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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    well guys Thanks so much for the help. I advanced cam 8 degrees and now I have 150 psi cranking cylinder pressure. we are thinking that ought to wake her right up. we are going to return to startup tune and start over. But again THANKS to everyone .
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    There is no check valve or jet in your pump loop/sizer circuit. There should be a jet in the brass fitting that screws into the top of the pump that the check valve screws into.
     
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  3. Bjs344

    Bjs344 Member

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    You need to understand what a pump loop is. You currently do not.
     
    #23
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  4. Big Steve

    Big Steve Member

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    Just comparing your pump and nozzles to my pump and nozzles, 540 bbc with 14/71 HH you are really fat imo
     
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  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Also make sure you only have one jet in the barrel valve.
     
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  6. Outlaw68

    Outlaw68 Member

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    I have ran this very combo in years past. The 990 pump will work but ... It needs 4 high speeds on a timer and I would want the main to be around 80-90 the nozzle area is BIG for this combo for sure. But it will work. Get SPUD to sell you his 4 stage lean out and get a timer for it. By the time you get a main in it that it needs it will be way too violent at the hit I am afraid.
     
    #26
  7. Bjs344

    Bjs344 Member

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    4 High speeds !!????!! LOL

    The OPs blower is questionable and that is the only reason he isn’t using the whole pump at 44 over.

    I have a good 1471 on a 500 Chevy with a 990 and can burn a 74 main with similar nozzle area to the OP. This went 226 mph in the 1/4 at 2100lbs and has been 162 at the 1/8 at 2550 lbs. The combo had a 582 long block at one time and could burn a little more fuel but I couldn’t keep the short block happy. The only time I ever turned on a leanout was to clean it up around 0.25 second after brake release.
     
    #27
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  8. Bjs344

    Bjs344 Member

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    Also, that cam is nuts for the combo. A bbc with an iffy blower is never going anywhere with 299 @.050 on the intake.

    288 x 310 on a 116 and spin it a little higher.

    Would be nice to check IAT or just stick a different (known good) blower on it.
     
    #28
    Motorworx127 likes this.
  9. Motorworx127

    Motorworx127 Member

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    #29
  10. Motorworx127

    Motorworx127 Member

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    Well we tried more cylinder pressure lost 8mph in1/8. loaded it up and came home. I have an offer from a co-racer to let me bolt on his LB22 and BAU to see whats up. After talking with Lunati I believe my grind was designed for a High boost engine 35+boost or at least way better quality air
     
    #30
  11. Motorworx127

    Motorworx127 Member

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    Only one Jet by the way
     
    #31
  12. Motorworx127

    Motorworx127 Member

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    Is there anyone near the Pittsburgh Area that I could possibly pay to help me with this?
     
    #32
  13. Mike Canter

    Mike Canter Top Dragster
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    It appears that you are ignoring the fact that racers are advising you that you are way rich and you haven’t answered the question on the pump loop if you have a check valve and jet in it. It has to or the motor will not run. Did you read the article on how to read spark Plugs?
     
    #33
  14. Dave Koehler

    Dave Koehler Member

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    Yup, the first post says it runs fine and doesn't blubber.
    That would lead most of us to think there has to be a pump sizer / loop somewhere in the mix.

    If no actual pump sizer / loop then it should be blowing fuel out the pipes. It would need a large main jet or 40+ lbs of boost neither of which sound logical for the combo listed.

    Motorworx. Can you upload a photo of the pump and attached lines to put this loop question to rest?
     
    #34
  15. Motorworx127

    Motorworx127 Member

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    Sorry guys I am not ignoring anyones advice, You guys are the GURUS Im a rookie. That being said will post a pic but my loop is just a return to before pump NO CHECK or SIZER. The high speed is in that area but I know what that is the other is just a loop and manifold that combines the returns and sends them back to the pump. The engine will spit fuel on rev limiter for burnout and seems to on launch outta 1&2 but Im driving this car also so all i can do is look at video. Im not milking oil For whatever that counts for it did on 125 main but not at 130 or up
     
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  16. Dave Koehler

    Dave Koehler Member

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    Are you sure that is a high speed?
    Jet size and spring pressure please.

    Spitting on the burnout can be expected. No load to burn fuel.
    Stay off that rev limiter.
     
    #36
  17. Motorworx127

    Motorworx127 Member

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    High speed set to open at 105 psi with a .075 jet
    Usually only opens around 1000 ft. does have some leakage at lower pressure (at least with leakdown tester) was gonna lap the seat. not too much leakage tho
     
    #37
  18. kosky racing

    kosky racing Comp Eliminator

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    where are you at in the Pittsburgh area
     
    #38
  19. Big Steve

    Big Steve Member

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    I know its not my money buy why dont you trade that 990 pump in for a 110? I have a 540 Chev with 14/71 HH with a 110 gear pump, I had it flowed and its 13.4 at 9K and 12.4 at 8K, I have a simple fuel system, no hi speed or pump loop needed. My nozzle area is way less than yours, fuel pressure right around 150 psi In killer air with about a 90 pill, flow meter says I am putting about 10 gpm in the motor, typical TX summer air right around 9.5 or so with a 110 pill. Car will run well under the 6.10 TD index in the heat. Super easy to tune and prints tickets.
     
    #39
    Last edited: Sep 7, 2019
  20. Mike Canter

    Mike Canter Top Dragster
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    Nozzle area is a factor of pressure. The higher the pressure the smaller the nozzle area. It is hard to compare one nozzle setup with another unless you have the same fuel pressure
     
    #40

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