| Author | Message | ||
     José_Quiñones |
Thunderbolt, That quote is from a Don Tilley interview in Cycle World's Power& Performance Harley-Davidson magazine currently in newstands or at places like Barnes & Noble and Borders. Really packed with information, it's like a Battle2win for HD's. | ||
| Vr1203 |
Here's a question. Why are the late model Sportster, dual plug, high comp. single fire ign. engines rated so poorly. Any Buell is rated higher. Why is that? I was told it was because of the crankshaft weight diff. The Buell is rubber mounted and can take higher vibs. So they are wound tighter to get higher rated HP's. | ||
| Blake |
Intake, exhaust, heads, pistons. Buell designs are WAY superior. | ||
| Schemky |
Vr1203, Blakes correct, H-D "has" to equip the Sportster Sport with the H-D "proper" exhaust, intake, etc. and they do not use the superior Buell Thunderstorm heads. With H-D, style is paramount, with Buell, extracting the maximum performance from the little Evo motor and outstanding handling puts the Buell way ahead of the Sportster. I have two friends that bought Sportsters this fall, and they both complain of ecessive vibration on the highway. Why don't they rubber mount?? My Buell will decimate these Sportsters in any kind of roll-on. I have to nearly stop on the side of the road and wait when the going gets curvy. And just think, the lucky Sportster owner gets to pay more for all these benefits!! I really like the looks of the Sportster Sport, I REALLY LIKE IT, I even entended to buy one in 99. After I told the salesman how I ride, he said, forget the Sportster, lets look at this Buell over here. . . . . | ||
| Vr1203 |
Schemky, So if a person was to forget about the styling and install a good exhaust and a carb would the Sport still be down on power until you transplanted a Buell motor? | ||
| José_Quiñones |
VR1203, No need to change the Carb, M2's get along fine with the stock one. The biggest difference between Sportsters and Buells can be summarized in one word: VOLUME As in the size of the airbox and the exhaust as compared with the Sportster. Buell's airbox and muffler may be ugly, but they let the engine pump air in and out of it a lot better, especially at high rpm, than a sportster. You can make a sportster make as much HP as a Buell, but you then would have to spend a lot of $$$ to make it handle the extra power (tires/suspension/brakes), and it would shake your eyeballs so bad you couldn't ride it. It's cheaper to buy an M2. José 98 XL1200S 99 S3T | ||
| Schemky |
Vr1203, I can't speak from experience, BUT, if you installed the Buell heads, Buell exhaust, and fitted a good intake like the Force Sidewinder, I don't see how the Sportster couldn't help but be competitive with the Buell. I have heard that H-D dropped the Screamin' Eagle heads for the 1203. They are now using the Thunderstorms for "off-road" applications. | ||
| Blake |
You'd need the heads and pistons. The stock carb is okay with a high flow filter like K&N. | ||
| Aaron |
I've had an ongoing debate with some of the Sportster list guys over the whole Buell/Sportster hp thing. Y'see, we all observed awhile back that Buells seem to make more hp than Sporsters at any given modification level. For example, it's the exceptional Sporty that breaks 100hp, but it's not that unusual with Buells at all. One of the guys claims that Buells have better exhaust systems available. Another claims it's the lighter flywheels. While they were over here in September tuning their LSR bikes, we finally figured it out. One of their bikes was making around 110hp, a little disappointing considering this was a 100" motor. We discovered they had left out the little spacer that sits under the rotor, on the left side of the crank. Since no dealer had one in stock, we pulled one off my wife's S1. Bam, 125hp just like that. So there you have it, it's that little spacer. BTW, when we got done tuning it that bike was making 142.9hp. They set 2 records with it, circa 167mph. I think the heads you're talking about that they dropped are the old SE Lightning heads. The HD p&a catalog that just came out a couple months ago still lists the SE dual plug heads, at $549.95 a pair. They have a couple advantages over t-storms for Sportster guys: appearance that matches Sportster motors (silver finish or black with machined fins), and they net about 9.8:1 compression with the stock pistons. AW | ||
| Jmartz |
Aaron: I briefly spoke about this topic with E Buell back in the summer of '97 when the T-storm motor as well as the Sportster Sport were being introduced. Can't recall his reasoning behind dual plugs but if memory serves right it had something to do with demanding power out of a motor spinning slowly (relatively speaking). He also mentioned that beacuse of the crippling vibraton on Sportsters if you were to put an engine that made power in the upper reaches of the engine's power envelope, such as the Buell, it would be hell to pay for the rider. Jose | ||
| Aaron |
Jose: I can certainly agree with the logic that Sporties ought not rev so high. Even at 4500rpm they can be downright obnoxious. As I understand dual plugging, it's to get around the slow burn/slow pressure rise of a large chamber, especially when that chamber is obstructed by a large dome (i.e. shovel/ironhead). The RR's race motor is dual plugged. You take out a fair amount of timing advance when you do it. AW | ||
| Sybren |
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| Schemky |
Just recieved my new set of Nallin Hurricane pistons, rings, and pins, along with a new set of Andrews N4's. These pistons are without question some of the best finished items I have ever seen. Hat's off for a quality set of pistons, worth the wait. | ||
| Jimidan |
Aaron, I have dual plugs in the STD heads on my 88" modified S1W engine. These heads have a bathtub chamber. We are only using one spark plug to fire it, as the other plug isn't connected to the ignition. The engine runs really well with only one plug. Would there be any advantages to firing the other plug...the guy that built it says not. Jim Daniel | ||
| Ralph |
Jim, I know I'm a big nobody, but what the heck. You don't need the other plug unless you go to an unreal amount of compression. You've got an efficient combustion chamber and evidently, a resonable amount of compression so it just isn't a big deal for you. Remember, Aarons RR has dual plugs because it has a comparitivley crappy combustion chamber with a tall piston dome (I think) to make up for the compression loss in the large chamber of the head. Also, the piston dome acts as a barrier to the flow of combustion, so the second plug gets it started from the other side. But you knew that. bighairyralph | ||
| Aaron |
I agree with Ralph. | ||
| Ralph |
I paid Aaron to say that  bighairyralph | ||
| Jmartz |
You guys are funny... | ||
| Lee |
Has anyone or is anyone planning on doing the Nallin 1250 big bore kit...it's got my curiousity peaking!!! Lee | ||
| Aaron |
Yes. Will post b & a results. | ||
| Jmartz |
Aaron: Do you beleive reports of a Buell Thunderstorm motor producing 115 RWHP with Nallin's 1248 kit, stage 2 heads (porting + larger valves) and SE II .536 cams? Don't know what manifold or carb. Seems a bit high. I thought just under 110 was reasonable. Can't see it happening w/o dual runner heads. jose | ||
| Aaron |
Jose: far be it from me to say that it can or can't be done ... having never tried that specific combination. I'll be using different cams myself. 110 would make me real happy. AW | ||
| Jmartz |
Aaron: Are you building a 1248? | ||
| Aaron |
Well, sorta. I bought the stuff, and even got a set of heads prepared. Then I used half the kit on the Blast. Blew it up when we overrev'ed it. Waiting on replacement parts. Got a few projects to clear out of the way first, but I intend to put the 1250 kit & the heads on the M2 within the next month or two. AW | ||
| Jim_Witt |
Aaron wrote: Got a few projects to clear out of the way first, but I intend to put the 1250 kit & the heads on the M2 within the next month or two. Aaron, It sure would be cool and helpful if you digitally documented the transformation to 1250! Cheers, -JW:>) | ||
| Buelliedan |
Aaron, So were you the tester for the new Blast big Bore kit? I thought you got 650cc out of your combo? Did you stroke it as well? P.S.- Is that a joke about the crank spacer on Sportsters? I could see you making thousands of dollars selling that if thats all it takes to give Sporsters Buell HP numbers. I see folks praising the Nallin Hurricane pistons. can anybody tell me what real world advantage they have over the Thunderstorm pistons? I am thinking about getting a set of Nallins stage II heads and just bolting them up. is there any real gain by going to his Hurricane piston or should I just stick with my T-storms? Dan | ||
| Jmartz |
AAron: You are a good person to test the combo since you have your own dyno which enables you to fine tune a motor and extract every possible bit of power out of it. I am reluctant to accept anything above 110 out of the Y manifolld but I'm sure you will share with us your findings. I waited a lot to modify my motor and now I'm considering the 1250 kit but don't quite know what to do about the parts that are on the bike that allow it to make 100 HP. Wish S&S would get their act together and offer modern integral shaft wheels that allow 3.5 stroke. Then I could bonkers and build that 4 x 3.5, Ti rodded, Shumaker topped monster I've dreaming about for years. Oh yeah, AAC needs to also relase their 4" bore jugs. Jose | ||
| Aaron |
Dan, Yes that was a joke ... but it's a true story! I'll let y'all know what I get out of the 1250 kit, before and after. | ||
| Jimidan |
Aaron, How are they getting 1250 cc out of these bores...thinner cylinder walls? What I.D. do they measure? I would think that strength would be a big factor in how thin they could make the walls without distortion creeping in. What kind of rings came with this kit? I saw in an add that they were Total Seal rings. I hope they are not chromed...plasma or nitride rings work much more reliably in these nic-sil. Don't ask me how I know (but that is why I am using Axtell cylinders now). Jim Daniel | ||
| V2win |
They are 70 oversize. |
