carb stumble???

Old 07-23-2009, 06:24 PM
  #11  
whitey70ss
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oh there is no powervalve in the back block. does that make a difference?
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Old 07-23-2009, 06:42 PM
  #12  
fla1976
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Default Valve

Without a power valve, I've been told that you have to jet up a couple to compensate. There are some good carb guys on this forum, so I'm sure they can set you straight.
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Old 07-23-2009, 07:27 PM
  #13  
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It doesnt seem like there has been that many guys on here lately?? :?: I was hoping someone could direct me in the right direction.
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Old 07-23-2009, 09:50 PM
  #14  
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You were definetly too lean with them 66's on the primaries.

When you added that single plane manifold you killed a ton of bottom end torque but gained alot of upper end HP, jetting it up the primaries should help out the stumble.

If it were me and I wasn't runnning a P/V I'd jet it 80 sqaure as a starting point, then after making a full pass I would read the plugs and jet up or down as needed.
let us know how it pans out.
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Old 07-24-2009, 04:56 AM
  #15  
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i agree with cepx, and with the front pv, you are running the carb square as you gain 6 to 8 jet sizes with it.
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Old 07-24-2009, 06:50 AM
  #16  
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I drove the car this morning, carb works 100 percent better. the stumble is gone.I am going to test and tune sat. after I make a few passes should I try gradually bringing the primary jets up in size???
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Old 07-24-2009, 08:40 AM
  #17  
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i would baseline the car with a few run, reading the plugs, takeing note of the mph, then go up 2 jet sizes, if mph increases, then you were a little lean, if mph drop, you are a little rich, i like to keep my jets square.
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Old 07-24-2009, 06:36 PM
  #18  
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OK guys I appreciate all the help. I'll let ya know how I make out.
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Old 07-25-2009, 02:23 PM
  #19  
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well I didnt make out real well today I only got 2 passes in and they was enough to make any judgement. the first pass was 13.78 and I missed 4th gear. then I had a leaky fuel cap problem and decided to take the exhaust off and the car ran a 13.77 and I had no shifting issues. :lol: . I went for another pass and stage the car and left the clutch and my driver side axle twisted off. :shock: Has anyone ever used superior axles?? the summit rep highly recomended them to me ... I'm still a little stumped on second pass being almost the same as the first. could it be that my engine likes a little back pressure?? I will post the time slips in order below.LET ME KNOW WHAT YOU THINK . THANKS IN ADVANCE!



RT...247
60'...2.094
330..5.791
1/8...8.807
MPH..82.31
1/4...13.787
MPH..99.03




RT...120
60'...2.058
330..5.805
1/8...8.873
MPH..80.84
1/4....13.771
MPH...101.59
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