Message-ID: <3FC75576.6070101@netzero.net>
Date: Fri, 28 Nov 2003 09:02:30 -0500
From: Finn Lassen <finnlassen@netzero.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: exhaust
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You don't need a cone. If you use thin (0.035) SS tubing,  1 3/4" will 
fit right into the port opening. You can use a mallet to pound the 
tubing into the exhaust opening, or squeeze the end in a vice to get the 
oval shape.

In other words, the end of the header will protrude maybe 1/2" past the 
flange into the exhaust port.

This will give you the smooth transition you'll want.

Finn

Ed Anderson wrote:

>Hi John,
>
>    My recommendation would be to use the "cone" for a smoother transistion
>from the size of the exhaust ports to your 1 3/4" dia exhaust ports.  Will
>it work without the transition - most certainly will, but such
>discontinunities in the gas flow route will imped the flow of exhaust out
>the pipe to a degree.  There are places such as "Burns Stainless
>http://www.burnsstainless.com/  who sell just about anything you need.
>Don't know if they have cones going down to 1 3/4" but you might give them a
>try.
>
>You would not need to have 2" pipes just a 2" to 1 3/4" cone  to your 1 3/4"
>tubing should do it.  I used schedule 40 stainless steel pipe (0.115" wall
>thickness) for my 2" headers and have over 300 hours on them and they are
>still in good shape.  However, they are a bit on the heavy side.
>
>Don't know which block you are using, the turbo or NA 13B, however, be
>advised the turbo block lacks the "exhaust splitters" that considerably
>reduce the energy of the exhaust pulse.  I can tell you from personal
>experience the exhaust pulse from the turbo block without the exhaust
>splitters is very powerful and has shredded stainless steel tubing that I
>had squished down at the ends (see photos).  This was after 15 minutes of
>flight.
>
>
>Ed
>
>
>Ed Anderson
>RV-6A N494BW Rotary Powered
>Matthews, NC
>eanderson@carolina.rr.com
>----- Original Message -----
>From: "john" <frmrjohn@netonecom.net>
>To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>Sent: Thursday, November 27, 2003 9:42 PM
>Subject: [FlyRotary] exhaust
>
>
>  
>
>>I need to order the ss for the exhaust.  Tracys' manual calls for 1-3/4"
>>size, is this connected to the flange by a cone shape or have you used a
>>hole smaller than the exhaust ports in the engine.  Awhile back someone
>>posted a picture of some enserts for the pipes, has anyone found some that
>>havn't burned out shortly.  Would the exhaust pipes need to be 2" at the
>>outlet so inserts could be installed.  The 13B is installed in a Tailwind
>>W-10 w/ tri-gear and I don't have any room for a muffler under the cowl.
>>Thanks for any and all input.  JohnD in Michigan
>>
>>
>>    
>>
>>>> Homepage:  http://www.flyrotary.com/
>>>> Archive:   http://lancaironline.net/lists/flyrotary/List.html
>>>>        
>>>>