High speed air bleeds

Old 05-08-2009, 04:01 AM
  #11  
TopspeedLowet
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The head change may be giving a better vacuum signal than previous which again points to a power valve tip in point if you run one. Otherwise you will have to go over everything again a find out what is different that you think is the same as last year. The timing curve need may be different on the street now if you run centrifugal and vacuum advance with the head change as well.
Food for thought
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Old 05-08-2009, 08:10 AM
  #12  
bryanm
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The timing is locked out now and has always been. I am starting to wonder if this will even be a problem when I am making passes.
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Old 05-08-2009, 09:01 AM
  #13  
dparker
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Originally Posted by bryanm
The timing is locked out now and has always been. I am starting to wonder if this will even be a problem when I am making passes.
What fuel pressure are you running? I've seen the mist from the needle seat as fuel goes into the bowl allow fuel in the vent in bowl. Make sure your fuel pressure is 7 or under. If it doesn't miss at wot I don't think it will be a problem.
Something I just thought of. Does your carb have progressive linkage? If so, that may be the point the back butterflies are starting to open. May need bigger squirters etc......
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Old 05-08-2009, 11:56 AM
  #14  
TopspeedLowet
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Go to the track and kick some ass. My 1200HP big chevy acts like it's unhappy on the return road at part throttle after a 7 second 184 MPH pass.
I used to let that bother me and I would tune it away, but by the time I get the intermediate circuit tuned perfect to prevent the burble, I would change the jets for weather and the cycle begins again. Who gives a crap what the engine runs like on the return road as long as its running back to the pit on it's own power? You know what I mean......
Bruce
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Old 05-08-2009, 06:38 PM
  #15  
jmarksdragster
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How about some info, what Demon carb, what engine and engine specs, what is it going in. The main air bleeds are not what you want to open up without knowing what you are trying to accomplish.
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Old 05-11-2009, 08:39 AM
  #16  
bryanm
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The air bleeds were opened up on the dyno when we were trying to get the a/f mixture that we wanted so I knew exactly what I was trying to accomplish. It is a sbf 408ci, mighty demon 800 carb, afr 205cc heads, victor jr intake, 680 lift roller cam, 266 duration at 050, 12:1 compression. I took it to the track this weekend and it is falling on its face as soon as I let off the brake and then it comes out of it and really hauls ass. It ran great on the dyno and I have never had any problems with the carb before. I also noticed that the fron float bowl keeps filling up even after I adjust it. I have another carb I borrowed that I am going to put on and try. I just dont know what else it could be.
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Old 05-11-2009, 12:35 PM
  #17  
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Demon carb..my friend i can only say i struggled with a demon .. always adjusting on it .. once i thought i had it right... next weekend -- there i was adjusting,jetting, idle mix.. ugg.. i sold it and bought a PRO SYSTEMS gas carb...all i did there was adjust 2 sizes jet and it was good to go!.. now im on Alcohol with an APD whole different animal.
FYI my Demon Dyno'd great but sucked at the track!!
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Old 05-11-2009, 02:14 PM
  #18  
dparker
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Originally Posted by bryanm
The air bleeds were opened up on the dyno when we were trying to get the a/f mixture that we wanted so I knew exactly what I was trying to accomplish. It is a sbf 408ci, mighty demon 800 carb, afr 205cc heads, victor jr intake, 680 lift roller cam, 266 duration at 050, 12:1 compression. I took it to the track this weekend and it is falling on its face as soon as I let off the brake and then it comes out of it and really hauls ass. It ran great on the dyno and I have never had any problems with the carb before. I also noticed that the fron float bowl keeps filling up even after I adjust it. I have another carb I borrowed that I am going to put on and try. I just dont know what else it could be.
Bryan, you do have jet extensions in don't you?
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Old 05-11-2009, 03:09 PM
  #19  
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Yeah, I have jet extensions in it. I just put a 750 Quick Fuel of my dads on it and it ran great, never missed or loaded up at all. I am going to order a rebuild kit for the Demon and go through it. Something must have gotten in it it or something, I dont know.
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Old 05-11-2009, 05:45 PM
  #20  
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Originally Posted by bryanm
Yeah, I have jet extensions in it. I just put a 750 Quick Fuel of my dads on it and it ran great, never missed or loaded up at all. I am going to order a rebuild kit for the Demon and go through it. Something must have gotten in it it or something, I dont know.
Thats a good idea. Also be looking for a new carb. I hate to bash something, but that's a never ending story with those carbs. good luck.
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