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Rick_A
| | Posted on Thursday, September 12, 2002 - 12:26 pm: | 
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Sportsters were competitive up to the early '70's, basically. When the XR1000 and XLCR bombed on the market, H-D continued with their traditional image. Anyone know of Lucifer's Hammer?
In the right class Buells can be competitive. I'm satisfied with that. |
X1glider
| | Posted on Thursday, September 12, 2002 - 12:59 pm: |
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Like everyone else said, SV racers won't race a Buell because of cost and reliability. Obviously a new design that allows parts consolodation would bring cost down. Reliability...get rid of the damn potato, potato, potato. Make it a 60 deg, twin crank journal, equal power stroke design to reduce vibration and keep the case pressure constant. That should take care of our puke problems and gain us a little power that is normally lost in the form of vibration. Also the 60 deg design would allow larger bores without worry of the pistons colliding with each other. Change the dims to 3.5625 bore and 3.00 stroke for a total of 980cc. That shorter stroke should give us 500 more rpms. The extra rpms would help with EPA noise requirements too since the bike will operate in a slightly better frequency range. I don't think going to overhead cams will benefit us, it just increases engine height. I think pushrods can be made to handle the revs.
Funny how we all can type up a wish list. Yeah, it'd be cool if they made what we wanted, but it wouldn't be a Buell anymore, now would it? Sometimes you have to give the people what they don't know they want. |
Spiderman
| | Posted on Thursday, September 12, 2002 - 01:06 pm: |
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I think you guys are going way out of contex here. I belive the quote is refering to getting more people involved in the racing program. IE Dealers, amatures and profesionals. Buell wants to see there current program succeed, not build the ultimate sportbike. |
Djkaplan
| | Posted on Thursday, September 12, 2002 - 01:14 pm: |
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Oh, no doubt the Sportster engine could soldier on for a number of years before most consumers just stop buying them. It still does have some features that are very desirable; the simplicity of aircooling, the serviceable gearbox (not on Buells anymore) and the compact, neat packaging. But as a viable platform for a competitive sporting motorcycle, it was marginal at best 20 years ago.
I actually like my Buell because it is different in every sense (truth in advertising) and it was a convenient way for me to experience my first American motorcycle (couldn't see me on a Harley). I never thought that this bike would ever be an alternative to a true sportbike - not with this engine.
The old pony might have a few tricks left, but it's time to put it out to pasture. It's been a long time since 1957.
By the same token, I really loved being a part of something new and groundbreaking with the old engine. I can't wait to be a part of what is coming next.
Years from now, I'll relish the fact that I can say, "Yeah, I have one of those old Buells". |
Blake
| | Posted on Thursday, September 12, 2002 - 02:12 pm: |
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"But as a viable platform for a competitive sporting motorcycle, it was marginal at best 20 years ago."
I think you have been brainwashed by the conventional wisdom of the UJM community. What kind of power were UJM 600's putting out 20 years ago? Imagine if HD had kept advancing the engine and chassis as Buell has done just recently.
I know a guy who can deliver a 100RWHP Buell XB9R that meets everything except the EPA noise requirements. It will use a 1050 cc engine. So what? It will be reliable and weigh no more than a stock XB9R. You don't think Buell can figure a way to meet the noise specs? I guarantee you it can be done and done with a reasonable investment of resources. So why would that bike fail to compete with the UJM 600's?
The Japs should be very afraid. Cause if I'm right, Buell could be fixin to rip open a mongo load o'whup-ass. |
Benm2
| | Posted on Thursday, September 12, 2002 - 02:15 pm: |
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Why would a change in head height be required? While there might be a slight change if DOHC to allow for bearings/caps/cam swing, it might be recovered by shorter stems (or by reducing the stroke of the engine & shortening the cylinders). If SOHC, it could be the same as stock. The reduction in valvetrain mass would be the elimination of lifters & pushrods. SOHC isn't as fancy as DOHC, but it should service a few thou rpm higher than pushrods. 2V Ducati heads aren't that tall, and there's all sorts of gizmo's whirring around in there. And, they're air cooled!
If the XR750 isn't production viable, then how's it produced? Where there's a will, there's a way. It certainly shouldn't fall under the "risky technology" excuse. The XB has all new cases, etc. The stroke / bore / valvetrain could be adapted into an XB7R. And, what's wrong with the knife & fork that prevents it from servicing high rpm? It's not a bearing limitation, two-stoke GP bikes seem able to spin 15,000rpm, and old suzuki's had roller-bearing cranks. If the load's higher at higher rpm, then increase the bearing diameter. The "big end" of the rod would be heavier, but it shouldn't prevent it from being possible. |
Blastin
| | Posted on Thursday, September 12, 2002 - 03:33 pm: |
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______________________________________________
"Cause if I'm right, Buell could be fixin to rip open a mongo load o'whup-ass."
______________________________________________
Yeeaahhh Baby!!!!!  |
Djkaplan
| | Posted on Thursday, September 12, 2002 - 03:36 pm: |
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The XR750 is essentially a handbuilt engine. It was not designed with any thought of production. The Company didn't have to look too long to see that this engine wasn't viable as a street engine. That's why they decided to use the XL engine as a starting point for the XR1000 Sportster (this is not my presumption).
If the knife and fork rod arrangement were viable for high rpm it would be used right now for that application. If the big end gets bigger to handle higher loads, the vibration goes up. If the vibration goes up, the cases have to get heavier. If the engines heavier, the frame has to get stronger - it goes on and on.
"So why would that bike fail to compete with the UJM 600's?"
Is it really competing if you need an extra 450cc's to be competitive?
I would rather see a 1000cc Buell on equal ground with an RC51 or 999 Ducati. |
Blake
| | Posted on Thursday, September 12, 2002 - 04:53 pm: |
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"Is it really competing if you need an extra 450cc's to be competitive?"
Turn that around... Are the UJM's really competing if they need four cylinders, each with four valves, overhead cams, 12.5:1 CR, a radiator, and ram air, and ... ? See my point?
I don't understand the hangup wrt engine displacement being the governing factor for comparing performance. I guess it's the simplest to understand. But in my opinion, it is very short sighted and unfair to do so. |
X1glider
| | Posted on Thursday, September 12, 2002 - 05:46 pm: |
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That's a very good point Blake.
If classes were separated into HP and weight limits, ie 100-115 HP and no less than 380 lbs wet, instead of by design types, then the classes would be pretty fair. It's really difficult for a race org to be fair when you have so many different makes and models that change constantly to consider. As long as the end result is achieved, who cares how you get there? Why should cc, # of valves, # of cyl, OHV/pushrod, air/water be the deciding factor of who can compete in a certain class? But the local orgs do try even if the national ones don't. This is where I think racing fails in what they are all about.
Is it really necessary to win a race with a 225 HP V-5 that spins 18000 rpm? Why not win the race at 9000 rpm and just boost the torque and use more realistic gearing? If I heard correctly at one time in my early years, racing is a good way to test technology so it can filter down to us mere mortals. Who the hell wants to ride a bike at 18000 rpm?!?!? Naturally winning was always the #1 reason, but it really got out of hand somewhere. Especially in the 4 wheeled world. C'mon, 30 guys with a computer each that can change every part on the car's performance depending on where it is on the track?! That's not racing. That's like saying the bike won the Tour de France when it was really Lance Armstrong who pedaled the thing.
But I think rice manufacturers actually design their bikes(concerning the above details) with the ever changing race org rules in mind. The fact that they are also legal for street use seems to be an advantageous side effect since they can sell them to the public. Buell never has looked at it that way. They build bikes for riders, not repli-riders. Is your topic opener a hint that this is going to change? |
Blake
| | Posted on Thursday, September 12, 2002 - 07:09 pm: |
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I dunno. I doubt it though. |
Benm2
| | Posted on Friday, September 13, 2002 - 11:07 am: |
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Knife & fork: Just because there's a better way, doesn't mean its not viable. It just means there's an easier way.
XR750 / hand built: Weren't some of the first Buell engines hand built?
Displacement: The current theory is use in WSB regarding displacement limits is based on a "theoretical" piston speed limit of 5000fpm (from Kevin Cameron's book, not me). The theory was that a 1000cc twin would be able to pump as much air as a 750 four due to the "speed limit" the piston could reach. IMHO, the reason that 750 fours aren't competitive in WSB is because Ducati pushed the envelope of piston speed beyond where the current 750 fours are (except the R7, which spins pretty fast from a short-stoke motor). The new Ducati (998R, 999) is shorter stroke than the 916-based motor it replaces, such that higher RPM could be reached, thus pumping more air for a given displacement limit. The result is more power. I think the 1000's have a bit more of an advantage not from the displacement, but from the fact the valvetrain can go slower, so they don't run into valve float situations. And, the twins seem to produce the power more "linearly", whatever that means.
Just the same, Honda's V-5 is neat technology. I personally am a fan of the GP shift to four stroke, but I like WSB better, for the exact reason that the bikes need to start off as street bike based. It seems I'm not alone, because the FIM GP rules were changed to 990cc four strokes because WSB racers were just as fast (or faster on some tracks), which was too much to bear for the "ultimate" class rulers. I'll rarely watch the GP's (there goes Rossi again...), but I won't miss a WSB round. The last two races were AMAZING. Bayliss must be kicking himself. Wouldn't it be cool, though, if Colin was riding a Buell????? (trying to stay on topic) |
Elvis
| | Posted on Friday, September 13, 2002 - 11:54 am: |
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Can anyone comment on how much the push-rod design limits RPM? Could the same basic engine revolve much faster and produce much more power with a better valve system, or would additional, more complex design elements need to be incorporated? |
X1glider
| | Posted on Friday, September 13, 2002 - 12:10 pm: |
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I'm not sure that the pushrod is a hinderance. Valve float is the issue when it comes to more rpms. Heavier springs would cure that. The problem really would then be more drivetrain weight because all the related parts need to be made stronger to overcome the extra spring pressure. If anything is the problem, it would be, as mentioned earlier, piston speed.
But for valvetrain, I really like the desmodromic system, since the cams open and close the valves instead of relying on spring pressure. I'm told it is a noisier system though and also expensive to adjust for some reason. I can't imagine why anyone with a bit of mechanical aptitude couldn't do it himself. But I like the noise. It lets me know that everything is working properly. |
Mikep
| | Posted on Friday, September 13, 2002 - 01:16 pm: |
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Blake,
"I know a guy who can deliver a 100RWHP Buell XB9R that meets everything except the EPA noise requirements. It will use a 1050 cc engine."
Please list me the parts to make up this 100rwhp xb motor, along with the prices, along with the dyno chart. :o)
mikep |
Torqd
| | Posted on Friday, September 13, 2002 - 02:09 pm: |
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If someone doesn't pony up and be the first firebolt owner to give Brian Nallin a call and give him the opportunity to do it... we will never find out. Years ago I was the first (or one of the first) buell owners to post 100hp out of a buell here on Badweb. Brian Nallin made it happen. He told me that he could do it and he did...I know that if he says that he can get 100 hp out of a firebolt he will! I talk to Brian on a daily basis and from what he says his stage three engine kit and the buell race kit will get you 100 hp and 80 ft lbs... Like I said Brian can make some power... if you want to see a killer dyno look in the dyno section and look at my latest sheet 131hp and 107ft/lbs. Good luck and have fun on the new bolts guys!
Nallin Racing Stage 3 Engine Kit- Complete - $2,125.11
95-100+ rwhp/ 80-85 lb/ft tq
Nallin Racing Stg. 3 Cylinder Heads (Exchange)
Nallin Racing 1050cc Bolt-On Big Bore Kit
Complete TE Gasket Set
Race Kit...$619 |
Djkaplan
| | Posted on Friday, September 13, 2002 - 02:09 pm: |
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Quote:
"I'm not sure that the pushrod is a hinderance. Valve float is the issue when it comes to more rpms."
Pushrods indeed hinder rpm for the very reason you indicate; they have a direct influence on valve float.
The valvespring is doing more than just closing the valve in a pushrod operated valvetrain. It's also pushing the rocker and, in turn, the pushrod and lifter back down the cam lobe. All this mass adds up. The valvespring will eventually reach a point where it can no longer seat the valve and force the pushrod and lifter back down as rpm's increase.
OHC engines reach stratospheric rpm's by eliminating all this hardware. Usually the only related components are a shim and bucket (desmos not included!). |
Blake
| | Posted on Friday, September 13, 2002 - 03:08 pm: |
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MikeP,
Like Torqd said...
Nallin 1050 kit
Stage-3 Headwork
Cams (not sure of the grind)
Race module
Race intake
Nallin Signature Series Force exhaust
Sorry, I don't have a Dyno chart.
Why the difficulty in believing 100+RWHP from a 1050cc XB9R when we know of Blast 515cc engines putting down 50+RWHP?
Of course the race module would violate EPA emissions. The stock module could of course be made to achieve the same peak HP with a significant hit to low and mid range performance.
Elvis,
If you want to see the limits of pushrod engine technology, a good place to look is the NASCAR Winston Cup where the engines can turn up to 9 grand and are putting out 2HP/CI. They do this reliably for 500 sometimes 600 miles at WOT for most of the race. |
Benm2
| | Posted on Friday, September 13, 2002 - 03:26 pm: |
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Also, you need to start being concerned about the pushrod buckling at higher loads. |
X1glider
| | Posted on Friday, September 13, 2002 - 03:39 pm: |
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I agree that the lifters would be a problem too. And the mass does make a difference. But even OHV arrangements have the issue of pumping up and bleeding down. Better lifters or solids might help. I've heard that the lifters in NASCAR are pneumatic and not hydraulic. Maybe this is the answer.
Blake, maybe some are worried that the XB FI won't do Brians work justice. Or the cash isn't available. Probably more like the 2nd issue. Even so, Dave G isn't complaining about the power. |
Djkaplan
| | Posted on Friday, September 13, 2002 - 03:55 pm: |
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Don't forget the Ilmor-Mercedes engine from the 1994 Indianapolis 500. That also was a pushrod engine.
It won the big race that year with Little Al and Penske. |
Benm2
| | Posted on Friday, September 13, 2002 - 04:01 pm: |
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NASCAR engines also use rockers to transmit from the pushrods via small rockers that transmit via bending, whereas the harley uses a big, long, torsion unit. Solids are a concern regarding cylinder growth; a tight clearance on a cold engine might grow .040" as the cylinder expands. That would lead to impact loads being transmitted to the lifters as the cam slams into it. Titanium hydraulic lifters would be neat, though. Also, what would be the impact of using low-lift cams with higher-ratio rockers? The net mass being moved would be lower, so presumably the float limit could be raised accordingly. The rocker would need a strong arm, but a long, roller rocker with a low-lift / longer duration cam might allow enough reduction in pushrod/lifter motion to allow the revs. Just an idea, wasting time.... |
Benm2
| | Posted on Friday, September 13, 2002 - 04:04 pm: |
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DJK: I looked (briefly) for some info on that motor to post in this very topic, but I couldn't find any reference to what RPM they spun it to. I think it was made mostly to take advantage of boost / displacement rules originally written to allow older engines to be competitive. I bet there's some neat lessons in it nonetheless, and I also imagine Erik & co. know a few more of the details regarding it. |
Djkaplan
| | Posted on Friday, September 13, 2002 - 04:04 pm: |
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Just a letting my mind wander about this.
The Sportster engine would be a perfect candidate for a computer controlled servo valve actuation.
No cams, no pushrods, no valvsprings - no valve float. Just an endless variety of lift and duration for any situation.
Could Erik and the Company pull this off? |
X1glider
| | Posted on Friday, September 13, 2002 - 04:09 pm: |
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"wasting time..." Aren't we all? I love getting paid while surfing the net. |
Djkaplan
| | Posted on Friday, September 13, 2002 - 04:15 pm: |
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Benm2,
This free thought is good for us all!
The ideas are great and not a waste of time in my opinion. Plus, this is fun and what the board should be about. I've learned plenty around here and intend to keep my mind open.
The Ilmor pushrod engine was good for 9800 rpm, not really that much higher than NASCAR engine builders get with the Detroit "cooking" engines.
http://www.ilmor.co.uk/index1.html
Drag racers can get really high rpm out of these engines (but not for too long!). |
Elvis
| | Posted on Friday, September 13, 2002 - 04:53 pm: |
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I agree 100% Djkaplan. I think I've learned more useful information about push-rod engines in the 5 minutes reading these responses than I have anywhere else I can think of.
This gives me a much better idea of the limitations of the current design and allows me to think about what the next engine (2, 5, 10 years from now) might look like.
I love the idea of computer controlled valves, but I've been under the impression current servo technology isn't yet advanced enough to make this realistic. Does anyone know of real world examples of this technology that is currently in place? |
Xgecko
| | Posted on Friday, September 13, 2002 - 05:33 pm: |
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What is Honda using in the VTEC VFR? |
X1glider
| | Posted on Friday, September 13, 2002 - 05:48 pm: |
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Keeping the actuators from burning up has been the problem. The last I ever heard about this was at least 8 years ago, so I don't know if it has been given up on. I don't recall who it was either, read about it in Scientific American mag. I don't know if they ever played with the idea of only opening the valves partially too. 100% cylinder fill isn't necessary all the time, WFO, yes, but not on the open, flat highway. 40% maybe to keep it going. I can see a 500 mile range on a tank with that concept. Nevertheless, it's something I've been waiting on ever since I read about it.
The VTEC VFR uses a mechanical link to disconnect 1 intake and 1 exhaust valve per cylinder at lower rpms. |
Blake
| | Posted on Saturday, September 14, 2002 - 01:38 am: |
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As I understand it, the inertial loads governing valve float on pushrod engines are on the valve/spring side of the rockers, not the pushrod side. This is due to the rocker arm ratio resulting in more actuation than the pushrods see from the cams. |
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