| Author | Message | ||
     Xl1200r |
I'm looking at finally doing the engine in my XB12R as a winter project - my problem is I don't know what I should do. This is going to be a total street motor, but I want a monster none-the-less. I also want reliability and drivability. Here are the options I've come up with: Option 1: Just do heads and cams. Option 2: Heads and cams with an 3 13/16" bore kit. Does anyone know how much more power those extra cubes will make over the stock bore with upgraded heads and cams? Option 3: Heads and cams with a 3 13/16" bore and the shorter stroke form the XB9 engine. I originally thought the shorter stroke engine would be neat, but I want to get as much usable power as I can, and make it everywhere. I was drawn by the higher redline, but in reality I don't spend much time over 5k as it is (though I want to FEEL it when I do touch the top of the revs). Any thoughts? | ||
| Freezerburn |
Option 1 - you will probably experience most dramatic gain in the upper RPM range(where you state you spend least of your time). Option 2 - power improvement everywhere, and most torque of your choices Option 3 - power everywhere but more rev Build to what you want and match your mods! What are you going to do with regards to fuel, cams, air and pipe? Good luck. | ||
| Xl1200r |
As far as your questions... Fuel - this all needs to run on pump gas, so the compression ratio needs to stay sane (about 10.5:1 is reasonable). Pipe - I already have a spec ops pipe and I really like it. If it proves to begin to limit things, I woudln't be opposed to getting a Micron or something. Air - I'm already running an open airbox with a K&N filter. Cams - not really sure. I want the most aggressive I can get and still have somethng I could live with everyday. something like a Redshift 585 or 643, or a Revolution Performance 610. I'm thinking more and more than keeping my stock crank and going with the big bore is going to keep me the most happy. While I've never felt like I needed more revs, I have hit the limiter from time to time when winding it out. | ||
| Freezerburn |
Since you mentioned Revolution Performance, you should consider dropping them a note as they could really set you up with your big bore kit, cam selection and headwork. Then you need to address your fuel management i.e. ECM etc. If the mods aren't too wild, Direct Link and a dyno tune would probably get you to a happy place. You might also want to talk to Al at American Sport Bike and see what they have maps for and do a similar build. PS - If I could go back in time, I would have got a 9 and done the big bore kit. | ||
| Xl1200r |
I already have DL, but I'll drop Al a note and see what he has (if anything) for big-bore maps. PS - If I could go back in time, I would have got a 9 and done the big bore kit. Are you saying you'd rather have the shorter stroke? | ||
| Slaughter |
I am a real advocate of the big bore/short stroke motor. 585 cams, stage 3 heads. If you have already thrashed your engine and are considering a new crank anyways, it's a great mod. You can PM me and I'll fill you in on the details. Keep the compression ratios at 10.5 to 1 and she'll run pump gas. You're going to want to mess with the fuel injection on a dyno regardless of how you do your engine UNLESS you get a map from somebody with EXACTLY the same configuration - BUT I'd still recommend a couple dyno pulls just to make sure you're not too lean anywhere (pretty common with more volume or RPM) Gotta run... end of the work day (shhhhh... abusing computer priveleges) | ||
| Xl1200r |
Slaughter - sent you a PM. Just to keep the info in this thread good - what heads do you have? NRHS? You have any dyno sheets for your motor? I'd be interested to see the shape of the curve. | ||
| Xb9 |
PM Sent, check the classifieds: http://www.badweatherbikers.com/cgibin/discus/show .cgi?tpc=21&post=1006567#POST1006567 | ||
| Slaughter |
Geeezis Xb9 - that's a pretty sweet motor - why you selling? I just got a line on an XB that has a thrashed motor (I need everything BUT the motor internals to fix the racebike) or I'd be all over that. | ||
| Cochise |
A cost effective, easy fix would be a balancing of the motor. (Message edited by cochise on November 27, 2007) | ||
| Freezerburn |
Are you saying you would rather have the shorter stroke? Well I have at times found the longer stroke of my stock unit a bit cumbersome.. Oh wait, longer stroke means shorter rods...How does that work??? Argh."That's a fargin trick question! | ||
| Jetrider802 |
XL1200R, I don't know if you have seen the classifieds, but we have a motor for sale listed there that will solve all your problems. Take a look at it. That will be the cheapest way to go and will work great for you. The motor configuration has been proven drivable and ridable in race applications. If you have any questions give us a call, 401.596.9507, I'd be happy to help you out. http://www.badweatherbikers.com/buell/messages/21/ 319202.html?1195329174 You could also check out our website, http://www.jetroadracing.com should you choose to go in another direction. Talk to you soon. Robert Johnson #802 | ||
| Xb9 |
Slaughter, Only reason I'm selling it is I got the 1125r disease - too many 1125r demo rides on the track. I know I'm going to kick myself for selling it.....then again if I don't find a buyer I'll just keep it and wait a couple of years on the r. It can only get better, right?  | ||
| Treadmarks |
I just put together a package on my XB12X. I selected items for killer midrange and to help it wind up. 1250 big bore kit with forged hurricane pistons and stage 1 head porting from NRHS. Kept stock cams. Full micron system, ceramic coated. American Sport Bike open air kit and matching ecm map for this combo. No dyno time was required and my grin is so big I think I'm getting lockjaw. | ||
| Budc |
Hey xl1200r I thought I would chime in here a bit. Hal's Speed Shop is the place for what you are looking for. We have several "street-able" packages that can yield you around 106hp without doing a 1250 kit and they still use "pump gas". PM me and I can get you some details. Thanks, BudC |
