|
|
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
|
|