X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-da06.mx.aol.com ([205.188.169.203] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5353807 for flyrotary@lancaironline.net; Tue, 17 Jan 2012 13:16:21 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.169.203; envelope-from=Lehanover@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-da06.mx.aol.com (8.14.1/8.14.1) with ESMTP id q0HIFipH015693 for ; Tue, 17 Jan 2012 13:15:44 -0500 Received: from core-moa004c.r1000.mail.aol.com (core-moa004.r1000.mail.aol.com [172.29.233.13]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 6663FE000088 for ; Tue, 17 Jan 2012 13:15:44 -0500 (EST) From: Lehanover@aol.com Message-ID: <3919.104a2a83.3c4714d0@aol.com> Date: Tue, 17 Jan 2012 13:15:44 -0500 (EST) Subject: Re: [FlyRotary] Re: tuning advice To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_3919.104a2a83.3c4714d0_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [97.96.76.144] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:391837120:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29494f15bad053b9 --part1_3919.104a2a83.3c4714d0_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 1/17/2012 6:47:41 A.M. Eastern Standard Time, msteitle@gmail.com writes: Lynn, Thanks so much for a very detailed reply. It sounds like the factory EC-2 setting for advance will be pretty close for cruise (5200 rpm) mode for my p-port engine. I usually lean pretty aggressively, so maybe a couple of degrees would be in order. Can you tell me if its normal for the MAP to be different for p-port engines, particularly around idle (1800 rpm)? My MAP readings are approx. 17.0 - 17.3 at idle. This is about 2" higher that with my side-port engine. I'm thinking this is because of the much higher intake/exhaust overlap with the p-port engine. Thanks, Mark Everything affects everything, all of the time. So where the side port can have less overlap, or even no overlap in the case of the Renesis, the Pport has a lot of overlap. So, the Pport is easily affected by exhaust system and muffler design. At any particular RPM a wildly differing set of factors plays out inside the engine. The most obvious is the exhaust gasses re-entering the chamber diluting the intake charge, and making it over rich (because some of the oxygen bearing charge has be displaced and the fuel delivery has remained unchanged. This whole scenario may change just a few RPM up or down the range. So you might get it idling really well today, and in the morning it barely runs at all until the oil temps come up a bit. What could cause that? The cold rotors are condensing fuel back into droplets, which makes for less surface area to mate up with any oxygen, and the engine is now very much over lean. Everything affects everything. If you have fiddled with dirt bike engines, this all comes to be very clear. There is a similar interaction between intake design and exhaust design in a piston port 2 cycle engine. Notice the strange mufflers on those bikes. A seemingly over sized muffler ending with a very small tube that seems far too small to make any power. And still it works. The rotary is a 4 stroke Otto cycle engine that tunes like a 2 stroke dirt bike engine. Less so for little or no overlap. Much more so for lots of overlap like the Pport. So, it will never tune up in idle quite as well as a side port. But the higher the idle RPM you can stand the better it will be. Another factor that removes the engine from its car like idle, is the fact that the prop load is higher than the engine would see in just stirring up trans oil at idle. So instead of say 3 HP required to idle you may need12 or 15 HP to spin that prop even 1,000 RPM. Your first Viking departure will make it all worth the trip. Lynn E. Hanover --part1_3919.104a2a83.3c4714d0_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
 
 
In a message dated 1/17/2012 6:47:41 A.M. Eastern Standard Time,=20 msteitle@gmail.com writes:
= Lynn, =20

Thanks so much for a very detailed reply.  It sounds like the= =20 factory EC-2 setting for advance will be pretty close for cruise (5200 rp= m)=20 mode for my p-port engine.  I usually lean pretty aggressively, so m= aybe=20 a couple of degrees would be in order.  

Can you tell me if its normal for the MAP to be different for p-port= =20 engines, particularly around idle (1800 rpm)?  My MAP readings are= =20 approx. 17.0 - 17.3 at idle.  This is about 2" higher that with my= =20 side-port engine.  I'm thinking this is because of the much higher= =20 intake/exhaust overlap with the p-port engine.  

Thanks,
Mark
 
Everything affects everything, all of the time.
 
So where the side port can have less overlap, or even no overlap in th= e=20 case of the Renesis, the Pport has a lot of overlap. So, the Pport is easil= y=20 affected by exhaust system and muffler design. At any particular RPM a wild= ly=20 differing set of factors plays out inside the engine. The most obvious is t= he=20 exhaust gasses re-entering the chamber diluting the intake charge, and maki= ng it=20 over rich (because some of the oxygen bearing charge has be displaced and t= he=20 fuel delivery has remained unchanged. This whole scenario may change just a= few=20 RPM up or down the range.
 
So you might get it idling really well today, and in the morning it ba= rely=20 runs at all until the oil temps come up a bit. What could cause that? The c= old=20 rotors are condensing fuel back into droplets, which makes for less surface= area=20 to mate up with any oxygen, and the engine is now very much over lean.=20 Everything affects everything.
 
If you have fiddled with dirt bike engines, this all comes to be very= =20 clear. There is a similar interaction between intake design and exhaust des= ign=20 in a piston port 2 cycle engine.
 
Notice the strange mufflers on those bikes. A seemingly over sized muf= fler=20 ending with a very small tube that seems far too small to make any power. A= nd=20 still it works.
 
The rotary is a 4 stroke Otto cycle engine that tunes like a 2 stroke = dirt=20 bike engine.
Less so for little or no overlap. Much more so for lots of overlap lik= e the=20 Pport.
 
So, it will never tune up in idle quite as well as a side port. But th= e=20 higher the idle RPM you can stand the better it will be. Another factor tha= t=20 removes the engine from its car like idle, is the fact that the prop load i= s=20 higher than the engine would see in just stirring up trans oil at idle. So= =20 instead of say 3 HP required to idle you may need12 or 15 HP to spin that p= rop=20 even 1,000 RPM.
 
Your first Viking departure will make it all worth the trip. 
 
Lynn E. Hanover
=

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