X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-wy0-f180.google.com ([74.125.82.180] verified) by logan.com (CommuniGate Pro SMTP 5.4c2o) with ESMTPS id 4893255 for flyrotary@lancaironline.net; Mon, 07 Mar 2011 02:54:15 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.180; envelope-from=fluffysheap@gmail.com Received: by wyf23 with SMTP id 23so4183502wyf.25 for ; Sun, 06 Mar 2011 23:53:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=vpuUGrQGvd/FpCQ/x0QfQBukDv+v2uxm3J0SZ1F6Uek=; b=oYfUXirg0u56lOKq3UCAbvQETR6ZaU70svPXNavEEhWlJnYRQencGyChlB8vIFrZKn ZNl13NNeOJySAZa/s2ZIeF1hdgWIfb6EpfOf/3MC4eUM0XOjCYNLmOPOatCLQTIOU7zl PV0TqKJY7JDTsA/bmzHz2QxJuNpjLnrOvyuRU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=f7jqsqaIshiz7S1Cx1EvBVVl+aLEM1OcXnkPWYQL4UuZC1DMDSXsyZ8UTtXKvbEz3d c3JUfsiV943URThAjt1DlASw9swbOtlKr+bc1fjQpTgdKlPMAzcEj3472bi7eTGmXfTV 0Y3g6EFJPdYVjYpAy6gjmFyRWXiRGnh/UEhFI= MIME-Version: 1.0 Received: by 10.227.174.199 with SMTP id u7mr3217257wbz.75.1299484419150; Sun, 06 Mar 2011 23:53:39 -0800 (PST) Received: by 10.227.142.202 with HTTP; Sun, 6 Mar 2011 23:53:39 -0800 (PST) In-Reply-To: References: Date: Mon, 7 Mar 2011 00:53:39 -0700 Message-ID: Subject: Re: [FlyRotary] Re: For Lynn_Effect of Leaning & Timing for Turbo Rotary From: William Wilson To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00248c0ef2d831d2b1049ddfcbc7 --00248c0ef2d831d2b1049ddfcbc7 Content-Type: text/plain; charset=ISO-8859-1 I would agree with this post 100%. I only disagreed with the idea that leaner mixtures would act to increase effective knock resistance under certain conditions, but Lynn isn't saying that, so I'm not disagreeing :) On Sun, Mar 6, 2011 at 11:29 PM, wrote: > In a message dated 3/6/2011 1:11:45 P.M. Eastern Standard Time, > keltro@att.net writes: > > Lynn, > > From your previous posts on this subject it seems that the Rotary does > not react in the exact same way as a typical > piston engine to leaning and or timing changes...................William > has used as reference a very detailed piece from > http://www.turborx7.com/fuel.htm (excerpt above) that he feels challenges > previous info that you have posted and > that I mentioned from memory so I may not have related it > accurately...........Would appreciate your additional thoughts > about this and any corrections if I misspoke.........(Tracy posted recently > that his EC2-3 does retard ignition timing as > boost increases < up to12 degrees>)................ > > Thanks, > > Kelly Troyer > > > I just reread this and am having difficulty finding the differences between > data. Except that I explain it much better. > > It is nice to look back to my 14 year old motor head readings of anything > published in any hot rod magazine. > > It also points out that the systems used to establish long used methods of > test in fuels have long ago been superceded by modern systems and practices. > The two base systems (one from Kettering's labs in Dayton Ohio) are still > referred to on fuel pumps everywhere. I would be surprized to find similar > equipment out side of a museum. > > You would think that we would know all there is to know about oil by now, > but we know very little. For example, the discovery of Bucky balls. (Not a > result of never washing you supporter). And Fullerines, both named after R. > Buckminster Fuller, of dome fame. Carbon structures under our noses for > billions of years and just now discovered. > > http://scifun.chem.wisc.edu/chemweek/buckball/buckball.html > > Saying that 6 degrees of advance does one thing and 10 degrees does this > other thing leaves a library of data left off the table. Those numbers are > typical of initial advance settings for distributors clear back to points > days. A valid statement if the full 600 parameters are also listed for each > test. > > Also, saying that 13:1 or 13.4:1 detonates more readily than 12:1 is > accurate if all test conditions are duplicated exactly. I could drive my > 14.4:1 compression racer all over the paddock on 97 octane fuel without > detonation. But I know that inlet air temperature and cylinder filling are > test parameters that I can control. > > This is the type of generalization that just adds confusion. For example, a > lightly loaded engine of any type running in the mid range of its parameters > can be leaned from too rich to run all the way to lean cutoff with no damage > of any kind. > > Detonation requires lots of energy, so we need lots of fuel to make lots of > heat, and that requires lots of air, so that means close to wide open > throttle. Small throttle openings means poor cylinder filling and low > effective compression ratio and almost no chance of detonation. > > The same system used to produce motor fuels is going on inside the > combustion chamber on every ignition event. But we start with base stocks > that are lighter and easy to light, instead of black goop. > > So we light the fuel and a ball of fire starts at the plug tip, and radiant > energy booms out from this event heating mixture ahead of the flame front. > So the flame front accelerates (Hotter mixture burns faster) adding more > energy to the unburned mixture and compressing that mixture at ever > increasing rates into an ever decreasing volume. While this is going on > your little refining operation is cracking up brand new chemicals for the > flame front to consume. Chemicals with long names and longer diagrams. Most > of your new chemicals will last only Picoseconds, Some will exit the engine > intact. Some will combine with oxygen and vanish adding heat, some will > absorb heat and become bigger longer chains, that slow the flame front. > > So if we start this process early (More advance) the results happen sooner > in the crank rotation. The process will be hotter (Having burned longer) for > each degree of crank rotation. All of the process will be hotter and move > faster. So as far as mixture strength is concerned the closer to the fastest > flame speed we get the more critical every operational parameter gets to > detonation. When we say "lean it out" we have to start at some number and > are then suggesting moving to another number with fewer parts of fuel per > cubic foot of air. > > So in the case where we are just one or two parameters away from > detonation, and we then lean to a number that provides a higher flame speed, > then we achieve detonation. But you need a large number of items to be in or > near the red line before just one more change gets you to detonation. > > So the wives tale is: I leaned it out just a bit, and it went soft (revs > dropped off) and the apex seals are in the muffler. Or, in piston engines: > the oil pump locked up from pieces of piston getting through the screen. > > So leaning destroys engines, is that correct? *NO* > > Advancing the ignition does not in itself cause detonation. Leaning the > mixture does not in itself cause detonation. Low octane fuel in itself does > not cause detonation. High intake air temperatures do not alone cause > detonation. Rapid throttle opening in itself does not cause detonation. High > load, low RPM, wide open throttle alone does not cause detonation. High oil > or water temperatures do not alone cause detonation. > > The NA rotary has a large cold combustion chamber. It has no good squish > areas, so fuel droplets tend to form near the apex seals, further cooling > the chamber. And leading to poor BSFC and high HC. But this helps prevent > detonation. The fire goes out because droplets do not burn worth a damn, and > show up as high EGT as they find excess oxygen to join up with just about > where your EGT probes are mounted. > > So it is difficult to detonate a rotary. Unless you really want to. So, if > you really want to, here are some tips. > Let the oil temperature get real high, well over 200 degrees. High rotor > face temps and no more cold chamber (Ace in the hole) for you. Let the water > temperature get well over 180 degrees, same as high oil temps. Add way more > advance than is required. The rotor moves slowly over TDC, and needs very > little ignition advance. > > Use last years lawn mower gas. It has some kind of oil in it right? > > Use rapid throttle movements on very hot days from low RPM. If it still > won't detonate, as a last resort, add a turbo charger and do all of the > above. Ouch, that worked didn't it? > > Lean of peak EGT operation: once lean of Peak EGT, we have more oxygen than > needed, and it absorbs energy so combustion temps start down along with less > energy from the leaner fuel mixture. So leaning makes things cooler once > past peak EGT. So, once again, Leaning does not alone cause detonation. > > Rules is rules. Screw with mother nature, and she will screw with you. > > Lynn E. Hanover > --00248c0ef2d831d2b1049ddfcbc7 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I would agree with this post 100%.=A0 I only disagreed with the idea that l= eaner mixtures would act to increase effective knock resistance under certa= in conditions, but Lynn isn't saying that, so I'm not disagreeing := )

On Sun, Mar 6, 2011 at 11:29 PM, <Lehanover@aol.com> wrote:
In a message dated 3/6/2011 1:11:45 P.M. Eastern Standard Time,=20 keltro@att.net writ= es:
Lynn,
=A0
=A0=A0=A0 From your previous posts on this subject it seems that=20 the Rotary does not react in the exact=A0same way as a typical
piston engine to leaning and or timing changes...................Wil= liam=20 has used as reference a very detailed piece from
http://www.turborx7.com/fuel.htm=A0(excerpt above)=20 that he feels challenges previous info that you have posted and
that I mentioned from memory so I=A0may not have related it=20 accurately...........Would appreciate=A0your additional thoughts
about this and any corrections if I misspoke.........(Tracy posted= =20 recently that his EC2-3 does retard ignition timing as
boost increases < up to12 degrees>)................
=A0
Thanks,
=A0
=A0Kelly Troyer
=A0
I just reread this and am having difficulty finding the differen= ces between=20 data. Except that I explain it much better.
=A0
It is nice to look back to my 14 year old motor head readings of anyth= ing=20 published in any hot rod magazine.
=A0
It also points out that the systems used to establish long used method= s of=20 test in fuels have long ago been superceded by modern systems and practices= . The=20 two base systems (one from Kettering's labs in Dayton Ohio) are still r= eferred=20 to on fuel pumps everywhere. I would be surprized to find similar equipment= out=20 side of a museum.
=A0
You would think that we would know all there is to know about oil by n= ow,=20 but we know very little. For example, the discovery of Bucky balls. (Not a= =20 result of never washing you supporter). And Fullerines, both named after R.= =20 Buckminster Fuller, of dome fame. Carbon structures under our noses for bil= lions=20 of years and just now discovered.
=A0
=A0
Saying that 6 degrees of advance does one thing and 10 degrees does th= is=20 other thing leaves a library of data left off the table. Those numbers are= =20 typical of initial advance settings for distributors clear back to points d= ays.=20 A valid statement if the full 600 parameters are also listed for each test.= =20
=A0
Also, saying that 13:1 or 13.4:1 detonates more readily than 12:1 is= =20 accurate if all test conditions are duplicated exactly. I could drive my 14= .4:1=20 compression racer all over the paddock on 97 octane fuel without detonation= . But=20 I know that inlet air temperature and cylinder filling are test parameters = that=20 I can control.
=A0
This is the type of generalization that just adds confusion. For examp= le, a=20 lightly loaded=A0engine of any type running in the mid range of its=20 parameters can be leaned from too rich to run all the way to lean cutoff wi= th no=20 damage of any kind.
=A0
Detonation requires lots of energy, so we need lots of fuel to make lo= ts of=20 heat, and that requires lots of air, so that means close to wide open throt= tle.=20 Small throttle openings means poor cylinder filling and low effective=20 compression ratio and almost no chance of detonation. =A0
=A0
The same system used to produce motor fuels is going on inside the=20 combustion chamber on every ignition event. But we start with base stocks t= hat=20 are lighter and easy to light, instead of black goop.
=A0
So we light the fuel and a ball of fire starts at the plug tip, and ra= diant=20 energy booms out from this event heating mixture ahead of the flame front. = So=20 the flame front accelerates (Hotter mixture burns faster) adding more energ= y to=20 the unburned mixture and compressing that mixture at ever increasing rates = into=20 an ever decreasing volume. While this is going on
your little refining operation is cracking up brand new chemicals for = the=20 flame front to consume. Chemicals with long names and longer diagrams. Most= of=20 your new chemicals will last only Picoseconds, Some will exit the engine in= tact.=20 Some will combine with oxygen and vanish adding heat, some will absorb heat= and=20 become bigger longer chains, that slow the flame front.
=A0
So if we start this process early (More advance) the results happen so= oner=20 in the crank rotation. The process will be hotter (Having burned longer) fo= r=20 each degree of crank rotation. All of the process will be hotter and move= =20 faster. So as far as mixture strength is concerned the closer to the fastes= t=20 flame speed we get the more critical every operational parameter gets to=20 detonation. When we say "lean it out" we have to start at some nu= mber and are=20 then suggesting moving to another number with fewer parts of fuel per cubic= foot=20 of air.
=A0
So in the case where we are just one or two parameters away from=20 detonation, and we then lean to a number that provides a higher flame speed= ,=20 then we achieve detonation. But you need a large number of items to be in o= r=20 near the red line before just one more change gets you to detonation.
=A0
So the wives tale is: I leaned it out just a bit, and it went soft (re= vs=20 dropped off) and the apex seals are in the muffler. Or, in piston engines: = the=20 oil pump locked up from pieces of piston getting through the screen.
=A0
So leaning destroys engines, is that correct?=A0 N= O
=A0
Advancing the ignition does not in itself cause detonation. Leaning th= e=20 mixture does not in itself cause detonation. Low octane fuel in itself does= not=20 cause detonation. High intake air temperatures do not alone=A0cause=20 detonation. Rapid throttle opening in itself does not cause detonation. Hig= h=20 load, low RPM, wide open throttle alone does not cause detonation. High oil= or=20 water temperatures do not alone cause detonation.
=A0
The NA rotary has a large cold combustion chamber. It has no good squi= sh=20 areas, so fuel droplets tend to form near the apex seals, further cooling t= he=20 chamber. And leading to poor BSFC and high HC. But this helps prevent=20 detonation. The fire goes out because droplets do not burn worth a damn, an= d=20 show up as high EGT as they find excess oxygen to join up with just about w= here=20 your EGT probes are mounted.
=A0
So it is difficult to detonate a rotary. Unless you really want to. So= , if=20 you really want to, here are some tips.
Let the oil temperature get real high, well over 200 degrees. High rot= or=20 face temps and no more cold chamber (Ace in the hole) for you. Let the wate= r=20 temperature get well over 180 degrees, same as high oil temps. Add way more= =20 advance than is required. The rotor moves slowly over TDC, and needs very l= ittle=20 ignition advance.
=A0
Use last years lawn mower gas. It has some kind of oil in it right?
=A0
Use rapid throttle movements on very hot days from low RPM. If it stil= l=20 won't detonate, as a last resort, add a turbo charger and do all of the= above.=20 Ouch, that worked didn't it?
=A0
Lean of peak EGT operation: once lean of Peak EGT, we have more oxygen= than=20 needed, and it absorbs energy so combustion temps start down along with les= s=20 energy from=A0the leaner fuel mixture. So leaning makes things cooler once= =20 past peak EGT. So, once again, Leaning does not alone cause detonation.
=A0
Rules is rules. Screw with mother nature, and she will screw with=20 you.=A0
=A0
Lynn E. Hanover=A0

--00248c0ef2d831d2b1049ddfcbc7--