X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1319159 for flyrotary@lancaironline.net; Thu, 27 Jul 2006 22:04:45 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-111-186.carolina.res.rr.com [24.74.111.186]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id k6S23ucX019107 for ; Thu, 27 Jul 2006 22:03:58 -0400 (EDT) Message-ID: <000901c6b1e9$f2579440$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Intake design 101 Date: Thu, 27 Jul 2006 22:02:57 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01C6B1C8.6AF2A420" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0006_01C6B1C8.6AF2A420 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Joe, Each chamber has a secondary and a primary port (six ports have an = auxiliary port which is like an additional secondary port). Even = thought a chamber has a primary and secondary, the primary and secondary = for a port normally have different intake timing. Additionally, the = opening of the intake port generally generates a very strong pulse = (residue exhaust gas bursting out of the intake when it opens). Since = the intake and secondary port of each rotor are 60 deg out of phase = timing wise with the other rotor, the pulse generated by each port can = interfere or assist with intake airflow (depending on rpm, manifold air = temp, density, etc). =20 I personally prefer to keep the intake ports separate to preclude = interference. Having said that - I have successfully flow with a system = that combined the secondary intakes and primary intakes, so what you = propose can be done. However, after trying six different intake = configurations, I have found though that I get the best performance = (for our rpm) with 4 separate tubes feeding the throttle body. Keeping = in mind I have a "Plugs Up" installation which generally gives me a bit = more room in running intake tubes. Other arrangements have been tired = and certainly work, so this is no magic formula - just based on my = personal experience.=20 Yes, the tuning (length) of the tubes should be determined by the rpm = band that you want the most airflow enhancement. It appears that a tube = length from block to Throttle body between 17 and 21" generally gives = good results. Also, avoid excessive large tubes diameters as intake = air velocity is important in stuffing the chambers and larger tubes = results in less velocity. I found that 1.25" dia tubes for the primary = and 1.5" dia tubes for the secondary works well.=20 I originally had my intakes merged into a two runner Weber style = manifold. A two port Weber style throttle body with two 2" dia intakes. = While this was the cats' meow for a racer turning 9000+ rpm, it turned = out to be disappointing in aircraft use with lower 5000-6000 rpm. = When I replace this "racers'" set up with 4 smaller dia tubes my ROC = increased by 300 fpm immediately. Unfortunately my original fuel = injection system died and I did not get to collect further data on my = old six port 1986 engine before deciding to switch to a 91 turbo block. Hope this helps. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW 1----- Original Message -----=20 From: Joe Berki=20 To: Rotary motors in aircraft=20 Sent: Thursday, July 27, 2006 9:24 PM Subject: [FlyRotary] Intake design 101 I am using a 89 block for mock up and maybe rebuild. Looking at the = intake ports, there are two ports at the front and rear of the block = then there are two rectangular ports in the center housing close to each = other. Others have fabricated intakes using 4 tubes. I assume it is OK = for the two outboard front and rear of block to be fed by one tube while = the center two ports need to be fed individually. Is this correct? The = length of the tubes is determined by where on the rpm vs Hp band you = want to operate at? Thanks=20 Joe Berki Limo EZ ------=_NextPart_000_0006_01C6B1C8.6AF2A420 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Joe,
 
Each chamber has a secondary and a primary port = (six ports=20 have an auxiliary port which is like an additional secondary = port).  Even=20 thought a chamber has a primary and secondary, the primary and secondary = for a=20 port  normally have different intake timing.  Additionally, = the=20 opening of the intake port generally generates a very strong pulse = (residue=20 exhaust gas bursting out of the intake when it opens).   Since = the=20 intake and secondary port of each rotor are 60 deg out of phase timing = wise with=20 the other rotor, the pulse generated by each port can interfere or = assist with=20 intake airflow (depending on rpm, manifold air temp, density, = etc).  =20
 
I personally prefer to keep the intake ports = separate to=20 preclude interference.  Having said that - I have successfully = flow=20 with a system that combined the secondary intakes and primary intakes, = so what=20 you propose can be done. However, after trying six different intake = configurations,  I have found though that I get the best = performance (for=20 our rpm) with 4 separate tubes feeding the throttle body.  Keeping = in mind=20 I have a "Plugs Up" installation which generally gives me a bit more = room in=20 running intake tubes.   Other arrangements have been tired and = certainly work, so this is no magic formula - just  based on = my=20 personal experience. 
 
Yes, the tuning (length) of the tubes should be = determined=20 by the rpm band that you want the most airflow enhancement.  It = appears=20 that a tube length from block to Throttle body between 17 and 21" = generally=20 gives good results.  Also, avoid excessive large=20 tubes  diameters as intake air velocity is important in = stuffing=20 the chambers and larger tubes results in  less velocity.  = I found=20 that 1.25" dia tubes for the primary and 1.5" dia tubes for the = secondary works=20 well.
 
I originally had my intakes merged into a two = runner Weber=20 style manifold.  A two port Weber style throttle body with two 2" = dia=20 intakes.  While this was the cats' meow for a racer turning 9000+ = rpm, it=20 turned out to be disappointing  in aircraft use with lower = 5000-6000=20 rpm.   When I replace this "racers'" set up with 4 smaller dia = tubes=20 my ROC increased by 300 fpm immediately.   Unfortunately my = original=20 fuel injection system died and I  did not get to collect = further data=20 on my old six port 1986 engine before deciding to switch to a 91 turbo=20 block.
 
Hope this helps.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
 
1----- Original Message -----
From:=20 Joe Berki=20
Sent: Thursday, July 27, 2006 = 9:24=20 PM
Subject: [FlyRotary] Intake = design=20 101

I am using a 89 block for mock up and = maybe=20 rebuild.  Looking at the intake ports, there are two ports at the = front=20 and rear of the block then there are two rectangular ports in the = center=20 housing close to each other.  Others have fabricated intakes = using 4=20 tubes. I assume it is OK for the two outboard front and rear of block = to be=20 fed by one tube while the center two ports need to be fed = individually. Is=20 this correct?  The length of the tubes is determined by where on = the rpm=20 vs Hp band you want to operate at? Thanks
 
Joe Berki
Limo = EZ
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