X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from pacmmta53.windstream.net ([162.39.147.112] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4598929 for flyrotary@lancaironline.net; Wed, 01 Dec 2010 17:08:37 -0500 Received-SPF: pass receiver=logan.com; client-ip=162.39.147.112; envelope-from=jskmberki@windstream.net Return-Path: X-WS-COS: WSOB804 X-Cloudmark-Category: Undefined:Undefined X-Cloudmark-Analysis: v=1.1 cv=9Rjp4Vr5DuerpSsxHWMWriWE1PYoQ/LdvL4nY1mYVa4= c=1 sm=0 a=ku24OJKnaaoA:10 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=ZbQg5mX3-jiwI44ni8QA:9 a=UENvupYT4B1ZQXB5pcIA:7 a=3bq1avelyBXLzcUcXr63nLEIkOgA:4 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=5xwh-qPnh-lOhJSq:21 a=2gaDGstJ2A5h4H9-:21 a=pGLkceISAAAA:8 a=E93lBu2AAAAA:8 a=dUmLWYLmnEZZH1YKn7kA:9 a=SvA8P-s0hy_SsTNc3PMA:7 a=akyhZta6N0D1q4zhR3tlVhKWUtQA:4 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=MpuOTR30KwMA:10 a=x6VBWS02HY8A:10 a=d1n8sfsg-lQA:10 a=NWVoK91CQyQA:10 a=aVdDl5HYDgiueSyDmP6EjA==:117 X-Cloudmark-Score: 0 Authentication-Results: pacmmta53 smtp.user=jskmberki; auth=pass (LOGIN) Received: from [174.130.46.1] ([174.130.46.1:60816] helo=joehomepc) by pacmmta53 (envelope-from ) (ecelerity 2.2.2.45 r()) with ESMTPA id 1E/98-07708-247C6FC4; Wed, 01 Dec 2010 17:08:02 -0500 Message-ID: <008001cb91a4$873bac10$01fea8c0@joehomepc> From: "josrph berki" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Modified header Calculations Date: Wed, 1 Dec 2010 17:10:12 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_007D_01CB917A.9DD794E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.2001 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.2001 This is a multi-part message in MIME format. ------=_NextPart_000_007D_01CB917A.9DD794E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable What does it say about intake runner lenght for a P Port? What happens = if the exhaust header length is longer? Can it be tuned. 10 to 11 = inches is pretty short although a collector could make the transition = and get the hot stuff out of the cowl. Joe Berki Limo EZ ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Wednesday, December 01, 2010 11:36 AM Subject: [FlyRotary] Re: Modified header Calculations Ed,=20 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.) =20 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. =20 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. =20 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.=20 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! =20 =20 Mark On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson = 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". =20 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 ------=_NextPart_000_007D_01CB917A.9DD794E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
What does it say about intake runner = lenght for a P=20 Port?  What happens if the exhaust header length is longer?  = Can it be=20 tuned.  10 to 11 inches is pretty short although a collector could = make the=20 transition and get the hot stuff out of the cowl.
 
Joe Berki
Limo EZ
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Wednesday, December 01, = 2010 11:36=20 AM
Subject: [FlyRotary] Re: = Modified header=20 Calculations

Ed,
 
It took a while, but my copy of Street Rotary - How = to Build=20 Maximum Horsepower & Reliability into Mazda's 12A, 13B & = Renesis=20 Engines finally arrived yesterday.  Thanks for the=20 recommendation.  Lots of good info, everyone on the list ought to = order a=20 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=20 copy.) 
 
As you suggested, I've been reading the chapter on exhaust = systems. =20 I found a paragraph that is right on target relating to what we've = been=20 discussing (exhaust system restriction).  They compare a 2-rotor = wankel=20 to a 2 cylinder 4-stroke where both cylinders share the = same=20 exhaust port. 
 
Quote, "...the exhaust system on a 12A or 13B rotary engine is = roughly=20 analogous to a two-cylinder piston engine in which both cylinders are = served=20 by a single exhaust port.  If cylinder #1 was in overlap period, = and the=20 exhaust valve of the #2 cylinder then opened, high pressure gas would = flow=20 from the #2 to #1 cylinders.  A highly restrictive exhaust system = would=20 aggravate the situation.  This, the authors point out, is the = major=20 reason why a free-flowing exhaust system is so important in a rotary=20 engine."  This explains why I saw such an improvement when = switching=20 exhaust systems. 
 
There is also much discussion on primary header length. =20 Disregarding the "long" header system as we don't have the room, the = "short"=20 header length shown for a p-port engine is between 10 and 18 = inches.  So,=20 your calculations for header length seem to be right in the = ballpark. =20 Now I have to figure how to get the three very short primary tubes of = 11 3/4"=20 to meet on the same tangent at the collector. 
 
Finally, I liked their comment regarding the peripheral = ported=20 engines.  It reads, "Traditionally relegated to = speciality=20 race cars, occasionally a peripherally ported engine finds its way = onto the=20 street in some high-performance vehicle. These engines are not, = however, for=20 the faint of heart."  LOL  Not to worry, my heart = is=20 strong! 
  
Mark

On Sun, Nov 21, 2010 at 7:53 AM, Ed Anderson = <eanderson@carolina.rr.com&g= t;=20 wrote:
Mark,
 
I did some additional reading in the rotary = book I=20 recommended to you and a bit more head scratching on exhaust=20 systems.
 
I modified the tube length formula = I used=20 earlier to compensate for the fact the rotary puts out two exhaust = pulses=20 per port per 720 deg cycle compared to 1 for the piston = engine.  This=20 in effect halved the length of tube needed to get the same = scavenging=20 effect.
 
Also using the recommended rotary  book = values=20 for area of a rotary exhaust tube , I calculated the tube = diameter=20 which came out to 1.8". 
 
In any case, I have attached the spreadsheet = with=20 those modifications
 
Ed
 
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

= --
Homepage:=20  http://www.flyrotary.com/
Archive and UnSub: =   http://mail.lancaironline.net:81/lists/flyrotary/List.htm= l


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