Register now to get rid of these ads!

Holley choke horn removal?

Discussion in 'The Hokey Ass Message Board' started by Mr. Sinister, Jun 27, 2011.

  1. lippy
    Joined: Sep 27, 2006
    Posts: 6,825

    lippy
    Member
    from Ks

    OOPS sorry I got this thread confused with the one where you were having carb troubles.. Sorry, my bad.:eek:
     
  2. oj
    Joined: Jul 27, 2008
    Posts: 6,454

    oj
    Member

    50 or more cfm one way or the other will not make any difference in 'seat of the pants' power - you will be able to see differences on a dyno but not in the real 'seat of your pants'.
    The 670 avenger is pretty much a pile of junk, a gussied up 4160 650cfm vacuum seconday that works ok in a dumptruck or school bus and cooked the numbers to get another 20cfm. In brief, the carb was invented by the marketing division to compete with edelbrock and has nothing to do with 'performance'.
    You got a hot rod and want 'seat of the pants' power you go with a double pumper. Hot rodders and racers figured that out decades ago, let the vacuum secondary street avengers sit on top of the guys intake in the other lane.
     
  3. The website is still up. I heard the same thing, but I also heard they were bought by a larger company and were making carbs again.
     

  4. It's alright. :)

    The car actually does run pretty well, but the way I had it idling in gear and in neutral with the Demon has me all hot and bothered. :D
     
  5. Well, weight, automatic with 2500 stall and 3.55 gear dictate vacuum advance, no? I plan on an eventual manual trans and more gear, so I'd definitely be in the market for a DP then. What are you thinking, like a 650 DP?
     
  6. I totally agree with OJ regarding "can this mod be felt in the seat of the pants". I doubt it (read that as NO) ... BUT it is a mod that can be done for basically nothing if he does it himself, it won't hurt performance (although it most likely will hurt the resale value of the carb if he wants to sell it and upgrade later) and he already owns the carb if I recall correctly. I say "go for it".
     
  7. Phucker
    Joined: Sep 12, 2010
    Posts: 185

    Phucker
    Member
    from Kansas

    For a mild 350, that is perfect, IMHO.

    Removing the airhorn is a complete waste of time.
     
  8. Response from Barry Grant:

    Barry Grant Demon Carburetion as posted on facebook " As of today, February 18, 2011, we are ceasing operations at our Dahlonega location and all subsidiary locations. Working with all of you has been the experience of a lifetime. I will value your support as friends, customers, vendors, and media contacts forever. The economic situation has put the company in the position of not being able to find working capital needed to continue operations and get a chapter 11 reorganization plan through the court. In addition to this, is that all of our equipment has been breaking down causing production delays and further hurting cash flow. Reluctantly now we must convert to chapter 7 liquidation after 26 years of business. The financial collapse has closed, or has caused severe restructuring of many companies in our industry. Many individuals have lost everything. We have even lost our home. This is the most humbling experience of my life, and I have no future plans at this point. Thank You for Your Many Years of Support. Barry and Robin Grant"


    As you can see from above Barry Grant/Demon carbureton is no longer in business. We are a small group of former technical employees who have started a small company that offers fee based technical advice as well as some parts and service for existing product that is in the field. We can be found on facebook under "ninja fuel systems" .
     
  9. Also just picked up a lightly used Performer RPM Air Gap intake for a song, so that will replace the standard RPM. From all the info I've seen, the air gap does make power over the standard RPM, and is good to 6500rpm, whereas the RPM is 6000.
     
  10. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    X2, just toss the choke blade and use a stub stack. Better yet, like I have said before, toss the whole thing and use an annular 750 DP with a stub stack.
     
    Last edited: Jun 29, 2011
  11. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    I'll pm you later about whats wrong with the formula. Not interested in a pissing match with the "true believers" that have never used a flow bench, and dont understand this stuff.
     
    Last edited: Jun 29, 2011
  12. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    Oh, and one more thing, decreasing flow restriction while maintaining the same venturi size and booster design will actually INCREASE booster signal, and make the carb MORE responsive, not less. When it comes to carbs, there is more pure, unadulterated bullshit accepted as fact than any other area.
     

  13. I'm more than happy to receive any input!!
     
  14. Brad54
    Joined: Apr 15, 2004
    Posts: 6,021

    Brad54
    Member
    from Atl Ga

    You really don't get the whole "Hot Rod" thing, do you?

    -Brad
     
  15. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    I don't mind it at all swappin' carbs.. :) And finding the right combo that suits the car.. :) I keep a number of those Holleys up on the shelf with the jet sizes written on the fuel bowls with a black Sharpie marker.. I've been meaning to attach Manilla tags on those with all the info written on them.. List #, cfm size, jet sizes on front an' rear, secondary diafram(sp) spring color for the vacuum secondary carbs, acc. shooter size front and or rear, etc., etc...
     
  16. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    I've installed the annular boosters on one of my BG carbs and it made one hell of a difference! :D Snappy out of the hole performance also!! :D I've got a Holley List# 4779 750 that someone gave me that has 2 busted venturie boosters on the secondaries.. I plan on machining that carb to accept the interchangable boosters that BG sells.. :)
     
  17. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    Ditto on playing with the booster size!!! :D
     
  18. rottenleonard
    Joined: Nov 7, 2008
    Posts: 1,993

    rottenleonard
    Member

    It would be interesting to use the 1/4 mile dyno before and after just to see if it does shave any time, I don't think you would be out much if it didn't improve it, I doubt it will hurt it if it didn't, and you said you never use the choke anyways.
     
  19. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    This is just heresay, but I considered doing this myself, and a pretty sharp, nationally known carb guy advised me against it, Apparently, the BG collars are prone to loosening. There are carb guys around that can remove and re-install flared in boosters same as the original holley installation. You can buy boosters from Braswell (Where I buy most of my carb stuff) and others. The carb I will be running on my chevy II has undercut dogleg boosters installed this way.
     
  20. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    You could always add a little "Loctite" around the collar threads if your worried about those coming loose... I've never had a problem with those 'cause I bought the tool to install those boosters.. And besides, the metering block gasket prevents those nutz from rotating to begin with!!!
     
  21. So I'm thinking mill the horn, put a stub stack on it, install the air gap intake and possibly play with the jetting.
     
  22. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    Here's a couple pics of that 780 venturie body I was tellen' ya's about... All I gotta do is grind up a form tool on a surface grinder to make the repairs so this carb can be put back into action... No big deal here.. I know it can be done.. :) I just need a damn Bridgeport and an od grinder to make it happen... :eek:
     

    Attached Files:

    Last edited: Jun 29, 2011
  23. When I see pictures of a carb with a choke horn, it only makes sense that it restricts airflow, since the carb pulls in air from 360*, not just straight down. Even the sharp edge of the choke horn looks like it would cause turbulence between the air being pulled straight down and the air flowing across the surface of the carb.
     
  24. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    Thats what I said to Troy when he told me that. he said, "no, they dont":rolleyes: Take it for what its worth. Think about it. The collar doesnt have to back all the way off, just enough to lose tension on the thread. Once that happens, theres nothing to stop the booster from vibrating its way out.
     
  25. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    Yep!... Maybe 2 sizes richer to begin with...
     
  26. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    "Loctite" :)
     
  27. David Chandler
    Joined: Jan 27, 2007
    Posts: 1,101

    David Chandler
    Member

    Have you considered adding some sort of spacer under the carb? If you do that, and play with opening up the casting between each size, the engine can theoretically see a larger carb, than what's on top. Personally I'd rather wreck a couple of cheap spacers, than start whittling on the carb. Also the added height might give you a bit more bottom end.
    The same applies to the substack idea. They are a lot cheaper than a carb, so if they don't do what you want them to do, you haven't lost much trying it. I've run a K+N air cleaner with a built in substack on 500 and 350 CFM 2 bbls. Both times there was a quite noticable increase in power, even while retaining the stock choke set up. Although I had to tweek the filter base a bit to clear the choke linkage.
    Good Luck!
     
  28. Lazlobassett
    Joined: Apr 12, 2010
    Posts: 475

    Lazlobassett
    Member

    Thats 'cause BG carbs really stands for BIG GARBAGE, not Barry Grant as is popularly assumed.

    I have a bunch of cars and have found that a stock Holley Double pumper works well, but if I send it out to nickerson performance, they cut the choke tower off and do other mysterious secret voodoo things and it comes back running GREAT! Huge seat of pants and 1/4 mile improvements. I've not tried doing it myself but now I am thinking....yeah, thats teh burning smell....sorry

    Cheers!

    Matt
     

  29. I fattened the carb up a few sizes from the get go, as it was pretty lean out of the box. I figure just between the stub stack and air gap, maybe try 2 sizes up on each end. I've got it dialed in pretty decent now, I think. Plugs are a nice medium tan color, but do have some black on the ring at the base of the threads, which I suspect is from a rich idle caused by the cam.
    Thanks!!
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.