Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.6) with ESMTP id 2703077 for flyrotary@lancaironline.net; Thu, 30 Oct 2003 11:45:08 -0500 Received: from o7y6b5 (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id h9UGj3hg016713 for ; Thu, 30 Oct 2003 11:45:06 -0500 (EST) Message-ID: <004e01c39f04$a41f34e0$1702a8c0@WorkGroup> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Intake manifold Date: Thu, 30 Oct 2003 11:41:17 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004B_01C39EDA.BAF54080" 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 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_004B_01C39EDA.BAF54080 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 Ed,=20 DIE at one single RPM is exactly what I want. The target RPM would be = what I get at something less than WOT at cruise altitude. Perhaps if = that was close to T/O RPM I would shoot for a "dual purpose" RPM, but = cruise is my objective. Takeoff should not be a major consideration = since if I can get anywhere near the cruise I want, I can take off (at = airports where I will operate) with room to spare.=20 If turbo rotor housings are ported symmetrically, how far off that = would NA housings be? Would "street porting" bring the path lengths (in = the block) closer together? If so, it might be possible to close the = gap between primary and secondary paths in the block so as to merge = them into a single runner and retain some DIE effect. Is it possible = that DIE might be enhanced if the closing of one port was a little later = than the closing of the other? Probably too much to ask. I guess I'll = understand a lot better when I get my engine torn down and get a look at = the porting.=20 It would be great to simplify the intake though ... Jim S.=20 =20 Some good questions, Jim Unfortunately I don't have definitive answers to the questions. = However, based on the DIE equations (and assuming they are in the ball = park), I would hazard an opinion that 13B NA 6 port engines might be the = one to use if you wanted an DIE effect at several different RPMs - after = all it already has three different port timings. Perhaps a turbo block = might be idea if only one RPM is wanted. However, there are any number = of options. For instance if your primary and secondary are ported the same that = means they are in effect identical - timing wise. So if your ports all = have the same timing then the DIE effect for all will happen at the (or = at least very near) the same RPM point. I think that would be easy on a = turbo block but you would have to remove so much metal to make the = primary of a 13B NA port timing equal to the secondary+ Aux ports that I = don't even know if its doable. You would need to change the primary on = a 13B NA from IO 32 IC 40 to IC 32 IO 70 to get them at the same timing. = Probably doable, but you might harm the basic airflow by doing so, in = which case trying to get that DIE rpm would likely be counterproductive. So now you know more about the DIE effect, but, that simple adds to = the decisions/compromises you now have to considered. Before, you knew = about it - you didn't worry about it {:>) If I had the resources to hook 13Bs to dynos and try out some of this = it would be nice to further expand our knowledge and answer such = questions. However, that will have to wait until I win the powerball = lottery {:>) or someone who has such facitlites and equipment might want = to try such experiments. Best Regards Ed Anderson ------=_NextPart_000_004B_01C39EDA.BAF54080 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
Ed,=20
DIE at one single RPM is exactly what I want.  The = target RPM=20 would be what I get at something less than WOT at cruise = altitude. =20 Perhaps if that was close to T/O RPM I would shoot for a "dual = purpose" RPM,=20 but cruise is my objective.  Takeoff should not be a major = consideration=20 since if I can get anywhere near the cruise I want, I can take off (at = airports where I will operate) with room to spare.=20

If turbo rotor housings are ported symmetrically, how far off that = would NA=20 housings be?  Would "street porting" bring the path lengths (in = the=20 block) closer together?  If so, it might be possible to close the = gap=20 between primary and secondary paths in the block so as to merge  = them=20 into a single runner and retain some DIE effect.  Is it possible = that DIE=20 might be enhanced if the closing of one port was a little later than = the=20 closing of the other?  Probably too much to ask.  I guess = I'll=20 understand a lot better when I get my engine torn down and get a look = at the=20 porting.=20

It would be great to simplify the intake though ... Jim S.=20

 

Some good questions, Jim

Unfortunately I don't have definitive = answers to=20 the questions.  However, based on the DIE equations (and assuming = they=20 are in the ball park), I would hazard an opinion that 13B NA 6 port = engines=20 might be the one to use if you wanted an DIE effect at several = different RPMs=20 - after all it already has three different port timings.  Perhaps = a turbo=20 block might be idea if only one RPM is wanted.  However, there = are any=20 number of options.

For instance if your primary and = secondary are=20 ported the same that means they are in effect identical - timing = wise. =20 So if your ports all have the same timing then the DIE effect for = all=20 will happen at the (or at least very near) the same RPM point.  I = think=20 that would be easy on a turbo block but you would have to  remove = so much=20 metal to make the primary of a 13B NA port timing equal to the = secondary+ Aux=20 ports that I don't even know if its doable.  You would need to = change the=20 primary on a 13B NA from IO 32 IC 40 to IC 32 IO 70 to get them at the = same=20 timing.  Probably doable, but you might harm the basic airflow by = doing=20 so, in which case trying to get that DIE rpm would likely be=20 counterproductive.

So now you know more about the DIE = effect, but,=20 that simple adds to the decisions/compromises you now have to=20 considered.  Before, you knew about it - you didn't worry about = it=20 {:>)

If I had the resources to hook 13Bs to = dynos and=20 try out some of this it would be nice to further expand our knowledge = and=20 answer such questions.  However, that will have to wait until I = win the=20 powerball lottery {:>) or someone who has such facitlites and = equipment=20 might want to try such experiments.

 

Best Regards

 

Ed Anderson

 

 

 

 

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