Received-SPF: none
 receiver=logan.com; client-ip=204.127.192.82; envelope-from=rlwhite@comcast.net
Date: Wed, 26 Jul 2006 08:30:41 -0600
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Joe Hull's OSH Trip - Part 2
Message-Id: <20060726083041.05332952.rlwhite@comcast.net>
In-Reply-To: <list-1316239@logan.com>
References: <list-1316239@logan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Hi Joe,

Great story.  Glad you were on top of everything and made the right
decisions.

I have a similar exhaust system I think.  Two short tubes into a large
can. On mine, the short tubes are 0.065 321 SS.  After 5 hours of ground
running there doesn't appear to be any deterioration, but it's
definitely something to keep an eye on.  Which was made more difficult
by the insulation I just added.  I think I will install one of my
'J'Thermocouples on the insulation just above the exhaust system.  That
temp should spike if there is any crack in the exhaust.  I also have
cool air flowing thru the center of the can but so far I haven't seen
much flow because of the low speed operations.  A lot of hot air flow
out after shutdown though.

Thanks for a great report.  Maybe we should plan a rotary fly-in at
Hyannis, Nebraska. :)  How many rooms did that hotel have?

Bob W.


On Tue, 25 Jul 2006 21:55:08 -0700
"Joe Hull" <joeh@pilgrimtech.com> wrote:

> > You definitely need expansion joints. Tubes sliding within tubes, or
> > some other type of flex joints.
> > The thermal expansion/contraction simply kills those short runners.
> > 
> > Finn
> 
> Yep, I'm re-doing the whole exhaust system. No more inconel and no more
> tangential collector.  It's probably going to be 2" x .065 wall, 321
> Stainless tubes going to a collector and muffler of some sort. I seriously
> like the idea of non-welded joints - nothing to break off!
> 
> Joe Hull
> Cozy Mk-IV N31CZ (65 hrs - Rotary 13B NA) 
> Redmond (Seattle), Washington
> 
> 
> 
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/


-- 
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/