Return-Path: <13brv3@bellsouth.net>
Received: from imf21aec.mail.bellsouth.net ([205.152.59.69] verified)
  by logan.com (CommuniGate Pro SMTP 4.1.3)
  with ESMTP id 2577056 for flyrotary@lancaironline.net; Fri, 12 Sep 2003 10:26:01 -0400
Received: from rad ([68.212.12.251]) by imf21aec.mail.bellsouth.net
          (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP
          id <20030912142600.VQGK1847.imf21aec.mail.bellsouth.net@rad>
          for <flyrotary@lancaironline.net>;
          Fri, 12 Sep 2003 10:26:00 -0400
From: "Russell Duffy" <13brv3@bellsouth.net>
To: "'Rotary motors in aircraft'" <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: turbo wastegate requirements
Date: Fri, 12 Sep 2003 09:26:00 -0500
Message-ID: <00f301c37939$ca1b2820$0201a8c0@rad>
MIME-Version: 1.0
Content-Type: multipart/alternative;
	boundary="----=_NextPart_000_00F4_01C3790F.E1452020"
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook, Build 10.0.4510
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165
Importance: Normal
In-Reply-To: <list-2576720@logan.com>

This is a multi-part message in MIME format.

------=_NextPart_000_00F4_01C3790F.E1452020
Content-Type: text/plain;
	charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable

My scheme is to have two "Throttle" levers
- a long one to the throttle and a shorter one to the wastegate.  The
wastegate would remain "OFF" or all the way back for ground and pattern
operations.  Take Off and initial climb would be with wastegate OPEN and
throttle adjusted so as to not exceed 30" MAP even with the "residual" =
boost
that we would have even with wastegate open.  Climb to altitude (after =
MAP
dropped below 30" at WOT) and cruise would generally be at WOT and =
gradually
increasing boost (closing the wastegate - advancing the Boost lever).  =
The
first step for descent would be "Boost - OFF".

You've described the system I'm flying with exactly.  I used the =
"mixture"
lever for my wastegate, largely because the quadrant was already fit to =
the
fuselage.  If I were choosing from scratch, I'd probably go with a =
vernier
type cable.  The wastegate lever has very little throw, and the most you =
can
get is about half travel on the lever to go from one stop to the other.  =
I'm
afraid the wastegate adjustment is going to be touchy.  Fortunately for =
you,
I should be able to answer that question in the near future. =20

I still have more power available than any NA engine and even if I get
excited and two-block the throttle, I only have a couple of inches of =
boost
- not enough to damage anything, even at SL. =20

Don't count on only having a couple inches of boost with the wastegate =
open.
As I mentioned before, I have more than 3 psi (I originally wrote this =
in
inches, but it sounded like I was bragging <g>), and won't know how much
more until I can increase the pressure of the relief valve spring, and =
go to
a safe altitude to test it.  My greatest hope is that I'm already very =
near
the limit, and the relief valve isn't really having to dump any boost.   =
=20

If I did away with the waste gate, I would have full boost all the time,
which would, as well as excessive care and attention, involve a great =
deal
more intercooling (and other heat rejection) than I am prepared to =
accept.
Additionally, I would be pumping full boost through partial throttle =
which I
presume to be quite inefficient.  It would involve taking off at a =
little
more than half throttle. =20

You won't really get boost at low throttle, even with the wastegate (wg)
fully closed.  In fact, the normal wg actuator keeps the wg closed until =
so
much boost is produced that it needs to open.  Having it closed will =
make
the plane a bit quieter in the ground also.  I've opened and closed the =
wg
on my engine at low throttle, and there's a noticeable change in sound.
It's not all that significant though.  =20

For all the talk, it's STILL ... just a theory .... Jim S.

Not for very much longer :-)
=20
Rusty (installing a real oil cooler today)

=20


------=_NextPart_000_00F4_01C3790F.E1452020
Content-Type: text/html;
	charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Dus-ascii">
<TITLE>Message</TITLE>

<META content=3D"MSHTML 6.00.2800.1226" name=3DGENERATOR></HEAD>
<BODY><!-- Converted from text/plain format -->
<P><FONT size=3D2>My scheme is to have two "Throttle" levers<BR>- a long =
one to=20
the throttle and a shorter one to the wastegate.&nbsp; The wastegate =
would=20
remain "OFF" or all the way back for ground and pattern =
operations.&nbsp; Take=20
Off and initial climb would be with wastegate OPEN and throttle adjusted =
so as=20
to not exceed 30" MAP even with the "residual" boost that we would have =
even=20
with wastegate open.&nbsp; Climb to altitude (after MAP dropped below =
30" at=20
WOT) and cruise would generally be at WOT and gradually increasing boost =

(closing the wastegate - advancing the Boost lever).&nbsp; The first =
step for=20
descent would be "Boost - OFF".</FONT></P>
<DIV><FONT size=3D2><FONT face=3DArial color=3D#0000ff size=3D3>You've =
described the=20
system I'm flying with exactly.&nbsp; I used the "mixture" lever for my=20
wastegate, largely because the quadrant was already fit to the =
fuselage.&nbsp;=20
If I were choosing from scratch, I'd probably go with a vernier type=20
cable.&nbsp; The wastegate lever has very little throw, and the most you =
can get=20
is about half travel on the lever to go from one stop to the =
other.&nbsp;=20
I'm&nbsp;afraid the wastegate adjustment is going to be touchy.&nbsp;=20
Fortunately for you, I should be able to answer that question in the =
near=20
future.&nbsp; </FONT></DIV>
<P>I still have more power available than any NA engine and even if I =
get=20
excited and two-block the throttle, I only have a couple of inches of =
boost -=20
not enough to damage anything, even at SL.&nbsp; </P>
<P><FONT face=3DArial color=3D#0000ff size=3D3>Don't count on only =
having a couple=20
inches of boost with the wastegate open.&nbsp; As&nbsp;I mentioned =
before, I=20
have more than 3 psi (I originally wrote this in inches, but it sounded =
like I=20
was bragging&nbsp;&lt;g&gt;), and won't know how much more until I can =
increase=20
the pressure of the relief valve spring, and go to a safe altitude to =
test=20
it.&nbsp;&nbsp;My greatest hope is that I'm already very near the limit, =
and the=20
relief valve isn't really having to dump any boost.&nbsp;=20
&nbsp;&nbsp;</FONT></P>
<P>If I did away with the waste gate, I would have full boost all the =
time,=20
which would, as well as excessive care and attention, involve a great =
deal more=20
intercooling (and other heat rejection) than I am prepared to accept.=20
Additionally, I would be pumping full boost through partial throttle =
which I=20
presume to be quite inefficient.&nbsp; It would involve taking off at a =
little=20
more than half throttle.&nbsp; </P>
<P><FONT face=3DArial color=3D#0000ff size=3D3>You won't really get =
boost at low=20
throttle, even with the wastegate (wg)&nbsp;fully closed.&nbsp; In fact, =
the=20
normal wg&nbsp;actuator keeps the wg closed until so much boost is =
produced that=20
it needs to open.&nbsp; Having it closed will make the plane a bit =
quieter in=20
the ground also.&nbsp; I've opened and closed the wg on my engine at low =

throttle, and there's a noticeable change in sound.&nbsp; It's not all =
that=20
significant though.&nbsp; &nbsp;</FONT></P>
<P>For all the talk, it's STILL ... just a theory .... Jim S.</P>
<DIV><FONT face=3DArial color=3D#0000ff size=3D3>Not for very much =
longer=20
:-)</FONT></DIV>
<DIV><FONT face=3DArial color=3D#0000ff size=3D3></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial color=3D#0000ff size=3D3>Rusty (installing a =
real oil cooler=20
today)</FONT></DIV>
<P><FONT face=3DArial color=3D#0000ff =
size=3D3></FONT>&nbsp;</P></FONT></BODY></HTML>

------=_NextPart_000_00F4_01C3790F.E1452020--