| Author | Message | ||
     Chickenhauler |
dont want to buy another bike right now. and im thinking about getting a 1200 motor and punching it to 1400.is there any diffarces besides computers to contend with?looking to get the motor from a donor...junkyard. | ||
| Buell666 |
why dont you just get nallin heads for your bike? you can get a 1200cc big bore kit for your engine for $1195.00. you should check it out. im sure it would be cheaper than buying a motor. | ||
| Wyckedflesh |
Your looking at about $3000 right now for an XB engine out of the boneyard. You would be better off just getting the 3 13/16" bore kit and putting that on your 9. This way you keep the redline and still get plenty of power. | ||
| Reepicheep |
As Aaron Wilson surmised about two days after the 12's were announced, The short stroke 9 punched out to a 1250 (I think)is reasonably economical and will do much better then a 12 would anyway. The long stroke 12 has great economy, and great low end power, but will be beat soundly on the top end by a bigger bore 9->1250. Because it has a shorter stroke, it can rev higher. A lot of the Buell race bikes are taking this approach, and the short stroke 1250's were making more power then the long stroke 1350's (as I recall). | ||
| BadS1 |
Reep???   | ||
| Bud |
my 9 to 12 ( 1160 cc ) nothing fancy, stock cam's 97hp/126 Nm on the rearwheel faster than a kitted 12  | ||
| Reepicheep |
Sorry, that does sound pretty confusing. Let me try an oversimplification, no doubt people will correct me where I go wrong. Every "bang" of a cylinder produces X amount of power. The more bangs you have, the more power you make, period. Another way of saying "more bangs" is saying "more RPM". You can also make each individual "bang" more powerful by making it bigger. You can do this by making the cylinder wider (oversquare short stroke) or by making the cylinder longer (long stroke). To make the cylinder wider, you just bolt on a new wider cylinder jug and insert a wider piston on the existing crank. To make the cylinder longer, you also have to change the crank, so that the piston then uses the new extra length of the cylinder. The XB9 uses a short stroke crank. The XB12 uses a long stroke crank. The current limiting factor on how fast our engines can rev and not self destruct is the speed of the piston relative to the cylinder wall. This has (I believe) to do with film strengths of lubricants, and other stuff, that people a lot smarter then me understand. So you can change an XB12 (1200 cc engine) into a 1350cc engine by putting wider piston / cylinder on it, but it is still long stroke, and will still only safely rev to 6500 (or whatever, I forget). You can change an XB9 (984cc engine) into a 1350 cc engine by putting an EVEN WIDER piston / cylinder on it, and it is still a short stroke, and will still safely rev to 7500 (or whatever). So when your XB12 crank 1350cc engine has to shift, your XB9 crank 1350cc engine will still be able to "bang faster" for an additional 1000 RPM or so before you have to shift, making an additional 15% horsepower. So given equal final displacements, the 9 based engine will give more power then the 12 based engine. The 12 based engine would have better low end torque though, and would get better fuel economy. Let the corrections begin | ||
| Rubdoggy |
not a correction but a question, i am looking towards making my 9r into a 12r. a buell dealer told me there was a conversion kit for the 9s but not the 9r. that it had to do with the fly wheel, they could piece together the kit. they didn't seem real eager to do it. they might have been busy when i called... can anyone explain the difference between the 9s drive train? just the fly wheel? not at all? i dunno. | ||
| Buell666 |
they seem like they have no clue wtf they are talking about. anything that can be done to an r's motor can be done to an s' motor. the only differences between the two bikes is the body work and seats. everything mechanical is the exact same. the biggest difference is the stroke. the 9 has a short stroke which makes for higher revs. the 12 has a long stroke which makes for not so high revs. your best bet would be to talk to a different dealer that knows what they are talking about, or talk to a speed shop. | ||
| Rubdoggy |
that's what i thought mr devil buell  . if ya can't trust your "not even local" buell dealer... THX | ||
| Joele |
The 1050 kit looked good because no case modification was needed - but what kind of power does it make and does an after-market ECM need to be installed as well? Of course, if you don't mind shipping them your case, the 1250 kit looks like the best option overall - but again, what kind of power would be expected? | ||
| Blake |
Buell666, "why dont you just get nallin heads for your bike? You can get a 1200cc big bore kit for your engine for $1195.00. You should check it out. I'm sure it would be cheaper than buying a motor." Even better, the 1170cc XB9 Monster Big Bore kit from Revolution Performance can be had for just $999.95. Bill, I'm not sure that the Buell short stroke racing machines use the stock XB9 stroke; pretty sure in fact that they do not. Pretty sure it is a bit more stroke than 3.125". Currently we cannot get more than 1170cc from an XB9 engine/crank, even with case boring (3-13/16" bore). At best, it is an exaggeration to characterize such a big bore kit as being "1200cc". Not sure why some vendors exagerate the specs like that. No way you will ever come close to 1250cc let alone 1350cc in an stock stroke XB9 engine. Currently the best one can do is to increase bore to 3-13/16" for a total displacement of right at 1170cc (80 CI). I've yet to see any information about an XB9 with the 1170cc (80CI) big bore conversion that has made anything significantly more than or even equal to what a stock XB12 with head-work, exhaust mods, and EFI augmentation has achieved. The stock rev limit on the 1200cc Buells has been 6,800 rpm since 1996 when the S1 hit the street. In performance form (like with high performance pistons and cylinders from Cycle-Rama or Revolution Performance or Hillbilly-Motors-Motors Motors), they can run reliably to 7,000 rpm no problem. Though I agree with the principle that greater rev capability should be an advantage for peak HP, it just hasn't come to pass that I've seen. Remember, both versions use the same exact valve-train. Consider also the limitations of trying to fill the same volume combustion chamber using the same cams and valves but in a shorter amount of time. Volumetric efficiency may be expected to suffer. It might be a mistake to assume that the weakest link in the chain is engine rev limit. Joel, I would suggest that you call the folks at Cycle-Rama or Revolution Performance and ask them what they are willing to promise in the way of engine performance if you send them your engine and your money. (Message edited by blake on July 05, 2005) | ||
| Rubdoggy |
the Revolution Performance website looks like car performance only. is the link bad???????? | ||
| Johnk3 |
www.revperf.com | ||
| Kowpow225 |
Chickenhauler, I know a guy who put the 12 internals (and some externals) on his 9. He swapped to 12 crank, rods, pistons, ecm, and throttle body. He still used the 9 header though. You might find that funny, but he had a much better low and midrange than a stock 12 on the dynosheet I saw. He did give up some on the top though probably because those smaller headers were choking it off. Something to consider... but still into the $1500 price tag. (Message edited by kowpow225 on July 04, 2005) | ||
| Wyckedflesh |
You can go with a full 4inch bore, but its recommended for a race engine only as the cylinders are getting mighty thin at that point. That puts the motor at 1287cc when you do the math with the 3.125 inch stroke of the XB9 motor. I won't make guesses about what stroke the FX race Buells are running nor will I guess at what other things have been done to let them rev as high as they do. | ||
| Chickenhauler |
from the dyno charts ive seen.the 1200 makes more power.if the motor will fit,was thinking about getting one of the bigger kits.1400cc. atleast thats what they claim... and still pay a cheaper insurance rate lol.i know it will be expensive but i hope cheaper than buying a new bike .  | ||
| Wyckedflesh |
Not sure which dynos your looking at, but all the ones I have seen for the 3 13/16inch (3.8125) bore kit with an XB9 stock crank makes more HP then the 1200, more horsepower then the slip in 1250 kit for the XB12. I cannot comment on a 12 with the 3 13/16inch kit because I have not seen a dyno, but when you figure 1000rpm lower redline, I can't see the amount being a big difference.And how you figure you will pay a lower insurance rate over a larger displacement engine makes me wonder. | ||
| Blake |
Where do you get a 1000 rpm lower redline??? Rev limit of a stock XB12 is 6,800 rpm, 700 rpm lower than the 7,500 rpm rev limit of the XB9. I've seen a number of stock displacement 1203cc Buells make at or even well over 120 SAE rwhp. Haven't seen anything close to that for an 1179cc version of an XB9. Doesn't make sense, but that's what I've observed. Teh reason? My theory is that the high performance market is still ramping up for the X-bikes. | ||
| Blake |
Rubdoggy, My bad. Geesh. Thanks Johnk3! | ||
| Martin |
There was a good article recently in 'Hot Rod' where they built identical motors apart from the bore and stroke and the big bore motor made the same torque as the stroker. The conclusion was that optimising the whole package to reach a particular outcome was the key and not just one aspect of the architecture. If bored XB motors are underperforming vs 'old' 1200s something other than the capacity is holding them back, but I understood that the heads and cams were 'better' so what gives? | ||
| Wyckedflesh |
Where do you get a 1000 rpm lower redline??? Rev limit of a stock XB12 is 6,800 rpm, 700 rpm lower than the 7,500 rpm rev limit of the XB9. Because my soft limiter hits just about 6500rpm, and is already killing power by the time the hardlimiter hits at 6800. Yet on the 9 I had, when it hit the soft limiter, the power didn't waver as much til the hard limiter hit. Haven't seen anything close to that for an 1179cc version of an XB9. The question here was about installing an XB12 motor which stock puts out 94rwhp average, or building an XB9. If you want to pay for the cost of the 12 motor, then throw in the cost of the upgrades, that is a different question. But simply taking an 9 motor, adding in the bigbore WITHOUT headwork, changing to a 12 intake and injectors, the dyno comes out around 110rwhp. Going on the AVERAGE price of XB engines on Ebay, you would still have about $500 left roughly if someone else puts it together, if you can do it yourself, your looking at about $750-$1000 left over to play with. As I said earlier, the AVERAGE price of a used XB engine is between $3000-$3500. There are some out there that will fetch a lower price. If you can find one cool, that means you have more money to play with. If bored XB motors are underperforming vs 'old' 1200s something other than the capacity is holding them back, but I understood that the heads and cams were 'better' so what gives? The problem is in the fuel supply of the XB's, we just really don't have a programable ECM that can be made to optimize the fuel delivery to give us the top performance of the motor. I think even the race ECM that joe average can buy is not up to the task of coping with the fuel demands that a hopped up XB engine calls for. I think that just a stock XB9 or XB12 with a tuned to within an inch of its life emissions be damned ECM, high flow exhaust, and a good, proven intake like the F.A.S.T system would be a godsend. I honestly beleive that alone would make a good 20% increase in power. Add cams and headwork and you can add another 10% for each level of the headwork. Bigbore it out to 1170 with stage 3 heads and I could see an XB9 engine putting down hitting a RELIABLE 120rwhp on the low side, 135rwhp on the high side for a very tight motor. Our engines are built for performance AND the ability to beat the Emission system in their raw form. The tuning we do with TFI's, exhausts, filters and such is just making ourselves happy. The gains are minimul at best. Look at the thunderbikes that had to meet the HP/Weight requirements, how many of them were over 100RWHP last year? I think the performance is there, its just up to US to tap it with something that isn't being offered to us yet. A computer that we can tune ourselves. We will see down the road what comes up. I have ideas I want to work out, but $$$ is not there for me at the moment. But if I didn't have to worry about emissions, and don't think that the "raceECM" that joe average can buy doesn't have programming to keep it close to emissions, its shown with what small amount of gain it gives, but its still just a blanket tunign program, it can't be totally tailered to the engine. If you could adjust the spark for each individual cylinder for optimum ignition and burn, to go along with the optimum fuel mix then what works on one bike wouldn't transfer over to another, so instead you make a blanket upgrade that tosses in a little more fuel and a little hotter spark across the board. It gives us a feel for a little more, but its not enough to give us what we want. We just don't have an aftermarket package together yet for the XB engine to really make it shine the way it can. There is ALOT of performance left in our machines just waiting for the right tools to tap it. | ||
| Steveshakeshaft |
If you really want to play seriously with EFI, then the device you need is a "MegaSquirt". Very low cost, very capable, fully opensource EFI controller. It will do whatever you want it to do and that includes toasting your motor! Just do a Google search for it. Good luck. Steve www.shs-consulting.co.uk | ||
| Benm2 |
I suspect you can make about as much power as you want with either the 9 or 12 crank. The Buell factory FX bikes are around 135, I think, or more. If I remember right from the article (cycle?) they have two motors, one with a short stroke & one with a longer one. The long stroke motor DID make more power, but it was also larger displacement. The short stroke motor will have lower piston speed & will allow a higher redline based solely on piston speed. However, bigger bores (in either short or long stroke) increase piston area which increases combustion loading on the crank directly. All that bs means is that you need to decide how much power you want, and which configuration seems more interesting to you. You can probably get a 9 motor to make between 90 & 100 hp without violating the bottom end. Stage 2 heads, 536 or 585 cams, maybe the 12 header & race kit exhaust, and of course EFI work would probably do it, and you'd never even have to take the motor off the bike. Blake's bike is a really good example of the "top end only" rebuild. With not an awful lot of investment (and not on an XB motor), his bike is near 105hp I think. I imagine that same level of work on the 9 platform should get you results in the same neighborhood. | ||
| Spike |
Wycked- Where are you getting your information about the soft limiter on the XB12s? Everything I have read has claimed that the soft limiter was at 6200rpm and didn't kick in until the engine had been held above that RPM for a certain period of time. I was under the impression that under normal acceleration the only limiter that would have any effect would be the hard limiter at 6800rpm. | ||
| Wyckedflesh |
Because my soft limiter hits just about 6500rpm That is where I get my info, it shows up real well on the 2 dyno runs I had done of the bike on 2 seperate dynos. You can feel the soft limiter start the stutter, then BAMM the hard limiter hits, you get just enough warning to pull in the clutch to shift on MY bike. If its a glitch in the ECM none of the techs have said anything about it. | ||
| M1combat |
The proper crank will bring the piston speed to the desired level at ~8500 RPM (I'd go for 8K RPM so I have a little more power while getting there and I'm never going to use the last 500 for anything but over-rev anyway). You CAN get custom cranks you know... To get there though, you will NEED to machine the cases for Timken bearings. I hear the stock case/bearing combo is only good for about 120ft/lbs before it does some wonky stuff and then goes kaboom. In any case, I still think we'll see an XB1350 this year. It'll have a stroke length in between the nine and twelve with a large bore... MAYBE more than 45 degrees and almost certainly dual throats... I think we'll see about 120HP... Just my opinion  . They refined the "S" last year right... I think we'll see a refinement to the "R" this year . | ||
| Silversurfer05 |
1350 MMMM..... Sounds like a Buell race bike. | ||
| Chickenhauler |
so far ive done the 12 lid,kn,and d&d.also desnorkeled it tfi.but its not what i want it to be. just dont want to spend a couple of grand and still be unhappy with it.if i do anything else going all the way.no half measures.i love what the the bike does handling wise.just want it to be able to crush ducs and the 51.so anythiny besides computer and sprokets would need to be changed?  | ||
| Blake |
"But simply taking an 9 motor, adding in the bigbore WITHOUT headwork, changing to a 12 intake and injectors, the dyno comes out around 110rwhp." Where do you get that information? I have seen no evidence that would support it. I would be very surprised to see any XB9 upgraded to 1170cc, without headwork or exhaust modifications make more than 100 SAE rwhp. I certainly wouldn't mind being proved wrong on the point though. Not sure, but I can one not purchase a brand new XB12 Buell engine for around $3,500 or not too much more. Can one not purchase an entire crashed XB for about that? On ebay the sell price is often a lot different/less than asking price. I suspect that you may be right about your bike, if you perceive that your bike is hitting a soft limiter at 6,500 rpm in a dyno run, something is probably amiss. I don't recall seeing any evidence of that type of behavior in any of the XB12 dyno charts posted on BadWeB. BTW, you can drop an XB12 crankshaft into an XB9 and go to an 88" or even 90" (1475cc) with a monster big bore kit. If you are going to the trouble to split and machine the cases in order to bump an XB9 up to 1170cc, why not go one step further for the mere cost of a new crankshaft? You have a lot of enthusiastic opinion on the issue. Give me some hard facts to support that opinion and you'll make me a believer. |
