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Vacuum Leaks: Carb, Manifolds

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  • Engine: Vacuum Leaks: Carb, Manifolds

    first of probably several repair threads - this is regarding my '51 Champion Business Coupe that was Tom Elliott's car - i am now its "caretaker". 6 cyl 170, automatic. the carb is a Carter #WE-715S.

    my first long trip last month to a club meet, Joe & Jamie noticed a gas drip from the the carb after she had been parked for awhile. when i got home, i discovered that all the screws were loose - some about 1/4 turn, a couple up to almost a full turn. that took care of the leak.

    after the holidays, i cleaned the oil bath filter. before putting it back on, i cleaned the carb with "carb spray" with the car running. every place i sprayed where there were screws holding it together, i got a significant increase in rpms, down to to intake manifold gasket to the engine.

    i mailed "mbstude" and he stated the carb was rebuilt by "Dave T-Bow" at some point, but was only put on last year. my thoughts are the gaskets dried out and i can get by with a carb gasket kit and new manifold gaskets.

    thoughts before i order just the gasket kits?

    Kerry. SDC Member #A012596W. ENCSDC member.

    '51 Champion Business Coupe - (Tom's Car). Purchased 11/2012.

    '40 Champion. sold 10/11. '63 Avanti R-1384. sold 12/10.

  • #2
    A few months after I rebuilt the WE on my Champion I noticed stains on the side of the carb. Same as you all the screws were loose. I tightened them more aggressively and that helped. Now checking the carb screws is part of my spring/fall maintenance checks. I still find a loose one once in a while. Between age, vibration, and dissimilar metals I am not too surprised. I suppose loctite is an option but it has not been that big of a problem for me.

    I bet your RPM increase is from the carb cleaner being sucked in the carb intake. Just spraying that stuff anywhere near the intake will richen the mixture. If the gaskets were leaking that much fuel would be coming OUT more than air going IN.



    • #3
      Kerry: Before going any further, start the engine and carefully spray carb cleaner around each manifold-to-side-of-the-block connection. Any change in RPM there indicates a leak between the intake manifold and the side of the block. That must be addressed before doing anything with the carb to make the engine run better.

      Tightening the nuts on the hold-down studs might help, but don't get carried away with it. If it persists in RPM change with the nuts properly tightened, you'll likely have to remove the intake manifold and have the outlet surface(s) planed to restore flatness.

      When reinstalling, leave the exhaust manifold-to-intake-manifold bolts a little loose until the intake manifold is firmly attached to the black. Then tighten the intake-manifold-to-exhaust manifold bolts. BP
      We've got to quit saying, "How stupid can you be?" Too many people are taking it as a challenge.

      Ayn Rand:
      "You can avoid reality, but you cannot avoid the consequences of avoiding reality."

      G. K. Chesterton: This triangle of truisms, of father, mother, and child, cannot be destroyed; it can only destroy those civilizations which disregard it.


      • #4
        thanks for the responses so far!

        Bob, i guess i wasn't clear - i did spray the intake manifold at the engine gaskets and also got the increase in rpms. i did tighten down some of the manifold nuts that were a little loose but used a socket wrench (or open end on a couple), so i didn't overtighten or break anything. the most i got was about a 1/4 turn on the nuts. still got the vacuum leak. i'll certainly get the manifold planed if needed (probably will).
        so, i'll be ordering intake manifold and carb gasket kits soon. and "while i'm there", the exhaust gasket and the gasket from the exhaust manifold to the head pipe, as i was told the head pipe gasket was bad.

        Nathan, checking the carb screws for tightness will be part of my normal maintenance procedure. fortunately, i live where i can drive her year round. regarding the carb spray going into the carb intake: i've never had an increase of rpms in any car - always lowers it.

        now, if anyone has a "cathcart" prepared dual carb 6 , or a good running Stude V-8 laying around taking up space, i'd be more than happy to pick one up at no charge (to me), except for shipping costs!
        Kerry. SDC Member #A012596W. ENCSDC member.

        '51 Champion Business Coupe - (Tom's Car). Purchased 11/2012.

        '40 Champion. sold 10/11. '63 Avanti R-1384. sold 12/10.


        • #5
          Be careful with a dual carberator setup. I have never seen one that was set up correctly, or that ran right. And I have seen a bunch of them that were done poorly.

          Generally the linkage is mickey moused, the chokes have not been properly set up, and the whole thing looked better than it operated.

          I'm not saying that it cannot be done, but the ones I have seen were not done properly. There is more to it than is immediately apparent.

          My thoughts are that if you want more carberation, try a larger carberator, like one from a truck. But whatever you do, a Champion automatic will still be underpowered.
          RadioRoy, specializing in AM/FM conversions with auxiliary inputs for iPod/satellite/CD player. In the old car radio business since 1985.

          17A-S2 - 50 Commander convertible
          10G-C1 - 51 Champion starlight coupe
          10G-Q4 - 51 Champion business coupe
          4H-K5 - 53 Commander starliner hardtop
          5H-D5 - 54 Commander Conestoga wagon
          56B-D4 - 56 Commander station wagon
          60V-L6 - 60 Lark convertible


          • #6
            thanks Roy for the input!
            when i was a mere yout' i had several cars with dual SU carbs and they were quite a pita to calibrate. plus a dual carb VW baja bug. those "cathcart" 6's just look so cool! i was kind of "wishing out loud" about that and/or a V8. i'm not really looking for "fast" - just drivable and something the former owner would be proud of...

            i'm trying to prioritize repairs, this seems to be the most important so far. valve guides for sure (as i've been told), maybe more engine/trans work. quite a bit of electrical - wiring, turn signals, reverse lights, gas gauge, and many more other repairs are needed.

            with some new health problems, there's no way i want want to miss this season of car shows/club events!
            Kerry. SDC Member #A012596W. ENCSDC member.

            '51 Champion Business Coupe - (Tom's Car). Purchased 11/2012.

            '40 Champion. sold 10/11. '63 Avanti R-1384. sold 12/10.