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00 12 bore /head porting only 180rwhp??? Help!!!!!!!

This is a discussion on 00 12 bore /head porting only 180rwhp??? Help!!!!!!! within the ZX-12R forums, part of the Kawasaki Motorcycles category; Ok,i made a posted a few weeks back about the same thing and got great answers.Now it seems my bike is making tons of power ...


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Old 07-01-2005, 08:24 AM   #1
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00 12 bore /head porting only 180rwhp??? Help!!!!!!!

Ok,i made a posted a few weeks back about the same thing and got great answers.Now it seems my bike is making tons of power (20-28)more in tne mid range and if falls off at peak.They said the cams were at 104/104.can someone give me some degee nubers that work.When i call around no one wants to help or they want to keep their numbers secret!Carpenter racing said 102/105(they did my head) i forgot what muzzy said but there all different.It also has a JE 1270 KIT JUST DONE.My bike made 177.4 before all this and 183.3 after head porting.
we were thinking about putting the cams at stock settings.
Thanks in advance to all!!
   
 
Old 07-01-2005, 08:45 AM   #2
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Did the porting made the holes bigger or smaller?

If bigger.... thhere is your problem I think.
   
 
Old 07-01-2005, 09:31 AM   #3
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no sure? But why did it make more before without the 1270 kit?After porting it actually got to 185.2 peak but after a mapping it ran better down low and made 183+ rwhp.I thought porting was just that though..bigger smoother for more unrestricted flow.
   
 
Old 07-01-2005, 11:28 AM   #4
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Well, why aren't the ports made as big as tomato cans if bigger is always better?

Anyway, seems a lot of porting jobs even from porters considered good wind up with about 6 hp.

However, if your 6 hp is the combination of porting AND the 1270, sounds like your porter cost you power, which is entirely possible.

There is no way that a couple of degrees on the cams (whether 105/105, 104/104, or 102/105) is going to be costing you large numbers of hp. That should not be the explanation.
   
 
Old 07-01-2005, 12:50 PM   #5
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That makes sense.It is with both mods done.How does one port a 12 head for peak power then.180 hp and 4k is dismal to me!! It was also milled for compression.This is to complicated ,my cars are much easier!So how or what should i do try a stock head?
   
 
Old 07-01-2005, 01:02 PM   #6
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1 degree is not much, I remember a zx7r and the diferences in seat in the pants performance was notiable wen both intake and exaust cams where changed more than 2 degrees. and Im not talking about much, is just the power curve.
   
 
Old 07-02-2005, 09:00 AM   #7
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just remember the same torque a couple hundred rpms higher = more hp. and port velocity is very important to making torque. the bigger the port the higher the rpm for the same velocity but done properly should = more cfms at higher rpms = more torque higher up and that is hp.
i am going through this on the 440 i am putting in my power wagon for pulling and i got used heads that flow almost 400cfms (indy heads iron) so i have a choice of reving the hell out of it or stroking it to get the port flow up.

do you still have the stock 12r fuel pump on? doug said the pump and injectors at 100% dwell at stock psi can only feed around 185ish hp everything working 100%

just a thought.
   
 
Old 07-02-2005, 09:08 AM   #8
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Some years back, and particularly with many cars, the situation with many engines was, yes, a moron could take a head, take its intake ports, and "making it bigger" would make more hp.

Yup, just eyeball that sucker, hog it out and there you go, more hp.

Those days are largely over. The factory is not designing those ports where just generally "making it bigger" is going to yield more hp.

A more sophisticated, accurate shape (perhaps not one amenable to casting or the particular machining procedures used in manufacture) may add some power, but not some guy hogging it out "by guess and by God."

You still get morons doing this. Those dumb enough to think that flow benches measure porting success are particularly dangerous, as their hogging is "proven correct" by increased numbers on the Superflow.

As would opening the ports up to tomato-can sized.

Of course in the engine you don't have a steady breeze running through the port. Not remotely the same thing at all.

There is a possibility that a moron has cost you hp here.
   
 
Old 07-02-2005, 09:56 AM   #9
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i do have the muzzy fuel pump on it.We have cover every other aspect of this bike as far as problems.I beleive you guys are right about my porting job.I'm not very happy i must say.Even though it did make mid range power thats not what i paid 4k for! I was interested in what a 12 could make...say 200rwhp without nitrous or cams.Wonder if i should send my bike to carpenter racing since its their head?
   
 
Old 07-02-2005, 10:00 AM   #10
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Well, wait a sec, if your midrange is nicely improved then I think it's unlikely your porting job is to blame for loss of high end hp, compared to the (small) improvement you should have expected from the displacement increase.

Maybe it is another issue such as wrong mapping, a mistake in degreeing the cams (as opposed to choosing one degree different than what someone else might choose), inadequate fuel supply (despite the pump, just including as possibility), ignition.

Can you post the dyno charts?

BTW, I hadn't noticed (or remembered) that you'd said Carpenter did your head. I don't consider him a moron at all. On the one hand it doesn't seem anyone is getting huge extra power from his porting on the 12, don't think anyone has claimed more than 6 hp from it, but what you have is a loss once accounting for the displacement increase, assuming that that is working properly.
   
 
Old 07-02-2005, 06:25 PM   #11
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I have heard people losing hp for porting the head alone in zx12r.
   
 
Old 07-02-2005, 07:12 PM   #12
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But if there's a nice midrange power increase apparently resulting from the porting -- more midrange improvement than expected from the displacement increase -- then it's hard for me to figure bad porting.

Carpenter also does CNC porting I believe -- though his designs change from time to time, within a given design every port job is the same. And his porting hasn't previously been accused of hurting peak power.
   
 
Old 07-03-2005, 10:57 AM   #13
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last time i talked to doug at muzzys he told me to put the cams at 105I 103E at 1mm lift he also said see where thier at before messing with them. he said they see anyware from 2 to 10 hp depending where they are at from factory.
   
 
Old 07-03-2005, 11:11 AM   #14
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With the 1270 Kit?
or stock?
   
 
Old 07-03-2005, 12:49 PM   #15
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i am going to say stock cause that is what we were talking about. the nice thing about larger displacement if keeping things the same cam wise it will make your torque peak a little lower and amplify the characteristics of the smaller engine so i would guess those numbers will work great or you could add 3 deg to each and shift the power up higher and see if it would like it. i know on my zx11 we had it working the best at around 100 100 and i think that is why it gaind 20 hp from 8000 to 9000rpms and spun or lifted 30 ft after a wide open shift to second. this winter i will check my vlvs and degree the cams to 105 103 and see what happens. i already have a old sparkplug turned into a piston stop for finding tdc leftover from my twins days at summit west va. i can't remember what we set his zx7r cams at.
   
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