Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Thu, 22 May 2003 17:10:19 -0400 Message-ID: X-Original-Return-Path: Received: from BAY0-SMTP11.adinternal.hotmail.com ([65.54.241.118] verified) by logan.com (CommuniGate Pro SMTP 4.1b6) with ESMTP id 2359224 for flyrotary@lancaironline.net; Thu, 22 May 2003 11:45:34 -0400 X-Originating-IP: [68.7.218.110] X-Originating-Email: [alventures@msn.com] Received: from BigAl ([68.7.218.110]) by BAY0-SMTP11.adinternal.hotmail.com with Microsoft SMTPSVC(5.0.2195.5600); Thu, 22 May 2003 08:45:33 -0700 Reply-To: From: "Al Gietzen" X-Original-To: "Rotary motors in aircraft" Subject: Tuned Induction X-Original-Date: Thu, 22 May 2003 08:45:37 -0700 Organization: ALVentures X-Original-Message-ID: <000001c32079$33c18cc0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C3203E.8762B4C0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4024 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Original-Return-Path: alventures@email.msn.com X-OriginalArrivalTime: 22 May 2003 15:45:33.0521 (UTC) FILETIME=[2E3A4C10:01C32079] This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C3203E.8762B4C0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Al, I don't know much about induction systems and they appear to be as much "Magic" as science. Obviously, I don't either. But I'd like to be able to get it out of the realm of magic. However, there is little question that Tracy's engine puts out closer to 180 HP than 165. While its not been on a dyno, he has flow with 180HP O360 RVs and bested them. In fact, during the Sun & Fun 100 airrace, he not only beat all 0320 (supposedly 165HP) entries in his class but also half of the entries in the 180HP class. Tracy's plane performs very well, no doubt about it. This comparison just doesn't tell you why. Also, fuel flow is a fair indicator of HP being produce and he and I have both seen 19-20 gph fuel flow (on cold dense air mornings.. that clearly gives you a strong indication that he is producing at least 180 HP. I agree. My own personal story is that when I had a Weber throttle body with two 2" dia throats with a relative short length induction (about 1/2 my current length), my static rpm was 5000 rpm, my top speed was 182 MPH TAS and rate of climb was around 900 fpm. When I created an intake using smaller (1 5/8 and 1 3/8" dia tubes) of the length that theoretically are tuned to provide the "dynamic charging effect" at 5900 rpm, my static went up to 5300 rpm, my ROC went up to 1200 fpm and my top speed to 196 MPH TAS. So while I can't prove that my current induction system is better "tuned" to my operating regime and rpm - I sure like the improved results much better. Given that speed goes by the cube root of HP; the speed change suggests that your power increased by 25%; so maybe something suspect there, or there was something really wrong with your original setup. What else changed besides your runner length? Too bad we don't have a wealthy member of the list who would fund a little R&D with dyno time and different induction system approaches on the rotary engines. But, as you know that takes time and money and both are limited for most - if not all of us. Indeed! Ed Anderson ------=_NextPart_000_0001_01C3203E.8762B4C0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

Al, I don't know much = about induction systems and they appear to be as much "Magic" as = science.

 

Obviously, I don’t = either.  But I’d like to be able to get it out of the realm of magic.

 

  However, there is = little question that Tracy's engine puts out closer = to 180 HP than 165.  While its not been on a dyno, he has flow with 180HP = O360 RVs and bested them.  In fact, during the Sun & Fun 100 = airrace, he not only beat all 0320 (supposedly 165HP) entries in his class but = also  half of the entries in the 180HP class. 

Tracy’s plane performs very well, no doubt about it. =  This comparison just doesn’t tell you why. 

 

Also, fuel flow is a fair indicator of HP being produce and he and I have both seen 19-20 gph fuel = flow (on cold dense air mornings..

<snip>

that clearly gives you a = strong indication that he is producing at least 180 HP.

I agree.

 

My own personal  = story is that when I had a Weber throttle body with two 2" dia throats with = a relative short length induction (about 1/2 my current length), my static = rpm was 5000 rpm, my top speed was 182 MPH TAS and rate of climb was around = 900 fpm.  When I created an intake using smaller (1 5/8 and 1 = 3/8" dia tubes) of the length that theoretically are tuned to provide the = "dynamic charging effect" at 5900 rpm, my static went up to 5300 rpm, my ROC = went up to 1200 fpm and my top speed to 196 MPH TAS.   So while I = can't prove that my current induction system is better "tuned" to my operating regime and rpm - I sure like the improved results much better. =

 

Given that speed goes by the cube = root of HP; the speed change suggests that your power increased by 25%; so = maybe something suspect there, or there was something really wrong with your = original setup.  What else changed besides your runner = length?

 

 Too bad we don't = have a wealthy member of the list who would fund a little R&D with dyno = time and different induction system approaches on the rotary engines.  But, = as you know that takes time and money and both are limited for most - if = not all of us.

 

Indeed!

 

Ed = Anderson

 

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