Return-Path: Received: from smtpauth01.mail.atl.earthlink.net ([209.86.89.61] verified) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 723571 for flyrotary@lancaironline.net; Thu, 10 Feb 2005 10:22:38 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.86.89.61; envelope-from=jerryhey@earthlink.net Received: from [65.176.160.213] (helo=earthlink.net) by smtpauth01.mail.atl.earthlink.net with asmtp (Exim 4.34) id 1CzG8c-0005pN-H8 for flyrotary@lancaironline.net; Thu, 10 Feb 2005 10:21:53 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=simple; s=test1; d=earthlink.net; h=Date:Subject:Content-Type:Mime-Version:From:To:In-Reply-To:Message-Id:X-Mailer; b=ZJSwZ7WAqCq486DNK+zdFKdyI4EAIV2ouMCSaPfFS2Uh7cYcVr0X+iXHijrfT3VB; Date: Thu, 10 Feb 2005 10:22:49 -0500 Subject: Re: [FlyRotary] Re: : Same HP = Same Air Mass <> same air Velocity II [FlyRotary] Re: Ellison, the missing piece Content-Type: multipart/alternative; boundary=Apple-Mail-14-892750567 Mime-Version: 1.0 (Apple Message framework v552) From: Jerry Hey To: "Rotary motors in aircraft" In-Reply-To: Message-Id: <9FA4F320-7B77-11D9-B3AA-0003931B0C7A@earthlink.net> X-Mailer: Apple Mail (2.552) X-ELNK-Trace: 8104856d7830ec6b1aa676d7e74259b7b3291a7d08dfec79fc534b361423e13c47dcfacacce31513350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 65.176.160.213 --Apple-Mail-14-892750567 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1; format=flowed I assume you are talking about a 6000 rpm limited rotary vs a wide open=20= 0-360. Run the rotary faster and thats the end of the story. Jerry On Thursday, February 10, 2005, at 10:12 AM, Ed Anderson wrote: > Tom, > =A0 > I don't really think=A0anyone can accurately make=A0a generalization = like=20 > that.=A0 Certainly a PP 13B (such as power sports) which reportedly=20 > =A0produces 215 HP produces more power than a carb 360 Lycoming.=A0 A=20= > street ported well tuned 13B will certainly produce 180HP.=A0 But, = given=20 > any two specific engines and depending on how well their=20 > induction/exhaust, etc. are set up, you could have one or the other=20 > producing the greater HP. > =A0 > But, if someone has specific data that shows the 360 produces more=20 > power, then I would certainly like to know about it. > =A0 > Ed A > > ----- Original Message ----- > From: Tom > To: Rotary motors in aircraft > Sent: Thursday, February 10, 2005 9:14 AM > Subject: [FlyRotary] Re: : Same HP =3D Same Air Mass <> same air=20 > Velocity II [FlyRotary] Re: Ellison, the missing piece > > It's my understanding that NA non-renesis rotary installations=20 > produce=A0less power than 360s, Perry Mick might have a word on this. > > > Eric Ruttan wrote: > > Warning top poster, who cuts the post size down. > > A hopothises for your examination. > > A 360 Lyc does not produce the same power as a rotary. > > If true, then the Ellison card may not get enough air. > > If not true, then there is no real reason why the Ellison cannot feed = a > rotary. > > Ed, I understand your math, but even if the local inlet velocity is=20 > much > higher, we dont care. the velocities adverage out to the same, as the > volume of air =3D velocity * carb area. > > If the velocities are higher, the rotary consumes more air, and makes=20= > more > power. > > Eric > > ----- Original Message ----- > From: "Ed Anderson" > To: "Rotary motors in aircraft" > Sent: Thursday, February 10, 2005 8:31 AM > Subject: [FlyRotary] : Same HP =3D Same Air Mass <> same air Velocity = II > [FlyRotary] Re: Ellison, the missing piece > > > Good question, Tom. > > That interpretation did occur to me. I think the answer depends on = your > assumptions, IF using commonly accepted formulas for calculating air=20= > flow vs > rpm and displacement (and considering both are positive displacement > pumps) - then the 360 CID lycoming turning 2800 rpm and the rotors in=20= > the > rotary turning 2100 rpm (6300 rpm E shaft) ingest the same total=20 > quantity of > air in one minute - approx 291 CFM. In comparing the two engines, its > accepted that you compare them over the standard 720deg 4 stroke cycle=20= > - > that means that 4 of the rotary faces have gone through their cycle in=20= > the > same 720 deg of rotation. > > But, assuming the formulas are correct, then they both end up with the=20= > same > amount of air in the engine to create the same HP. I think my math is > correct on the smaller/unit displacement and longer period of rotation=20= > for > the rotary for the same intake of air. However, in both cases the air=20= > flow > is pulsating and pulsating differently. So if the total displacement=20= > for > the rotary over that 720 deg is less than the Lycoming and the time it=20= > takes > to complete that rotation is slower AND you still ingest the same=20 > amount of > total Air then the only way I can see that happening is the velocity=20= > of the > air in the rotary's intake has to be considerably higher than in the > Lycoming. > > The only other alternative answer I see if that the commonly accepted > formula for comparing the rotary to the reciprocating 4 stroke is=20 > incorrect > (I got beat about the head mercilessly by a number of respected rotary > experts challenging that formula , so I wont' go there again (at least=20= > not > now {:>)). > > Air Flow =3D Total Displacement * RPM/(2 - accounting for only every=20= > other > cylinder sucking on each rev * 1728 (conversion of cubic inches to=20 > cubic > feet) =3D TD*RPM/(2*1728) > > For the 360 CID Lycoming at 2800 rpm, Air Flow =3D 360*2800/(2*1728) =3D= =20 > 291.66 > CFM > > Using the commonly accepted notion that a rotary is equivalent to a=20 > 160 CID > 4 stroke reciprocating engine because of the 4 faces of 40 CID that=20 > complete > there cycle in 720 deg. > > For the 160 CID Rotary at 6000 rpm, Air Flow =3D 160 * 6300/(2*1728) =3D= =20 > 291.66 > CFM > > So if both ingest the 291 CFM and the rotary has less total=20 > displacement > (over 720 deg) then disregarding any of my math on rotation period > differences you still have to account for why the rotary can ingest=20 > the same > amount of air with less displacement. (Now I must admit I have my > suspicions about the commonly accepted (racing approved) formula for=20= > the > rotary. However, if my suspicions about the rotary formula are=20 > correct, it > would make the rotary even more efficient at ingesting air - so I=20 > won't go > there {:>)). > > If my logic and calculations are correct then this implies the Ve of=20= > the > rotary is considerably better than the Lycoming and is great than=20 > 100%. I > mentioned a few of the reasons why the Ve of the rotary may indeed be=20= > better > in the previous message. > > Now, its possible that the stories about the Ellison not working well=20= > on the > rotary is just that - a story OR there could be a plausible physical=20= > reason > as I have poorly attempted to present. > > > Ed > > > ----- Original Message ----- > From: Tom > To: Rotary motors in aircraft > Sent: Wednesday, February 09, 2005 11:54 PM > Subject: [FlyRotary] Re: Same HP =3D Same Air Mass <> same air = Velocity > [FlyRotary] Re: Ellison, the missing piece > > > Ed, > > >The rotary has 40 CID displacement per face and 2 facesx 2 rotors =3D=20= > 4*40 > or 160 CID for one rev. So the rotary has 22% less displacement per > revolution and the longer rotation period.< > > and > > >So if the rotary has less displacement of the sucking component and=20= > must > take 25% longer for each revolution. Therefore the only way it can=20 > obtain > an equal amount of air is for the intake air to have a higher velocity=20= > than > the Lycoming does.< > > Isn't 'displacement' equal to the amount of air needing to be = ingested? > So 22% less displacement equates to 22% less air and the rotarys = longer > rotation period gives it more time for air to push in? And then the > intake air velocity should be lower? > > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html > > > > > Do you Yahoo!? > Yahoo! Search presents - Jib Jab's 'Second Term' > --Apple-Mail-14-892750567 Content-Transfer-Encoding: quoted-printable Content-Type: text/enriched; charset=ISO-8859-1 I assume you are talking about a 6000 rpm limited rotary vs a wide open 0-360. Run the rotary faster and thats the end of the story.=20 Jerry =20 On Thursday, February 10, 2005, at 10:12 AM, Ed Anderson wrote: = ArialTom, =A0 ArialI don't really think=A0anyone can accurately make=A0a generalization like that.=A0 Certainly a PP 13B (such as power sports) which reportedly =A0produces 215 HP produces more power than a carb 360 Lycoming.=A0 A street ported well tuned 13B will certainly produce 180HP.=A0 But, given any two specific engines and depending on how well their induction/exhaust, etc. are set up, you could have one or the other producing the greater = HP. =A0 ArialBut, if someone has specific data that shows the 360 produces more power, then I would certainly like to know about it. =A0 ArialEd A ----- Original Message ----- From: = 1999,1999,FFFFTom To: 1999,1999,FFFFRotary motors in aircraft Sent: Thursday, February 10, 2005 9:14 AM Subject: [FlyRotary] Re: : Same HP =3D Same Air Mass <<> same air Velocity II [FlyRotary] Re: Ellison, the missing piece It's my understanding that NA non-renesis rotary installations produce=A0less power than 360s, Perry Mick might have a word on this. Eric Ruttan = <<1999,1999,FFFFericruttan@chartermi.net<= /color>> wrote: Warning top poster, who cuts the post size down. A hopothises for your examination. A 360 Lyc does not produce the same power as a rotary. If true, then the Ellison card may not get enough air. If not true, then there is no real reason why the Ellison cannot feed a rotary. Ed, I understand your math, but even if the local inlet velocity is much higher, we dont care. the velocities adverage out to the same, as the volume of air =3D velocity * carb area. If the velocities are higher, the rotary consumes more air, and makes more power. Eric ----- Original Message ----- From: "Ed Anderson"=20 To: "Rotary motors in aircraft"=20 Sent: Thursday, February 10, 2005 8:31 AM Subject: [FlyRotary] : Same HP =3D Same Air Mass <<> same air Velocity = II [FlyRotary] Re: Ellison, the missing piece Good question, Tom. That interpretation did occur to me. I think the answer depends on your assumptions, IF using commonly accepted formulas for calculating air flow vs rpm and displacement (and considering both are positive displacement pumps) - then the 360 CID lycoming turning 2800 rpm and the rotors in the rotary turning 2100 rpm (6300 rpm E shaft) ingest the same total quantity of air in one minute - approx 291 CFM. In comparing the two engines, its accepted that you compare them over the standard 720deg 4 stroke cycle - that means that 4 of the rotary faces have gone through their cycle in the same 720 deg of rotation. But, assuming the formulas are correct, then they both end up with the same amount of air in the engine to create the same HP. I think my math is correct on the smaller/unit displacement and longer period of rotation for the rotary for the same intake of air. However, in both cases the air flow is pulsating and pulsating differently. So if the total displacement for the rotary over that 720 deg is less than the Lycoming and the time it takes to complete that rotation is slower AND you still ingest the same amount of total Air then the only way I can see that happening is the velocity of the air in the rotary's intake has to be considerably higher than in the Lycoming. The only other alternative answer I see if that the commonly accepted formula for comparing the rotary to the reciprocating 4 stroke is incorrect (I got beat about the head mercilessly by a number of respected rotary experts challenging that formula , so I wont' go there again (at least not now {:>)). Air Flow =3D Total Displacement * RPM/(2 - accounting for only every other cylinder sucking on each rev * 1728 (conversion of cubic inches to cubic feet) =3D TD*RPM/(2*1728) For the 360 CID Lycoming at 2800 rpm, Air Flow =3D 360*2800/(2*1728) =3D 291.66 CFM Using the commonly accepted notion that a rotary is equivalent to a 160 CID 4 stroke reciprocating engine because of the 4 faces of 40 CID that complete there cycle in 720 deg. For the 160 CID Rotary at 6000 rpm, Air Flow =3D 160 * 6300/(2*1728) =3D 291.66 CFM So if both ingest the 291 CFM and the rotary has less total displacement (over 720 deg) then disregarding any of my math on rotation period differences you still have to account for why the rotary can ingest the same amount of air with less displacement. (Now I must admit I have my suspicions about the commonly accepted (racing approved) formula for the rotary. However, if my suspicions about the rotary formula are correct, it would make the rotary even more efficient at ingesting air - so I won't go there {:>)). If my logic and calculations are correct then this implies the Ve of the rotary is considerably better than the Lycoming and is great than 100%. I mentioned a few of the reasons why the Ve of the rotary may indeed be better in the previous message. Now, its possible that the stories about the Ellison not working well on the rotary is just that - a story OR there could be a plausible physical reason as I have poorly attempted to present. Ed ----- Original Message ----- From: Tom To: Rotary motors in aircraft Sent: Wednesday, February 09, 2005 11:54 PM Subject: [FlyRotary] Re: Same HP =3D Same Air Mass <<> same air Velocity [FlyRotary] Re: Ellison, the missing piece Ed, >The rotary has 40 CID displacement per face and 2 facesx 2 rotors =3D 4*40 or 160 CID for one rev. So the rotary has 22% less displacement per revolution and the longer rotation period.<< and >So if the rotary has less displacement of the sucking component and must take 25% longer for each revolution. Therefore the only way it can obtain an equal amount of air is for the intake air to have a higher velocity than the Lycoming does.<< Isn't 'displacement' equal to the amount of air needing to be ingested? So 22% less displacement equates to 22% less air and the rotarys longer rotation period gives it more time for air to push in? And then the intake air velocity should be lower? >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html < Do you Yahoo!? Yahoo! Search presents - 1999,1999,FFFFJib Jab's 'Second = Term' = --Apple-Mail-14-892750567--