X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta06-srv.windstream.net ([166.102.165.167] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2112225 for flyrotary@lancaironline.net; Tue, 19 Jun 2007 18:16:44 -0400 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.167; envelope-from=montyr2157@alltel.net Received: from ispmxaamta04-gx.windstream.net ([71.29.68.46]) by ispmxmta06-srv.windstream.net with ESMTP id <20070619221605.IRHS4133.ispmxmta06-srv.windstream.net@ispmxaamta04-gx.windstream.net> for ; Tue, 19 Jun 2007 17:16:05 -0500 Received: from Thorstwin ([71.29.68.46]) by ispmxaamta04-gx.windstream.net with SMTP id <20070619221605.DSNC23532.ispmxaamta04-gx.windstream.net@Thorstwin> for ; Tue, 19 Jun 2007 17:16:05 -0500 Message-ID: <004d01c7b2bf$6dc938f0$6501a8c0@Thorstwin> From: "Monty Roberts" To: "Rotary motors in aircraft" Subject: Different Rotary Port configurations Date: Tue, 19 Jun 2007 17:16:05 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01C7B295.84D41030" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_004A_01C7B295.84D41030 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I've always wondered about this. Realizing that the P-port exhaust lets = the unburnt fuel into the the exhaust to be burnt there and lost as a = potential for power. What about a Renisis with the side port exhaust? = Wouldn't a P-port Renisis not have this problem, and therefore possibly = produce more power per GPH fuel flow over your typical 13B? Or am I = missing the big picture..=20 I've always wondered this.. Jarrett Johnson Jarrett, I'm working on a Pport Renesis. It works out being fairly mild port = timing. The key is that the side exhaust closes much sooner, therefore = the overlap is much less than even the old 6 port motor and the intake = closes WAY sooner than the new Renesis six port. Essentially I am moving = the intake down somewhat and creating a little bit of overlap. I don't = think that zero overlap is a good thing for anybody except CARB and the = EPA. The other nice thing is that the exhaust opens much later and more = gradually, so there is more expansion, and a lower EGT. Things that tend = to be kinder to the muffler etc. The port timing is somewhere between = the Mazda factory Pport and an old four port motor with the "lobe = center" retarded a bit to borrow from the piston world.=20 I'm not going for radical port size. Just 44mm. There is also the = question of how well the Renesis apex seals will do with a peripheral = port. At least it is an intake and not getting blasted with hot exhaust = gas, but there is still the question..... My reason for doing the Pport have more to do with my airframe, and some = other problems specific to my installation. I am not sure it is worth = the effort otherwise. As to BSFC....who knows. I hope to find out soon. Monty ------=_NextPart_000_004A_01C7B295.84D41030 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I've always = wondered about this.=20 Realizing that the P-port exhaust lets the unburnt fuel into the the = exhaust to=20 be burnt there and lost as a potential for power. What about a Renisis = with the=20 side port exhaust? Wouldn't a P-port Renisis not have this problem, and=20 therefore possibly produce more power per GPH fuel flow over your = typical 13B?=20 Or am I missing the big picture..=20

I've always wondered=20 this..

Jarrett = Johnson

Jarrett,

I'm working on a Pport Renesis. It works = out being=20 fairly mild port timing. The key is that the side exhaust closes much = sooner,=20 therefore the overlap is much less than even the old 6 port motor and = the intake=20 closes WAY sooner than the new Renesis six port. Essentially I am moving = the=20 intake down somewhat and creating a little bit of overlap. I don't think = that=20 zero overlap is a good thing for anybody except CARB and the EPA. The = other nice=20 thing is that the exhaust opens much later and more gradually, so there = is more=20 expansion, and a lower EGT. Things that tend to be kinder to = the muffler=20 etc. The port timing is somewhere between the Mazda factory Pport = and an=20 old four port motor with the "lobe center" retarded a bit to borrow from = the=20 piston world.

I'm not going for radical port size. Just = 44mm. There=20 is also the question of how well the Renesis apex seals will do with a=20 peripheral port. At least it is an intake and not getting blasted with = hot=20 exhaust gas, but there is still the question.....

My reason for doing the Pport have = more to do=20 with my airframe, and some other problems specific to my installation. I = am not=20 sure it is worth the effort otherwise.

As to BSFC....who knows. I hope to find = out=20 soon.

Monty

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