Received-SPF: pass
 receiver=logan.com; client-ip=209.85.215.180; envelope-from=msteitle@gmail.com
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=obKJHm0GZXdLAPrJxzCyhv3CrW7oD8dLHvtVw2R//OiH193frvIPl9WOVNyfgXJz9z
         45yaIGGQ66zQYFV4h+UXUUzlI7T0ax/2FvXIijGW/7HLIf/lQyAv/jXbvccFNLPE2jEk
         89j7TD7Rb09Db/EpDDNTXmTFMz7T54yPtYg1A=
MIME-Version: 1.0
In-Reply-To: <list-4598610@logan.com>
References: <list-4598610@logan.com>
Date: Wed, 1 Dec 2010 11:43:52 -0600
Message-ID: <AANLkTintScxgsZYuAuW+W74-4Le-uZFW3L6NAPsTE-GN@mail.gmail.com>
Subject: Re: [FlyRotary] Re: Modified header Calculations
From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Content-Type: multipart/alternative; boundary=0015174c138a42a6e104965cd9c0

--0015174c138a42a6e104965cd9c0
Content-Type: text/plain; charset=ISO-8859-1

Bill,

Not sure what you're asking.  My p-port will idle down to below 1000 rpm,
although not as smoothly as my side port 20B did, or like my LS1 Chevy V-8.
This thread was addressing WOT issues caused by an overly restrictive
exhaust system.  Changing to my previous "tangential" exhaust made a HUGH
improvement in WOT power (exactly as the chart that Ed posted earlier
showed).  I am now in the process of building an equal-length header/exhaust
to maximize power at around 6500 rpm.  The runners on my current exhasut are
not all the same length and are made from 2.0 DIA .140" 304SS.  The
new exhasut will be made of 625 inconel.

I hope to get it right this time.

Mark

On Wed, Dec 1, 2010 at 11:23 AM, <wrjjrs@aol.com> wrote:

> Mark, and group,
> If p-ports are so difficult why was the first car with a rotary equiped
> with them? P ports can be fairly tame if you put the throttle plate,
> (butterfly or slide), close to the port, or in the port. The original
> powersport guys put together an in-port butterfly that idled very well. In
> fact Steve Beckham told me that when using their pendrolous damper they
> could idle their p-port engine at 1000 RPM! Their p-ports were 1-5/8
> diameter.
> Bill Jepson
>
>
> Finally, I liked their comment regarding the peripheral ported engines.  It
> reads, "Traditionally relegated to speciality race cars, occasionally a
> peripherally ported engine finds its way onto the street in some
> high-performance vehicle. These engines are not, however, for the faint of
> heart."  LOL  Not to worry, my heart is strong!
>
> Mark
>
>
>
>
>  -----Original Message-----
> From: Mark Steitle <msteitle@gmail.com>
> To: Rotary motors in aircraft <flyrotary@lancaironline.net>
> Sent: Wed, Dec 1, 2010 8:37 am
> Subject: [FlyRotary] Re: Modified header Calculations
>
>
> Ed,
>
> It took a while, but my copy of Street Rotary - How to Build Maximum
> Horsepower & Reliability into Mazda's 12A, 13B & Renesis Engines finally
> arrived yesterday.  Thanks for the recommendation.  Lots of good info,
> everyone on the list ought to order a copy and read it from cover to cover,
> except for Lynn H. - he ought to write his own book on rotary engines.  (I'd
> buy the first copy.)
>
> As you suggested, I've been reading the chapter on exhaust systems.  I
> found a paragraph that is right on target relating to what we've been
> discussing (exhaust system restriction).  They compare a 2-rotor wankel to a
> 2 cylinder 4-stroke where both cylinders share the same exhaust port.
>
> Quote, "...the exhaust system on a 12A or 13B rotary engine is roughly
> analogous to a two-cylinder piston engine in which both cylinders are served
> by a single exhaust port.  If cylinder #1 was in overlap period, and the
> exhaust valve of the #2 cylinder then opened, high pressure gas would flow
> from the #2 to #1 cylinders.  A highly restrictive exhaust system would
> aggravate the situation.  This, the authors point out, is the major reason
> why a free-flowing exhaust system is so important in a rotary engine."  This
> explains why I saw such an improvement when switching exhaust systems.
>
> There is also much discussion on primary header length.  Disregarding the
> "long" header system as we don't have the room, the "short" header length
> shown for a p-port engine is between 10 and 18 inches.  So, your
> calculations for header length seem to be right in the ballpark.  Now I have
> to figure how to get the three very short primary tubes of 11 3/4" to
> meet on the same tangent at the collector.
>
> Finally, I liked their comment regarding the peripheral ported engines.  It
> reads, "Traditionally relegated to speciality race cars, occasionally a
> peripherally ported engine finds its way onto the street in some
> high-performance vehicle. These engines are not, however, for the faint of
> heart."  LOL  Not to worry, my heart is strong!
>
> Mark
>
>
> On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson <eanderson@carolina.rr.com>
> wrote:
>
>
> Mark,
>
> I did some additional reading in the rotary book I recommended to you and a
> bit more head scratching on exhaust systems.
>
> I modified the tube length formula I used earlier to compensate for the
> fact the rotary puts out two exhaust pulses per port per 720 deg cycle
> compared to 1 for the piston engine.  This in effect halved the length of
> tube needed to get the same scavenging effect.
>
> Also using the recommended rotary  book values for area of a rotary exhaust
> tube , I calculated the tube diameter which came out to 1.8".
>
> In any case, I have attached the spreadsheet with those modifications
>
> Ed
>
>
> Edward L. Anderson
> Anderson Electronic Enterprises LLC
> 305 Reefton Road
> Weddington, NC 28104
> http://www.andersonee.com
> http://www.eicommander.com
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
>
>
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>

--0015174c138a42a6e104965cd9c0
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div>Bill, </div>
<div>=A0</div>
<div>Not sure what you&#39;re asking.=A0 My p-port will idle down to below =
1000 rpm, although not as smoothly as my side port 20B did, or like my LS1 =
Chevy V-8.=A0 This thread was=A0addressing WOT issues caused by an overly=
=A0restrictive exhaust system.=A0 Changing to my previous &quot;tangential&=
quot;=A0exhaust made a HUGH improvement in WOT power (exactly as=A0the char=
t that Ed posted earlier showed).=A0 I am now in the process of building an=
 equal-length=A0header/exhaust to maximize power at around 6500 rpm.=A0 The=
 runners on my current=A0exhasut are not all=A0the same=A0length and are=A0=
made from 2.0 DIA .140&quot; 304SS.=A0 The new=A0exhasut will be made of 62=
5 inconel.</div>

<div>=A0</div>
<div>I hope to get it right this time.=A0=A0</div>
<div>=A0</div>
<div>Mark=A0=A0 <br><br></div>
<div class=3D"gmail_quote">On Wed, Dec 1, 2010 at 11:23 AM, <span dir=3D"lt=
r">&lt;<a href=3D"mailto:wrjjrs@aol.com">wrjjrs@aol.com</a>&gt;</span> wrot=
e:<br>
<blockquote class=3D"gmail_quote" style=3D"PADDING-LEFT: 1ex; MARGIN: 0px 0=
px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Mark, and group,<br>If p-ports a=
re so difficult why was the first car with a rotary equiped with them? P po=
rts can be fairly tame if you put the throttle plate, (butterfly or slide),=
 close to the port, or in the port. The original powersport guys put togeth=
er an in-port butterfly that idled very well. In fact Steve Beckham told me=
 that when using their pendrolous damper they could idle their p-port engin=
e at 1000 RPM! Their p-ports were 1-5/8 diameter.<br>
Bill Jepson=20
<div class=3D"im"><br><br>Finally, I liked their comment=A0regarding the pe=
ripheral ported engines.=A0 It reads,=A0&quot;Traditionally relegated to sp=
eciality race cars, occasionally a peripherally ported engine finds its way=
 onto the street in some high-performance vehicle. These engines are not, h=
owever, for the faint of heart.&quot;=A0 LOL=A0 Not to worry, my heart is s=
trong!=A0<br>
=A0=A0<br>Mark<br><br><br><br><br></div>
<div>
<div></div>
<div class=3D"h5">-----Original Message-----<br>From: Mark Steitle &lt;<a h=
ref=3D"mailto:msteitle@gmail.com" target=3D"_blank">msteitle@gmail.com</a>&=
gt;<br>To: Rotary motors in aircraft &lt;<a href=3D"mailto:flyrotary@lancai=
ronline.net" target=3D"_blank">flyrotary@lancaironline.net</a>&gt;<br>
Sent: Wed, Dec 1, 2010 8:37 am<br>Subject: [FlyRotary] Re: Modified header =
Calculations<br><br><br>Ed,<br>=A0<br>It took a while, but my copy of=A0Str=
eet Rotary - How to=A0Build Maximum Horsepower &amp; Reliability into Mazda=
&#39;s 12A, 13B &amp; Renesis Engines=A0finally arrived yesterday.=A0 Thank=
s for the recommendation.=A0 Lots of good info, everyone on the list ought =
to order a copy and read it from cover to cover, except for Lynn H. - he ou=
ght to write=A0his own=A0book on rotary engines.=A0 (I&#39;d buy the first =
copy.)=A0<br>
=A0<br>As you suggested, I&#39;ve been reading the chapter on exhaust syste=
ms.=A0 I found a paragraph that is right on target relating to what we&#39;=
ve been discussing (exhaust system restriction).=A0 They compare a 2-rotor =
wankel to a 2 cylinder 4-stroke=A0where both cylinders share the same exhau=
st port.=A0<br>
=A0<br>Quote, &quot;...the exhaust system on a 12A or 13B rotary engine is =
roughly analogous to a two-cylinder piston engine in which both cylinders a=
re served by a single exhaust port.=A0 If cylinder #1 was in overlap period=
, and the exhaust valve of the #2 cylinder then opened, high pressure gas w=
ould flow from the #2 to #1 cylinders.=A0 A highly restrictive exhaust syst=
em would aggravate the situation.=A0 This, the authors point out, is the ma=
jor reason why a free-flowing exhaust system is so important in a rotary en=
gine.&quot;=A0 This explains why I saw such an improvement when switching e=
xhaust systems.=A0<br>
=A0<br>There is also much discussion on primary header length.=A0 Disregard=
ing the &quot;long&quot; header system as we don&#39;t have the room, the &=
quot;short&quot; header length shown for a p-port engine is between 10 and =
18 inches.=A0 So, your calculations for header length seem to be right in t=
he ballpark.=A0 Now I have to figure how to get the three very short primar=
y tubes of 11 3/4&quot; to meet=A0on the same tangent at the collector.=A0<=
br>
=A0<br>Finally, I liked their comment=A0regarding the peripheral ported eng=
ines.=A0 It reads,=A0&quot;Traditionally relegated to speciality race cars,=
 occasionally a peripherally ported engine finds its way onto the street in=
 some high-performance vehicle. These engines are not, however, for the fai=
nt of heart.&quot;=A0 LOL=A0 Not to worry, my heart is strong!=A0<br>
=A0=A0<br>Mark<br><br><br>On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson &lt;=
<a href=3D"mailto:eanderson@carolina.rr.com" target=3D"_blank">eanderson@ca=
rolina.rr.com</a>&gt; wrote:<br><br><br>Mark,<br>=A0<br>I did some addition=
al reading in the rotary book I recommended to you and a bit more head scra=
tching on exhaust systems.<br>
=A0<br>I modified the tube length=A0formula I=A0used earlier to compensate =
for the fact the rotary puts out two exhaust pulses per port per 720 deg cy=
cle compared to 1 for the piston engine.=A0 This in effect halved the lengt=
h of tube needed to get the same scavenging effect.<br>
=A0<br>Also using the recommended rotary =A0book values for area of a rotar=
y exhaust tube=A0, I calculated the tube diameter which came out to 1.8&quo=
t;.=A0<br>=A0<br>In any case, I have attached the spreadsheet with those mo=
difications<br>
=A0<br>Ed<br>=A0<br>=A0<br>Edward L. Anderson<br>Anderson Electronic Enterp=
rises LLC<br>305 Reefton Road<br>Weddington, NC 28104<br><a href=3D"http://=
www.andersonee.com/" target=3D"_blank">http://www.andersonee.com</a><br><a =
href=3D"http://www.eicommander.com/" target=3D"_blank">http://www.eicommand=
er.com</a><br>
<br><br>--<br>Homepage: =A0<a href=3D"http://www.flyrotary.com/" target=3D"=
_blank">http://www.flyrotary.com/</a><br>Archive and UnSub: =A0 <a href=3D"=
http://mail.lancaironline.net:81/lists/flyrotary/List.html" target=3D"_blan=
k">http://mail.lancaironline.net:81/lists/flyrotary/List.html</a><br>
<br><br><br><br><br><br>--<br>Homepage: =A0<a href=3D"http://www.flyrotary.=
com/" target=3D"_blank">http://www.flyrotary.com/</a><br>Archive and UnSub:=
 =A0 <a href=3D"http://mail.lancaironline.net:81/lists/flyrotary/List.html"=
 target=3D"_blank">http://mail.lancaironline.net:81/lists/flyrotary/List.ht=
ml</a><br>
</div></div></blockquote></div><br>

--0015174c138a42a6e104965cd9c0--