X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 26 Apr 2009 09:23:01 -0400 Message-ID: X-Original-Return-Path: Received: from n6.bullet.re3.yahoo.com ([68.142.237.91] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with SMTP id 3596463 for lml@lancaironline.net; Sat, 25 Apr 2009 11:45:01 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.237.91; envelope-from=casey.gary@yahoo.com Received: from [68.142.237.87] by n6.bullet.re3.yahoo.com with NNFMP; 25 Apr 2009 15:44:28 -0000 Received: from [66.196.97.143] by t3.bullet.re3.yahoo.com with NNFMP; 25 Apr 2009 15:44:28 -0000 Received: from [127.0.0.1] by omp201.mail.re3.yahoo.com with NNFMP; 25 Apr 2009 15:44:28 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 20374.17939.bm@omp201.mail.re3.yahoo.com Received: (qmail 62678 invoked by uid 60001); 25 Apr 2009 15:44:27 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=m7XYFffGkxaCxJyMNvY9B7/Aa63UQqZlZoN1fS4Sy2egp5acS2tGYX6lHPvymwELlfKqamEVxrU/2hjC2wDxotS5pT57+OPiAo59cHualK6iLUWWrVMPnaA0+Qrxsz/i1upxfuYHOuVnZqeCv6IBHw7By9GgK4ccUxl2k7dGgYM=; X-Original-Message-ID: <626266.62626.qm@web57510.mail.re1.yahoo.com> X-YMail-OSG: H5WZ5qMVM1nBqbwvwxbYz35nyvQJFZnAY5ufwUedaj.7PVWDAAShdsNqO2bzdqDYPxVK.QMaNbpU0KM2QG_VIbEXyyYIgC2_uCjbi5XB1CIlay0xlBB.HAknKiHGXjJE9iTg882.EiqA25TO9QgOxLTOZwcNgFmAFJcq3VcVYQU7qnU068G5uqx.H4x.hTuCBAzoyAAPaddjFHA.ynyhhV.PETMV_mn5XYYvcITyLfFk9gMXJr8hlYiPJ_JztrJWFFex7NCQrUPE3_C8qbesynNpjAaUgS.e7Z4WEO17tPwWFyolzupy Received: from [97.122.158.231] by web57510.mail.re1.yahoo.com via HTTP; Sat, 25 Apr 2009 08:44:26 PDT X-Mailer: YahooMailRC/1277.35 YahooMailWebService/0.7.289.1 References: X-Original-Date: Sat, 25 Apr 2009 08:44:26 -0700 (PDT) From: Gary Casey Subject: Re: Ram Air Design X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-206242520-1240674266=:62626" --0-206242520-1240674266=:62626 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Fred,=0AYour design is as good as the Lancair design is bad. Very elegant.= And it was me that wrote the original comment, not Glen - wouldn't want h= im to get blamed {:-).=0AGary Casey=0A =0AFrom Fred:=0A=0AGlen wrote =E2=80= =9CIn my=0Aopinion, the "ram air" (quotes used deliberately) tube that is o= n=0Amost Continental-engined Lancairs is the worst I have ever seen.=E2=80= =9D=0AI concur. And=0Ahaving all those flapper valves with attachment hard= ware to swallow is asking=0Afor trouble in a high vibration environment. = =0AI have attached a photo=0Aof my arrangement on my IO-550 Lancair IV. Th= e alternate air inlet is=0Adeliberately set back so that rain water is not = inducted directly into the=0Aintake manifold. The filter is one of Glen=E2= =80=99s esteemed K&N=0Amodels, not a paragon of filtering efficiency, but O= K (not great) for airplanes=0Aoperating in clean air in my opinion. The fl= apper valve is attached to=0Aits shaft via epoxy and fibreglass wrap-around= , no hardware to come loose and=0Aget sucked into the engine. =0AThe alter= nate air inlet=0Awas included to eliminate any air filter loss and get that= last little bit of=0Apressure rise. =0AIt was a waste of time.=0AThere is = no benefit compared to the air filter tucked inside the cowl.=0AI modified = my cowl inlets=0Ato have 6 inch inlet diameter. They are set away from the= hub as shown in=0Athe second photo to maximize ram recovery, removing the = low energy air stream=0Anear the spinner. The ram pressure on top of the e= ngine is the ram=0Apressure delivered to engine intake manifold. =0ABy rea= ding full throttle manifold=0Apressure and comparing to indicated air speed= I find that I am getting about=0A75%-80% ram efficiency with these inlets = on my IO-550, but that is with the=0Acowl flaps closed. This equates to ab= out 1.5 inches of Hg at 200-210 IAS=0Awhen the total ram pressure is about = 2.0 inches of Hg. I get a bit less pressure=0Arise with the cowl flaps ope= n, perhaps half as much. =0AI get virtually no=0Abenefit by opening the al= ternate air door and bypassing the air filter. =0ASometimes I can see 0.1 i= n. Hg on the digital manifold pressure gauge, but that=0Asuggests that most= of the time the benefit is less than 0.05 in. Hg. The air=0Afilter, sized= per K&N guidelines, has virtually negligible pressure drop.=0AOne of my ha= ngar mates=0Ahas a new (to him) Cirrus SR-22 with the IO-550N engine. It u= ses an oiled=0Afoam conical air inlet filter installed much like my K&N, bu= t on the left=0Aside, and has an alternate air hose that sucks unfiltered w= arm air from the=0Alower cowl area. I suspect the warm air inlet is to mee= t certification=0Arequirements for flying in snow and ice crystals which ma= y block the=0Afilter. No reports yet on ram efficiency. However, the engin= e baffling=0Aset up is a thing of beauty, well thought out; no leaks, preci= sion formed sheet=0Ametal, and extremely tight fitting rubber trim. It is = the best factory=0Abaffling set up I have ever seen. If you see a Cirrus w= ith the cowl off,=0Ahave a very close look.=0AFred Moreno=0A=0A=0A=0A --0-206242520-1240674266=:62626 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Fred,
Your design is as good as the Lanc= air design is bad. =C2=A0Very elegant. =C2=A0And it was me that wrote the o= riginal comment, not Glen - wouldn't want him to get blamed {:-).
Gary Casey

=C2=A0

From Fred:


=0A=0A
= =0A=0A
=0A=0A
=0A=0A

Glen wrote =E2=80=9CIn my=0Aopinion, the "ram air" (quotes used de= liberately) tube that is on=0Amost Continental-engined Lancairs is the wors= t I have ever seen.=E2=80=9D

=0A=0A

<= span style=3D"font-size:12.0pt;">I concur.=C2=A0 And=0Ahaving all those fla= pper valves with attachment hardware to swallow is asking=0Afor trouble in = a high vibration environment.

=0A=0A

I have attached a photo=0Aof my arrangem= ent on my IO-550 Lancair IV.=C2=A0 The alternate air inlet is=0Adeliberatel= y set back so that rain water is not inducted directly into the=0Aintake ma= nifold.=C2=A0 The filter is one of Glen=E2=80=99s esteemed K&N=0Amodels= , not a paragon of filtering efficiency, but OK (not great) for airplanes= =0Aoperating in clean air in my opinion.=C2=A0 The flapper valve is attache= d to=0Aits shaft via epoxy and fibreglass wrap-around, no hardware to come = loose and=0Aget sucked into the engine.=C2=A0

=0A=0A

The alternate air inlet= =0Awas included to eliminate any air filter loss and get that last little b= it of=0Apressure rise.

=0A=0A

It was a waste of time.=0AThere is no benefit c= ompared to the air filter tucked inside the cowl.

=0A=0AI modified my cowl i= nlets=0Ato have 6 inch inlet diameter.=C2=A0 They are set away from the hub= as shown in=0Athe second photo to maximize ram recovery, removing the low = energy air stream=0Anear the spinner.=C2=A0 The ram pressure on top of the = engine is the ram=0Apressure delivered to engine intake manifold.=C2=A0

=0A=0A

By reading full throttle manifold=0Apressure and comparing to indicated a= ir speed I find that I am getting about=0A75%-80% ram efficiency with these= inlets on my IO-550, but that is with the=0Acowl flaps closed.=C2=A0 This = equates to about 1.5 inches of Hg at 200-210 IAS=0Awhen the total ram press= ure is about 2.0 inches of Hg.=C2=A0 I get a bit less pressure=0Arise with = the cowl flaps open, perhaps half as much.=C2=A0

=0A=0AI get virtually no= =0Abenefit by opening the alternate air door and bypassing the air filter.= =C2=A0=0ASometimes I can see 0.1 in. Hg on the digital manifold pressure ga= uge, but that=0Asuggests that most of the time the benefit is less than 0.0= 5 in. Hg.=C2=A0 The air=0Afilter, sized per K&N guidelines, has virtual= ly negligible pressure drop.

=0A=0A

<= span style=3D"font-size:12.0pt;">One of my hangar mates=0Ahas a new (to him= ) Cirrus SR-22 with the IO-550N engine.=C2=A0 It uses an oiled=0Afoam conic= al air inlet filter installed much like my K&N, but on the left=0Aside,= and has an alternate air hose that sucks unfiltered warm air from the=0Alo= wer cowl area.=C2=A0 I suspect the warm air inlet is to meet certification= =0Arequirements for flying in snow and ice crystals which may block the=0Af= ilter.=C2=A0 No reports yet on ram efficiency. However, the engine baffling= =0Aset up is a thing of beauty, well thought out; no leaks, precision forme= d sheet=0Ametal, and extremely tight fitting rubber trim.=C2=A0 It is the b= est factory=0Abaffling set up I have ever seen.=C2=A0 If you see a Cirrus w= ith the cowl off,=0Ahave a very close look.

=0A=0A

Fred Moreno

=0A
=

=0A=0A --0-206242520-1240674266=:62626--