1260 build

ok so i'm 90% done with my 1000 project. i have bought 1260 pistons, had the jugs done got a j-head with 33mm valves and spent $500 having it cleared and set for my kz block.the pistons are 10.25 to 1 and i still need carbs.my cams i got spec out @418 lift and 262 duration. am i going to small for this motor? i'm looking for 36 smoothbores for this application. what would everyone recomend for cams in this motor? i want low and mid for this motor since i don't do to much highway driving. this one is my fun-bike, not my daily driver. i got a 650 for transportation, this one is just for fun.help! i want a combo that will run like hell for the weekend!

Post edited by: kawsakiman, at: 2006/09/12 23:15

those 10.25:1 kz pistons are gonna be closer to 8.25:1 with that j-head,j-head has a lot bigger combustion chambers than kz style head.

check the classifieds...

got a set of 38's on there for a good price.

--r

wireman wrote:

those 10.25:1 kz pistons are gonna be closer to 8.25:1 with that j-head,j-head has a lot bigger combustion chambers than kz style head.

Seriously, that sounds like it could blow your plan there unless you got a turbo tucked away somewhere? :whistle: Wireman would know better than me probably, but I think you usually spring for race pistons at 12:1 or so to get your compression back to where you want with the J-head.

You online kawsakiman? There's an ebay auction for a pair of WebCam 109/110 (109in/110ex) This is a pretty hot setup for big street -- could work for your final plan, however it turns out. AUCTION ENDS IN ABOUT 2 HOURS FROM NOW! I have the 110s in my much smaller bike (1015cc) -- could be a nice match for you.

cgi.ebay.com/ebaymotors/KAWASAKI-Z1-KZ-W...QQrdZ1QQcmdZViewItem

Post edited by: elseed, at: 2006/09/13 19:47

ive got a shiney set of wiseco 1385 10.25:1 pistons stashed in a box for the same reason it will be right around 8.25:1 with the gpz/j head im using.

1385 + turbo is nuts :ohmy:

I like this big bore talk, find myself perusing Jay's catalog recently. Have absolutely no idea why I would be looking at it, but there's an '84 GPZ1100 head out on ebay right now too, though I think it's attracting some attention. Bathtub chambers to bolt on to something in your garage, wireman?

I'm just about mentally ready for my cc increase tear-down/build-up (but not sure if the wife, boy, overgrown yard, bank account, etc. are onboard too). :whistle:

Thinking of something that would work in Tucson traffic if necessary. 1197 with my big ol' oil cooler? But perhaps a more modest 1075 is rational. Or somewhere in between? Please watch for a suitable cylinder/piston setup for me. CCs is the one thing I think would wake up my setup to it's potential.

Well a couple of things......

If we had done the cylinder for you, first we would not want to put the 1260 sleeve in a stock 1000 block as it would be an oil leaker. But if we did, we would use a J model 1260 piston and send you a .050" spacer plate for under the cylinder. Then your pistons would have the correct dome and valve pockets for the J head.

Please elaborate on the $500 for clearancing the head.

Jay

elseed wrote:

1385 + turbo is nuts :ohmy:

I like this big bore talk, find myself perusing Jay's catalog recently. Have absolutely no idea why I would be looking at it, but there's an '84 GPZ1100 head out on ebay right now too, though I think it's attracting some attention. Bathtub chambers to bolt on to something in your garage, wireman?

I'm just about mentally ready for my cc increase tear-down/build-up (but not sure if the wife, boy, overgrown yard, bank account, etc. are onboard too). :whistle:

Thinking of something that would work in Tucson traffic if necessary. 1197 with my big ol' oil cooler? But perhaps a more modest 1075 is rational. Or somewhere in between? Please watch for a suitable cylinder/piston setup for me. CCs is the one thing I think would wake up my setup to it's potential.

we are also fabbing up a mount for nitrous bottle where the mono-shock used to be mounted on the gsxr swingarm we are heavily modifying to use on this bike,now thats nuts!:evil: a smaller motor like the 1197 i had in this bike previously is definately much more practical but since wireman has way too much time and way too many extra parts laying around i decided what the hell!i spent some time in sierra vista az at ft huachuca in early 80s i remember how hot it was and how hard it could be on a bike,if it was me i would build a good running little 1075 with a good cylinder head and good oil cooler it should work out good in those conditions. goodluck,happy wrenching!

ok, i'm new and putting all my faith in my builder who has never steered me wrong. he tells me i need to have it cleared for big cams, bigger/stronger valve springs etc.. i need to get my pistons fly-cut to work with a j head. we are going to mill my head .40 so i keep the compression ratio. even if i get the best porting job done on my kz head, it will never flow as good as a j head.the cams i got spec out @ 417 lift, 268 duration@40 and 107 center lobes. i am an auto tech and these sound like sick cams for a car. but we all know bikes are a different beast. the center lobe will give me a rumbty idle if it was a car so i need to know if these are good for a bike. like i said, he never steered me wrong so far and i would rather pay him twice than let anyone else work for free once.i talked to him again todat ape and he says to notpolish the intake ports cause it can cause a rich condition.we need the turbalanbce. bonz has better bikes in his garage then i can ever afford and he has been doing this for 20 years so i got to belive him. (hell, even jeff knows him! he is in jeff's backyard. jeff has even ridden his 1260) i just think that 417 lift is a little small for what i want this bike to do. (wireman, i'm looking for your advice!) also from you apeman. i'm sorry i'm such a nuebie but isn't this what this sight is for/ so us new guys can learn from the masters? ( i still want to ride your turbo wireman!)

kawsakiman wrote:

ok, i'm new and putting all my faith in my builder who has never steered me wrong. he tells me i need to have it cleared for big cams, bigger/stronger valve springs etc.. i need to get my pistons fly-cut to work with a j head. we are going to mill my head .40 so i keep the compression ratio. even if i get the best porting job done on my kz head, it will never flow as good as a j head.the cams i got spec out @ 417 lift, 268 duration@40 and 107 center lobes. i am an auto tech and these sound like sick cams for a car. but we all know bikes are a different beast. the center lobe will give me a rumbty idle if it was a car so i need to know if these are good for a bike. like i said, he never steered me wrong so far and i would rather pay him twice than let anyone else work for free once.i talked to him again todat ape and he says to notpolish the intake ports cause it can cause a rich condition.we need the turbalanbce. bonz has better bikes in his garage then i can ever afford and he has been doing this for 20 years so i got to belive him. (hell, even jeff knows him! he is in jeff's backyard. jeff has even ridden his 1260) i just think that 417 lift is a little small for what i want this bike to do. (wireman, i'm looking for your advice!) also from you apeman. i'm sorry i'm such a nuebie but isn't this what this sight is for/ so us new guys can learn from the masters? ( i still want to ride your turbo wireman!)

the thing that scares me about the 1260 is having enough cylinder wall thickness to keep rings sealed and keep it from overheating in a stock block.this bike had a welded 900 crank, 1197 pistons with way too much compression :S :evil: 900 head clearanced for big cams, small valves,good valve springs ,ports just cleaned up no serious porting,and a set of 28s on it,i had a big hairy set of 435 cams in in for a while but it was no fun to drive on street,i put smaller cams in and it turned into an instant missile that could overpower chassis/rear tire anytime i felt the urge to do so!:evil: just remember to build up the rest of your chassis to handle what you are going to through at it,thats a lot of power you are about to turn loose there!:evil: goodluck,happy wrenching!

oh yeah,i definately agree about leaving intake ports a little rough to keep fuel from settling from mixture.