X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 16 Oct 2013 13:06:29 -0400 Message-ID: X-Original-Return-Path: Received: from nm19-vm4.bullet.mail.ne1.yahoo.com ([98.138.91.179] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6543148 for lml@lancaironline.net; Wed, 16 Oct 2013 12:17:08 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.91.179; envelope-from=chris_zavatson@yahoo.com Received: from [98.138.101.130] by nm19.bullet.mail.ne1.yahoo.com with NNFMP; 16 Oct 2013 16:16:32 -0000 Received: from [98.138.88.234] by tm18.bullet.mail.ne1.yahoo.com with NNFMP; 16 Oct 2013 16:16:32 -0000 Received: from [127.0.0.1] by omp1034.mail.ne1.yahoo.com with NNFMP; 16 Oct 2013 16:16:32 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 118632.4075.bm@omp1034.mail.ne1.yahoo.com Received: (qmail 81989 invoked by uid 60001); 16 Oct 2013 16:16:32 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=4xjPIFBBT8mj4ae1xexMH++GlqeVpLS9RKr2kMdHSAeX5nEuE9fp7nR9CR9yMoTnz+RzZDSA1sGmiTRfZskZBcZsr3jWTXGNFp816RrK4cpy2mXIc3NPQfAkOg9h/0vPUzCLEoXWgvBxpTaBRIs2dER+RrgZ91gCg9XMkS4O0us=; X-YMail-OSG: PbIU7FcVM1muyzLwW568jxdcfNigFJeUjXzgHZqT3_omK2j c1RIdcyDG5GbJVYGS8EWXhK7aFc6gSWEbw5673OHUBiAg5ZPg_5hFU5zJz.e KYRIFhsYKqy0G5Zt8KsW8Ldpvc.fnc5w0T4sGRiBRR5kl_dE2161fqfMC7pK 26TMbXDXI9kvyIsXSzjVjS8VVNPghT38AMoihZfX7BRnlFtPOy92LHHX65ic Jw43ky6Brsic7c.cBaemTkxcIwpZMFDIa3BLMOEglA4R6Kmkqtd.FNXvQ.9M FWy.mfck48fh9.eICO72ShY6VeYPS1I9m83bAM9qZTER1gr3UjPnG1Ms8ifR v6.ESyZ_EGAdfPULClJrctRxb1lyU2dec88Gbpb8x0J5FWrC6Bo.vUipY6L7 hSxd0RfLpeuoyAMai21OxNewtz7B0tiw6BME_t3xutAaCCT07rE8BBdMoWU5 TXrNjcj7fZejgdB72_QcUdXZF5EHIQNUqHTybZ5ebIVh7KUxJmWPkkqNZH3G IBCIlxPrO7hns_SB_pAuHKyzVo6o6cb3t.wtFckzf_v81D27B6pvUw9DrayA u56J6rJ5mviYBo0eZIIHZxSZkLWRB5Awm8iMQY4_VyqyH1jmtsqCPj7igd8U _4cCDFSjNZtpdVGiWcon2ZwcGHUTPBg-- Received: from [172.14.16.72] by web121605.mail.ne1.yahoo.com via HTTP; Wed, 16 Oct 2013 09:16:31 PDT X-Rocket-MIMEInfo: 002.001,S2VpdGgsClZlcnkgaW50ZXJlc3RpbmcgaW5mby7CoCBJIHBsYXllZCBhcm91bmQgd2l0aCBMT1Agb24gbXkgTzM2MC1BMUEgYWZ0ZXIKdGhlIExhbmNhaXIgQWRhIFNlbWluYXIgbWFueSB5ZWFycyBhZ28uwqAgTGlrZQp5b3UsIEkgcmFuIGludG8gaXNzdWVzIGRvd24gbG93IGJ1dCBkaWRu4oCZdCB0aGluayB0byB0cnkgaXQgdXAgaGlnaCwgc28gcGVyaGFwcwp0aGVyZSBpcyBzdGlsbCBob3BlLiBJIHdhcyBhYmxlIHRvIGdldCBMT1AgZG93biBsb3csIGJ1dCBoYWQgdG8gY29jayB0aGUKdGhyb3R0bGUgcGwBMAEBAQE- X-Mailer: YahooMailWebService/0.8.160.587 References: X-Original-Message-ID: <1381940191.71166.YahooMailNeo@web121605.mail.ne1.yahoo.com> X-Original-Date: Wed, 16 Oct 2013 09:16:31 -0700 (PDT) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] Re: LOP ops on O-360 A1A X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="2053635335-930408512-1381940191=:71166" --2053635335-930408512-1381940191=:71166 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Keith,=0AVery interesting info.=C2=A0 I played around with LOP on my O360-A= 1A after=0Athe Lancair Ada Seminar many years ago.=C2=A0 Like=0Ayou, I ran = into issues down low but didn=E2=80=99t think to try it up high, so perhaps= =0Athere is still hope. I was able to get LOP down low, but had to cock the= =0Athrottle plate so far that I was losing too much MP to be practical.=C2= =A0 For stretching range on long trips, I simply go up to=0A17.5k/16.5k.=C2= =A0 Even with my less than=0Aideal ROP fuel distribution I am flowing about= 7.5 gph.=C2=A0 Book values say it should be closer to 6, so=0AI figure my = rich cylinders are throwing away about 1.5 gph.=C2=A0 It hasn=E2=80=99t qui= te been enough to drive me to=0Afuel injection just yet.=C2=A0 On the CHT f= ront, the 360 inlets are=0Avery small relative to the required cooling air = mass flow.=C2=A0 This drives the velocity through the inlet to be very high= .=C2=A0 Typically inlets are sized so that the=0Aoncoming air is slowed pri= or to reaching the inlet throat to recover some pressure=0Aexternally.=C2= =A0 With the 360, the inlet=0Avelocity is roughly the same as cruise speed,= so all pressure recovery is=0Ainternal.=C2=A0 Unfortunately internal=0Apre= ssure recovery is much more difficult and really requires controlled diffus= ion of=0Asome sort.=C2=A0 The stock inlet lip creates a=0Ajet that turns mo= st of the energy into turbulence. After many partial fixes I=0Aresolved my = temperature issue once and for all with a complete makeover:=C2=A0 new inle= ts, diffusers and a plenum.=C2=A0 The inlets retain the original diameter, = but=0Athe internal flow expansion is now controlled.=C2=A0 At=0A2,500 rpm, = WOT and leaned for best power, my hottest cylinder runs 360 +/-15,=0Adepend= ing on time of year.=C2=A0 The next two=0Acylinders are 20 degrees below th= at and the last cylinder is 40 degrees lower.Chris ZavatsonN91CZ360stdhttp:= //www.n91cz.net/=C2=A0=C2=A0=C2=A0=C2=A0=0A=0A=0A=0AOn Tuesday, October 15,= 2013 9:49 AM, George Braly wrote:=0A =0ATry using some= carb heat.=C2=A0 =C2=A0 It will smooth out that engine significantly when = LOP.=C2=A0 =0A=0AThe warmer induction air does a much more uniform job of d= istributing the fuel as vapor with less liquid drop outs in the induction p= lumbing. =0A=0A=0A=0A-----Original Message-----=0AFrom: Lancair Mailing Lis= t [mailto:lml@lancaironline.net] On Behalf Of vtailjeff@aol.com=0ASent: Tue= sday, October 15, 2013 8:21 AM=0ATo: lml@lancaironline.net=0ASubject: [LML]= Re: LOP ops on O-360 A1A=0A=0AHave you checked your baffling?=0A=0ASent fr= om my iPad=0A=0AOn Oct 15, 2013, at 7:53 AM, Keith Smith wrote:=0A=0A> Hey all,=0A> =0A> I'm waiting for winter to come around= but it seems like my O-360 A1A has been running warmer than usual, requiri= ng me to power back very shortly after takeoff to avoid an excursion north = of 425 degree CHT's.=0A> =0A> In any case, I know that LOP ops are hard to = come by with an O-360 due to poor fuel distribution. Indeed, my #4 cylinder= peaks well before the others, making it tricky to get them LOP.=0A> =0A> I= 've been running in two modes...one is around 20 LOP to cool it down to aro= und 385 CHT while the others run just slightly rich of peak. I can do this = without much effort, and under a wide range of throttle positions, and dens= ity altitudes.=0A> =0A> On a recent flight, though, I found #1 and #3 settl= ing on temps that were just too high to be happy with. I would go well ROP = to get them cooled, but burned a lot of fuel in the process and still had a= warm 4th cylinder due to the fact that it runs quite a bit leaner. This wa= s all done at 75% power or less, btw, density altitude was well above 11k (= I was at 11k and it was +10C)=0A> =0A> Eventually, I tried something somewh= at dramatic. I was determined to get ALL the cylinders LOP. I leaned relati= vely rapidly and ignored the disconcerting knocking/shuddering associated w= ith the uneven amounts of power being produced between the 4th cylinder and= all the rest.=0A> =0A> It all happened a bit quickly, but with cylinder 1-= 3 roughly 20-40 LOP and #4 70-90 LOP, the CHTs dropped like a stone, seemin= gly in seconds, down to 380-385 across the board for #1-3 with #4 now in th= e 350-360 range. With careful fiddling of the mixture, and countless experi= ments with throttle position, I got the vibration down to the point where i= t was barely noticeable. Eventually it just felt smooth...but I can't tell = if I got used to it, or things just settled down, although I wouldn't think= it was possible.=0A> =0A> Final fuel flow was around 8.8-9.0 gph.=0A> =0A>= Finally, living the LOP dream with my O-360 :)=0A> =0A> I tried repeating = this later on, down low and wasn't able to repeat it (ie, never got it smoo= th).=0A> =0A> So, it's elusive, but possibly doable under just the right ci= rcumstances. Since I do long trips on a regular basis, I'm definitely inter= ested in making this work.=0A> =0A> Separately, I'll try to find out why it= 's running warmer in general. I did have a mag replaced, the other rebuilt,= and 4 new plugs installed in the last year.=0A> =0A> Honestly, I'm going t= o try to save some clams and get this converted to an IO-360 (didn't realiz= e it was relatively inexpensive until my mechanic suggested it), get balanc= ed injectors and run LOP as SOP. The difference in cooling really is stagge= ring. I know I'm probably preaching to the choir, but I thought that O-360 = owners might find it eye opening. Get up high and give it a try if you have= a 4 point engine monitor. You'll know it's working when your leaning resul= ts in EGT and CHT's coming down :)=0A> =0A> The trip, btw, was N07-KFTW-KSA= V-N07, around 2600nm.=0A> =0A> Keith=0A=0A--=0AFor archives and unsub http:= //mail.lancaironline.net:81/lists/lml/List.html=0A=0A--=0AFor archives and = unsub http://mail.lancaironline.net:81/lists/lml/List.html --2053635335-930408512-1381940191=:71166 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
=0A=0A
Keith,
<= div class=3D"MsoNormal" style=3D"margin: 0in 0in 0pt; line-height: normal;"= >Very interesting info.  I played around with LOP on my O360-= A1A after=0Athe Lancair Ada Seminar many years ago.  Like=0Ayou, I ran into issues down low but didn=E2= =80=99t think to try it up high, so perhaps=0Athere is still hope. I was ab= le to get LOP down low, but had to cock the=0Athrottle plate so far that I = was losing too much MP to be practical.&= nbsp; For stretching range on long trips, I simply go up to=0A17.5k/= 16.5k.  Even with my less th= an=0Aideal ROP fuel distribution I am flowing about 7.5 gph.  Book values say it should be closer to 6,= so=0AI figure my rich cylinders are throwing away about 1.5 gph.  It hasn=E2=80=99t quite been enough = to drive me to=0Afuel injection just yet. 
= On the CHT front, the 360 inlets are=0Avery small relative to the required = cooling air mass flow. =0ATh= is drives the velocity through the inlet to be very high.  Typically inlets are sized so that the=0Aonc= oming air is slowed prior to reaching the inlet throat to recover some pres= sure=0Aexternally.  With the= 360, the inlet=0Avelocity is roughly the same as cruise speed, so all pres= sure recovery is=0Ainternal.  Unfortunately internal=0Apressure recovery is much more difficult and rea= lly requires controlled diffusion of=0Asome sort.  The stock inlet lip creates a=0Ajet that turns most = of the energy into turbulence. After many partial fixes I=0Aresolved my tem= perature issue once and for all with a complete makeover:  new inlets, diffusers and a plenum.  The inlets retain the original diam= eter, but=0Athe internal flow expansion is now controlled.  At=0A2,500 rpm, WOT and leaned for best pow= er, my hottest cylinder runs 360 +/-15,=0Adepending on time of year.  The next two=0Acylinders are 20 d= egrees below that and the last cylinder is 40 degrees lower.Chris ZavatsonN91CZ360stdhttp://www.n91cz.net/    =
=0A=0A


On Tuesday, October 15, 2013 9:49 AM, George Braly <gwbral= y@gami.com> wrote:
Tr= y using some carb heat.    It will smooth out that engine signifi= cantly when LOP. 

The warmer induction air does a much more un= iform job of distributing the fuel as vapor with less liquid drop outs in t= he induction plumbing.



-----Original Message-----
From: = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of= vta= iljeff@aol.com
Sent: Tuesday, October 15, 2013 8:21 AM
To: lml@lancaironline.net
Subject: [LML] Re: LOP ops on O-360 A1A
Have you checked your baffling?

Sent from my iPad

On Oct 15= , 2013, at 7:53 AM, Keith Smith <keith.smith@gmail.com> wr= ote:

> Hey all,
>
> I'm waiting for winter to come a= round but it seems like my O-360 A1A has been running warmer than usual, re= quiring me to power back very shortly after takeoff to avoid an excursion n= orth of 425 degree CHT's.
>
> In any case, I know that LOP ops= are hard to come by with an O-360 due to poor fuel distribution. Indeed, m= y #4 cylinder peaks well before the others, making it tricky to get them LOP.
>
> I've been running in two modes...one is around 20 LO= P to cool it down to around 385 CHT while the others run just slightly rich= of peak. I can do this without much effort, and under a wide range of thro= ttle positions, and density altitudes.
>
> On a recent flight,= though, I found #1 and #3 settling on temps that were just too high to be = happy with. I would go well ROP to get them cooled, but burned a lot of fue= l in the process and still had a warm 4th cylinder due to the fact that it = runs quite a bit leaner. This was all done at 75% power or less, btw, densi= ty altitude was well above 11k (I was at 11k and it was +10C)
>
&= gt; Eventually, I tried something somewhat dramatic. I was determined to ge= t ALL the cylinders LOP. I leaned relatively rapidly and ignored the discon= certing knocking/shuddering associated with the uneven amounts of power bei= ng produced between the 4th cylinder and all the rest.
>
> It all happened a bit quickly, but with cylinder 1-3 roughly 20-4= 0 LOP and #4 70-90 LOP, the CHTs dropped like a stone, seemingly in seconds= , down to 380-385 across the board for #1-3 with #4 now in the 350-360 rang= e. With careful fiddling of the mixture, and countless experiments with thr= ottle position, I got the vibration down to the point where it was barely n= oticeable. Eventually it just felt smooth...but I can't tell if I got used = to it, or things just settled down, although I wouldn't think it was possib= le.
>
> Final fuel flow was around 8.8-9.0 gph.
>
&g= t; Finally, living the LOP dream with my O-360 :)
>
> I tried = repeating this later on, down low and wasn't able to repeat it (ie, never g= ot it smooth).
>
> So, it's elusive, but possibly doable under= just the right circumstances. Since I do long trips on a regular basis, I'= m definitely interested in making this work.
>
> Separately, I'll try to find out why it's running warmer in general. I did= have a mag replaced, the other rebuilt, and 4 new plugs installed in the l= ast year.
>
> Honestly, I'm going to try to save some clams an= d get this converted to an IO-360 (didn't realize it was relatively inexpen= sive until my mechanic suggested it), get balanced injectors and run LOP as= SOP. The difference in cooling really is staggering. I know I'm probably p= reaching to the choir, but I thought that O-360 owners might find it eye op= ening. Get up high and give it a try if you have a 4 point engine monitor. = You'll know it's working when your leaning results in EGT and CHT's coming = down :)
>
> The trip, btw, was N07-KFTW-KSAV-N07, around 2600n= m.
>
> Keith

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