[Racer X]

I got the Adjustable cam sprockets .APE makes them for the 250 ninja along with a mechanical tensioner. I plan on doing a valve adjustment and figure I might as well fool with this as well.

I have to do some research before I start. I do know that less overlap is good for top end and more is good for mid range . But how much is something I will have to figure out on my own.

I figure I will run the 1/4 mile time then retard the exhaust cam 2 or 3 deg and retest . Then move the intake cam .And retest. It is a bitch with out a dyno but the results will be better in the end.

Dose anyone have any sugggestions where I should start.

 

[hi-tech]

i dont.. but good luck keep us posted..

 

[spooph]

Darkhorse, I think you're on the right track. But if I were to do this, I'd advance the intake cam 2-3 degrees, and retard the exhaust cam 3-4 degrees, see what that gets ya... That's what I'm gonna do, eventually, one day, when I get the other beast out of the wrench space....

 

[Racer X]

So you think I should just do it all at once ? Probably better . I cant find my deg wheel . I have a nice one some where.I did find my dial indicator set up .

Thanks I will keep you posted.

 

[eric]

Dose anyone have any sugggestions where I should start.

darkhorse,you should start with this: LSA (Lobe Separation Angle)

I fooled around with it before and mess up the whole setup.Lucky it was a single so it was ez to make it std again.

Good luck.

http://www.wallaceracing.com/cambasics.htm

 

[Racer X]

Thanks a bunch for that .

I will study the whole thing tonight . I know this stuff . But the only engines I have tunes have the intake lobes and exhaust lobes on the same stick .
Being able to spread the overlap is very useful.
I want this to be a learning experience . Not from mistakes (the way I usually do it ) But from careful documented experimentation.

So this is my plan ...

First I need to adjust the valves . I want to make them tight . To get maximum lift .
Specs are .15~.24mm intake
.22~.29mm exhaust
I want to get them to .23 intake and .28 exhaust.

After that I will install the adjustable sprockets.And put it together.

The first thing is I need a degree wheel and a dial indicator . The dial indicator I have so I bought a degree wheel today 25 dollars.

Then I will degree the cams.
I will go through how this is done later but I will first need to measure everything before I take anything apart. That includes Cam lift and duration . valve clearance
and the cam timing . That way when I put it back together with the adjustable sprockets I have a starting point.

the next thing is to determine what to adjust the cams to . I cant just move them some and try it . It is a waist of time . So I need to figure some things out.

First is where am I know and how will I test improvements . I am not expecting much but the little bits add up in land speed racing. So for starters I have my KOSO dash that will measure 1/4 or 1/2 mile time ,speed and max rpm . So I need to see what I can do now . Last test was 15.3 sec @85 mph . I will run some tests and then pull the engine out to set this all up and photo graph it

 

[spooph]

Darkhorse, WTF man, I just noticed your name got changed to Racer X...

Anyways, to answer your question from before, I think you need to go even more basic than you described above....

I think if you want this to be scientific, first, obviously shim the valves accordingly, like you stated. My question here is how are you going to get that close? Don't shims come in .05 increments? How are you going to get .23 or .28 without actually grinding your head out? Or is there somewhere that sells shims in .01 increments? If so, I need that link.

Second, with the valves shimmed accordingly, like you said, again, degree the engine from the crank up, with the ABSOLUTE stock setup. That way you know when your fly wheel says your lined up, your cams are EXACTLY where they should be at STOCK.

Third, Make all the measurements you've said you're going to make, and I'm going to state this for everybody else, but I know you're running different ignition timing, and that will affect all of these settings as well. So, if I were you, I'd go back to the stock timing, and start playing with the exhaust cams first, and only them. Get them dialed in to where the performance is starting to drop off....

Fourth, then go to the intake cams and see if you can gain some more power there. My hunch is you won't get a lot, but like you said, every little bit counts...

Since you already have the air system as wide open as possible, and by this time, the cams all set up with stock ignition timing, this will a good time to add the other ignition timing module. I think the more advance ignition timing will allow you to spread the cams even farther apart.

The reason I think you should do in this fashion, is because by the time you've documented everything up to changing the ignition timing, you should have enough data to draw up a model, and some trends of our motor, and based off that, you could then go to a cam company and have them custom grind you some cams that'll put everything right in place for some MASSIVE power...

I think that'll be the most scientific, but I could be very much wrong....

 

[Racer X]

Names have bin changed to protect the innocent

My first thought was to adjust the exhaust first. I don't expect much from the intake.
But the scientific approach is a must . I had not thought about the .05 increments of the valve shims . Lets say that is my target clearance .

I definitly need to mesure everything . before I remove anything .So I have a base to start from . I will measure lift duration and overlap and other stuff like the ignition timing to be sure it is where is should be /. Stock or not . I don't trust it .

My problem is no Dyno so I have to run 1/4 1/2 mile runs to test improvements . This will take some time . I have till September . My goal is the 111 mph record . I want a 250 partial streamline record this year. I got 110.371 but I still need more.

I am having cams made for a real race engine . For this engine I want to play with bolt on stuff . In an attempt to show what can be gotten buy the average 250 owner.

Thanks for the help I need it .

 

[metbandit1]

protection against what? and apparently your profile doesnt exist

 

[hi-tech]

oh oh here we go...

 

[Racer X]

Ya I know . I cant put in my fancy new picture either ,Red can fix it .I know he can.

 

[Racer X]

Or maybe I have become a man of mystery.

 

[metbandit1]

oooo darkhorse get you haha
hows you doing with this mod?

 

[Racer X]

Waiting for a new Degree wheel and doing some research. I gathered up everything I need I just have to start testing bike performance .
I will do a couple 1/4 mile runs when ever it stops raining . then on the 20 of jun i am going to Cecil County drag way . I want to try to beat 14.9 sec My best so far is 15.3.

 

[Felix]

How do you prep the bike for the drag strip? Tyre pressures, strapping the front suspension etc?

Reason I ask, is I'm planning on heading out soon on the ZX6R, its gonna be odd running a quicker time than my ute considering how powerful it was

Felix

 

[Racer X]

I set it up like I go to Maxton But with a 43 tooth rear gear low tire psi . Like 20 .\
I remove the seat and put on race bodywork . I cut my gas tank in half to get me lower.and my race exhaust . I have lot of mods to test . before I start new mods.

 

[Felix]

Nice, I'm kinda freaking out about lifting the front on launch and on gear changes. Our track is soooo well prepped, first time I launch in the ute, I thought something was wrong with it!

Felix

 

[Racer X]

Just don't try to hard just have fun . After a few tries you will just toss the clutch and nail the throttle

 

[Felix]

Yeah a few sighting runs and I'll be fine. Plus the bikes get a heap more runs than the cars since they roll up, stage and run a heap quicker.

Felix

 

[Zandit]

I've been meaning to ask Felix, what kind of ute do you have? Would have to be either Falcon or Bombadore!!! Sounds like you have it tuned well!