X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <13brv3@bellsouth.net> Received: from imf19aec.mail.bellsouth.net ([205.152.59.67] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 951179 for flyrotary@lancaironline.net; Fri, 20 May 2005 13:48:44 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.67; envelope-from=13brv3@bellsouth.net Received: from ibm60aec.bellsouth.net ([65.6.194.9]) by imf19aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050520174758.WNSK2061.imf19aec.mail.bellsouth.net@ibm60aec.bellsouth.net> for ; Fri, 20 May 2005 13:47:58 -0400 Received: from rd ([65.6.194.9]) by ibm60aec.bellsouth.net (InterMail vG.1.02.00.01 201-2136-104-101-20040929) with ESMTP id <20050520174757.TUHT11146.ibm60aec.bellsouth.net@rd> for ; Fri, 20 May 2005 13:47:57 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Intermediate housing ports/porting Date: Fri, 20 May 2005 12:48:16 -0500 Message-ID: <013e01c55d64$1a4bb890$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_013F_01C55D3A.3175B090" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_013F_01C55D3A.3175B090 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Has anyone ever joined the intermediate housing ports by removing some = of the material between the ports in the housing to make a larger single = port and runner? If so, did it help or adversely affect operation? =20 Hi Cary, =20 Funny you should ask, as I've been wondering about the very same thing. You've no doubt heard me whining about how I believe my 40mm runners and = TB barrels (primary and secondary combine in the cast intake, then one = runner and barrel for each rotor) are likely too restrictive. =20 =20 In talking to TWM a while back, they suggested a balance tube from one runner to the other. This would allow each rotor to draw air from both barrels of the TB. They didn't know how well it would work, but saw it = as the only way to get more effective TB area with my current intake. In thinking about this, I came across the idea of simply milling out the divider between the primary ports inside the intake flange. = Unfortunately, I have the same question as you do as far as how well it will work. =20 =20 On one hand, it would have to give the engine easier access to air, but there is some concern about interference between the two rotor pulses. = I haven't really studied the intake and exhaust timing, but if there is = any overlap between the intake of one rotor and the other, then I can see = this being very bad. =20 =20 Imagine one rotor having it's intake cycle. The port opens, there's a = large rapid surge of suction pulling air into the rotor housing, but as it = nears the end of the cycle, that suction subsides and the air is just more or = less coasting in as the port starts to close. Now, imagine the second rotor starting it's large suction portion of it's cycle as the first rotor is coasting. The second rotor will be perfectly happy to suck some of the = air and fuel out of the first rotor, as it also sucks new air in from the runners. =20 =20 I guess I need to study the timing, but ported engines would be worse. Fortunately, the primary porting isn't usually quite the same as the secondary, so perhaps there's a better chance it can work. I'm not = quite ready to mill out that divider yet though. =20 =20 Cheers, Rusty (too many experiments) =20 ------=_NextPart_000_013F_01C55D3A.3175B090 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Has anyone ever joined the intermediate housing ports = by=20 removing some of the material between the ports in the housing to make a = larger=20 single port and runner? If so, did it help or adversely affect=20 operation?

 
Hi=20 Cary,
 
Funny = you should ask, as=20 I've been wondering about the very same thing.   You've no = doubt heard=20 me whining about how I believe my 40mm runners and TB barrels (primary = and=20 secondary combine in the cast intake, then one runner and barrel for = each rotor)=20 are likely too restrictive. 
 
In = talking to TWM a=20 while back, they suggested a balance tube from one runner to=20 the other.  This would allow each rotor to draw air from both = barrels=20 of the TB.  They didn't know how well it would work, but saw it as = the only=20 way to get more effective TB area with my current intake.  In = thinking=20 about this, I came across the idea of simply milling out the divider = between the=20 primary ports inside the intake flange.  Unfortunately, I have the = same=20 question as you do as far as how well it will=20 work.  
 
On one = hand, it would=20 have to give the engine easier access to air, but there is = some=20 concern about interference between the two rotor pulses.  I = haven't=20 really studied the intake and exhaust timing, but if there is any = overlap=20 between the intake of one rotor and the other, then I can see this being = very=20 bad.  
 
Imagine = one rotor having=20 it's intake cycle.  The port opens, there's a large rapid = surge=20 of suction pulling air into the rotor housing, but as it nears = the end=20 of the cycle, that suction subsides and the air is just more or less = coasting in=20 as the port starts to close.  Now, imagine the second rotor = starting it's=20 large suction portion of it's cycle as the first rotor is = coasting. =20 The second rotor will be perfectly happy to suck some of the air = and fuel=20 out of the first rotor, as it also sucks new air in from the=20 runners.  
 
I guess = I need to study=20 the timing, but ported engines would be worse.  Fortunately,=20 the primary porting isn't usually quite the same as the secondary, = so=20 perhaps there's a better chance it can work.  I'm not quite = ready to=20 mill out that divider yet though.  
 
Cheers,
Rusty = (too many=20 experiments)   



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