Return-Path: Received: from mail16.syd.optusnet.com.au ([211.29.132.197] verified) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP-TLS id 741116 for flyrotary@lancaironline.net; Wed, 16 Feb 2005 02:57:33 -0500 Received-SPF: none receiver=logan.com; client-ip=211.29.132.197; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-214-138.dsl.nsw.optusnet.com.au [220.236.214.138]) by mail16.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j1G7uhcC002009 for ; Wed, 16 Feb 2005 18:56:44 +1100 Message-ID: <007201c513fd$615d8660$8ad6ecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Big Butterflies vs Runners , was: Bruce Turrentine Intake Date: Wed, 16 Feb 2005 17:59:02 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006F_01C51451.32B8B740" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_006F_01C51451.32B8B740 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Tom, It's the port opening waves that clash in the runner that makes a 2 into = 1 not work so well. I was of the same opinion as yourself until it was = explained to me. Sorry about the terminology - blame the beers! George (down under) ----- Original Message -----=20 From: Tom=20 To: Rotary motors in aircraft=20 Sent: Wednesday, February 16, 2005 2:58 PM Subject: [FlyRotary] Re: Big Butterflies vs Runners , was: Bruce = Turrentine Intake Bob,=20 Just to exercise my lack of understanding so I can get beat-up and = develop an understanding... I was going to say, it looks like this manifold has 4.1sq inches of = throttle-plate to support 2.71 sq inches of sucking runners (one outside = runner and one inside runner) since only one rotor would draw at any = given time, but it looks more complicated than that. =20 2-rotors correct? Then whatever is being drawn thru the middle = intake port is dividing the load between both middle runners, (while = you're probably gonna set it up so that only one of the two middle = injectors fire at any time?) If, the size of the two ports within = each rotor chamber is the same, but you have two runners to the middle = port, wouldn't more air come in the middle port since it's less = restrictive? And therefore the middle feed is more lean than the outer = feed? Not that in the overall scheme of things it's any kind of issue. = =20 And I wonder why bother with providing two runners for the middle = port, why not just a single runner? With a single middle runner = could you program a single middle injector to fire properly for both = ports? If not then retain two injectors for the single middle runner? = But in any case, it may still effectively work out to 2.71sq = inches of porting behind the 4.1 sq inches of throttle-plate.=20 Tom Hi George, The best I can measure them, the outside runners are 1 3/8 ID and the=20 inside runners are 1 1/4 ID. They blend smoothly into the shape of = the=20 ports on the engine side. Bob White On Wed, 16 Feb 2005 09:00:14 +1000 "George Lendich" wrote: > Bob > What is the ID of the runners. > George ( down under) >=20 Bob White wrote:=20 Hi Jerry, I noticed that the inlet to the TB has a slight taper and the actual = TB=20 throat is only about 58 mm. Interestingly, That's also about 4.1 sq. = in. I have Tracy's RD-1C, so have some hope of making at 7500 rpm. It fits real nice in the cowling. I had Bruce bend it up so the TB = was=20 about 1 1/2 inches higher than if it was made horizontal. If I had = left=20 it horizontal, the TB would have come real close to interfering with = the=20 rubber isolator on the engine mount. I left the camera at home, so=20 couldn't take any pictures. Bob White On Tue, 15 Feb 2005 13:04:43 -0500 Jerry Hey wrote: > Bob, that does seem large. For reference, the p port has two=20 > butterflies for a TOTAL of 4.1 sq in. This was based on=20 > calculations done by Rolf and should be good up to 8000 rpm. The=20 > size is similar to what Power Sport is using and what Paul Yaw has = > recommended. Jerry > > --=20 http://www.bob-white.com N93BD - Rotary Powered BD-4 (soon) >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html -------------------------------------------------------------------------= ----- Do you Yahoo!? Yahoo! Search presents - Jib Jab's 'Second Term' ------=_NextPart_000_006F_01C51451.32B8B740 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Tom,
It's the port opening waves that clash = in the=20 runner that makes a 2 into 1 not work so = well. I=20 was of the same opinion as yourself until it was explained to = me.
Sorry about the terminology - blame the = beers!
George (down under)
----- Original Message -----
From:=20 Tom
Sent: Wednesday, February 16, = 2005 2:58=20 PM
Subject: [FlyRotary] Re: Big = Butterflies=20 vs Runners , was: Bruce Turrentine Intake

Bob,
 
Just to exercise my lack of understanding so I can get beat-up = and=20 develop an understanding...
 
I was going to say, it looks like this manifold has 4.1sq inches = of=20 throttle-plate to support 2.71 sq inches of sucking runners (one = outside=20 runner and one inside runner) since only one rotor would draw at any = given=20 time, but it looks more complicated than that.     =
 
2-rotors correct?     Then whatever is being = drawn=20 thru the middle intake port is dividing the load between both middle = runners,=20 (while you're probably gonna set it up so that only one of the two = middle=20 injectors fire at any time?)    If, the size of = the two=20 ports within each rotor chamber is the same, but you have two runners = to the=20 middle port, wouldn't more air come in the middle port since = it's=20 less restrictive?   And therefore the middle feed is more = lean than=20 the outer feed?   Not that in the overall scheme of things = it's any=20 kind of issue.    
 
   And I wonder why bother with providing two = runners for=20 the middle port, why not just a single=20 runner?     With a single middle runner could = you=20 program a single middle injector to fire properly for both=20 ports?    If not then retain two injectors for the = single=20 middle runner? 
 
    But in any case, it may still=20 effectively work out to 2.71sq inches of porting behind the = 4.1 sq=20 inches of throttle-plate.
 
Tom
 
 
 
Hi George,

The best I can measure them, the outside = runners are 1=20 3/8 ID and the
inside runners are 1 1/4 ID.  They blend = smoothly into=20 the shape of the
ports on the engine side.

Bob = White


On=20 Wed, 16 Feb 2005 09:00:14 +1000
"George Lendich" <lendich@optusnet.com.au> = wrote:

>=20 Bob
> What is the ID of the runners.
> George ( down=20 under)
>


Bob White = <bob@bob-white.com>=20 wrote:=20

Hi=20 Jerry,

I noticed that the inlet to the TB has a slight taper = and the=20 actual TB
throat is only about 58 mm. Interestingly, That's also = about=20 4.1 sq.
in. I have Tracy's RD-1C, so have some hope of making at = 7500=20 rpm.
It fits real nice in the cowling. I had Bruce bend it up so = the TB=20 was
about 1 1/2 inches higher than if it was made horizontal. If = I had=20 left
it horizontal, the TB would have come real close to = interfering=20 with the
rubber isolator on the engine mount. I left the camera = at home,=20 so
couldn't take any pictures.

Bob White

On Tue, = 15 Feb=20 2005 13:04:43 -0500
Jerry Hey = wrote:

>=20 Bob, that does seem large. For reference, the p port has two =
>=20 butterflies for a TOTAL of 4.1 sq in. This was based on
>=20 calculations done by Rolf and should be good up to 8000 rpm. The =
>=20 size is similar to what Power Sport is using and what Paul Yaw has =
>=20 recommended. Jerry
> >


--=20
http://www.bob-white.com
N93BD - Rotary Powered BD-4=20 (soon)

>> Homepage: = http://www.flyrotary.com/
>>=20 Archive:=20 = http://lancaironline.net/lists/flyrotary/List.html
=

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