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Thanks Bill for your advise. I guess I will make my
own, although it seems the Reneses manifold is quit well constructed to reduce
noise as well as stand up to the heat in conjunction with a muffler, based on
what I have read on this list so far.. What I'm most concerned about is the
noise. I currently fly a BD-4 with a Ford V-6 and I'm constantly trying to
get the noise to some reasonable level. Would adapting the Reneses be
worth the trouble, in your opinion? Or how about adapting two 13-B manifolds?
Any thoughts on this would be appreciated.
Robert
Robert Bollinger
MR 722, 1000 N,4th ST
Fairfield IA 52557
(641)919-3213
rob@mum.edu
----- Original Message -----
Sent: Thursday, February 05, 2009 11:00
AM
Subject: [FlyRotary] Re: 20B
manifold
Robert,
The manifold could probably be lightened for
non-turbo applications. The problem is that if you remove material in the
wrong place the cast iron is likely to crack. Even if you want a non-tuned log
manifold you are going to be way ahead by making it from SS tubing and plate.
The only reason for the cast manifolds at all is the ability to make them
cheaply in production.
Bill Jepson
-----Original
Message-----
From: Rob <rob@mum.edu>
To: Rotary motors in aircraft
<flyrotary@lancaironline.net>
Sent: Thu, 5 Feb 2009 8:16
am
Subject: [FlyRotary] Re: 20B manifold
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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