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<DIV><FONT face=Arial size=2>Bob,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I should say that I have been using CD header and
pipe which requires the1/2" tubing and my headers are about 6" long...Hyde
Mount. I also know of people using the Central/AAP type wrap-around headers
with the 5/8" tubing...without problems.So, I am puzzled as to why you are
having problems.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Good luck in figuring it out.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ken B.</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=getterflash@yahoo.com href="mailto:getterflash@yahoo.com">Bob
Kane</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, October 09, 2003 12:27
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Teflon headers,
followup</DIV>
<DIV><BR></DIV>
<DIV>I bought two sizes of tubing, the 5033K39 is 5/8 ID, 3/4 OD with a 1/16
wall thickness for the header tube, and 5239K19 which is ID of 3/4", OD of
53/64" with a .040" wall thickness to use as a bushing on the header end where
it clamps to the header brace.</DIV>
<DIV> </DIV>
<DIV><BR><B><I>Kenneth Blackwell <<A
href="mailto:blackwellk@snowhill.com">blackwellk@snowhill.com</A>></I></B>
wrote:</DIV>
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<DIV><FONT face=Arial size=2>Bob,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Note that there is a thicker tubing that most
of us are using. I think that it has a 1/16" wall thickness. I believe that
this may be your problem. I have been using the thicker tubing for several
years without a failure.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Cheers,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ken Blackwell</FONT></DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=getterflash@yahoo.com href="mailto:getterflash@yahoo.com">Bob
Kane</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">nsrca</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, October 09, 2003 8:31
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Teflon headers,
followup</DIV>
<DIV><BR></DIV>
<DIV>I thought I would let you know what is going on with my teflon header
issues. I was using blue teflon 5/8 ID, 3/4 OD PTFE ordered from
McMaster-Carr, and getting as few as 6 flights from the header. Setup is
YS140 Fizzle, Hyde mount, NMP High Performance header, Johnson SQ pipe on
a single Lord mount. </DIV>
<DIV> </DIV>
<DIV>It was time to get some more teflon, so I ordered semi-clear part#
5033K39 (5/8ID, 3/4OD), and a short piece of 5239K19 (3/4ID, .040 wall
thickness). The larger size is a slip-fit over the 3/4OD stuff. I use a
1.5" piece of it over the end of the header where it is clamped to the
header brace. One other procedural change I made was to place the clamp
over the teflon in front of the bead in the steel header instead of
directly over it. The teflon formerly failed at the bead, moving the clamp
ahead of the bead seems to reduce the erosion of the teflon.</DIV>
<DIV> </DIV>
<DIV>Well, they still fail, but are lasting quite a bit longer. Now
the failure point is right where small teflon exits the larger teflon
bushing. Judging from the looks of the header where it failed, it
could be caused by torsional vibration between the Hyde-mounted engine and
single soft point mounted pipe. There might be some kind of harmonic thing
going on where the engine is going one way and the pipe is going the
other, and the teflon has to twist. I have noticed the teflon softens
quite a bit when heated and may not be up to the mechanical demands put on
it from vibration. </DIV>
<DIV> </DIV>
<DIV>For those of you getting long header life, are your engine and pipe
soft mounted? </DIV>
<DIV> </DIV>
<DIV>BTW, I must praise McMaster-Carr for their delivery service. I
ordered on Monday morning, the teflon arrived Tuesday evening by standard
ground UPS.</DIV><BR><BR>Bob Kane<BR>getterflash@yahoo.com
<P>
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