| Author | Message | ||
     Migs16 |
I heard about this today if you put a xb12 crankshaft in a 9 and also put 12 heads and throttle body and you will get all the power of a 12 and some more. has anyone heard of this or done this. The guy i heard it from said it can all be done for about $400 if you get all used parts. sounds like a really good winter project. just let me know thanks | ||
| Strato9r |
Check the KV; plenty of info there on doing this mod. Heads are the same, and you will need the right crank/rod assembly for your particular year. (the 9 and 12 pistons have the same compression distance, 9 rods are longer.) From what I gather, the 9 throttle body, modified for a larger throttle plate is the way to go. You will also need an ECU that has been tweaked, or is programmable to deal with the higher compression ratio that comes with using the 9 pistons with the extra stroke of the 12 crank. | ||
| Natexlh1000 |
I think the connecting rods are different too. I thought the real kick-ass thing to do was overbore the XB9 to 1100 for massive oversquare. Were those found to be unreliable? | ||
| Slaughter |
The over-bored XB9 is (in my perveted mind) - the PERFECT XB. 1169cc and with lightened flywheel and lighter pistons - all balanced, it'll spin up faster. Sweet throttle response. Actually, putting a 2008 flywheel/rods into the older cases means you can get the bigger bottom end bearings PLUS you can take nearly 3 pounds of weight out of the flywheels! Sweet - and it lasts nearly for-freaking-ever. | ||
| Migs16 |
ive heard so many problems with overheating and blowing when you bore any motor out. but i guess from what i heard about the bigger flywheel and heads and throttle body arent the best to then which is kinda a bummer. | ||
| Kdogshirow |
The best way to hop up a XB9 and the most cost effective is the service Nallin Racing has to bore your Cylinders to 1000cc and provide the Pistons and rings ( I think its around $700 ) . It will raise the compression to a true 10.5 to 1 . Most XB9 owners dont realize their compression stock is way below 10 to 1 , close to 9 to 1 . Raising your compression will give you the most bang for your buck . I have talked to racers about this and thats what they say is the best thing to do to a XB9 . You wont give up the higher reving characteristics of the nine with this mod . If you start boring and stroking , why not just get a XB12 ? | ||
| Natexlh1000 |
2008 engines are different. I don't think the parts are interchangeable. | ||
| Migs16 |
ya that was my last resort was just getting a xb12. ill keep looking around and see what i can do. thanks | ||
| Kdogshirow |
I have a 07 XB9 and I like it , but... If I could do it over , I would have got a XB12 for the Grin factor . The bike I had before the XB , was a 00 Buell M2 that I hopped to 1250cc , it was quite a let down to the XB . That being said , The XB9 handles better and is a very nice modern sportbike . But sometimes I miss the raw horsepower of the 1200cc . I hope to do the compression mod this next year . | ||
| Migs16 |
exactly i first started with an m2 which had great power. i didnt bore it out like you did. but i had the mikuni 42 on it and stuff and like you said coming to the xb9 was kinda like lame.. but it is a great bike and with the open airbox and race map and pipe im pretty happy. | ||
| Whitetrashxb |
Eventually I'm hoping to send my 03 9 crank to Hoban Bros so they can lighten it up and beef up the bottom end at the same time. Along with the 1050 kit, i'm hoping for ear-to-ear grim factor with the reliability of an anvil. | ||
| Delta_one |
how big can you go with a 9 and maintain the short stroke before you start pushing the limits of reliability? can 1169 even be reached without stroking it? over square and balanced out for more revs would be sweet, I cant imagine how fun an 1150 XB winding out to 9k rpm would be if mine ever starts to wear out and gets to the point that I need new rings ect. I figure it will be the perfect time to upgrade/build it bigger/crazier | ||
| Slaughter |
1169 IS the short (3 1/8) stroke, overbored out to 3 13/16. You can take the 08 flywheels/rods and put them in the older engine - but it takes machining the cases to accept the bigger bottom end bearings. Starts geting pricey. Darkhorse Crankworks does this mod. It makes a Hell-for-stout motor build. I'd raced my motor almost 150 races before destroying the entire motorcycle/engine in a high-speed get-off. Without lightening the flywheels, you can still use lighter CP Pistons, have the flywheels/pistons balanced and I doubt you'd be able to come up with a longer-lived motor. | ||
| Xoptimizedrsx |
what Slaughter said; That's what I was told to do as well by the great Buell man. Henry Duga. Henery said; "to use the xb9 run a lightened crank and go to the 3 13/16 bore. open the exhaust port some on the race and leave the port alone besides cleaning it up. once done adjust the ecu to match the fuel needed and pipe combo. He also told me to use XL cams and install backwards in number order. then reposition the rotor keyway to fit the new (different key slot) set to TDC and hold on. In his world thats the best revving most track reliable Hp build. He stated the 536 cams a few times and referenced the lift and duration is great allowing less squish and less chance to have the intake value hit the piston with a very small squish. He also told me the newer bikes were going to have a lighter primary front sprocket and to order one of those because its a direct replacement. So I did. the front is machined out on the new one where the old one is flat faced and a lot heaver in the hand. He mentioned the CP pistons as well and if you have the cash get the inserts in those with total seal rings. Genuine James gaskets and Cometic gaskets were mentioned as well. all XL 1200 Sportster parts on the top end. He favored the two piece intake cause you could run a different TB on the top section. Larger Headers than a xb12 for this build was recommended." my best memory recall on his words while he was at Daytona. Thats all I remember for now. Henry was the man that gave me some very good info which I gladly pass on cause it's accurate and correct. I cant thank him enough for the great data. Mike | ||
| Xoptimizedrsx |
My xb 9 adjustment. 5TH GEAR RUN. I went with cp pistons. better dome. I think +5. I dont remember for sure. I had the heads decked .030. I used com cam pro magnum tappets anti pum up design. I went with .010 base gasket. I went with a .030 head gasket cometic and disassembled it using two of the parts for .020. to get the lowest squish I could feel safe with. with gasket changes and piston changes. my squish is .040 now from.075 aprox stock in my engine.I would have to see if I have the sheet on exact stock. It was huge though. my compression read aprox 9.12 stock and is now 10.5.aprox. It seems like a lot more compression than I expected but thats what the gauge showed. new pistons rings, gaskets and all ran me 425.00 +- some. Then I did all the work at the shop. Including dyno time after the data logging to see where it ended up.I had some sort of weird hump aprox 6000 rpm but later that was fixed with other settings in the ecm. Chain 520 drive with offset ratio for more speed. the dyno would get 155 aprox but on the track it was probably 144/148 max. 7200 wot on the track is all she would do. The dyno would do 7800 rpm. with Xb12 header and voodoo race exhaust  |
