X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm29.access.bullet.mail.sp2.yahoo.com ([98.139.44.156] verified) by logan.com (CommuniGate Pro SMTP 5.4c2o) with SMTP id 4892764 for flyrotary@lancaironline.net; Sun, 06 Mar 2011 13:11:38 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.44.156; envelope-from=keltro@att.net Received: from [98.139.44.101] by nm29.access.bullet.mail.sp2.yahoo.com with NNFMP; 06 Mar 2011 18:11:03 -0000 Received: from [98.139.44.83] by tm6.access.bullet.mail.sp2.yahoo.com with NNFMP; 06 Mar 2011 18:11:03 -0000 Received: from [127.0.0.1] by omp1020.access.mail.sp2.yahoo.com with NNFMP; 06 Mar 2011 18:11:03 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 40117.88099.bm@omp1020.access.mail.sp2.yahoo.com Received: (qmail 83697 invoked by uid 60001); 6 Mar 2011 18:11:02 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1299435062; bh=JSddTNzrOJZZ4SfibUIWgpoXCWcMWN+yOxPdkFxLSO0=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=wlPfcjBffX6CtYxOiqOTwi3A7nGayBw/+AgqPKFzAH71mUNiVdK+jITaqaCkeaGkgywJjGGY/9psnNVJ/xjOLS6zZcDnSasW9l4ohLgLm/uNllTk4QR/zOU06CAH7fp6+v2pSZ42+5I8+gpL9Ha0XwQk9DWlgaI0PjdqCtznjcw= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=att.net; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=IB1h1sotNJhjzfxE9B8cMfCTRJrXK0zshUDVinEBfUkyz/6TzSvmbHzB4c+magT6wKtyTmWAYJYYb9xrMGsqcvBTeKqL+EKUF5qr79wczkmQPr1aD75f63ilXnJLBcDeHy717dZ6um0CxiXXPRkZr8ER07iBFdnmtnE+5cjE7Wo=; Message-ID: <790281.79858.qm@web83914.mail.sp1.yahoo.com> X-YMail-OSG: WDFOS5kVM1lWg84AHxgSuUzDMw_.RPffiddfKf38iVM1PWN F7GUoR6M_oIXG_H9Bn6p1netqZX.1cWlaA2RvvhE2Ohr2gRafEepWQBY4JOi beXG7Z.LhtDo6yaPaa4gjTf8cEt78Ucu.tqNv1EGuCr3B0jWsf1diuatLxih 4HZBc0FJxIHa2xfncZW7C68L6UgG56hu5J_AWCS_201IlxK2JcwxpFAQFc3_ 1wokEvEd8mm.zElrKUc7QF29vojL2VFINLH5tJJ1EGfKHwsQZARffbo1uGkI i40v1xzH.cQ-- Received: from [208.114.44.149] by web83914.mail.sp1.yahoo.com via HTTP; Sun, 06 Mar 2011 10:11:02 PST X-Mailer: YahooMailRC/559 YahooMailWebService/0.8.109.292656 References: Date: Sun, 6 Mar 2011 10:11:02 -0800 (PST) From: Kelly Troyer Subject: Re: [FlyRotary] For Lynn_Effect of Leaning & Timing for Turbo Rotary To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1604448153-1299435062=:79858" --0-1604448153-1299435062=:79858 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable =A0 =0ALynn,=0A=0A=A0=A0 Additional excerpt =A0from http://www.turborx7.com= /fuel.htm with two more =0Afactors =0A=0Ato consider about potential for=A0= detonation for the Rotary engine...............=0A=0AWhat is the effect of = temperature and load? =0A=0AIncreasing the engine temperature, particularly= the air-fuel charge temperature, =0Aincreases the tendency to knock. The S= ensitivity of a fuel can indicate how it =0Ais affected by charge temperatu= re variations. Increasing load increases both the =0Aengine temperature, an= d the end-gas pressure, thus the likelihood of knock =0Aincreases as load i= ncreases. Increasing the water jacket temperature from 71C to =0A82C, incre= ases the (R+M)/2 ONR by two [111]. =0A=0A=0A=A0=0AWhat is the effect of eng= ine speed?.=0A=0AFaster engine speed means there is less time for the pre-f= lame reactions in the =0Aend gases to occur, thus reducing the tendency to = knock. On engines with =0Amanagement systems, the ignition timing may be ad= vanced with engine speed and =0Aload, to obtain optimum efficiency at incip= ient knock. In such cases, both high =0Aand low engines speeds may be criti= cal.=0A=0A=A0=0AKelly Troyer=0A=0A=0A=0AFrom: William Wilson Add to Contacts =0ATo: Rotary motors in aircraft =0A________________________________=0A=0AKelly Troyer wrote:= =0A=0A=0A"I just remembered one other tidbit of info from our rotary guru = =0ALynn.........One of=0Ahis informative posts on fuel and the effects of o= ctane ratings stated that as =0Ayou lean=0Athe auto fuel that many of us us= e (87 to 91 octane) that the flame front is =0Aslowed and=0Athis mimics the= effect of lead in fuel"=0A=0A=0A=A0William wrote:=0A=0AGenerally, leaner m= ixture increases the risk of detonation, regardless of octane =0Aor presenc= e of lead.=A0 On a naturally aspirated rotary it doesn't usually matter =0A= much.=0A=0AI find this page to be an excellent reference for the effects of= octane:=0Ahttp://www.turborx7.com/fuel.htm=0A=0A=0A=A0=A0 Kelly Troyer wri= te :=0A=0A"One other point that I forgot to mention was ignition timing....= ......It is my =0Aunderstanding=0Athat turboed engines should not use exces= sive timing advance and that the higher =0Athe=0Aboost the less timing adva= nce is needed (or wise).........As I recall ignition =0Atiming as high=0Aas= 27 + degrees BTDC has/is used for naturally aspirated Rotarys"=0A=0A=A0=A0= William wrote:=0A=0AI think the confusion here is between talking about th= e timing at idle and the =0Atiming at high RPM.=A0 When you set the timing = you are usually setting the idle =0Atiming, then the ECU adds a certain amo= unt of advance based on the RPM, =0Atemperature, whatever.=A0 10 degrees is= probably the idle setting, not the maximum =0Aadvance, whereas the 27+ is = probably the maximum advance (maximum advance in my =0Acar is about 35).=0A= =0A=0AThis is an excerpt from............http://www.turborx7.com/fuel.htm= =0A=0A=0A=A0What is the effect of changing the air-fuel ratio?=0A=0ATraditi= onally, the greatest tendency to knock was near 13.5:1 air-fuel ratio, =0Ab= ut was very engine specific. Modern engines, with engine management systems= , =0Anow have their maximum octane requirement near to 14.5:1. For a given = engine =0Ausing gasoline, the relationship between thermal efficiency, air-= fuel ratio, and =0Apower is complex. Stoichiometric combustion (air-fuel = =0A=0Aratio =3D 14.7:1 for a typical non-oxygenated gasoline) is neither ma= ximum power - =0Awhich occurs around air-fuel 12-13:1 (Rich), nor maximum t= hermal efficiency - =0Awhich occurs around air-fuel 16-18:1 (Lean). The air= -fuel ratio is controlled at =0Apart throttle by a closed loop system using= the oxygen sensor in the exhaust. =0AConventionally, enrichment for maximu= m power air-fuel ratio is used during full =0Athrottle operation to reduce = knocking while providing better drivability [38]. =0AAn average increase of= 2 (R+M)/2 ON is required for each 1.0 increase (leaning) =0Aof the air-fue= l ratio [111]. If the mixture is weakened, the flame speed is =0Areduced, c= onsequently less heat is converted to mechanical energy, leaving heat =0Ain= the cylinder walls and head, potentially inducing knock. It is possible to= =0Aweaken the mixture sufficiently that the flame is still present when th= e inlet =0Avalve opens again, resulting in backfiring.=0A=0A=A0=0AWhat is t= he effect of changing the ignition timing?=0A=0AThe tendency to knock incre= ases as spark advance is increased. For an engine =0Awith recommended 6 deg= rees BTDC (Before Top Dead Center) timing and 93 octane =0Afuel, retarding = the spark 4 degrees lowers the octane requirement to 91, whereas =0Aadvanci= ng it 8 degrees requires 96 octane fuel [27]. It should be noted this =0Are= quirement depends on engine design. If you advance the spark, the flame fro= nt =0Astarts earlier, and the end gases start forming earlier in the cycle,= providing =0Amore time for the autoigniting species to form before the pis= ton reaches the =0Aoptimum position for power delivery, as determined by th= e normal flame front =0Apropagation. It becomes a race between the flame fr= ont and decomposition of the =0Aincreasingly squashed end gases. High octan= e fuels produce end gases that take =0Alonger to autoignite, so the good fl= ame front reaches and consumes them =0Aproperly. =0A=0A=0AThe ignition adva= nce map is partly determined by the fuel the engine is intended =0Ato use. = The timing of the spark is advanced sufficiently to ensure that the =0Afuel= -air mixture burns in such a way that maximum pressure of the burning charg= e =0Ais about 15-20 degree after TDC. Knock will occur before this point, u= sually in =0Athe late compression - early power stroke period.=0AThe engine= management system uses ignition timing as one of the major variables =0Ath= at is adjusted if knock is detected. If very low octane fuels are used =0A(= several octane numbers below the vehicle's requirement at optimal settings)= , =0Aboth performance and fuel economy will decrease.=0A=0AThe actual Octan= e Number Requirement depends on the engine design, but for some =0A1978 veh= icles using standard fuels, the following (R+M)/2 Octane Requirements =0Awe= re measured. "Standard" is the recommended ignition timing for the engine, = =0Aprobably a few degrees BTDC [38].=0A=0ABasic Ignition Timing=0AVehicle R= etarded 5 degrees Standard Advanced 5 degrees=0AA 88 91 93=0AB 86 90.5 94.5= =0AC 85.5 88 90=0AD 84 87.5 91=0AE 82.5 87 90 =0A=0AThe actual ignition tim= ing to achieve the maximum pressure from normal =0Acombustion of gasoline w= ill depend mainly on the speed of the engine and the =0Aflame propagation r= ates in the engine. Knock increases the rate of the pressure =0Arise, thus = superimposing additional pressure on the normal combustion pressure =0Arise= . The knock actually rapidly resonates around the chamber, creating a serie= s =0Aof abnormal sharp spikes on the pressure diagram. The normal flame spe= ed is =0Afairly consistent for most gasoline HCs, regardless of octane rati= ng, but the =0Aflame speed is affected by stoichiometry. Note that the flam= e speeds in this FAQ =0Aare not the actual engine flame speeds. A 12:1 CR g= asoline engine at 1500 rpm =0Awould have a flame speed of about 16.5 m/s, a= nd a similar hydrogen engine yields =0A48.3 m/s, but such engine flame spee= ds are also very dependent on stoichiometry. =0A=0A=0A=0ALynn,=0A=0A=A0=A0= =A0 From your previous posts on this subject it seems that the Rotary does = not =0Areact in the exact=A0same way as a typical=0Apiston engine to leanin= g and or timing changes...................William has =0Aused as reference = a very detailed piece from=0Ahttp://www.turborx7.com/fuel.htm=A0(excerpt ab= ove) that he feels challenges =0Aprevious info that you have posted and=0At= hat I mentioned from memory so I=A0may not have related it =0Aaccurately...= ........Would appreciate=A0your additional thoughts=0Aabout this and any co= rrections if I misspoke.........(Tracy posted recently that =0Ahis EC2-3 do= es retard ignition timing as=0Aboost increases < up to12 degrees>).........= .......=0A=0AThanks,=0A=0A=A0Kelly Troyer=0A"DYKE DELTA JD2" (Eventually)= =0A"13B ROTARY"_ Engine=0A"RWS"_RD1C/EC2/EM2=0A"MISTRAL"_Backplate/Oil Mani= fold=0A"TURBONETICS"_TO4E50 Turbo=0A________________________________=0AFrom= : Kelly Troyer =0ATo: Rotary motors in aircraft =0ASent: Sun, March 6, 2011 11:43:01 AM=0ASubject: [FlyRo= tary] For Lynn_Effect of Leaning & Timing for Turbo Rotary=0A --0-1604448153-1299435062=:79858 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
=0A
 
=0A
Lynn,
=0A
 =0A
   Additional excerpt  from <= A href=3D"http://www.turborx7.com/fuel.htm">http://www.turborx7.com/fuel.ht= m with two more factors
=0A
to consider about potentia= l for detonation for the Rotary engine...............
=0A
&nb= sp;
=0A
=0A

W= hat is the effect of temperature and load?

Increasing the engine temperature, particularly the air-fuel charge tempe= rature, increases the tendency to knock. The Sensitivity of a fuel can indi= cate how it is affected by charge temperature variations. Increasing load i= ncreases both the engine temperature, and the end-gas pressure, thus the li= kelihood of knock increases as load increases. Increasing the water jacket = temperature from 71C to 82C, increases the (R+M)/2 ONR by two [111].
 

=0A

What is the effect of engine speed?.

Faster engine speed means there is less time for the pre-flame reactio= ns in the end gases to occur, thus reducing the tendency to knock. On engin= es with management systems, the ignition timing may be advanced with engine= speed and load, to obtain optimum efficiency at incipient knock. In such c= ases, both high and low engines speeds may be critical.
 

=0A

Kelly Troyer

= =0A

=0AFrom: Ke= lly Troyer <keltro@att.net>
T= o: Rotary motors in aircraft <flyrotary@lancaironline.net>=
Sent: Sun, March 6, 201= 1 11:43:01 AM
Subject: [= FlyRotary] For Lynn_Effect of Leaning & Timing for Turbo Rotary

=0A

=0A
=0A
=0A
=0A
=0A
=0A=
=0A= =0A=0A= =0A=0A=0A=0A=0A
From:=0A
=0A
William Wilson <fluffysheap@gmail.com>
Add to Contacts
To:Rotar= y motors in aircraft <flyrotary@lancaironline.net> =0A
=0A
=0A=0A
K= elly Troyer wrote:
=0A
 =0A
"I just remembered one other tidbit of= info from our rotary guru Lynn.........One of
his informative posts on = fuel and the effects of octan= e ratings stated that as you lean
the auto fuel that many of us u= se (87 to 91 octane) that the flame front is slowed and
this mimics the = effect of lead in fuel"
=0A
 
=0A
 William = wrote:
=0A

Generally, leaner mixture increases the risk of det= onation, regardless of octane or presence of lead.  On a naturally asp= irated rotary it doesn't usually matter much.

I find this page to be= an excellent reference for the effects of octane:
http://www.turborx7.c= om/fuel.htm
=0A

   Kelly Troyer write :
=0A=
 
=0A
"One other point that = I forgot to mention was ignition timing..........It is my understanding
= that turboed engines should not use excessive timing advance and that the higher the
boost the= less timing advance is needed (or wise).........As I recall ignition timin= g as high
as 27 + degrees BTDC has/is used for naturally aspirated Rotar= ys"
=0A
   William wrote:
=0A

I think t= he confusion here is between talking about the timing at idle and the timin= g at high RPM.  When you set the timing you are usually setting the id= le timing, then the ECU adds a certain amount of advance based on the RPM, = temperature, whatever.  10 degrees is probably the idle setting, not t= he maximum advance, whereas the 27+ is probably the maximum advance (maximu= m advance in my car is about 35).
=0A
 
=0AThis is an excerpt from............http://www.turb= orx7.com/fuel.htm

=0A
 What is the effect of changing the air-fuel ratio?

Traditionally, the greatest tendency to knock w= as near 13.5:1 air-fuel ratio, but was very engine specific. Modern engines= , with engine management systems, now have their maximum octane requirement= near to 14.5:1. For a given engine using gasoline, the relationship betwee= n thermal efficiency, air-fuel ratio, and power is complex. Stoichiometric = combustion (air-fuel
ratio =3D 14.7:1 for a typical non-oxygenated gaso= line) is neither maximum power - which occurs around air-fuel 12-13:1 (Rich= ), nor maximum thermal efficiency - which occurs around air-fuel 16-18:1 (L= ean). The air-fuel ratio is controlled at part throttle by a closed loop sy= stem using the oxygen sensor in the exhaust. Conventionally, enrichment for= maximum power air-fuel ratio is used during full throttle operation to red= uce knocking while providing better drivability [38]. An average increase of 2 (R+M)/2 ON is required for each= 1.0 increase (leaning) of the air-fuel ratio [111]. If the mixture is weak= ened, the flame speed is reduced, consequently less heat is converted to me= chanical energy, leaving heat in the cylinder walls and head, potentially i= nducing knock. It is possible to weaken the mixture sufficiently that the f= lame is still present when the inlet valve opens again, resulting in backfi= ring.

 
=0A
=0A

What is the effect of changing the ignition ti= ming?

The tendency to knock increases as s= park advance is increased. For an engine with recommended 6 degrees BTDC (B= efore Top Dead Center) timing and 93 octane fuel, retarding the spark 4 deg= rees lowers the octane requirement to 91, whereas advancing it 8 degrees re= quires 96 octane fuel [27]. It should be noted this requirement depends on = engine design. If you advance the spark, the flame front starts earlier, an= d the end gases start forming earlier in the cycle, providing more time for= the autoigniting species to form before the piston reaches the optimum pos= ition for power delivery, as determined by the normal flame front propagati= on. It becomes a race between the flame front and decomposition of the incr= easingly squashed end gases. High octane fuels produce end gases that take = longer to autoignite, so the good flame front reaches and consumes them properly.

The ignition advance map is pa= rtly determined by the fuel the engine is intended to use. The timing of th= e spark is advanced sufficiently to ensure that the fuel-air mixture burns = in such a way that maximum pressure of the burning charge is about 15-20 de= gree after TDC. Knock will occur before this point, usually in the late com= pression - early power stroke period.
The engine management system uses = ignition timing as one of the major variables that is adjusted if knock is = detected. If very low octane fuels are used (several octane numbers below t= he vehicle's requirement at optimal settings), both performance and fuel ec= onomy will decrease.

The actual Octane Number Requirement depends on= the engine design, but for some 1978 vehicles using standard fuels, the fo= llowing (R+M)/2 Octane Requirements were measured. "Standard" is the recomm= ended ignition timing for the engine, probably a few degrees BTDC [38].

Basic Ignition Timing
Vehicle Retarded 5 degrees Standard = Advanced 5 degrees
A 88 91 93
B 86 90.5 94.5
C 85.5 88 90
D 84 = 87.5 91
E 82.5 87 90

The actual ignition timing to achieve the m= aximum pressure from normal combustion of gasoline will depend mainly on th= e speed of the engine and the flame propagation rates in the engine. Knock = increases the rate of the pressure rise, thus superimposing additional pres= sure on the normal combustion pressure rise. The knock actually rapidly res= onates around the chamber, creating a series of abnormal sharp spikes on th= e pressure diagram. The normal flame speed is fairly consistent for most ga= soline HCs, regardless of octane rating, but the flame speed is affected by= stoichiometry. Note that the flame speeds in this FAQ are not the actual e= ngine flame speeds. A 12:1 CR gasoline engine at 1500 rpm would have a flam= e speed of about 16.5 m/s, and a similar hydrogen engine yields 48.3 m/s, but such engine flame speeds are also very dependent on stoichiometry= .

=0A
 
=0A
Lynn,
=0A 
=0A
    From your previous posts on this s= ubject it seems that the Rotary does not react in the exact same way a= s a typical
=0A=0A
=  
=0A
Thanks,
=0A
 
=0A
 Kelly Tr= oyer
"DYKE DELTA JD2" (Even= tually)
=0A

"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/E= M2
"MISTRAL"_Backplate/Oil Manifold

=0A

"TURBONETICS"_TO4E50 Turbo<= /P>=0A

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