X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 12 Mar 2009 10:30:48 -0400 Message-ID: X-Original-Return-Path: Received: from web80004.mail.sp1.yahoo.com ([69.147.92.102] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with SMTP id 3544435 for lml@lancaironline.net; Wed, 11 Mar 2009 17:51:07 -0400 Received-SPF: none receiver=logan.com; client-ip=69.147.92.102; envelope-from=bu131@swbell.net Received: (qmail 24578 invoked by uid 60001); 11 Mar 2009 21:50:31 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=swbell.net; h=Message-ID:Received:X-Mailer:References:Date:From:Subject:To:MIME-Version:Content-Type; b=hyoFt6xXeiTG3YwRwpkyHpdlcRQFzb12mRF7guelXifILW4uktPkB/nojxY2Kx3ZtkOZjU0TK0C2uuDBAk7ib3kTVn8Y8P2LFSjiwIWnl7CAR699rkAOSFhQQtDGSI8X15BJtENV0DXOmaVzigHgM5rIV4dhJwsV//i9UkAEc8k=; X-Original-Message-ID: <800206.24522.qm@web80004.mail.sp1.yahoo.com> Received: from [70.254.187.254] by web80004.mail.sp1.yahoo.com via HTTP; Wed, 11 Mar 2009 14:50:31 PDT X-Mailer: YahooMailRC/1155.45 YahooMailWebService/0.7.260.1 References: X-Original-Date: Wed, 11 Mar 2009 14:50:31 -0700 (PDT) From: Dr Andre Katz Subject: Re: [LML] Re: LOP vs ROP Climb: Time and Fuel Burn (LIVP) X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-156732794-1236808231=:24522" --0-156732794-1236808231=:24522 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello Jeff:=0A=0AI climb most of the time WOT full RPM 2700 and get about 4= 2 g/hr but at altitude that number decreases and my CHT climbs to over 410 = by the time I get to 14,000 15,000 feet. I always have to stop the climb, g= o to LOP in order to get my temps below 400. I accept the decrease in climb= for keeping the engine cool. My cowling probably needs to be tweaked but I= am going P-W and=A0 temps should not be a problem.=0AAs soon as I turn LOP= temps drop to 360-370 and stay like that but my climb rate drops a lot.=0A= =0AAndres=0A=0A=0A=0A=0A________________________________=0AFrom: "Jeffrey L= iegner, MD" =0ATo: lml@lancaironline.net=0ASent: We= dnesday, March 11, 2009 2:48:36 PM=0ASubject: [LML] Re: LOP vs ROP Climb: T= ime and Fuel Burn (LIVP)=0A=0A=0AI did this trial to answer a nagging quest= ion for me: what is the cost and penalty of ROP vs LOP climb.=A0 To make th= e comparison as similar as possible (reduce the confounding variables), I k= ept MAP (34.8") and RPM (2500) the same, as well as OAT, wind (direction of= climb) and distance downrange.=A0 The VSI was chosen to produce at least a= minimum 500 fpm climb (notably required by ATC), hence a lower forward IAS= when LOP.=A0 The goal was a comparison, not necessarily the most efficient= ROP climb compared to the most efficient LOP climb, although this sounds l= ike it might be an interesting examination.=0A=0AIf I climbed ROP at 152-15= 7 KIAS, the CHT would have been much higher, much sooner.=A0 As it was, I c= ould not maintain CHT <410*F at 160 KIAS during the ROP climb.=A0 Of course= , if I throttle back (to 26"-27", 2500 RPM), this might produce the same VS= I as the higher LOP MAP given I've reduced my ROP horsepower, but then I've= still got unconsumed (and wasted) fuel exiting the exhaust manifold, and f= or what HP gain?=0A=0ARegarding the ROP fuel burn of 34.2 gph vs WOT 45 gph= (on take off), my engine is set to feed the recommended 45 gph at 38.5" MA= P, 2700 RPM to produce the rated 350 HP.=A0 These numbers, particularly the= ROP 34.2 gph, were at 34.8" MAP 2500 RPM full mixture, not WOT.=A0 An inte= resting footnote is that these engines are rated forcontinuous operation at= WOT 38.5" 2700 RPM.=0A=0AHow many pilot are climbing out to altitude at MA= P 38" 2700 RPM and 140 KIAS (and 2000 fpm)?=A0 This is an interesting idea,= not something I've tried (or was taught).=A0 Colyn's numbers suggest it wo= uld get one to altitude quick enough that the CHT2 might not be an issue (h= e sees 380*F), despite the reduced forward air flow, and still have similar= fuel consumption as 34.8" 2500.=A0 This would be a bonus.=0A=0AI'd welcome= some comments about people's ROP climb numbers typically used.=0A=0AJeff L= =0ALIVP=0A=0A=0A=0A=0A=0ANext you might run ROP at the same performance num= bers as you had LOP (152-157 KIAS and 600-900 fpm VSI) and see what the fue= l burn is.=A0 You probably will use a significantly lower MAP to get equiva= lent performance.=A0 I bet 26-27" MAP.=A0 That may significantly impact the= difference you found in fuel economy.=0A=0A=0A=0A=0AI think your full rich= FF is (way) too low.=0AHow ROP are you at 34.2gph?=0AI believe continental= specs for full throttle (38") are 43gph.=0AFor overhaul economy it would b= e good to get it up there.=0A=A0=0AI have mine set at 45gph for 38"/2700rpm= .=0AI don't know what temps that would give at 160knots=0Abut at 140 knots = the hottest cylinder is 380 and it will climb at 2000fpm (not that I do tha= t a lot)=0A=A0=0AIf you want to use those numbers it takes 5 minutes to do = that climb which would be 3.75 gallons.=0Aswitch to cruise @260 knots at 16= ,000 and I think you burn another 1.38 gals for a total of 5.13.=0A...so ma= ybe a little less bad than you said.=0A=A0=0Abut somehow, a gallon and a ha= lf doesn't register compared to the build cost, insurance, training, etc.= =0Aif I'm feeling environmentally responsible I just think how much fuel I = saved by not owning a turbine....=0A=0A=0A=0A=0AIt=B9s curious to me that y= ou experienced higher CHTs at =B3Rich.=B2=0A=0AHave you tried just climbing= out at 38 MAP?=0A=0A=0A=0A=0A=0AOn 3/9/09 10:41 AM, "Jeffrey Liegner, MD" = wrote:=0A=0AHere's some analysis on time to climb = and fuel consumption in my LIVP during a controlled ascent of 10,000' (from= 6000' MSL to 16000' MSL) in both Lean of Peak (LOP) and Rich of Peak (ROP)= engine configuations.=0A=0AThis test occurred over Pennsylvania 3/7/09, fi= xed heading (350*), fully configured and stabilized in level flight (6000' = MSL) at 34.8" MAP and fuel flow, followed by a pitch up (over a known GPS r= eference point) and climb (to 16000' MSL) either LOP (18.2 gph) or ROP (34.= 2 gph). =A0Winds were light out of the northwest (a quartering headwind), r= emained consistent during both tests; temps were above ISO. =A0The test was= conducted over a 32 min span of time. =A0Engine: TSIO-550E.=0A=0ALean of P= eak (LOP) Data:=0A10,000' climb at 34.8" MAP=0AFuel flow 18.3 gph (estimate= 100*F LOP)=0ATime Required: 11:28 min=0ADistance Downrange: 30.9 nm=0AAirs= peed during climb: 152-157 KIAS (Calculated Groundspeed: 161)=0AIndicated V= SI: 600-900 fpm (Calculated: 870 fpm)=0AFuel Burn: 3.5 gallons (confirmed w= ith totalizer)=0AHighest CHT Temp: 360*F (CHT2)=0A=0A=0A=0ARich of Peak (RO= P) Data:=0A10,000' climb at 34.8" MAP=0AFuel flow 34.2 gph (Mixture full in= )=0ATime Required: 9:07 min=0ADistance Downrange: 26.5 nm=0AAirspeed during= climb: 160 KIAS initially, but 165 KIAS last 1:30 min due to CHT2 >410*F= =0AIndicated VSI: 1000-1400 fpm (Calculated: 1100 fpm)=0AFuel Burn: 5.2 gal= lons (confirmed with totalizer)=0AHighest CHT Temp: 412*F (CHT2)=0A=0ABonus= Data in Level Flight after ROP climb:=0AImmediate LOP to 18.3 gph=0AProcee= ded to 30.9 nm down range=0AAdditional time required in level flight: 1:17 = min=0AAdditional fuel required in level flight (LOP): 0.4 gallons=0ATotal t= ime to reach 30.9 nm down range: ROP 10:24 min (versus LOP 11:28 min)=0ATot= al fuel burn to reach 30.9 nm and 10,000' gain: ROP 5.6 gal (vs LOP 3.5 gal= )=0A=0AMy personal conclusion:=0ALOP during climb consumes 37% less fuel an= d only extends travel time 11%.=0ACHT are much better LOP during the climb.= =0A=0A=0A=0AJeff Liegner=0ALIVP in New Jersey=0A --0-156732794-1236808231=:24522 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello Jeff:
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I climb m= ost of the time WOT full RPM 2700 and get about 42 g/hr but at altitude tha= t number decreases and my CHT climbs to over 410 by the time I get to 14,00= 0 15,000 feet. I always have to stop the climb, go to LOP in order to get m= y temps below 400. I accept the decrease in climb for keeping the engine co= ol. My cowling probably needs to be tweaked but I am going P-W and  te= mps should not be a problem.
=0A
As soon as I turn LOP temps drop = to 360-370 and stay like that but my climb rate drops a lot.
=0A
&= nbsp;
=0A
Andres
=0A

=0A
=0A
=0A= From: "Jeffrey Liegner, MD" <liegner@embarqmail.com>
To: lml@lancaironline.net
= Sent: Wednesday, March 11, = 2009 2:48:36 PM
Subject:= [LML] Re: LOP vs ROP Climb: Time and Fuel Burn (LIVP)

=0A=0A=0A
I did this trial to answer a nagging q= uestion for me: what is the cost and penalty of ROP vs LOP climb.  To = make the comparison as similar as possible (reduce the confounding variable= s), I kept MAP (34.8") and RPM (2500) the same, as well as OAT, wind (direc= tion of climb) and distance downrange.  The VSI was chosen to produce = at least a minimum 500 fpm climb (notably required by ATC), hence a lower f= orward IAS when LOP.  The goal was a comparison, not necessarily the m= ost efficient ROP climb compared to the most efficient LOP climb, although = this sounds like it might be an interesting examination.
=0A

<= /DIV>=0A
If I climbed ROP at 152-157 KIAS, the CHT would have been much= higher, much sooner.  As it was, I could not maintain CHT <410*F a= t 160 KIAS during the ROP climb.  Of course, if I throttle back (to 26= "-27", 2500 RPM), this might produce the same VSI as the higher LOP MAP giv= en I've reduced my ROP horsepower, but then I've still got unconsumed (and = wasted) fuel exiting the exhaust manifold, and for what HP gain?
=0A
=0A
Regarding the ROP fuel burn of 34.2 gph vs WOT 45 gph = (on take off), my engine is set to feed the recommended 45 gph at 38.5" MAP= , 2700 RPM to produce the rated 350 HP.  These numbers, particularly t= he ROP 34.2 gph, were at 34.8" MAP 2500 RPM full mixture, not WOT.  An= interesting footnote is that these engines are rated for continuous= operation at WOT 38.5" 2700 RPM.
=0A

=0A
How many p= ilot are climbing out to altitude at MAP 38" 2700 RPM and 140 KIAS (and 200= 0 fpm)?  This is an interesting idea, not something I've tried (or was= taught).  Colyn's numbers suggest it would get one to altitude quick = enough that the CHT2 might not be an issue (he sees 380*F), despite the red= uced forward air flow, and still have similar fuel consumption as 34.8" 250= 0.  This would be a bonus.
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=0A
I'd welcome = some comments about people's ROP climb numbers typically used.
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=0A
Jeff L
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LIVP
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=
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Next you = might run ROP at the same performance numbers as you had LOP (152-157 KIAS = and 600-900 fpm VSI) and see what the fuel burn is.  You probably will= use a significantly lower MAP to get equivalent performance.  I bet 2= 6-27" MAP.  That may significantly impact the difference you found in = fuel economy.
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=0AI think your full ric= h FF is (way) too low.
=0A
How ROP are you at 34.2gph?=0A
= I believe continental specs for full throttle (38") are 43gph.=0A
= For overhaul economy it would be good to get it up there.=0A
 
=0A
I have mine set at 45g= ph for 38"/2700rpm.
=0A
I don't know what temps that would give at = 160knots
=0A
but at 140 knots the hottest cylinder is 380 and it wi= ll climb at 2000fpm (not that I do that a lot)
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If you want to use those numbers = it takes 5 minutes to do that climb which would be 3.75 gallons.=0A
switch to cruise @260 knots at 16,000 and I think you burn another 1.38 g= als for a total of 5.13.
=0A
...so maybe a little less bad than y= ou said.
=0A
 =0A
but somehow, a gallon and a half doesn't register compared to the bui= ld cost, insurance, training, etc.
=0A
if I'm feeling environment= ally responsible I just think how much fuel I saved by not owning a turbine= ....
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=0A

=0A

=0A
It=B9s curious = to me that you experienced higher CHTs at =B3Rich.=B2

Have you tried= just climbing out at 38 MAP?
=0A

=0A

=0A


=0A

On 3/9/= 09 10:41 AM, "Jeffrey Liegner, MD" <liegner@embarqmail= .com> wrote:
=0A
Here's some analysis on time to climb= and fuel consumption in my LIVP during a controlled ascent of 10,000' (fro= m 6000' MSL to 16000' MSL) in both Lean of Peak (LOP) and Rich of Peak (ROP= ) engine configuations.

This test occurred over Pennsylvania 3/7/09,= fixed heading (350*), fully configured and stabilized in level flight (600= 0' MSL) at 34.8" MAP and fuel flow, followed by a pitch up (over a known GP= S reference point) and climb (to 16000' MSL) either LOP (18.2 gph) or ROP (= 34.2 gph).  Winds were light out of the northwest (a quartering headwi= nd), remained consistent during both tests; temps were above ISO.  The= test was conducted over a 32 min span of time.  Engine: TSIO-550E.=0A

Lean of Peak (LOP) Data:
10,000' cli= mb at 34.8" MAP
Fuel flow 18.3 gph (estimate 100*F LOP)
Time Required= : 11:28 min
Distance Downrange: 30.9 nm
Airspeed during climb: 152-15= 7 KIAS (Calculated Groundspeed: 161)
Indicated VSI: 600-900 fpm (Calcula= ted: 870 fpm)
Fuel Burn: 3.5 gallons (confirmed with totalizer)
Highe= st CHT Temp: 360*F (CHT2)



Rich of Peak (ROP) Data:
10,000' climb at 34.8" MAP
Fuel flow 34.2 gph (Mixture full in)
Time= Required: 9:07 min
Distance Downrange: 26.5 nm
Airspeed during climb= : 160 KIAS initially, but 165 KIAS last 1:30 min due to CHT2 >410*F
I= ndicated VSI: 1000-1400 fpm (Calculated: 1100 fpm)
Fuel Burn: 5.2 gallon= s (confirmed with totalizer)
Highest CHT Temp: 412*F (CHT2)

Bo= nus Data in Level Flight after ROP climb:
Immediate LOP to 18.3 gph<= BR>Proceeded to 30.9 nm down range
Additional time required in level fli= ght: 1:17 min
Additional fuel required in level flight (LOP): 0.4 gallonsTotal time to reach 30.9 nm down range: ROP 10:24 min (versus LOP 11:28 mi= n)
Total fuel burn to reach 30.9 nm and 10,000' gain: ROP 5.6 gal (vs LO= P 3.5 gal)

My personal conclusion:
LOP during climb consum= es 37% less fuel and only extends travel time 11%.
=0ACHT are much better LOP during the climb.
=0A
=0A

=0A

=0A
Jeff Liegner
=0A
LIVP in New Jerse= y
=0A

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