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Technical Looking for a n experienced tuner in my area

Discussion in 'The Hokey Ass Message Board' started by Elliott Taylor, Nov 19, 2017.

  1. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    from idle to the floor
     
  2. okay so it could be the secondaries causing it to because they're going to open instantly on a DP. What I would do is disconnect the secondaries. Then work with the primary until it will burn rubber off idle. Then connect the secondaries and work on it. I really don't tune by the numbers but rather by seat-of-the-pants. The squirters cams, Jets Etc that work the best are the ones you use. Don't really care about the numbers. every combination is different.
     
  3. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,308

    theHIGHLANDER
    Member

    Ok, we're getting somewhere. There's 2 culprits to a stumble on launch that's fuel related, one is too much fuel ( a bog), the other too little fuel ("flat spot"). The flat spot is like it want's to stall for 1/2 a second but then picks right up, the bog is, well, a lazy blob of a launch, likely accompanied by a moment of black smoke. For zipping around town a 650 is fun but you're not setting any MPH records with it. A 6000+ RPM 327 can process more CFM and with 12:1 you should be able to burn the fuel (where the energy is!). I smell some performance in the ignition too. Something tells me that if you sort your flat spot out I'd tell you to take 2 degrees out, launch at 2000, shift it at 5800 and run it "out the back door". Would likely go through the traps at about 62-6400 which is all the way through the powerband without leaving it completely. Yes, I am indeed saying sometimes a simple change in technique knocks off some ET or finds MPH. You can raise the launch RPM until it slows down, raise the shift point until ET suffers.

    But, let's dig deeper. The cam timing, is it straight up, advanced or retarded? Usually 2 to 4 degrees advance will net more low end power, the opposite nets top end power. With the dome on the piston sometimes you can't mess with it and it has to go in as designed. Too bad you can't borrow a 750 Holley. I predict 2 MPH or better in the 1/4 mi with a 750. And yes, you'll always get the Holley haters but they are one of the easiest carbs in existence to tune and modify. The worst thing about a Holley is the "1st date" where you spend more time on cleaning up the sealing surfaces than tuning. Friggen OEM gaskets are like a fatal attraction but once you do it they always come right off. The old trick before improved gaskets was Chap Stick.

    Your changes are telling you which way to go. Listen to it, it's almost talking to you...;)
     
    BigChief likes this.
  4. southcross2631
    Joined: Jan 20, 2013
    Posts: 4,414

    southcross2631
    Member

    I have a cleaned ready to build 3310 Holley that I will let you have cheap. I even have a kit for it.
    PM me if interested.
     
  5. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    Highlander, i installed the cam straight up. when you say drop the timing you mean about 33 total? im running a bushing that gives me 19 initial and im using the fastest springs, which the motor seems to like best

    What does "run it out the back door" mean?

    I call this a bog, but i see no smoke. no backfiring either so i assume isnt lean
     
  6. tinkirk
    Joined: Jan 16, 2017
    Posts: 111

    tinkirk

    Elliott
    take and put number 330 cam in with 31 squirts front and rear
    try running 32 jets on all corners
    with the msd box i always lock out the advance curve and set my timing at 38 degrees and see what happens
    does the 650 still have the choke horn on it? if so might want to think about getting rid of that or buy a new center section for the carb (proform builds a very nice one #67203 i believe)
    also not sure what power valve you are running 65 is normally stock so depending on your vacuum level you might want to go down to maybe a 45 valve or lower
    a lot of trail & error
     
  7. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    Hey. ok so i have that pump cam, just ordered a set of size 32 nozzles. I have aj assortment of power valves. a 5.5 is what im currently running.

    can i just that choke horn ?

    Ive thought about locking out my timing, and right now Im running aa much initial i can without locking the dist with my bushing setup.

    im worried about locking the timing. Will it crank up? I have a mini torque starter.
     
  8. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    btw what do you mean by "32 jets on all corners"?
     
  9. tinkirk
    Joined: Jan 16, 2017
    Posts: 111

    tinkirk

    you can mill the choke horn off yes but just not the same as buying the proform center section
    i'm thinking that your vacuum could be a little low check that so you know where to go with the power valve
    as far as jetting goes one thing you can do is keep up the jet tell it starts missing on the higher rpm's, then back them down until it will run flat out smooth
    small block likes lots of advance but i wouldn't go over maybe 42, 38 always seems to be the right amount
     
  10. tinkirk
    Joined: Jan 16, 2017
    Posts: 111

    tinkirk

    i,m sorry i meant to say 72
     
  11. JOECOOL
    Joined: Jan 13, 2004
    Posts: 2,760

    JOECOOL
    Member

    My advice would to stop getting advice from everybody you talk to.Find someone" one person" who has a car that runs well and work with them until you get it . Tuning a car by commitee will never work.I won't give you any tuning advice, buy a Holley book off Amazon and figure it out .Best of luck.
     
  12. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    Joe,
    Im not tuning by a car commitee..Im getting suggestions. I plan to take all of this info, apply what I already know, and try things out/draw conclusions.

    I know lots of awesome people around here who help me out tremendously. I just dont have a good reliable motor guy. This is the first motor Ive ever built, for reference.

    I could be wrong but Im pretty sure thats how you learn and im pretty sure thats the point of these forums. I' love to buy a book and "figure it out" if I felt that would work.

    In addition, the reason Im asking these questions on this forum is Im pretty sure everyone doesnt have the perfect answer to every single question I ask. Hence, the reason I had many sources from many experts when I built this car.

    I appreciate your input
     
  13. squirrel
    Joined: Sep 23, 2004
    Posts: 50,308

    squirrel
    Member

    You'll get it....try a few things, one at a time, and see what happens. It's how most of us learned.
     
    pprather likes this.
  14. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

  15. wick22
    Joined: Nov 23, 2012
    Posts: 27

    wick22
    Member

    have you cut the threads off a plug and see how fuel rings look?
     
  16. wick22
    Joined: Nov 23, 2012
    Posts: 27

    wick22
    Member

    have you cut the threads off a plug to see how fuel rings on plugs look?
     
  17. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 3,646

    2OLD2FAST
    Member
    from illinois

    You refer to this carb as a 650 DP but you only mention 1 accelerator pump & 1 pump cam , I'll take a guess that this is a 650 dual - feed w/ mech secondaries ...if that's the case then the tuning procedures would be different than a double -pumper...just trying to keep the record straight..
     
  18. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    2 accel pumps and 1 pump cam. thanks
     
  19. tinkirk
    Joined: Jan 16, 2017
    Posts: 111

    tinkirk

    Elliott
    If you have two excel pumps you need two pump cams
    The carb is a 4150 right?


    Sent from my iPhone using The H.A.M.B. mobile app
     
  20. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    4150. 2 pumps cams. Youre right, sorry
     
  21. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    Happy Thanksgiving everyone. Here's a little update: I tried size 31 pump nozzle which didn't help at all. I had a set of 25's which I also tried for kicks with no luck.

    I even unhooked the secondary pump cam to see what would happen when I floored the throttle, and I got the same response from the car which is what I believe to be a bog. Any ideas ?
     
  22. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    Correction from earlier: from what I've gathered, I believe what I'm experiencing is an off idle stumble/hesitation.
     
  23. No surprise there. Of course that's not gonna work .Mechanical secondary with no dampener and very little pump shot? Now give it a whole bunch of secondary shot and see what happens.
     
  24. Elliott Taylor
    Joined: Nov 19, 2017
    Posts: 23

    Elliott Taylor

    The reason I unhooked the secondaries was to see if they were even the culprit/rule them out, not to see if that would fix the problem.

    What do you mean give it a lot of secondary shot? What are you referring to adjusting?
     
  25. 19Eddy30
    Joined: Mar 27, 2011
    Posts: 1,361

    19Eddy30
    Member
    from VA

    Take DP off , 650-750 vac , change out Air gap intake ,In my opinion Miss match combination , there is so much more to a tuned engine then Jets , power Vavle , There are so many ajustments to a Carb, timing is critical in tuning, engine temps ,Fuel ratio threw entire Rpm rang , idle , Cruise ,to WOT , seat of yr pants is not a good reference , I have posted several times on tuning a engine , Lots of notes time trial and error ,
    Invest in a Good Wide band O2 gauge , find yr self a commercial 4,5,6 inch Vacuum gauge , document
    RPM’s Vac & AFR’s in all different rpms ranges,
    Then Read up on how to Really tune a carburetor
    Yr hard work will pay off
    Here is a good start to learning how to tune a carb
    http://www.bob2000.com/carb.htm
     
    Last edited: Nov 23, 2017
  26. You said you unhooked the secondary cam, not the linkage. Which is it ?
     

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