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Carby Trouble

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  • Carby Trouble

    Hi guys,

    I am trying the sort out a problem with a Holley carb on my '62 Hawk. When I bought her some idiot had fitted a 650 cfm Holley, I swapped that for recon'd 465 cfm and have had some tuning problems. Recently while trying to get the idle mixtures right, ( as she was running rich), using a vacuum gauge I screwed the mixture screws ALL the way in on both sides, and the engine still ran. Now to my way of thinking this means she is getting fuel some where else, or am I totally wrong and is it a vacuum leak ?

    Some help please !

    Oh, by the way, I've just joined, I'm from Brisbane Australia - it's about half way up the east coast. I've had Stude's on and off all my life after being bitten by the bug when I was about 17. I now have a '54 Champion, and the '62 Hawk.

    Cheers
    Matt

  • #2
    Hi Matt, it's 12:28 here on the West coast of the US, must be noon down under! Studes. never used any Holleys, so I don't know much about them, but it is possible that the metering rods and or jets in that small 4 brl. are very large, making her run rich. Holleys are famous for blowing the power valve, maybe check that!
    Good luck with it, time for bed, see ya! Rich.

    quote:Originally posted by Aussie Hawk

    Hi guys,

    I am trying the sort out a problem with a Holley carb on my '62 Hawk. When I bought her some idiot had fitted a 650 cfm Holley, I swapped that for recon'd 465 cfm and have had some tuning problems. Recently while trying to get the idle mixtures right, ( as she was running rich), using a vacuum gauge I screwed the mixture screws ALL the way in on both sides, and the engine still ran. Now to my way of thinking this means she is getting fuel some where else, or am I totally wrong and is it a vacuum leak ?
    Some help please !
    Oh, by the way, I've just joined, I'm from Brisbane Australia - it's about half way up the east coast. I've had Stude's on and off all my life after being bitten by the bug when I was about 17. I now have a '54 Champion, and the '62 Hawk.
    Cheers, Matt
    StudeRich
    Studebakers Northwest
    Ferndale, WA
    StudeRich
    Second Generation Stude Driver,
    Proud '54 Starliner Owner

    Comment


    • #3
      Hey Matt

      As you know...no metering rods, so don't worry about that.
      Look at the 6 (like R1848-1) digit number on the base of the carburetor and let us know what it is.

      If that is the number...
      The jets should be #57's,
      A #8.5 power valve,
      A #.025 discharge nozzle,
      A green spring in the secondary body

      You may have the throttle blades open too far. That messes up the whole tune-up.
      Another thing to look at is the power valve, it may be leaking. Either not tight or the rubber part may have split open. If it getting enough gas to run with the mixture screws all the way in, theres a gas leak somewhere. Did it back fire at any time? That is the weak link on an early Holley. There kits availible to protect the valve from back fires. Check the Jegs or Sumit catalogs for those.

      Could also be a leaking internal gasket. If your rebuilders there are like the average rebuilder here in the states...look out...who knows what they did inside!

      Looks like you have the smallest Holley four barrel made....and I'd bet not many were made in the first place.

      Check the power valve, clean it off...and suck (!) on the flat side. you should get no air.

      Good luck.

      Mike

      Comment


      • #4
        In a simplified echo of Mike's rundown, WAS the idle adjust screw backed off completely when you ran the mixture screws all the way in??? If it wasn't backed off completely, any mixture adjustement you do is not gonna be right, in the end.

        Miscreant at large.

        1957 Transtar 1/2ton
        1960 Larkvertible V8
        1958 Provincial wagon
        1953 Commander coupe
        1957 President 2-dr
        1955 President State
        1951 Champion Biz cpe
        1963 Daytona project FS
        No deceptive flags to prove I'm patriotic - no biblical BS to impress - just ME and Studebakers - as it should be.

        Comment


        • #5
          Hey guys,

          Wow, thanks for all the advice, looks like I've got some tinkering to do. I'll check out all your suggestions and see how I go. I've been visiting the Holley page and trying to get a handle on it from there, but as you can see from my posting to you guys they didn't help much. If I can't get this 465 to work I'll try and locate a good original carb and maybe an overhaul kit. As you can imagin we didn't get as many Stude's down here as you guys have, so parts are become fairly scarce these days.

          Once again, thanks for all the help - should have known Stude guys were tops.

          Matt
          Matt
          Brisbane
          Australia
          sigpic

          Visit my Blog: http://www.mattsoilyrag.blogspot.com.au/

          Comment


          • #6
            One more minor point, the idle screws adjust air, not fuel. If they are screwed all the way in and it is running, the engine is getting air somewhere else, either around the throttle plates or perhaps around the throttle shaft. Look for possile air leaks.

            Tom Bredehoft
            '53 Commander Coupe
            '60 Lark VI
            '05 Legacy Ltd Wagon
            All three Indiana built cars

            Comment


            • #7
              Concur; there is an air leak somewhere. Other sources of vacuum leaks:

              1. distributor vacuum advance
              2. vacuum gauge, if fitted
              3. intake manifold gaskets
              4. power brake booster.
              5. secondaries improperly adjusted or stuck slightly open

              the other possibility is you have an obstruction in your idle air bleeds and the throttle stop is adjusted wide enough to let in air.

              thnx, jv.



              PackardV8
              PackardV8

              Comment


              • #8
                While the mixture screws do adjust the amount of air the is mixed with the fuel, I can't count the amount of times that excess fuel masked other problems and made the mixture screws unresponsive.

                So yes, it can still be fuel related.
                Holleys don't normally leak much air unless the base is broken (?).

                Mike

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