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Header wrap

Discussion in 'The Garage' started by dontoe, Nov 2, 2004.

  1. dontoe

    dontoe 3/4 ton status GMOTM Winner

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    Anyone using/tried the fabric header wrap? I bought three rolls from JC Whitney a while back and wondered if it is a waste to put on me 73 K-5 with Thorley headers.
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    my friend put them on his ford and they cracked down just about every tube in about 6 months. im not gonna use them.
     
  3. dontoe

    dontoe 3/4 ton status GMOTM Winner

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    Cracked down? What'cha mean?
     
  4. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Header wrap ruins headers. Get coated headers if you want to hold the heat in.
     
  5. sled_dog

    sled_dog 1 ton status

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    with thorley headers they should already be coated, so basically you'd be puting them on just to protect spark plug wires, and as long as you route them right there is no problem.
     
  6. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    the cracks ran along the tube, most were about 1' long.
     
  7. dontoe

    dontoe 3/4 ton status GMOTM Winner

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    I bought the chrome Thorley headers a few years back. Hoping the wrap would substantially reduce the heat in the engine compartment and floorboard. Actual tubes cracked or the wrap?
     
  8. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    the tubes, he had to replace the headers
     
  9. dontoe

    dontoe 3/4 ton status GMOTM Winner

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    WoW /forums/images/graemlins/doah.gif Wonder why? /forums/images/graemlins/confused.gif
     
  10. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    WoW /forums/images/graemlins/doah.gif Wonder why? /forums/images/graemlins/confused.gif

    [/ QUOTE ]

    Because they get hotter this way, heat = expansion = cracks.
     
  11. sickquad

    sickquad 1/2 ton status

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    I used to work with a guy that made custom headers for hot rods. I asked him about the wrap and he said never do it. Gave the same reason of expansion and cracks and such.

    -Chris
     
  12. tx_sub

    tx_sub 1/2 ton status

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    the wrap works to reduce underhood temps and speed up exhaust flow but at the cost of accelerated header breakdown. cracks like you guys are describing would be caused by temperature differentials in the material. any sudden change in temp would cause the molecular structure to expand or contract. any existing stress concentrations would be increased and start crack propagation. at those temperatures the exhaust gasses may react more readily with the steel inside the tubes to accelerate breakdown. racers who do limited runs on their engine components can afford to use the wrap. they tear apart their engines almost as often as we fill up our gas tanks.
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    Yep, I agree, don't run it.

    Headman states not to use it as it voids their warranty.

    What I have experienced first hand though, is that headers coated INTERNALLY greatly reduce the amount of heat dissipated into the engine bay. I've seen the same in testing in magazine articles.
     

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