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ebay brake rotors--forging...

David,
  A forging process is instantaneous.   And I've never heard of anyone forging cast iron (those forged crankshafts are steel).
 Stress relieving is not the same as forging.
The maximum temp delta a part would see laying outside for years would be about 100F.  To you and I, one hundred degrees is a bunch...to cast iron it is virturally nothing and would have no effect on grain structure.  You and I have a working range of about 50 degrees (50deg at the coldest to about 100deg at the hottest), cast iron has a working range of about 1500degF.
 As I said, the only metallic material in common use today that will respond to just laying around is some aluminum alloys.

 Your friend may have misunderstood or the Morgan people were having fun with him....which wouldn't be unusual.

Larry  
  ----- Original Message ----- 
  From: David Utley 
  To: L F ; Euroroc II 
  Cc: Scirocco-l@scirocco.org 
  Sent: Wednesday, March 10, 2004 8:33 PM
  Subject: RE: ebay brake rotors--forging...


  Larry,
    I agree that forging is more effective, and quick, if it is done under
  pressure.  However, this is coming from Morgan, so I do not know what to
  say?  If they are online, I will send them an email and see if they can shed
  some light on it?  I trust the friend with my life, so I do not think he is
  pulling anything with me.

    To carry through on what you just mentioned, I grant you that a used
  engine will work-forge (or stress-relieve as you put it), with the thousands
  of heat cycles.  Is it not true to a lesser degree with an item that has
  hundreds of heat cycles with the warming of the day, and the cooling of the
  night?  Especially considering that it is done very slowly, which as I
  understand it is done in some forging practices?  If you would, please help
  me remember which ones and why slower warming/cooling is effective/helpful.

  Thanks,
    David Utley

  -----Original Message-----
  From: L F [mailto:rocco16v@netzero.net]
  Sent: Wednesday, March 10, 2004 8:19 PM
  To: David Utley; Euroroc II
  Cc: Scirocco-l@scirocco.org
  Subject: Re: ebay brake rotors--forging...

  David,
    Somebody gave your friend some bad info.
  Used cast iron blocks are desireable because the heat cycling tends to
  stress relieve them, whereas a 'green' block still has some "moving around"
  to do.
  Cast iron parts do nothing just laying around, as opposed to some aluminum
  alloys which DO age over time.
  I take that back; cast iron parts DO go through a change.....they convert to
  iron oxide.

  Nothing gets 'forged' just watching the weeds grow...it takes heat and
  pressure to forge.

  Larry
  ----- Original Message -----
  From: David Utley <mailto:mr.utility@highstream.net>
  To: Euroroc II <mailto:flaatr@yahoo.com>
  Cc: Scirocco-l@scirocco.org <mailto:Scirocco-l@scirocco.org>
  Sent: Tuesday, March 09, 2004 12:15 PM
  Subject: Re: ebay brake rotors--forging...

  LOL...

    Yeah, I did learn something interesting about this though...  A close
  friend
  went where they make Morgans in England years ago.  He saw in the back that
  they had brake drums and blocks waist-high, piled out in the open...  He
  asked
  what was all the waste rubble lying around, and they replied that those were
  new rotors and blocks, aging...  They said that they let them age a minimum
  of
  two years, then bring them in and machine them for use.  Why?  They actually
  forge over time, from the hot-cold of day and night repeated several hundred
  times.  That, and this is in England, which has to be one of the rustiest
  (is
  that a word?) places in the world...  I thought that was very interesting...

    On a side note, most seasoned engine builders prefer to build a good used
  block over a brand new one for this reason.  The number of heat cycles work
  hardens the block...  The one obvious exception to this rule has to be VW
  aircooled blocks.  Ultimately, they should not be reused....

  Just food for thought....

  Regards,
    David Utley
  Quoting Euroroc II < flaatr@yahoo.com <mailto:flaatr@yahoo.com> >:

  > Some one needs to buy these... they're like new!!!
  >
  > http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?
  ViewItem&category=33564&item=2465387184
  >
  > -Raffi
  >
  >
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  >



  David Utley
  -----------
  Cable Volkswagen
  405-470-3129
  1-800-522-6793

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