Exhaust to carb line??

Discussion in 'Technical' started by 72Comet35, Jan 27, 2010.

  1. 72Comet35

    72Comet35 New Member

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    I was reinstalling the valve covers and the line on the right side that goes from the exhaust manifold to the carb and screws in broke off right at the manifold, looks like it has something to do with the choke. is that line needed of can i just bypass it?
     
  2. rthomas771

    rthomas771 Member

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    Really don't need it but it is nice to have it for the choke to work properly. They make a kit that clamps to the exhaust pipe that has provisions for the choke tube.

    [​IMG]
     
    Last edited: Jan 27, 2010
  3. FordsForever

    FordsForever Member

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    If the tube broke at the exhaust manifold and you had clear access to it, you may be able to just drill out the broken piece. Then if there is enough remaining length of the tube, reinsert the tube back in place.

    That is the heat riser tube for the choke. Without it the choke may never open up. Of course the alternative is to install an electric choke element to the carb and wire switched 12 v to it. Then you don't need the heat riser tube anymore which can be capped off at the carb.

    Ron
     
    Last edited: Jan 27, 2010
  4. jncastell

    jncastell Member

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    Can you buy an electric choke for a two barrel? When I was checking on getting headers and an electric choke I was told it had to be a four barrel. Later I thought didn’t the last two or three years of Mavericks have them or am I thinking electronic ignition?
     
  5. FordsForever

    FordsForever Member

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    You can use a electric choke from any ford autolite carb whether 2 bbl or 4 bbl are all the same design. They vary in opening rates but otherwise are all useable. Some are different in how the bi-metal element links to the the internal mechanism. Your local salvage yard is a good source. Just take a pocket ohmeter with you and check for continuity of the choke element. If no continuity the element is no good.

    Another choice is a Holley choke element which also fits. Made for a Holley but also fits ford Autolite carbs.

    http://www.holley.com/types/Choke%20Service%20Parts.asp

    Choke element: #45-258
    Choke conversion kit: #45-226

    Some electric choke elements operate way to fast which means they open too fast. A way to fix that is to add Holleys' 'Electro-Dyn Heat Sensor which is a temp control which mounts to the intake manifold and is wired in series with the choke element. It controls the choke element so it doesn't open up all the way untill it senses coolant temp through the intake manifold. Will control any choke element no matter which model or how fast it opens.

    Click on link for install info for the Electro-Dyn:

    http://www.holley.com/data/Products/Technical/199R8264.pdf

    Electro-Dyn Heat sensor: #45-267

    The sensor will work with any non-holley choke element with a simple modification to the wiring connections.

    Ron

    To use a non-holley element:

    Cut off metal tabs on sides of choke element housing. File or grind some of the cad' plating off one of the tabs(doesn't matter which one). Solder a wire to the tab. Ginding off the plating makes soldering much easier. This wire will connect to the lead to the Electro-Dyn module. Bolt the module to the intake manifold in a location that it will sense coolant temp.

    Where the bi-metal coil connects to the internal mechanism must be insulated so they make no electrical connection. Use shrink tubing if possible. Must still make mechanical connection so bi-metal coil can move mechanism.

    Some ford elements have a loop on end of bi-metal which fits over a single tab on the carb. Others have a flat or dog-legged end that fits in a slot on carb mechanism.
     

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    Last edited: Jan 27, 2010
  6. PaulS

    PaulS Member extrordiare

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    The electric choke carbs on my two 73 Mavericks use the same heater tubes as the old automatic chokes. I just drill out the broken tube and make a new one using 1/4" brake / fuel line with the old nut and a new ferule. I just had to do this on my wife's 302 when I pulled the heads. The old one was rusted and broke as I was removing the heads.
    I didn't even have to remove the manifold from the head to drill it. (I replaced it after I had put the engine back together) I had plenty of room to access, drill and install. The hardest part (not that hard) was bending the new tube.
     

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