Return-Path: <13brv3@bellsouth.net> Received: from imf20aec.mail.bellsouth.net ([205.152.59.68] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 761515 for flyrotary@lancaironline.net; Sun, 27 Feb 2005 10:27:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.68; envelope-from=13brv3@bellsouth.net Received: from rd ([65.6.194.9]) by imf20aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050227152710.YIWW1995.imf20aec.mail.bellsouth.net@rd> for ; Sun, 27 Feb 2005 10:27:10 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: A little down on power Date: Sun, 27 Feb 2005 09:27:45 -0600 Message-ID: <000001c51ce0$e513cfa0$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C51CAE.9A795FA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C51CAE.9A795FA0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable I'm also running 87 octane, but now that you mention it, I'm wondering = if I should run 91. I have the stock low compression (turbo) rotors in mine, = so I "assume" that 87 octane is OK. I'll be interested to see what kind of feedback you get on this.=20 =20 I'm not sure what Mazda required for the 2nd gen turbo, but I would = never even think about running 87 octane in a turbo rotary. I know that the = FD required premium, and they weren't kidding. I'd bet that using regular = 87 octane fuel probably killed more FD engines than anything else. My = advice would be to immediately switch the the highest octane you can get, particularly John, since he's running higher boost levels. Also, make = sure you keep the mixture quite rich during boost time. =20 =20 John, since everyone's picking on your prop, I guess I'll pile on. = Remind me again why you want this oversize prop? Are you trying to set max = speed cruise at some low rpm like 5000? On the list of safe ways to increase power in a rotary, running higher rpms is probably number 1, and turbo charging is waaaaaaay down there. I think you'll be much safer with = 7000 rpm, and minimal boost, vs 5000 rpm and lots of boost. =20 =20 I believe Ed has mentioned before that you can't just look at the top = power number when setting up a prop for your engine. The rotary doesn't = produce a ton of power at low rpms. (Lots of made up figured follow) If you told Clark that you would be making 250 HP at 6000 rpm, then I'm sure he = would be able to make the prop correctly for that amount of power. The problem = is that the same prop might require 150 HP to turn at 4000. Even with a = turbo, the rotary probably will have trouble making that due to the low RPM. = In other words, your prop might be just right for max power, but "you just can't get there from here". =20 =20 Cheers, Rusty (probably raining out my engine run)=20 =20 =20 =20 =20 =20 =20 ------=_NextPart_000_0001_01C51CAE.9A795FA0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
I'm also running 87 = octane, but now=20 that you mention it, I'm wondering if I should run 91.  I have the = stock=20 low compression (turbo) rotors in mine, so I "assume" that 87 octane is=20 OK.  I'll be interested to see what kind of feedback you get on = this. 
 
I'm not sure what Mazda required for the 2nd = gen turbo,=20 but I would never even think about running 87 octane in a turbo=20 rotary.   I know that the FD required premium, and they = weren't=20 kidding.  I'd bet that using regular 87 octane fuel probably killed = more FD=20 engines than anything else.  My advice would be to immediately = switch=20 the the highest octane you can get, particularly John, since he's = running higher=20 boost levels.  Also, make sure you keep the mixture quite rich = during boost=20 time. 
 
John, since everyone's picking on your prop, = I guess=20 I'll pile on.  Remind me again why you want this oversize = prop?  Are=20 you trying to set max speed cruise at some low rpm like = 5000?  On the=20 list of safe ways to increase power in a rotary, running higher = rpms is=20 probably number 1, and turbo charging is waaaaaaay down = there.  I=20 think you'll be much safer with 7000 rpm, and minimal boost, vs 5000 rpm = and=20 lots of=20 boost.  
=
 
I believe Ed has mentioned before that you = can't just=20 look at the top power number when setting up a prop for your = engine.  The=20 rotary doesn't produce a ton of power at low rpms.  (Lots of made = up=20 figured follow)  If you told Clark that you would be making 250 HP = at 6000=20 rpm, then I'm sure he would be able to make the prop correctly for that = amount=20 of power.  The problem is that the same prop might require 150 HP = to turn=20 at 4000.  Even with a turbo, the rotary probably will have = trouble=20 making that due to the low RPM.  In other words, = your prop might=20 be just right for max power, but "you just can't get there from=20 here".  
=
 
Cheers,
Rusty (probably raining out my engine=20 run) 
 
 
  
 
 
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