X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <13brv3@bellsouth.net> Received: from imf20aec.mail.bellsouth.net ([205.152.59.68] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 1010613 for flyrotary@lancaironline.net; Wed, 22 Jun 2005 18:26:44 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.68; envelope-from=13brv3@bellsouth.net Received: from ibm62aec.bellsouth.net ([65.6.194.9]) by imf20aec.mail.bellsouth.net with ESMTP id <20050622222544.ERSH1983.imf20aec.mail.bellsouth.net@ibm62aec.bellsouth.net> for ; Wed, 22 Jun 2005 18:25:44 -0400 Received: from rd ([65.6.194.9]) by ibm62aec.bellsouth.net with ESMTP id <20050622222542.CUMU8050.ibm62aec.bellsouth.net@rd> for ; Wed, 22 Jun 2005 18:25:42 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: PP debate was Re: Single PP HP? Date: Wed, 22 Jun 2005 17:25:42 -0500 Message-ID: <000001c57779$545e6df0$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C5774F.6B8865F0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C5774F.6B8865F0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable NO, it does not. Every piston engine has overlap, with far worse consequences as the valves are very close together.=20 =20 For the record, I speak mostly of 13B engines, not the Renesis. The 13B = has always had overlap, a street port has more, bridge port more still. = This is no different than increasing the overlap with cam profiles on those = funny up and down engines. Typically, the PP is on par, or above the Bridge port when it comes to size and overlap, because it's the only possible way to = get more size and overlap than a bridge port has. To my understanding, = that's the only reason a PP is worth having, to get what you can't with a side port. =20 =20 Now you can make a custom PP, and reduce the size and overlap, which = knocks it right down the scale. Once you do that, it won't be making any more power than a side port can make at our rpm's. I just don't think Powersports is doing anything a well built 13B side port engine couldn't = do just as well. =20 =20 The reason the renesis makes good power is the size of the side ports. = Look at the complexity of the manifold on the RX-8. =20 =20 I totally agree, but the complex manifold it there to make the engine = behave in a car. They have to make the engine capable of continuing to run = when someone floors the gas, in 5th gear, at 20 mph. This has nothing to do = with side ports vs PP. =20 =20 My personal guess is that if Tracy applied his knowledge of the = induction system and EFI to a PP engine He would blow away the renesis. This might = not be a result he could sell to all of his customers though. =20 =20 I don't understand that last sentence. You're saying he could make a superior engine, but it's not what his customers would want? I must not = be a typical customer :-) I figure you mean that he could make more = power, but with limitations that some customers wouldn't be willing to accept, which has been my point all along. =20 =20 Run your renesis Rusty, I'm sure you will be happy with it. =20 =20 I don't have a Renesis, and don't have any immediate plans to have one. = I'm not sure they provide a tremendous power advantage over a good 13B, = unless you're willing to turn them up to 8500 rpm, but they do have other advantages like cooler, quieter exhaust.=20 =20 I am just saying that I believe your desire for a high power single = rotor could be met easier with the PP. =20 =20 I haven't been pursuing a high power single rotor. In fact, anything = over 100 HP in the Kolb will require serious restraint (note to Al W- BIG = risk factor with me on the throttle ), because the plane was only made for = 80 HP originally. Since I just bought a small turbo to use as a muffler, = it's going to be tough to avoid producing too much power. =20 BTW, I hope you're enjoying this in the spirit of good clean discussion = like I am. If not, we need to call it off, because I don't really mean to = piss anyone off. =20 =20 Cheers, Rusty (must have something better to do) =20 =20 =20 ------=_NextPart_000_0001_01C5774F.6B8865F0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
NO, it does not. Every piston engine = has overlap,=20 with far worse consequences as the valves are very close together. 
 
For the record, I speak mostly of 13B engines, not=20 the Renesis.  The 13B has always had overlap, a street = port has=20 more, bridge port more still.  This is no different than increasing = the=20 overlap with cam profiles on those funny up and down engines.  = Typically, the PP is on par, or above the Bridge port when it comes to = size and=20 overlap, because it's the only possible way to get more size and overlap = than a=20 bridge port has.  To my understanding, that's the only reason = a PP is=20 worth having, to get what you can't with a side port.   =20
 
Now you can make a custom PP, and reduce the size and = overlap,=20 which knocks it right down the scale.  Once you do that, it won't = be making=20 any more power than a side port can make at our rpm's.  I just = don't=20 think Powersports is doing anything a well built 13B side port = engine=20 couldn't do just as well.     =20
 
The reason the renesis makes good = power is the=20 size of the side ports. Look at the complexity of the manifold on the=20 RX-8.  
&nbs= p;
I totally agree, but the complex = manifold it there=20 to make the engine behave in a car.  They have to make the = engine=20 capable of continuing to run when someone floors the gas, in 5th gear, = at 20=20 mph.  This has nothing to do with side ports vs PP.  =  
 
My personal guess is that if Tracy applied = his=20 knowledge of the induction system and EFI to a PP engine He would blow = away the=20 renesis. This might not be a result he could sell to all of his = customers=20 though.  
 
I don't = understand that=20 last sentence.  You're saying he could make a superior engine, = but=20 it's not what his customers would want?  I must not be a typical = customer=20 :-)   I figure you mean that he could make more power, but = with=20 limitations that some customers wouldn't be willing to accept, which has = been my=20 point all along. 
 
 Run=20 your renesis Rusty, I'm sure you will be happy with it.  
 
I=20 don't have a Renesis, and don't have any immediate plans to have = one.  I'm=20 not sure they provide a tremendous power advantage over a good 13B, = unless=20 you're willing to turn them up to 8500 rpm, but they do have other = advantages=20 like cooler, quieter = exhaust. 
 
 I am just saying that I believe = your=20 desire for a high power single rotor could be met easier with the=20 PP.  
&nbs= p;
I haven't been pursuing a high power single=20 rotor.  In fact, anything over 100 HP in the Kolb will require = serious=20 restraint (note to Al W- BIG risk factor with me on the throttle = <g>),=20 because the plane was only made for 80 HP originally.  Since I just = bought=20 a small turbo to use as a muffler, it's going to be tough to avoid = producing too=20 much power.
&nbs= p;
BTW, I hope you're enjoying this in the = spirit of good=20 clean discussion like I am.  If not, we need to call it off, = because I=20 don't really mean to piss anyone off. =20
&nbs= p;
Cheers,
Rusty (must have something better to = do) =20
&nbs= p;
&nbs= p;
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