HEAT RISER

TOM-WA-
TOM-WA- Senior Contributor
edited November -1 in HUDSON
The spring on my Heat Riser (1954 Wasp 262) is broken so I have removed it and the
heat riser is now free and can be moved by hand.

I want to wire it so that all the HOT exhaust is directed out the TAIL pipe and not up to the carb. Can someone describe to me what position it should be in and how I determine that.





THANKS

Comments

  • Uncle Josh
    Uncle Josh Senior Contributor
    edited July 2011
    If it's free, the weight on the rear, (left as you're looking at it) will fall down and close it. (Correcton: I was twisted. The weight will fall toward the engine, opening the baffle to exhaust. Wire it up (toward the engine) like Walt says to keep it open.

    The original springs (like in my 49) tend to change over the years and close the baffle too tight, requiring too much heat to allow opening. Instead of hooking the end of the spring over the pin, use a small piece of wire to loosen it.
  • RonS
    RonS Senior Contributor
    I was under the belief that when the spring is disconnected the valve defaults to open. The spring, when cold and connected to the pin, holds the baffle valve closed and slowly opens when the engine warms. Correct me if wrong.
  • [Deleted User]
    [Deleted User]
    Tie it so that the counter weight is all the way up. Use stainless wire or a wire coat hanger and make sure it can not move. Heat will still get to the carb base but exhaust is now free to exit. Walt
  • RonS
    RonS Senior Contributor
    Walt, Are you saying that if the spring is disconnected the valve will fall into a closed position?
  • TOM-WA-
    TOM-WA- Senior Contributor
    Josh:

    Ok I have it wired correctly, but the carb is still getting so hot inside that the gas is vaporizing and the car will NOT run,

    I have a stack of gaskets (5) under a heat deflector and a stack (5) above it and am getting good fuel flow from the pump but when the car reaches operating temp it
    will not run.

    Any thoughts or recommendations??
  • RonS
    RonS Senior Contributor
    Tom. I have my doubts re. wiring the weight up. Unless Hudson is differant, My 1950 Cadillac works the same way. With the spring disconnected the weight drops. When the spring is connected on a cold engine tension on the spring holds the weight to the top. As the engine gets warm, tension is reduced and the weight drops. So... how can wiring the valve to the cold position(up) help when the engine gets warm? The spring might be on the shaft wrong, but any other way, it doesn't do anything. If you discon the wire and let the weight, drop what happens?
  • onerare39
    onerare39 Expert Adviser, Member
    edited July 2011



    Tom,

    I'm siding with Ron S. on this one. Take a look at the pictures below.


    I have a spare 308 with a functional heat riser. When cold, the weight is straight up and the heat riser is closed. (first picture)

    The second picture is the weight on the heat riser being pushed down with a screwdriver, opening the heat riser. (second picture)

    IMHO... wiring it in the up position will be wiring it closed

    John Forkner
  • onerare39
    onerare39 Expert Adviser, Member
    edited July 2011


  • onerare39
    onerare39 Expert Adviser, Member


    [attachment:2]C:\fakepath\7 9 2011 015.JPG[/attachment]
  • onerare39
    onerare39 Expert Adviser, Member


    [attachment:2]C:\fakepath\7 9 2011 015.JPG[/attachment]
  • onerare39
    onerare39 Expert Adviser, Member
    edited July 2011




    Tom,

    I'm siding with Ron S. on this one. Take a look at the pictures above


    I have a spare 308 with a functional heat riser. When cold, the weight is straight up and the heat riser is closed. When I push down on the weight it opens the heat riser.

    IMHO... wiring it in the up position will be wiring it closed

    John Forkner
  • RL Chilton
    RL Chilton Administrator, Member
    That's correct . . . wiring it up will keep it closed. Best thing to do, is if you don't need it, is to remove the flapper inside. You are in a cold climate, so you may not want to do that. Next best is to get a replacement spring.
  • RonS
    RonS Senior Contributor
    You could just leave it fall open.Two downsides 1) cold weather is going to cause stumbling etc (not in Az), 2) noise can be a pest as the valve bounces creating clanking sounds. Good side of that is it keeps the shaft from freezing up. If it operational then I agree, use it.
  • tigermoth
    tigermoth Expert Adviser
    on my terraplane i made a stainless steel blanking plate to keep all exhaust gases from the carb base. regards, tom
  • Uncle Josh
    Uncle Josh Senior Contributor
    Edited original post
  • TOM-WA-
    TOM-WA- Senior Contributor
    Josh:

    I am now completely confused after reading the various comments.

    I have no spring on the heat riser and it is free to move....

    With no spring the weight falls toward the engine....Is this the position it should be in when the car is running at normal operating temperature??

    If it is then to insure that it stays in this position constantly then it must be hard wired to insure that it dosent move freely when the car is running...

    This is how I have had it wired for the past 2 years and it seemed to run fine.. Just recently with it wired in this position the fuel has been vaporizing
    in the carb bowl and the car will NOT run until it cools down...

    What would cause this to happen now when in the past it ran fine with the heat riser wired as you have described??



    Thanks
  • [Deleted User]
    [Deleted User]
    Try this test. remove wire and let it hang free. Now start engine, must do this quick before heat builds up, Hold counter weight in down position, and give engine gas, then hold in other position and give engine gas again, this will tell you open or closed as closed it will try to open when you give it the gas. Let me know the results, Walt.
  • TOM-WA-
    TOM-WA- Senior Contributor
    Can you explain a bit clearer....I have removed the wire and the heat riser is now free to move both forward and back....If I hold it in place by hand how will I see if it is trying to move when the engine heats up?

    Will I feel pressure against my hand?
  • Uncle Josh
    Uncle Josh Senior Contributor
    edited July 2011
    You're heat riser is OK Tom. I think your problem may be that the anti-perculation valves are stuck and not opening when you turn the car off. The Carter WDO carb is prone to this.

    They are on top of the carb under the cover and if they don't open to vent the float bowl, pressure builds up in the float bowl when hot and forces gas down the carb, flooding it and causing it to start hard when hot.
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