X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail06.syd.optusnet.com.au ([211.29.132.187] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTPS id 2604306 for flyrotary@lancaironline.net; Tue, 18 Dec 2007 18:33:42 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.187; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-79-144.dsl.nsw.optusnet.com.au [220.236.79.144]) by mail06.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id lBINWtPC012077 for ; Wed, 19 Dec 2007 10:32:56 +1100 Message-ID: <001801c841ce$5440a410$904fecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" Subject: Degrees overlap Date: Wed, 19 Dec 2007 09:32:59 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01C84222.24ED9390" 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-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0015_01C84222.24ED9390 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Lynn, I was all over the shop before, but now I think I've got it all sorted. = I was trying to see the differences the PP gave in overlap and open ( = intake) time. I was confusing myself yet again, until I realised I was looking at the = degrees of crank, when I should have been looking at the degrees of the = rotor. With IO @ 32 degrees ATDC and IC @ 40 degrees ABDC (12A engine) or IC @ 310 degrees ATDC =3D 278 degrees/3 =3D 93 degrees of the rotor I did the same for Exhaust =3D 415 degrees/3 =3D131 degrees. Overlap ( standard) =3D25 degrees/3 =3D 8 degrees. Overlap PP =3D 144 degrees/3 =3D 48 degrees. PP inlet =3D 430/3 =3D143 degrees. Inlet time with the PP is an additional 50 degrees (very good) but with = a penalty of 40 extra degrees of overlap (bad) but only bad at low = RPM's. Interestingly the overlap is 6 times the original - this all varies = accordingly with the different models. While doing this exercise it is interesting to see the RX8 port and why = it's placed where it is to eliminate overlap. While it might be nice to = have say 180 degree of rotor ( or more) for complete burn of the fuel, = realistically the power derived from this exercise would be marginal at = best. The power from combustion would (I believe) be totally converted = to mechanical power ( to the rotor) by the time it reaches the existing = exhaust opening. George ( down under) ------=_NextPart_000_0015_01C84222.24ED9390 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Lynn,

I was all over the shop before, but now = I think=20 I've got it all sorted. I was trying to see the differences the PP gave = in=20 overlap and open ( intake) time.

I was confusing myself yet again, until = I realised=20 I was looking at the degrees of crank, when I should have been = looking at=20 the degrees of the rotor.

With IO @ 32 degrees ATDC

and IC @ 40 degrees ABDC (12A = engine)

or IC @ 310 degrees ATDC =3D 278 = degrees/3 =3D 93=20 degrees of the rotor

I did the same for Exhaust =3D 415 = degrees/3 =3D131=20 degrees.

Overlap ( standard) =3D25 = degrees/3 =3D 8=20 degrees.

Overlap PP =3D 144 degrees/3 =3D 48=20 degrees.

PP inlet =3D 430/3 =3D143 = degrees.

Inlet time with the PP is an additional = 50 degrees=20 (very good) but with a penalty of 40 extra degrees of overlap (bad) but = only bad=20 at low RPM's.

Interestingly the overlap is 6 times = the original -=20 this all varies accordingly with the different models.

While doing this exercise it is = interesting to see=20 the RX8 port and why it's placed where it is to eliminate overlap. While = it=20 might be nice to have say 180 degree of rotor ( or more) for complete = burn of=20 the fuel, realistically the power derived from this exercise would be = marginal=20 at best. The power from combustion would (I believe) be totally = converted to=20 mechanical power ( to the rotor) by the time it reaches = the existing=20 exhaust opening.

George ( down = under)

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