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 931279 for flyrotary@lancaironline.net; Tue, 03 May 2005 15:05:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.67; envelope-from=13brv3@bellsouth.net Received: from rd ([65.6.194.9]) by imf19aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050503190510.JCAU2470.imf19aec.mail.bellsouth.net@rd> for ; Tue, 3 May 2005 15:05:10 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Static MAP readings? Date: Tue, 3 May 2005 14:05:21 -0500 Message-ID: <034a01c55013$0db7fed0$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_034B_01C54FE9.24E1F6D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_034B_01C54FE9.24E1F6D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Doesn't pressure go down with an increase in velocity? Is there any way you could take readings with just a blower moving air through with no restrictions? I don't follow Ernest. Are you trying to suggest a way to see if the = port on the TB changes with airflow? =20 =20 I would think you'd need suction (some blowers do have that capability) = to test this. At some point, the suction would certainly be great enough = to cause the pressure to go down, but without a way to compare the velocity = of the engine, with the blower (sucker), I'm not sure it would tell me anything. =20 =20 I know there are tradeoffs, and sometimes higher velocity will work = better than a slightly higher pressure at a lower velocity. My intake joins = the primary and secondary close to the engine, and continues about 15 inches = to the TB as a single runner for each rotor. The ID of the runner and the = TB is 1-5/8" (1.75" tubing), which I believe is likely a bit too small for = best power. If I believed there was a lot to gain, I've got another = Mazdatrix intake, and 2" bends to make another complete intake out of. I also = have another TB with about the right size barrels for the 2" tubing, though = if I were doing it over, I'd probably take the runners to a plenum, with a = single barrel TB on the inlet of the plenum. At least I'd get a better MAP reading. =20 =20 For the record, I don't really want to do any of this, unless there's significant power to be gained.=20 =20 Rusty =20 =20 ------=_NextPart_000_034B_01C54FE9.24E1F6D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Doesn't pressure go down with an increase in = velocity?  Is=20 there any way
you could take readings with just a blower moving air = through=20 with no
restrictions?

I don't follow = Ernest.  Are=20 you trying to suggest a way to see if the port on the TB changes with=20 airflow? 
 
I would = think you'd need=20 suction (some blowers do have that capability) to test this.  At = some=20 point, the suction would certainly be great enough to cause the pressure = to go=20 down, but without a way to compare the velocity of the engine, with the = blower=20 (sucker), I'm not sure it would tell me anything.  =20
 
I know = there are=20 tradeoffs, and sometimes higher velocity will work better than a = slightly higher=20 pressure at a lower velocity.  My intake joins the primary and = secondary=20 close to the engine, and continues about 15 inches to the TB as a single = runner=20 for each rotor.  The ID of the runner and the TB is 1-5/8" (1.75" = tubing),=20 which I believe is likely a bit too small for best power.  If = I=20 believed there was a lot to gain, I've got another Mazdatrix intake, and = 2" bends to make another complete intake out=20 of.  I also have another TB with about the right=20 size barrels for the 2" tubing, though if I were doing it = over, I'd=20 probably take the runners to a plenum, with a single barrel TB on the = inlet of=20 the plenum.  At least I'd get a better MAP=20 reading.  
 
For the = record, I don't=20 really want to do any of this, unless there's significant power to = be=20 gained. 
 
Rusty
  
 


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