a major weak area at high power levels. | ||
| Spatten1 |
Well said. | ||
| Blake |
"...at high power levels." I didn't realize we were including hot-rod-ability in the evaluation criteria. If that is the case, then the Buell engine is lacking compared to others more conventional engines. The Buells engines are already hot-rodded for more than a 50% increase in performance compared to their Sportster bretheren. There is nothing that prevents roller bearing use on the crankpin or crank. The XBRR uses them, yes? Another advantage of the roller bearings is their greater efficiency. They do add mass though, not a desirable thing. All transmissions use roller bearings, do they not? Like I said, I've not seen any evidence that the roller bearings in the Buells are problematic. | ||
| Spatten1 |
My 1999 X1 had about the same peak power as the 2007 XBs. Something is a limitation on increasing HP with reliability..... The XBRR has in no way shown that it would have any sort of reliability as a street engine, or high mileage race engine for that matter. If it had that potential, I'm sure the guys at Buell would have boosted XB power a long time ago. | ||
| Sarodude |
I'll tell ya the thing that irks me most about the XL / XB motors.... Everyone likes to mention how much grunt these things have down low. Funny thing is that it's also frequently mentioned just how bad it is do drag the motor into the lower regions of the rev range under load. Just my microcents. -Saro | ||
| Hughlysses |
There is nothing that prevents roller bearing use on the crankpin or crank. The XBRR uses them, yes? Another advantage of the roller bearings is their greater efficiency. They do add mass though, not a desirable thing. All transmissions use roller bearings, do they not? Like I said, I've not seen any evidence that the roller bearings in the Buells are problematic. Blake, It's been posted in at least one article (Cycle World IIRC) that the durability of the roller bearing assembly in the big end of the connecting rods is pretty much the limiting factor on reliability at high RPM with the Buell engines. The initial article on the XB12's mentioned the use of the two-step rev limiter to avoid abusing the connecting rod roller bearings. The 06 XB's added a silver-plated cage to these bearings evidently to improve their reliability. As I understand it, roller bearings only provide a significant advantage over conventional (plain) bearings in certain types of service. The starting friction of a railroad car equipped with roller bearings for instance, is MUCH lower than that of a car equipped with plain bearings. At speed, this advantage disappears. (Railroads have gone virtually 100% roller bearing however on the basis of improved reliability and standardization of components.) Manual transmissions aren't pressure lubricated either, so rollers may be the best bearing for that application. OTOH, in a pressure lubricated engine, which relies on a film of oil to prevent any metal-to-metal contact, I don't believe there is any frictional advantage to roller bearings. There may be perfectly valid engineering reasons that the HD and Buell engines are still running with rollers in the connecting rods. OTOH you have to figure S&S has built a whole bunch of these engines and when they decided to go "clean sheet" design, they got rid of the rollers. It may be that the rollers do offer some advantage, but this advantage is more than outweighed by the ability to use a one-piece forged crank, something that can't easily be done with roller bearings. Split-race roller bearings are available, but I'm sure they're more expensive and probably have limits to their application. | ||
| Liquorbox |
I'm more irked by the fact that almost any 600 has more HP than my 1200, and most 1000's weigh about the same and have equal, or more torque and gobs more HP. If the Buell/Sportster engine is being considered as a sophisticated, or modern design, I beg to differ. | ||
| Skully |
Please do not get me wrong; many of you on both sides of this debate have brought up some very interesting points and I have learned a lot. However, does horsepower = sophistication? | ||
| Ridrx |
Been watching this for a while now and had a ? How many ZXCBGSXR1's do think would sell if they made 100hp?...NONE!!! Buell has provided the average STREET rider with a compact,nimble bike that is actually FUN to ride w/out having 150+hp. Maybe it's just me, but I would rather spend my saddle time working out the tires rather than the shifter. Obviously a Buell is not the bike for everyone, and if you spend more time trying to make hp than working on your riding skills you should probably look elsewhere. I ride a bone stock 0612R, the bikes ability far exceeds my own. Mind you, I have been riding for nearly 15yrs, I'm not new to this. While I have owned faster bikes, NONE have given me the satisfaction I get from riding my Buell. I believe as long as Buell keeps the "fun factor" high they will continue to sell bikes. For those who think they need 150hp to be fast, buy Hondayamazukasaki. I know this thread was going on about bearings, but ultimately it is about power gain(+rpm's) and IF you did have that V2 that turned 9000rpm's and made 150hp you would sound like all the other sportbikes, have to rev it like all the other sportbikes, have to shift it like all the other sportbikes,and would no longer be part of the "we don't care how they do it in Japan" crowd that we are so proud of. I'm new here and my opinion is worth naught, just adding my $.02, I'm goin' ridin'.  | ||
| Blake |
Hugh, "It's been posted in at least one article (Cycle World IIRC) that the durability of the roller bearing assembly in the big end of the connecting rods is pretty much the limiting factor on reliability at high RPM with the Buell engines." Every engine has a "limiting factor." That doesn't make it a problem; it simply makes it the weakest link in the chain. The roller bearings in Buell engines have not in any way been problematic as far as I know. Do you know differently? I can assure you that roller bearings are MUCH more efficient compared to journal bearings when subject to the same loading and operating speeds, no matter the speed. This is one reason why HD/Buell engines are so fuel efficient. Reference this technical discussion (see page 5). I'm certain that what S&S knows about engines is significant. I'm also certain that what S&S knows about engines pales in comparison to what H-D/Buell know about engines. If properly engineered, there is no reason that a split crank will not perform perfectly well. Any engine that is pushed far beyond its intended operational envelope will experience accelerated incidnece of failure, even possibly running into limitations for torque, HP, or engine speed. That in no way testafies to the integrity of the technology employed. Overbuilding an engine adds weight, but it expands the hot-rodability. "However, does horsepower = sophistication?" Excellent point bro! HP certainly isn't the only measure of sophistication in engine design. If peak HP is a major goal, like for a racebike, then yes maybe. If peak HP is not the primary goal of an engine, like those employed for a low maintenance, highly efficient and reliable street bike, then no it isn't. Sophistication to me is not having to rev the thing to 8,000 rpm to get into the powerband or to 13,500 to reach peak HP. Saro, Lugging would be problematic below say 2000 rpm. The low-end grunt that folks talk about comprises from 2500 RPM to 4000 RPM or so. In that range, the typical IL4 600cc motorcycle falls on its face trying to accelerate. "If the Buell/Sportster engine is being considered as a sophisticated, or modern design, I beg to differ." Right, cause a radiator, water pump, all that associated plumbing, quadruple the number of throttle bodies, quadruple the number of valves, double the number of cylinders, chain driven cams, a valvetrain that requires periodic maintenance, a wet sump, catalytic converters, inferior fuel efficiency and a power-band that doesn't come on until 8,000 rpm is so much more "modern". Not in my view. Here's an interesting question. I don't know the answer. Can anyone name the year of the first commecially produced liquid-cooled DOHC four valve/cyl engine? Anyone? (Message edited by blake on February 05, 2007) | ||
| Hughlysses |
Every engine has a "limiting factor." That doesn't make it a problem; it simply makes it the weakest link in the chain. The roller bearings in Buell engines have not in any way been problematic as far as I know. Do you know differently? I'mm pretty sure that roller bearings are more efficient compared to journal bearings subject to the same loading and speed. This is one reason why HD/Buell engines are so fuell efficient. I didn't mean to suggest the roller bearings are a problem, just that they may well be a limiting factor keeping the engine from attaining even higher power and RPM limits. Now, my experience with comparing roller bearing/ conventional bearing applications is admittedly limited, but I don't think they offer improved efficiency compared to pressure lubricated conventional bearings in high RPM service. I may be wrong. I've always been under the impression that Buell's thermal efficiency is obtained on the combustion end of things. If properly engineered, there is no reason that a split crank will not perform perfectly well. I'm sure that's true, but a 3 piece pressed-together crank sure seems like 19th century engineering to me. I would NOT want to have to fool with assembling one, having to align the assembly in 3 planes under a time limit before the red Locktite sets up. It's truly amazing to me that they can reliably do this on a production basis, and it just seems that a one-piece crank would be a lot easier to engineer and manufacture. Hey, I'm definitely a "believer" in the validity of the basic air cooled, 2-valve, pushrod, V-twin design. I just think Erik and co. could probably do even better than S&S if they were given the opportunity to design a clean sheet engine. Here's an interesting question. I don't know the answer. Can anyone name the year of the first commecially produced liquid-cooled DOHC four valve/cyl engine? Anyone? Well, the 1928 Duesenburg Model J had a 4-valve DOHC engine. It wouldn't surprise me if there are even earlier examples. (Message edited by hughlysses on February 05, 2007) | ||
| Liquorbox |
I love my Lightening, but if any of you have ever ridden a Duc, or almost ANY other twin, I think you'd be in for a big surprise. For one thing, IMHO the 45 degree design Harley uses is absurd. That’s part of the reason they make more vibrations than HP & are forced to come up with "dampening methods" to make it ridable. By merely evolving into the "sophistication" of a 90 degree twin, they would be far better off. Ridability, performance, virtually everything about the bike would benefit, except for maybe the aesthetics, which is the MAIN feature & selling point of Buell IMO. As far as HP not being a measure of sophistication, why not just use a Briggs & Stratton? I don't know about you guys, but the first thing I did to my Lightening was try and make it faster. I think just about everyone here is in the same boat? | ||
| Sarodude |
Well, let's start approaching tech from a different perspective.... Honestly, internal displacement, engine configurations, and design compromises are one thing. However, a prime consideration in the engine design of personal transportation and motorsports and everything in between has to do with mass and EXTERNAL displacement. Really, mass is the enemy. The more you must move, the more you need to move it. External size ain't much better. Seat height, ground clearance, frontal area, etc can be affected by this. I've felt F1 should start using a different formula for a long time. Create a box or some volumetric capacity number for the OUTSIDE of that engine (gotta define what comprises an engine!) to fit inside. That's IT. Anyway, in the realm of motorcycles, size (EXTERNAL size / displacement) and weight of the powerplant (I mean EVERYTHING it takes to make the engine work) would seem to sorta have something to do with suitability. Tech or no tech, if someone was trying to impress me with an engine, I'd want to see something the size of a gumball propell the Spruce Goose. Maybe what winds up being more impressive about UJM IL4's isn't swept volume. Maybe it's more the other stuff - external size & total package weight for the power produced - that's impressive. People just may not really be thinking of it that way explicitly. I've heard weight numbers thrown about. I'm just not certain of their accuracy or what components they consider. -Saro (Message edited by sarodude on February 05, 2007) |
