<HTML><FONT FACE=arial,helvetica><FONT SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Maybe it's me but I just don't get this apparent love affair <BR>
with the carbon pipes. Epoxy as the binder, as Gray states, is marginal in almost all 4 stroke cases I have heard about. And to make these things super light, you have got to make then thin, so strength is doubly compromised, especially on four strokes with their 500+ degree stack temp.<BR>
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A hi temp plastic binder such as a PTFE emulsion, or maybe polyimide emulsion is a better alternative but then the cost would be 2x and impractical. And ceramics, aka Space Shuttle heat shield tiles, are out of this world (sorry Gray, I couldn't resist)<BR>
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How much weight is actually saved over a "lightweight"ally pipe anyway? The Greves is a little over 4 ounces, the Macs 20 cc is a little over 5 ounces and the Hatori is a little over 6. Are we talking, what, 4 ounces tops??
Isn't there someplace else one could remove 2 to 4 ounces?<BR>
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Hey, I am a big proponent of progress and composites offer great advantages in the correct places, but I have to question if this is one of these places<BR>
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Firesuit..... hell forget the firesuit> I'm thick skinned enough, literaly, so fire away<BR>
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matt K<BR>
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<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj:<B>Re: ES Composite Pipe Repair </B><BR>
Date:9/23/2003 6:38:01 PM Eastern Daylight Time<BR>
From:<A HREF="mailto:edbon85@optonline.net">edbon85@optonline.net</A><BR>
Reply-to:<A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
To:<A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
<I>Sent from the Internet </I><BR>
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Gray, I'm listening. A short lived $200 plus pipe is not affordable either. Short of going back to aluminum and the weight penalty, do we have another alternative ??</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Ed M.</FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"><BR>
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<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">----- Original Message ----- <BR>
<B>From:</B> <A HREF="mailto:gfowler@raytheon.com">Gray E Fowler</A> <BR>
<B>To:</B> <A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A> <BR>
<B>Sent:</B> Tuesday, September 23, 2003 5:40 PM<BR>
<B>Subject:</B> Re: ES Composite Pipe Repair<BR>
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Concerning this repair, there is not a commercially available adhesive that is going to do the job long term. The adhesive I used on Wayne's pipe is an aerospace grade epoxy called Hysol 9394, rated at 350F. AT 350F this epoxy exhibits about 25% of its room temperature strength-and this is about the best room temperature curing high temp epoxy available-in short all the stuff such as JB weld is crap at the temperatures we are talking about. The inlet temp of our mufflers makes for a brutal environment and unfortunately anything that cures at room temperature just is not going to do the job very well. In reality Hysol 9394 is borderline. No easy answer here, and is evident by the constant postings about burned out inlets....there is a problem with the composite mufflers. Actually there is an answer, but I do not think our pattern market can afford it. </FONT><FONT COLOR="#000000" style="BACKGROUND-COLOR: #ffffff" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0"></BLOCKQUOTE><BR>
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