To insert a pipe in the exhaust manifold ?

Discussion in 'Projects & Proposals' started by Externet, Jun 28, 2009.

  1. Externet
    Joined: May 2009
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    Location: Mideast U.S.

    Externet Junior Member

    Hello all.

    For a small block GM V8, there may be many different types of wet exhaust manifolds, but sticking to whatever is typical stockish; how would you insert a straight 5/16"~3/8" stainless steel pipe lenghtwise into the hot gases chamber and exiting at both ends of the manifold ? (a pass-trough pipe)

    Perhaps compression fittings on threaded holes at the ends ? Or some other suggestions and considerations ?

    Yes, the hot gases would encounter a little restricted path because of the intrusion of such pipe in the chamber.

    Is there a type of wet manifold that such contraption would not be advisable on ?

    A crude 'ideal' drawing,
    top and bottom "====" the double wall jacket;
    centre "====" the inserted pipe;
    "O" the head outlets;
    "^^^" the flange to riser shown centered, but could be at one end.
    Ignore the dots.

    .....|==============|^^^|=============|
    =====================================
    .....|======O======= O O =======O======|

    Miguel
     
  2. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    why do you want this ?? if its for hot water why not wrap copper pipe around the outside ? you could drill and braze /silver solder your thro pipe into place
     
  3. Frosty

    Frosty Previous Member

    I too am confused , what are you wanting to do?

    If you want some hot water???? just hook in a heat exchanger in the cooling system.

    Make one up --st/steel box --copper pipe. braze it in.

    The exhaust is far too hot it will boil.
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Are you trying to run a pipe through two water jackets and the inside of the manifold? What for?
     
  5. Externet
    Joined: May 2009
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    Externet Junior Member

    Trying to find a proper securing method for the pipe to be in the hot exhaust flow only, not trough water jackets.
    Am reluctant to welding/brazing as the linear expansion of the pipe for a delta T of >~1000FÂș could break welds. :(
     
  6. Frosty

    Frosty Previous Member

    Still dont know what you are trying to do???

    Is this a water injection pipe.
     
  7. Externet
    Joined: May 2009
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    Externet Junior Member

    Steam from seawater. To distill. For 'pennies'
    I made fresh water supply on a tuna fishing boat too many years ago. It had a plain 'insulation wrapped' exhaust stack on Detroit Diesels 671, easier to tackle.
    Trying to do it on a small yacht.
    Miguel
     
  8. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The exhaust manifolds have water jackets. There is no way around it.
     
  9. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    You would have to build a custom exhaust manifold based on car engine manifold then use wet exhaust after that. Wrap exhaust manifold with copper tubing and trickle just enough salt water to generate right amount of steam and then send it somewhere to cool like keel cooler. I don't know if the extra heat in engine is worth the problem, also gas engine being run a large amount of hours to make water is not very efficient. That said the idea is not bad on a diesel with a section of dry exhaust, problem would be corrosion.
     
  10. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    you could put a 3 inch coupler after the manifold and feed the pipe in and up tpwards the engine then double back and out again ....BUT yes you can only have pure steam but where does the salt go ...it bungs up the pipe .like a kettle in a hard water area .......bad idea
     
  11. Externet
    Joined: May 2009
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    Externet Junior Member

    As myself am not familiar with their construction, the question is which of these:

    http://www.webspawner.com/users/hitekmarine/front-manifolds-lrg.jpg

    http://www.cpperformance.com/images/421-PF-8.JPG

    http://www.wholesalemarine.com/mm5/graphics/00000001/SIE-18-1953-2_med.jpg

    http://www.tristband.com/ebay/sierra1983-1.jpg

    or other common exhaust has no double wall water jacket at the ends, as that has to be the place to drill to insert the pipe lengthwise, kind of sketched on the initial post. Perhaps this one? :

    http://www.sterndrive.info/sitebuil.../Mercruiser-marine-manifold-140-1968-1982.jpg

    If none :( has a spot that a perforation will not cross on jacket water, I will have to come up with a more elaborated double walled fitting to bridge the jacket.

    pistbroke: Yes, a curved pipe in the manifold is a bad idea.

    mydauphin : it is not to run an engine to make water, it is to make water when the engine is running. :)

    Miguel
     
    Last edited: Jun 30, 2009
  12. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    nothing wrong with the pipe going up the manifold and then bending 360 and comming out again
    WHERE WILL THE SALT REMOVED IN THE BOILING END UP ????

    BUNGING UP THE PIPE ...why do they use distilled water in a model steam train ???? think on it (_!_)

    you will also have to pump the water in as 1cubic inch of water ( for you non metric yanks ) makes 22400 cu in of steam ( Avagadros number ) ...At NTP of course ....if the steam temp doubles you will get twice that volume ....
     
  13. Externet
    Joined: May 2009
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    Externet Junior Member

    Hi.
    There is many ways of doing it wrong, a non-straight pipe is one of them.

    The "should be straight" pipe takes a "+" (cross) fitting at its flow exit end. The lower branch drains brine carrying the salt away, the top branch carries steam, a side branch is a plug, plus other details.

    But you can make one with a 180, or 360 turn.

    Miguel
     
  14. murdomack
    Joined: Jun 2007
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    murdomack New Member

    Could you use sandwich flanges with the tubes in place at the head outlets? Would a leak be liable to run back into the engine once it was stopped?
     

  15. Frosty

    Frosty Previous Member

    What about a 12v kettle???
     
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