X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 934209 for flyrotary@lancaironline.net; Thu, 05 May 2005 21:30:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-189-178.carolina.res.rr.com [24.74.189.178]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j461Tb0W008568 for ; Thu, 5 May 2005 21:29:38 -0400 (EDT) Message-ID: <003401c551db$160ebf00$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Ramair-airfilters-Revisited Date: Thu, 5 May 2005 21:29:45 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0031_01C551B9.8ED23E70" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0031_01C551B9.8ED23E70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks, Al Yes, I keep forgetting that air-cooled engines often have high pressure = under the cowl. While at or near the same pressure, the under the cowl = air would be hotter, so the straight in would provide cooler ram air = even if of the same pressure. Ed ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Thursday, May 05, 2005 8:49 PM Subject: [FlyRotary] Re: Ramair-airfilters-Revisited Good points, Ed. It occurs to me that the reason "lazy8s" setup could = result in ram pressure is that the cowling is seeing about the same ram = pressure as the induction intake, so there is little or no flow in or = out of the filter. =20 Al I agree, Bill, very creative. However, while it appears to give him a = nice increase in MAP due to Ram air, from what I have been reading about = those types of filters, two thoughts come to mind: Given that the filter elements offer little resistance to air flow = what keeps 1. The Hot air under the cowl from being ingested through the sides = of the filter even when the ram butter fly is open - I would expect most = of the air to be ram air but not all. I presume the higher ram pressure = would in effect act as a positive pressure area and keep the hot air = out, in which case it brings up the next question. =20 2. What prevents, The ram air (since its at higher pressure ) from = leaking out through the sides of the filter when the ram valve is open? = Is it just not enough to make any difference - hard to believe given all = that filter area. Interesting though. Ed ----- Original Message -----=20 From: Bill Dube=20 To: Rotary motors in aircraft=20 Sent: Thursday, May 05, 2005 6:56 PM Subject: [FlyRotary] Ramair-airfilters-Revisited There has been an interesting thread on ram air and = filtering on the RV list. Here is a link to a clever looking solution: http://www.lazy8.net/intakesystem.htm Looks simple and lightweight, but I am not quite sure where = you would mount it on a rotary. Also, it doesn't have a bend in the path = to drop out bugs and big chunks when the valve is open. This is easily = corrected, however. and a more traditional approach http://www.rvproject.com/ramair.html Again, no "bug bend".=20 >> Homepage: http://www.flyrotary.com/ >> Archive: = http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0031_01C551B9.8ED23E70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Thanks, Al

Yes, I keep forgetting that air-cooled = engines=20 often have high pressure under the cowl. While at or near the same=20 pressure, the under the cowl air would be hotter, so the straight in = would=20 provide cooler ram air even if of the same pressure.

Ed

----- Original Message -----
From:=20 Al = Gietzen=20
To: Rotary motors in = aircraft

Sent: Thursday, May 05, 2005 = 8:49=20 PM

Subject: [FlyRotary] Re:=20 Ramair-airfilters-Revisited

Good = points,=20 Ed. It occurs to me that the reason =93lazy8s=94 setup could = result in ram=20 pressure is that the cowling is seeing about the same ram pressure as = the=20 induction intake, so there is little or no flow in or out of the = filter. =20

Al

I agree, Bill, very=20 creative. However, while it appears to give him a nice increase = in MAP=20 due to Ram air, from what I have been reading about those types of = filters,=20 two thoughts come to mind:

Given that the filter = elements=20 offer little resistance to air flow what keeps

1. The Hot air = under the=20 cowl from being ingested through the sides of the filter even when the = ram=20 butter fly is open - I would expect most of the air to be ram air but = not all.=20 I presume the higher ram pressure would in effect act as a positive = pressure=20 area and keep the hot air out, in which case it brings up the next=20 question.

2. What = prevents, The=20 ram air (since its at higher pressure ) from leaking out through the = sides of=20 the filter when the ram valve is open? Is it just not enough to = make any=20 difference - hard to believe given all that filter=20 area.

Interesting=20 though.

Ed

----- Original Message = -----=20

From: Bill = Dube=20

To: Rotary motors in = aircraft=20

Sent:=20 Thursday, May 05,=20 2005 6:56=20 PM

Subject:=20 [FlyRotary] Ramair-airfilters-Revisited

        There=20 has been an interesting thread on ram air and filtering on the RV = list. Here=20 is a link to a clever looking=20 = solution:

        <= /X-TAB>=20 http://www.lazy8.net/intakesystem.htm

        Looks=20 simple and lightweight, but I am not quite sure where you would = mount it on=20 a rotary. Also, it doesn't have a bend in the path to drop out bugs = and big=20 chunks when the valve is open. This is easily corrected,=20 = however.

        and=20 a more traditional=20 = approach

        =20 http://www.rvproject.com/ramair.html

        Again,=20 no "bug bend".

>> Homepage: = http://www.flyrotary.com/

>> Archive:   = http://lancaironline.net/lists/flyrotary/List.html

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