Message-ID: <c=US%a=_%p=CDI_Corporation%l=CDIM-PTS-MAIL-981103185915Z-2437@cdim-pts-mail.ports-va.marine.cdicorp.com>
From: "Rumburg, William" <wrumburg@cdicorp.com>
To: 'Scott Dahlgren' <dahlgren@itsnet.com>, '_Lancair list'
	 <lancair.list@olsusa.com>
Subject: RE: heat wrap
Date: Tue, 3 Nov 1998 13:59:15 -0500
Mime-Version: 1.0

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I have 321 stainless exhaust system from lancair. I have been reading
about heat exhaust tape which some use to reduce the temperature in the
engine compartment. does anyone have any experience with this material?
does it work? will it corrode the exhaust pipes? is it worth the
trouble?

Scott-
 
    About one year ago, I was considering installing exhaust tape
because of a claim that it improved engine efficiency and power, 
as well as reduced heat in the cowling. Interested, but skeptical, 
I contacted Bill Rumsey at Dawley Aviation (800) 338-5420.
He had done VERY satisfactory work for me previously in modifying
the "Style V " exhaust sold to me by Lancair (it had to be altered to
clear the mixture control on my engines forward facing injector servo. 
I later learned that Lancair had known of that problem with their 
exhaust design for several years, but hadn't yet corrected it ! ...It cost
me $ 300. to correct it ). 
   He advised against using exhaust tape, stating that exhaust heat 
must be allowed to freely radiate. To attempt to contain it was to invite
damaging the pipes, i.e. embrittlement and cracking. Usually, the most
critical time for heat inside the cowling is after shutdown on a hot day. 
It's a law of thermodynamics that heat has to be radiated. The only 
variable would be the time.

                                            Bill Rumburg
                                            N403WR (Sonic Boom)