Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.93.67.84] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2627454 for flyrotary@lancaironline.net; Tue, 07 Oct 2003 13:40:40 -0400 Received: from o7y6b5 (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-03.southeast.rr.com (8.12.10/8.12.2) with SMTP id h97HcKW0026428 for ; Tue, 7 Oct 2003 13:38:21 -0400 (EDT) Message-ID: <001e01c38cf9$e2292b00$1702a8c0@WorkGroup> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: True Displacement of the 13B rotary Egnine Date: Tue, 7 Oct 2003 13:38:56 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001B_01C38CD8.5ACCC660" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_001B_01C38CD8.5ACCC660 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Well, Tracy, I've been wrong before and this would not likely be the = last time {:>). Lets see, the two rotors have equal volume (I think = that's safe to say). First, we need to agree on total displacement of an engine. My = understanding is that the total displacement of an engine is the = displacement that ALL its power producing volume. Not just for 3/4 of = its cylinders or chambers, not 2/3rds but ALL! Now, If I am incorrect = about that definition then I guess I missed that class in auto school = {:>). (See definitions below this message) The rotary has six power producing faces each which "Scoops" up its = "share" of the total volume displacement of the rotary. Now if you want = to throw out two of the chambers and claim what remains is the total = displacement then we should throw out two cylinders of a V8 when we = consider its displacement {:>) I think we can agree that the two rotors provide 1308 CC displacement = in 720 degrees that means 4 rotor faces have scooped out their share of = the 1308 displacement (which is only 2/3 of the rotors 1080 deg cycle). = But sticking with the 1308 cc for four chambers worth we have each = chamber =3D 1308/4 =3D 327 cc/rotor face/chamber. Ok so shoot me - I = was 6 cc off. But if we take the FULL engine cycle of the rotary which is 1080 deg = not the reciprocating 4 strokes 720 degrees, that means there are two = more chambers worth before we have exercised all rotor faces/chambers = once for a complete engine cycle. Then we add 2 more 327 cc chamber = cycles to the 1308 we already have and we have a grand total of approx = 1952 cc or approx 120 CID As I pointed out, if you truncate the rotor's 1080 degree cycle, then = you indeed come up with the 1308 cc displacement. But the definition of = displacement of an engine generally means the total displacement of all = its power producing surfaces (like piston top,rotary faces, etc), not = just some of them. I've listed several defintions for engine displacement I found on the = web below: I think you will find that the definition of total engine = displacement call for ALL the power producing volumns be included - not = just 2/3 of them. But, then that is my interpretation of the definitons = below. So until future evidence to the contrary, I'll stick by the 120 CID See! I told you this would invoke discussion {:>) Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com /flyrotary/List.html Engine displacement (or size) of the engine is the number of cylinders = times=20 the displacement of one of the pistons.=20 In an engine, displacement is the total volume of air and fuel that an = engine is theoretically capable of drawing into all its cylinders in one = cycle. Since an engine is three-dimensional (volume), displacement is = measured in cubic inches for U.S. cars. Some cars may have = displacements measured in liters.=20 Displacement The total volume of air displaced by all the pistons within an engine = block. In general, the greater an engine's displacement, the more power = it can produce. ------=_NextPart_000_001B_01C38CD8.5ACCC660 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Well, Tracy,  I've been wrong = before and this=20 would not likely be the last time {:>).  Lets see, the two = rotors have=20 equal volume (I think that's safe to say).
 
First, we need to agree on total = displacement of an=20 engine. My understanding is that the total displacement of an engine is = the=20 displacement that ALL its power producing volume.  Not just for 3/4 = of its=20 cylinders or chambers, not 2/3rds but ALL!  Now, If I am incorrect = about=20 that definition then I guess I missed that class in auto school = {:>). =20 (See definitions below this message)
 
The rotary has six power producing = faces each which=20 "Scoops" up its "share" of the total volume displacement of the = rotary. =20 Now if you want to throw out two of the chambers and claim what remains = is the=20 total displacement then we should throw out two cylinders of a V8 when = we=20 consider its displacement {:>)
 
I think we can agree that the two = rotors provide=20 1308  CC displacement in 720 degrees that means 4 rotor faces have = scooped=20 out their share of the 1308 displacement (which is only 2/3 of the = rotors 1080=20 deg cycle).  But sticking with the 1308 cc for four chambers worth = we have=20 each chamber =3D 1308/4 =3D 327 cc/rotor face/chamber.  Ok so shoot = me - I was=20 6 cc off.
 
But  if we take the FULL engine = cycle of the=20 rotary which is 1080 deg not the reciprocating 4 = strokes=20 720 degrees, that means there are two more chambers = worth=20 before we have exercised all rotor faces/chambers once for a complete = engine=20 cycle.  Then we add 2 more 327 cc chamber cycles to the 1308 = we=20 already have and we have a grand total of approx 1952 cc or approx 120=20 CID
 
As I pointed out, if you truncate the = rotor's 1080=20 degree cycle, then you indeed come up with the 1308 cc = displacement.  But=20 the definition of displacement of an engine generally means the total=20 displacement of all its power producing surfaces (like piston top,rotary = faces,=20 etc), not just some of them.
 
I've listed several defintions for = engine=20 displacement I found on the web below:  I think you will find that = the=20 definition of total engine displacement call for ALL the power=20 producing  volumns be included - not just 2/3 of them.  = But, then=20 that is my interpretation of the definitons below.
 
So until future evidence to the = contrary, I'll=20 stick by the 120 CID
 
See! I told you this would invoke = discussion=20 {:>)
 
 
Ed Anderson
RV-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com /flyrotary/List.html
 
Engine displacement = (or size)=20 of the engine is the number of cylinders times=20
the displacement of one = of the=20 pistons.
 

In an engine, displacement is the total volume of air and fuel that = an engine=20 is theoretically capable of drawing into all its = cylinders=20 in one cycle.  Since an engine is three-dimensional = (volume),=20 displacement is measured in cubic inches for U.S. cars.  Some cars = may have=20 displacements measured in liters.


Displacement
The total volume of air displaced by all the=20 pistons within an engine block. In general, the greater an = engine's=20 displacement, the more power it can produce.
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