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Bill,
Do you think the 20B manifold could be lightened or
would it be a waste of time to even attempt it.
Robert Bollinger MR722 MUM Fairfield IA 52557 (641)472-7000
ex2068 (641)919-3213 cell rob@mum.edu
----- Original Message -----
Sent: Wednesday, February 04, 2009 12:46
PM
Subject: [FlyRotary] Re: 20B
manifold
Rob,
I have a 20B and the manifold without the turbos is a
very heavy chunk of cast iron. I don't think it would be in danger of melting,
but is just too heavy. I do NOT believe the Renesis Exhaust manifold would be
made to fit practically. The Renesis has side ports with a rectangular
profile. The 20B is a 13B with an extra rotor and one of the spacings is
longer due to the intermediate housing. The best method is going to be a built
up manifold, aand several are available over the counter. Usually expensive,
but much less hassle. Racing Beat made one for using a single turbo for racing
in the past. I don't know if it is still available.
Bill
Jepson
-----Original Message-----
From: Mark Steitle
<msteitle@gmail.com>
To: Rotary motors in aircraft
<flyrotary@lancaironline.net>
Sent: Wed, 4 Feb 2009 9:34
am
Subject: [FlyRotary] Re: 20B manifold
Rob,
The Renesis manifold has an inner shell, an outer shell, and a heat
shield on top of that. I'm not positive, but the inner shell could
possibly be made of inconel. The outer shell appears to be
stainless (probably 321).
Since the Renesis has three exhaust ports, I have often wondered if it
could be modified to work on a 3-rotor. Keep in mind that the port
spacing on the Renesis is the same while the 20B unequally
spaced. That's due to the one larger side housing that contains the
3rd main bearing. So, if the ports are big enough, and
the bolt pattern matches, you would still have to add an extension
between two of the ports to make it line up. If that is all it
requires to make it fit, it could be worth a try.
Mark S.
On Wed, Feb 4, 2009 at 11:12 AM, Rob <rob@mum.edu> wrote:
I would be interested to know the weight. I
didn't realize that a cast exhaust manifold made for a 20B could actually
melt. It sounds like the Renesis manifold would be better.. Is the
Renesis manifold stainless steel or what?
Robert Bollinger MR722 MUM Fairfield IA 52557 (641)472-7000
ex2068 (641)919-3213 cell rob@mum.edu
----- Original Message -----
Sent: Wednesday, February 04, 2009
8:10 AM
Subject: [FlyRotary] Re: 20B
manifold
Robert,
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.
Mark S.
On Wed, Feb 4, 2009 at 7:43 AM, Rob <rob@mum.edu>
wrote:
Al and Greg,
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
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.
Greg Ward
Lancair 20B in
progress
----- 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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