Big bore questions

Good morning everyone, I have to my 900 back down for winter and have some questions on building a motor for it. I have built a six inch over swingarm and in the process of aquiring a zx10 front end for it. It has a 180/55/17 tire on the back now. My first thought was to purchase a crashed zx9 or 10 and use the motor and parts for the ltd but I'm reading on here that they don't fit in the frame. Building and modifing the frame is no big deal, I have plenty of experince in that area. So my question is how big or what should i do to a kz motor to get this bike to run mid 6's in the eight. Starting to think this may be easier then the new motor idea(although not as much fun of a challange). This bike will not be street ridin very often, mostly for the strip. There are pretty much all crotch rockets at our local strip and i want to smoke there ass on some old iron LOL!!! Anyhow all your knowledge is great and totally helpful. Have a great day everyone and keep the rubber side down.

Mid 6's in the 1/8th would be 10.0-10.2 in the quarter. There are a couple guys at local track running 9.5-9.7 with a 1105cc, .410 cams, air shifter, 6" over arm and with a ported head. At least that is what they are saying. I have heard rumors that they are actually using a 1200cc motor. Personally, I would think a 1200cc with .410-.425 cams, ported head (this is the important part in the combination) with the longer wheelbase and air shifter should get you there. Lots depends on the rider though. I've seen 1075 motors get there but they would have to be high stung I would think for a street bike. Lighten it up as much as you can. I think the ratio is for every 20 lbs. you remove is good for a tenth (.10) of a second. Also, every lbs. in weight removed off unsprung parts (wheels, bottom half of forks, swingarms, etc. not supported by shocks or forks,) is same as removing 3-5 lbs. off frame and body). Lots of guys around here use an auto-shifter when racing which should help some also. I've always been told an air-shifter is worth approx. .2-.3 seconds. Wheelie bars are good for .3-.4 seconds just to know. Of course, there is no replacement for displacement so if you can afford it, go big....makes it easier. Lots of ways to get there. Bigger motor doesn't have to work so hard as a small one does. Headwork is the big part. Spend money on the head!

Thanks for the info I am thinking about running an air shifter and a two stage rev limiter. I don't think I need wheelie bars on it, but i do have some if needed. The 1200cc motor was what I had in mind but was not sure if i needed to go that big, I do want it to be somewhat reliable. Don't have the money to fix it all the time cause I like to ride them hard and fast. Thinking of buying another motor to build and keeping the 900 incase something would happen to it. Then i could still ride it just not as fast. LOL!!

racer54 wrote:

Mid 6's in the 1/8th would be 10.0-10.2 in the quarter. There are a couple guys at local track running 9.5-9.7 with a 1105cc, .410 cams, air shifter, 6" over arm and with a ported head. At least that is what they are saying. I have heard rumors that they are actually using a 1200cc motor. Personally, I would think a 1200cc with .410-.425 cams, ported head (this is the important part in the combination) with the longer wheelbase and air shifter should get you there. Lots depends on the rider though. I've seen 1075 motors get there but they would have to be high stung I would think for a street bike. Lighten it up as much as you can. I think the ratio is for every 20 lbs. you remove is good for a tenth (.10) of a second. Also, every lbs. in weight removed off unsprung parts (wheels, bottom half of forks, swingarms, etc. not supported by shocks or forks,) is same as removing 3-5 lbs. off frame and body). Lots of guys around here use an auto-shifter when racing which should help some also. I've always been told an air-shifter is worth approx. .2-.3 seconds. Wheelie bars are good for .3-.4 seconds just to know. Of course, there is no replacement for displacement so if you can afford it, go big....makes it easier. Lots of ways to get there. Bigger motor doesn't have to work so hard as a small one does. Headwork is the big part. Spend money on the head!

brings a tear to my eye!:woohoo:

OR.....you could do like PLUMMEN here and "Go west young man!" and find one of those silo's and strap your butt onto one of those ballistic missles aka (also known as) a 1385 injected turbo with nitrous!!! LOL

That would be AWESOME!!!!! Where do i sign. LOL!!!

im working on it guys,im working on it!:laugh: although i have been spending a lot of time on the dragbike.com classifieds looking at dragbikes for sale!:laugh:

do a 1197 kit a set of 33's wheelie bar and slick, decent cams a good pipe and there you are low 10's high 9's easy. or in 1/8th mile speak mid to low 6's once you get that hook from a slick you wont want to go back to a street tire, by the way i've always been told 25 lbs is equal to a tenth. a two-step is a good thing, as well i use 15-41 gearing in my little bike and it works pretty good.