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Thanks Ed,
I'm going that way also - there's no way around it
IMHO.
George (down under)
----- Original Message -----
Sent: Thursday, February 05, 2009 10:58
PM
Subject: [FlyRotary] Tube Thickness
[FlyRotary] Re: 20B manifold
For what it’s worth,
George, I had my exhaust manifold made out of the stainless steel pipe
used for stair railing that Mark mentioned. The walls are approx 0.10
-0.12” thick. Mine has lasted over 500 hours and 10 years. It
appears to be 304 SS, but I can not swear to that. There is some minor
scaling and it does eventually turn a rust color – at least mine
did. I’ve been very please with it. It’s wall thickness also makes
it easier to weld in bungs for O2 and temperature sensors than thinner wall
tubing. Also it was much cheaper than buying SS exhaust tubing and you
could get just about any degree bend you wanted from stock rather than paying
cost for special bending.
Ed
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Wednesday, February 04, 2009 5:15
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 20B
manifold
I thickness of the tube is what I
was after.
----- Original Message -----
Sent:
Thursday, February 05, 2009 7:59 AM
Subject:
[FlyRotary] Re: 20B manifold
If you're asking how thick my 20B exhaust flanges
were, they were 1/2" (12mm). I made them this thick so they
would provide support for the exhaust system. Tubes were a press
fit and were welded from the back side. That part of the design
has worked great... although probably heavier than necessary.
Regarding the Renesis manifold, there is a bunch of
cast material that could be removed to lighten it up. But I agree
that it would be best to build a lightweight exhaust system from
scratch.
On Wed, Feb 4, 2009 at 3:36 PM, George Lendich
<lendich@optusnet.com.au>
wrote:
How thick was that again, 1.6mm
?
Bite the bullet and make one
from scratch, Just make the thick flanges from SS ( 304 or 316) and use the
hand rail pipe as suggested - cheapest and best for the 3
rotor.
Sounds a lot lighter than the
cast manifold.
----- Original Message -----
Sent:
Thursday, February 05, 2009 12:10 AM
Subject:
[FlyRotary] Re: 20B manifold
I have one that came with my 20B. I don't
want to sound negative, but I don't think it is realistic to use on an
a/c. First, it is incredibly heavy because it is designed to
incorporate the twin turbos. And it is made of cast iron, so it
would probably melt at prolonged WOT operation. And the
passages are very restrictive to exhaust flow. I
could weigh mine and send some pictures if you wish. Sorry, but I
don't want to get rid of it because I have plans for a 3-rotor auto
installation where it would be useable. Maybe you could modify a
Renesis manifold to fit. It would require some welding, but it is
probably more likely to work than the original 20B
manifold.
The cheapest manifold would be to use 304SS
handrail material. I built my first manifold using that material and
after 100 hours it looks like it would last for a very long time. Ed
Anderson has been using this material on his a/c for a long
time. My exhause flange material was 1/2" mild carbon steel and it
was holding up fine as it doen'st see the high heat that the pipes
do. The problem was with the mufflers. They take a real
beating. Try to space the muffler as far away from the engine as
possible.
On Wed, Feb 4, 2009 at 7:43 AM, Rob <rob@mum.edu>
wrote:
Thanks for your replys on this
subject. I realize the manifold would be too heavy but I was hoping I
could widdle it down some how. Greg, I would be interested in your
suggestion for doing that. I'm putting this 20B in a
BD-4.
Robert Bollinger
MR722 MUM
Fairfield IA 52557
(641)472-7000
ex2068
(641)919-3213 cell
rob@mum.edu
----- Original Message -----
Sent:
Tuesday, February 03, 2009 11:10 PM
Subject:
[FlyRotary] Re: 20B manifold
Al, you don't want the stock exhaust. Get
one built. If you want to know one way it's done, let me
know.
----- Original Message
-----
Sent:
Tuesday, February 03, 2009 8:25 PM
Subject:
[FlyRotary] Re: 20B manifold
Does anyone on this list
have a 20B exhaust manifold that came with their engine that I
could buy?
No; but I
do know the thing is massively heavy. I looked at one when I got
my engine, and decided quickly it was not very interesting for an
aircraft. Maybe if radically modified . . . Just my
opinion.
Al
G
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