X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1321584 for flyrotary@lancaironline.net; Sat, 29 Jul 2006 08:23:42 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; 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-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id k6TCMs4B009722 for ; Sat, 29 Jul 2006 08:22:56 -0400 (EDT) Message-ID: <001701c6b309$969284a0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Intake design 101 Date: Sat, 29 Jul 2006 08:21:58 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C6B2E8.0F349960" 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_0014_01C6B2E8.0F349960 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Joe, my personal opinion is that any benefit of the oval tube would = probably not justify the difficulty in fabrication compared to a round = tube. I made my intake with tubes inside tubes so that it would be = adjustable. The lower tubes are sized to slide up into the upper tubes = and I can adjust the length by approx 4". I find that the adjustment = appears to give me a bit better static depending on the OAT (so I adjust = it for summer and then again for winter months of flying. If you try = this - make certain to use "Drawn tubing" and not the more common = "Extruded tubing"). The drawn tubing is more dimensionally precise and = is used for telescoping tubes. You can do it out of extruded but they = do not slide easily. Ed ----- Original Message -----=20 From: Joe Berki=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 29, 2006 7:35 AM Subject: [FlyRotary] Re: Intake design 101 Ed, Thanks for the explanation. Now i know why they are separated. = Looking at the ports I was wondering if an oval tube shape for the = runners would be appropriate. I don't think that it is available, = however. Joe ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Thursday, July 27, 2006 10:02 PM Subject: [FlyRotary] Re: Intake design 101 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 -------------------------------------------------------------------------= --- Internal Virus Database is out-of-date. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.10.3/395 - Release Date: = 7/21/2006 ------=_NextPart_000_0014_01C6B2E8.0F349960 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Joe, my personal opinion is that any benefit of = the oval=20 tube would probably not justify the difficulty in fabrication compared = to a=20 round tube.  I made my intake with tubes inside tubes so that it = would be=20 adjustable.  The lower tubes are sized to slide up into the upper = tubes and=20 I can adjust the length by approx 4".  I find that the adjustment = appears=20 to give me a bit better static depending on the OAT (so I adjust it for = summer=20 and then again for winter months of flying.   If = you try=20  this - make certain to use "Drawn tubing" and not the more common=20 "Extruded tubing").  The drawn tubing is more dimensionally precise = and is=20 used for telescoping tubes.  You can do it out of extruded but they = do not=20 slide easily.
 
Ed
 
----- Original Message -----
From:=20 Joe Berki=20
Sent: Saturday, July 29, 2006 = 7:35=20 AM
Subject: [FlyRotary] Re: Intake = design=20 101

Ed,
Thanks for the explanation.  Now = i know why=20 they are separated.  Looking at the ports I was wondering if an = oval tube=20 shape for the runners would be appropriate.  I don't think that = it is=20 available, however.
 
Joe
----- Original Message -----
From:=20 Ed Anderson
To: Rotary motors in = aircraft=20
Sent: Thursday, July 27, 2006 = 10:02=20 PM
Subject: [FlyRotary] Re: = Intake design=20 101

Hi Joe,
 
Each chamber has a secondary and a primary = port (six=20 ports have an auxiliary port which is like an additional secondary=20 port).  Even thought a chamber has a primary and secondary, the = primary=20 and secondary for a port  normally have different intake = timing. =20 Additionally, the opening of the intake port generally generates a = very=20 strong pulse (residue exhaust gas bursting out of the intake when it = opens).   Since the intake and secondary port of each = rotor are 60=20 deg out of phase timing wise with the other rotor, the pulse = generated by=20 each port can interfere or assist with intake airflow (depending on = rpm,=20 manifold air temp, density, etc).  
 
I personally prefer to keep the intake ports = separate=20 to preclude interference.  Having said that - I have = successfully=20 flow with a system that combined the secondary intakes and primary = intakes,=20 so what you propose can be done. However, after trying six = different=20 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=20 gives me a bit more room in running intake tubes.   Other=20 arrangements have been tired and certainly work, so this is no magic = formula=20 - just  based on my personal = experience. 
 
Yes, the tuning (length) of the tubes should = be=20 determined by the rpm band that you want the most airflow = enhancement. =20 It appears that a tube length from block to Throttle body between 17 = and 21"=20 generally gives good results.  Also, avoid excessive large=20 tubes  diameters as intake air velocity is important = in=20 stuffing the chambers and larger tubes results in  less=20 velocity.  I found that 1.25" dia tubes for the primary and = 1.5" dia=20 tubes for the secondary works well.
 
I originally had my intakes merged into a = two runner=20 Weber style manifold.  A two port Weber style throttle body = with two 2"=20 dia intakes.  While this was the cats' meow for a racer turning = 9000+=20 rpm, it turned out to be disappointing  in aircraft use with = lower=20 5000-6000 rpm.   When I replace this "racers'" set up with = 4=20 smaller dia tubes my ROC increased by 300 fpm = immediately.  =20 Unfortunately my original fuel injection system died and = I  did=20 not get to collect further data on my old six port 1986 engine = before=20 deciding to switch to a 91 turbo block.
 
Hope this helps.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
 
1----- Original Message ----- =
From:=20 Joe=20 Berki
To: Rotary motors in = aircraft=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=20 front and rear of the block then there are two rectangular ports = in the=20 center housing close to each other.  Others have fabricated = intakes=20 using 4 tubes. I assume it is OK for the two outboard front and = rear of=20 block to be fed by one tube while the center two ports need to be = fed=20 individually. Is this correct?  The length of the tubes is = determined=20 by where on the rpm vs Hp band you want to operate at? Thanks=20
 
Joe Berki
Limo EZ

Internal Virus Database is out-of-date.
Checked by AVG = Free=20 Edition.
Version: 7.1.394 / Virus Database: 268.10.3/395 - = Release Date:=20 7/21/2006
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