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Return-Path: <13brv3@bellsouth.net> Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2899606 for flyrotary@lancaironline.net; Sun, 21 Dec 2003 11:21:31 -0500 Received: from rad ([68.212.7.74]) by imf22aec.mail.bellsouth.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20031221162130.WMMA20397.imf22aec.mail.bellsouth.net@rad> for ; Sun, 21 Dec 2003 11:21:30 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Dumb intake question Date: Sun, 21 Dec 2003 10:21:31 -0600 Message-ID: <024e01c3c7de$7e7a7e90$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_024F_01C3C7AC.33E00E90" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_024F_01C3C7AC.33E00E90 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable But, since they are not interconnected, can not use the DIE equation. However, Here is what the calculations come out to using just a pipe = from intake port out to your throttle body. I assume from your comment that = you don't have a lot of length to deal with. I further assumed you do want = to get some help from Intake "tuning". =20 =20 I either have about 28 inches over to the right cheek, or something much shorter in the left cheek. If I can work with either of these, and get = some intake tuning out of it, then I'll give it a shot. =20 So based on that - it looks like your length from port to butterfly = inlet of TB ranges from 13.1" for 6500 RPM to 11.5 RPM for 7500 RPM. This provides time for the pulse to be generated by the closing of the port = and to arrive after that port opens again after bouncing back from the = throttle body once. So from that Length you would need to subtract your block to port distance of 2.5" and the length of your throttle body.=20 =20 Excellent! This is just the sort of info I was hoping for, but there's = one thing I still don't understand. When you say the pulse bounces back = from the TB, what is it bouncing off of? I believe the throat of the TB is straight, with no venturi effect at all, and we'll assume that the = intake runner matches the TB size perfectly. That just leaves the open = butterfly, which has a pretty small profile. Is it really getting a strong bounce from the open butterfly? What if you had a slide type opening, like the Ellison TB, where there is nothing left in the path of the air? Would = there just be no bounce? =20 Thanks a bunch, Rusty (special needs student) =20 PS- Somewhere, I know I've seen a short intake, that points straight out = to the side, and uses a side draft carb. I've been looking for that all morning, and can't find it now. Can anyone point me to one of these? = I'm thinking it might make a good starting point for a left cheek intake. Thanks.=20 =20 =20 ------=_NextPart_000_024F_01C3C7AC.33E00E90 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

But, since they = are not=20 interconnected, can not use the DIE equation. However, Here is = what the=20 calculations come out to using just a pipe from intake port out to your = throttle=20 body. I assume from your comment that you don't have a lot of = length to=20 deal with. I further assumed you do want to get some help from = Intake=20 "tuning".

I either have about 28 = inches over=20 to the right cheek, or something much shorter in the left=20 cheek. If I can work with either of these, and get some = intake=20 tuning out of it, then I'll give it a=20 shot.

So based on that - it looks like = your=20 length from port to butterfly inlet of TB ranges from 13.1" for 6500 RPM = to 11.5=20 RPM for 7500 RPM. This provides time for the pulse to be generated = by the=20 closing of the port and to arrive after that port opens again after = bouncing=20 back from the throttle body once. So from that Length you would = need to=20 subtract your block to port distance of 2.5" and the length of your = throttle=20 body.

Excellent! = This is just=20 the sort of info I was hoping for, but there's one thing I = still don't=20 understand. When you say the pulse bounces back from the=20 TB, what is it bouncing off of? I believe the throat of = the TB=20 is straight, with no venturi effect at all, and we'll assume that the = intake=20 runner matches the TB size perfectly. That just leaves=20 the open butterfly, which has a pretty = small=20 profile. Is it really getting a strong bounce from the open=20 butterfly? What if you had a slide type opening, like the Ellison = TB,=20 where there is nothing left in the path of the air? Would there = just be no=20 bounce?

Thanks a = bunch,

Rusty (special needs=20 student)

PS- Somewhere, I know I've seen a short = intake, that=20 points straight out to the side, and uses a side draft carb. = I've=20 been looking for that all morning, and can't find it now. Can = anyone=20 point me to one of these? I'm thinking it might make a good = starting point=20 for a left cheek intake. = Thanks.

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