Power is off changes not helping.

Discussion in 'InsideTopAlcohol.com Tech Questions' started by Motorworx127, Sep 2, 2019.

  1. Motorworx127

    Motorworx127 Member

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    Running 565 BBC 11.5 static, bird with down nozzles, 990 pump, 14/71 HH big opening top at 34% in a 3100# door car. Has ran best of 7.91 at 167 and 5.04 at 141 in 1/8 starts and runs fine doest seem to blubber and 60s a 1.18 or 1.17 off idle hit rpms runup to about 7500 shift within 1.5 seconds but in high gear rpms just don't come up. power doesn't seem to change no matter what I do. Cam is a Lunati grind 299,299 in at 38.5 btdc at.050 and cl of 111 its dead on as ive checked it we have made drastic changes to both fuel and timing and it hasn't picked up a .001 will not color plugs till about 4 or 5 passes. started with system setup by Spud and safe start was a .125 main, Hat noz are 52,52,54,54,56,56 and 2 60s in blower, Port noz are 48,46,46,46,44,44,44,42. have increased timing to 34 * progressively from 28 and have leaned it to a 140 runs same number ????? we also put on a pulley for 44% over on a 130 main still same number???? getting a 1500 rpm drop on shift at 7500 , and she runs up to about 6600 in 1/8. Boost guage shows 20# at 34% and 25 at 44% yet did not show lean. I am at a loss
     
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  2. Dave Koehler

    Dave Koehler Member

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    I suspect based on your own observations that you are still too rich.
    However
    Measured Pump flow?
    Altitude you race at?
    Magneto?
     
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  3. Critical Mass

    Critical Mass Member

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    Are you using a crank trigger?
    I would recheck your timing again just to be sure.
     
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  4. Motorworx127

    Motorworx127 Member

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    Sir thanks for reply pump was flowed by Spud 15.7 at 4000
    Pro Mag 20 All from spud has 31 passes on entire setup including motor and blower. Has done same numbers essentially from start up I am new to this and took me a few passes just to stay in it all way down track. but it easily went in 7s on the startup tune 125 main 28* with nozzels that are stated above just has not gained anything no matter what we do
     
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  5. Motorworx127

    Motorworx127 Member

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    yes using crank trigger and Grid and have even tried compensating for the 5 degrees of timing variance but returned it per Mike Canters advice. Nothing seemed to change does not build heat EGTS are barely 350 at idle after 3 minutes can get it hotter if i pull shutoff some to lean her out. Think we may just run it off mag alone see if it runs better then switch to trigger the reintroduce grid just to rule that stuff out.
     
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  6. Motorworx127

    Motorworx127 Member

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    is it possible that the cam duration is not far enough advanced and causing reversion or actually pushing fuel charge out exhaust? Its in according to the card but has more duration than anything ive seen posted here.
     
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  7. Motorworx127

    Motorworx127 Member

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    at 38.5 it closes at 85* which leaves very small window to build compression
     
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  8. Critical Mass

    Critical Mass Member

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    Usually a 990 pump is too big for a BBC setup like yours, unless you have a pump loop. I have a few questions:

    What barrel valve you are using?
    Barrel valve leak down settings?
    What are your checks set at?
    What is your hat butter clearance?

    I agree with Dave - its rich.
     
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  9. Dave Koehler

    Dave Koehler Member

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    Looks to me like you only made about a 1% tuneup change so it makes some sense that it looked like nothing happened.
    Are you running at high altitude or at sea level?
     
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  10. Mike Canter

    Mike Canter Top Dragster
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    Your plugs should color in one run. If not then you are probably way rich so much so that small changes to the fuel are not making any difference. Once you start getting color in the plugs at the end of the run then tuning changes will make a difference
    Read this and see if it helps
    https://www.dragstuff.com/techarticles/reading-alcohol-spark-plugs.html
     
    #10
  11. Fuel Cars

    Fuel Cars AA/AM

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    If you're running alcohol, in doing a quick check and assuming no pump sizer, looks like you need around a .215 pill.

    With your current setup, I'm getting an afr of around 3.2, pretty fat.
     
    #11
    32 bantam likes this.
  12. Motorworx127

    Motorworx127 Member

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    K valve barrel 80/20 started 75/25 leaned it tryinng to build some heat.
    pump saver is 130
    port check is 16
    idle check is 10 butterflies are about .008
    I was messing with her today and found that i have 104 PSI cranking cylinder pressure.All cylinders same and did leakdown on all less than 10%
     
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  13. Motorworx127

    Motorworx127 Member

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    Yes on alcohol and have loop on pump but it just returns to inlet
     
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  14. Motorworx127

    Motorworx127 Member

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    D/A is about 1500
     
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  15. Dave Koehler

    Dave Koehler Member

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    Actual altitude please or which track.
     
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  16. Motorworx127

    Motorworx127 Member

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    Keystone Raceway Park
     
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  17. Motorworx127

    Motorworx127 Member

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    Did you see the 104 psi cranking cylinder pressure?
     
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  18. Motorworx127

    Motorworx127 Member

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    Keystone Track elevation is 1177ft
     
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  19. Fuel Cars

    Fuel Cars AA/AM

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    Just to be clear, a pump saver is not a pump loop/sizer, the saver is for when getting off the throttle at high rpm, pump loop/sizer always bypasses some of the fuel at a much lower pressure, mine is @37 psi.
     
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  20. Motorworx127

    Motorworx127 Member

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    Yessir i understand i do have a loop but it is no a sizer just returns to inlet
     
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