Increase the performance of my 401

Discussion in ''Da Nailhead' started by nailheadfrench, Jul 22, 2014.

  1. doc

    doc Well-Known Member

    Hey,,, Frenchy,,,, while you have that manifold off,,, grind all that knuckle skinning casting flash off of the outside of it....:Brow: easy to do now,,, and it will , will,, save you some knuckle skin later on..... :Brow:
     
  2. nailheadfrench

    nailheadfrench Active Member

    Hello,


    Well, I have problems with my new quadrajet carb, fuel flows through the main jet at idle and the engine drowns!


    The needle is good and I have a pressure regulator set to 5 psi.


    Impossible to have a correct idle, the engine drowns! grrrrrrrrrrrrr

    IMG_0173.JPG
     
  3. Bigpig455

    Bigpig455 Fastest of the slow....

    Check the float level....set to 6.3-7.5 mm. Is the needle and seat working correctly (can it stop compressed air?) Watch to make sure the needle retaining clip is positioned correctly... if you don't know, just put it together without it and see if it makes a difference. Also make sure the primary rods have enough vacuum to keep them seated in the jets at idle (weak spring). Do you know the build specs on it? Jets/rods and idle channel restriction?
     
    Last edited: Nov 7, 2014
  4. nailheadfrench

    nailheadfrench Active Member

    Hello,

    I control the needle and adjusting the float. It closes properly, we can depart this problem.


    The guy in France who built me this quadrajet to calibrate for a 1979 400 pontiac engine.


    I think he does not knows the buick to do good work, so I'll give him the carb and buy usa and calibrated to the real specialist Buick.


    Bigpig455 I contacted Ken-performance It will therefore build my quadrajet!

    Thank you for the address.


    Thank you very much for all your help!


    Jerem
     
    Last edited: Nov 8, 2014
  5. doc

    doc Well-Known Member

    I can tell that Jerem is thinking in
    french and talking in English.....:Brow::grin:,,,that is what makes us Cajuns so charming....:laugh: love it...
     
  6. Bigpig455

    Bigpig455 Fastest of the slow....

    I'm impressed that anyone can juggle two languages in the first place. I cant even think in English and talk in English!

    NH French - good call with Ken. I'm actually thinking he might be using one of my extra 66 linkages that I'm dropping off today. Keep us posted!
     
  7. nailheadfrench

    nailheadfrench Active Member

    That's exactly right Doc:Brow:
     
  8. Mark Demko

    Mark Demko Well-Known Member

    Damn! THAT CAR IS SWEEEEEET!!:TU:
     
  9. nailheadfrench

    nailheadfrench Active Member

    Hello,

    My nailhead works great on your TA25 cam works very well!

    But this afternoon, for a big acceleration, I broke two rockers. Fortunately, no other damage.
    I was not near my home when it happened, I replaced these two rockers by old that I had kept and I could bring the car.



    After thorough examination, it appears that the push rod takes the passage of the rod in the cylinder head. The push rod touching the cylinder head when the valve opens, levering on the rocker arm. Rocker rods are marked and slightly bent! I do not know if I'm clear.

    By and large, adjustable push rod is too thick for the passage of the latter into the breech. The geometry is not good!

    2 rockers his 2 valve of n1.

    I noticed that when the valve on the cylinder 1 was opened, the rocker shaft is dangerously close to the edge of the passage in the cylinder head.

    I did not pay more attention, it was a mistake!

    We'll have to see the geometry of the rocker can be roller rocker?

    The valve stem tips to valve cover gasket surface is a little less 1.600"

    How to solve the problem? The use of ta performance roller rocker arm and stock push rod thin , it can solve the problem?

    Thank you very much for your help.

    Jerem


     
  10. 8ad-f85

    8ad-f85 Well-Known Member

    I would be curious as to the limitation of reaming the pushrod hole before having to tube it.
    Sorry if this is a derail.
     
  11. gs66

    gs66 Silver Level contributor

    Very interesting thread here and what a great looking car!
     
  12. Bigpig455

    Bigpig455 Fastest of the slow....

    I had the same issue with my stock pushrods, they were just touching the head. You could make the pushrod hole larger, but you'd have to take the head off to do it. Mine were only touching at the top of the head, not down at the block.

    When I went with a larger hollow pushrod and Tom's rockers, the geometry actually improved because of the ratio of the rockers - I do not know if TA's rockers will have the same advantage...Maybe Tom will chime in here.
     
  13. doc

    doc Well-Known Member

    If the push rods are a bigger diameter than the stock ones , you may have to drill the pushrod holes in the head out some to accomodate them.... I have put stock tubular push rods in a lot of times and never had a interference problem....
    sounds like you would do fine with stock rocker arms and just drilling out the pushrod holes some....
     
  14. nailheadfrench

    nailheadfrench Active Member

    hello,

    Here is my opinion after using the adjustable pushrod 3/16. My opinion is that it is too big for the passage of the cylinder head. Even by enlarging the passage of the cylinder head, the pushrod 5 / 16ths "diameter Which Then rubs on the valve spring.
    It does not please me. So I will not use the adjustable pushrod.


    There is no problem with the stock 1/4 push rod. But I absolutely have to be able to adjust the rockers for preload the lifter Correctly.


    Can I use the stock 1/4 pushrod with the tom telesco rockers?


    Can we have a set "tom telesco" quickly?

    Thank you.
     
  15. wkillgs

    wkillgs Gold Level Contributor

    Yes, stock pushrods work with Tom's roller rockers. Using the thin steel head gasket, the pushrods were 'almost' too long... I had the adjuster turned out all the way to get the lifter preload correct.
     
  16. nailheadfrench

    nailheadfrench Active Member

    it's good to know. I send an email to tom telesco.
     
  17. nailheadfrench

    nailheadfrench Active Member

    Hello,

    The new rockers with new ramp quality were assembled.


    My problem was that the valve was 1.5 mm too high. To use the adjustable pushrod, the valve stem above-the rocker arm cover gasket surface of the cylinder head must be 1540 "


    On my nailhead, all the valve stem were 0.60 " too high. So I placed shim thickness under the rocker arm support pad.


    After driving about 650 miles fairly steady, my nailhead run very great!

    http://youtu.be/NC7HdT-H3ZQ
     
  18. sodak65

    sodak65 Well-Known Member

    Wow fantastic videos! OK who wants to trade there 66 for my 65?
     
    Last edited: Feb 9, 2015
  19. Bigpig455

    Bigpig455 Fastest of the slow....

    What did you use for rockers? TA's?
     
  20. nailheadfrench

    nailheadfrench Active Member

    Bigpig455,

    The rockers are sold by "global falcon" on ebay. The quality looks very good.


    The adjustable pushrod are "ta perf"

    Sodak65,

    Thank you for the offer, but I'll stick with my 66:laugh:
     

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