X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ew0-f52.google.com ([209.85.215.52] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4552927 for flyrotary@lancaironline.net; Tue, 02 Nov 2010 19:50:08 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.52; envelope-from=msteitle@gmail.com Received: by ewy1 with SMTP id 1so8871ewy.25 for ; Tue, 02 Nov 2010 16:49:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=NlJQFiPsy7j8D8T02gBO3T54Wz+TQknHqVJd1+QejHA=; b=P0FSQSq7kchNV+I0PzPjhi1uU+yKI2jHRc7nZq4dUurqDih0JiO+VULwAqB36tvXi3 HI5W0fJKYb9sM+6DaxWHoJLok+er+P5mhezRTwzb4Ud9TBgO+EkDnpQJuUjjszUqTS8b NtuP9zH0UjfFBxcfaEBVIDh/4Q3NR4fVHXVY0= 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=FdyHGsvyGAL1yyIgw9MW3YKnii5m/Z6TYyZ3oYjIfB5JG50gqa3LL8y8mp0jkJHljW GJMGi2BIiZ0fGIPR7uDTNjKDLhDQCi3hjVwxxEsNgto91CHdejTlUh0bBWuvz3RMI04A 01VPiK8LPlzWgfcit4HDJM5wQ0dnVkXkgIdn8= MIME-Version: 1.0 Received: by 10.213.5.11 with SMTP id 11mr794702ebt.9.1288741773532; Tue, 02 Nov 2010 16:49:33 -0700 (PDT) Received: by 10.213.26.8 with HTTP; Tue, 2 Nov 2010 16:49:33 -0700 (PDT) In-Reply-To: References: Date: Tue, 2 Nov 2010 18:49:33 -0500 Message-ID: Subject: Re: [FlyRotary] Re: EM2 Numbers From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174be5ec9e5f2a04941a93b7 --0015174be5ec9e5f2a04941a93b7 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable David, Mark S. (Colorado) had problems getting a good steady MAP signal with his slide throttle p-port engine. He ended up using the oil injection ports fo= r MAP. Worked out well for him, so I copied his approach. The slide throttl= e is very close to the housing, so there is just a couple of inches of runner between it and the rotor port. Mark S. (Austin) On Tue, Nov 2, 2010 at 6:39 PM, wrote: > Ed, Mark, manifold absolute pressure should be measured from the intake > manifold as close to throttle plate as possible, this is your controlling > authority for MAP & we all know with the rotary eng. strong pulses are > generated & the t-body is where they are dampened the most, you can check > this with a cheap vac. gauge connected near housing & near t-body & monit= or > the needle at the diff. positions, shaking violently near housing, > shimmering slightly at t-body. David R. Cook RV6A Rotary. > ----- Original Message ----- > From: "Mark Steitle" > To: "Rotary motors in aircraft" > Sent: Tuesday, November 2, 2010 11:03:12 AM > Subject: [FlyRotary] Re: EM2 Numbers > > Ed, > > I measure the manifold pressure at the unused oil injection ports in the > rotor housings. The EM-2 MAP reads in the upper 20's while at WOT, so I > don't think I have a problem with this. The MCT was as received, which w= as > set up for Tracy's injectors. I assume they were 460cc, but that's just = a > guess. I'm running 60# DEKA IV injectors. Could there possibly be an > impedance mismatch between the two types? > > Mark > > On Tue, Nov 2, 2010 at 9:09 AM, Ed Anderson wr= ote: > >> Hi Mark, >> >> Injectors are certainly large enough - six injectors at 60 lb/hr would >> give you a max flow rate capacity of around 58 gallons/hour - far more t= han >> you are reporting fuel burn wise. >> >> I guess what I am wondering is how your manifold pressure is registering >> at WOT. The PP as I recall can have a problem providing reliable/consis= tent >> manifold pressure - no good source? So exactly how is your EC2/3 gettin= g >> its manifold pressure signal ? What comes to mind is that if there is = a >> problem getting a good consistent manifold pressure reading at WOT - cou= ld >> that possibly result in your injectors injecting less than you would exp= ect. >> >> In other words, if manifold pressure was low relative to what you would >> expect at WOT (near ambient) then turning up the manual mixture control >> would only provide adjustment against the smaller target pulse duration = for >> that lower Manifold pressure rather than WOT manifold pressure. >> >> Ed >> >> Edward L. Anderson >> Anderson Electronic Enterprises LLC >> 305 Reefton Road >> Weddington, NC 28104 >> http://www.andersonee.com >> http://www.eicommander.com >> >> >> >> >> >> *From:* stevei@carey.asn.au >> *Sent:* Tuesday, November 02, 2010 8:24 AM >> *To:* Rotary motors in aircraft >> *Subject:* [FlyRotary] Re: EM2 Numbers >> >> Hi Mark >> >> Are you in a position to confirm your fuel rail pressure? >> Fuel injected =3D Pulse width AND injector size AND fuel pressure. >> Cheers >> >> Steve Izett >> >> >> On 02/11/2010, at 4:42 AM, Mark Steitle wrote: >> >> Tracy, >> >> As I recall the low end numbers are around -50ish. So there is still ro= om >> for adjustment. When running WOT, turning the mixture knob full CW does= n't >> get the mixture bar to show up on the EM-2 screen. I find this odd as I= 'm >> running 60# injectors. I guess that's why the low end numbers are in th= e >> -50 range. >> >> I'll post a question on the Lancair list regarding the most efficient >> cruise speed for the Lancair ES airframe. >> >> Mark >> >> >> >> On Mon, Nov 1, 2010 at 3:03 PM, Tracy wrote: >> >>> *"So, if it is going LOP in those addresses, which it is, it would >>> explain why power drops off as I open the throttle to WOT.*" >>> >>> That's new data to me. Yes, that would certainly cause a loss of >>> power. Are you able to compensate by turning up the mixture control?= Are >>> the MAP table values at the low end above minimum value? The right thi= ng to >>> do depends on these answers. If answer is yes to the 2nd one, then yo= u >>> should bump up the value in Mode 3. >>> >>> The most efficient point on most airframes is the point where the induc= ed >>> drag curve crosses the parasitic drag curve. On RV's that happens at a= round >>> an indicated airspeed of 135 mph. It will probably be higher than that= on a >>> Lancair but I've never seen the curves on that airplane. >>> >>> Tracy >>> >>> >>> On Mon, Nov 1, 2010 at 3:34 PM, Mark Steitle wrote= : >>> >>>> *Tracy wrote:* >>>> *Having said that, I think there is still a good possibility that your >>>> drop in power above 6000 is not due to runner length.* >>>> >>>> Tracy, >>>> I suspect it could be tuning as I've hit the max adjustment (+127) on >>>> the EC-2 MCT for the addresses in the upper 20" range, so it looks lik= e I >>>> need to adjust the injector pulse width and then start over on the >>>> tuning. So, if it is going LOP in those addresses, which it is, it wo= uld >>>> explain why power drops off as I open the throttle to WOT. I'll do mo= re >>>> tuning when I get my updated EC-2 back. (will go out in today's mail) >>>> >>>> Where does one find the "most efficient operationg point" for a >>>> particular airframe? Is this the same as LDmax? >>>> >>>> Mark >>>> >>>> On Mon, Nov 1, 2010 at 1:28 PM, Tracy wrote= : >>>> >>>>> *"The lowest fuel burn per HP generated always occurs at the torque >>>>> peak as that is where the engine takes in the most amount of air for = each >>>>> revolution of the engine. The VE is optimum. In other words it is t= he most >>>>> efficient operating point for the engine." >>>>> * >>>>> Mark, >>>>> That is the point of minimum pumping losses in the engine, NOT the >>>>> most overall efficient point of operation. It ignores the many oth= er >>>>> factors that affect BSFC. If you look at Mazda's data on BSFC, the = best >>>>> point is usually around 5000 rpm. >>>>> >>>>> It also ignores the most efficient operating point of your airframe. >>>>> If you tune the engine for a higher rpm torque peak you WILL make mor= e HP, >>>>> you will fly faster but you will burn a lot more fuel. >>>>> >>>>> Having said that, I think there is still a good possibility that your >>>>> drop in power above 6000 is not due to runner length. >>>>> >>>>> Tracy >>>>> >>>>> >>>>> >>>>> On Mon, Nov 1, 2010 at 11:54 AM, Mark Steitle wro= te: >>>>> >>>>>> Al, >>>>>> >>>>>> Isn't the formula HP=3D (torque x rpm)/5252. >>>>>> >>>>>> I'm more focused on peak Volumetric Efficiency (VE). According to = *Fundamentals >>>>>> of Intake System Design*, (ACRE) "The lowest fuel burn per HP >>>>>> generated always occurs at the torque peak as that is where the engi= ne takes >>>>>> in the most amount of air for each revolution of the engine. The VE= is >>>>>> optimum. In other words it is the most efficient operating point fo= r the >>>>>> engine." >>>>>> >>>>>> So, I will be good tuning for peak torque. Do you have a dyno char= t >>>>>> on your 20B that you will share? I find it interesting that your in= take >>>>>> runners are only 13". >>>>>> >>>>>> Mark >>>>>> >>>>>> On Mon, Nov 1, 2010 at 11:10 AM, Al Gietzen wr= ote: >>>>>> >>>>>>> Keep in mind that the graph is peak torque (T)); not peak HP. The >>>>>>> peak HP (which is what you=92re after would be at higher rpm. HP = =3D T x >>>>>>> RPM >>>>>>> >>>>>>> >>>>>>> >>>>>>> Al >>>>>>> >>>>>>> >>>>>>> >>>>>>> -----Original Message----- >>>>>>> *From:* Rotary motors in aircraft [mailto: >>>>>>> flyrotary@lancaironline.net] *On Behalf Of *stevei@carey.asn.au >>>>>>> *Sent:* Monday, November 01, 2010 1:09 AM >>>>>>> *To:* Rotary motors in aircraft >>>>>>> *Subject:* [FlyRotary] Re: EM2 Numbers >>>>>>> >>>>>>> >>>>>>> >>>>>>> Hi Mark >>>>>>> >>>>>>> >>>>>>> >>>>>>> I have attached the Leman intake dimensions from Paul L. >>>>>>> >>>>>>> Hope this is helpful. Can't remember whether this measurement was t= o >>>>>>> the rotor face or manifold face. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Steve Izett >>>>>>> >>>>>>> Perth Western Australia >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 01/11/2010, at 8:40 AM, Mark Steitle wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> Bill, >>>>>>> >>>>>>> >>>>>>> >>>>>>> I understand the sausage illustration. But if what you propose wer= e >>>>>>> true, then why did Mazda make such a major effort to design and >>>>>>> implement the variable intake on their LeMans 26B p-port motor? Th= at tells >>>>>>> me that runner length does make a significant difference on the p-p= ort >>>>>>> motor. Also, if tuned runners didn't matter for peripheral ports, = then why >>>>>>> do they tune the exhaust runners on the 13B's? Somewhere I have a = chart >>>>>>> showing the effect of runner length, but I'm not sure that the data= is from >>>>>>> a p-port motor. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Mark >>>>>>> >>>>>>> On Sun, Oct 31, 2010 at 7:27 PM, Bill Bradburry < >>>>>>> bbradburry@bellsouth.net> wrote: >>>>>>> >>>>>>> Mark, >>>>>>> >>>>>>> I don=92t think that will work with the PP. You never actually blo= ck >>>>>>> the inlet. You just cut off the end of the flow of air as the apex= flies by >>>>>>> and it starts to fill the next chamber. Think of the flow as a lon= g sausage >>>>>>> that is going through a propeller made of a strand of wire 2 or 3 M= M thick >>>>>>> and being cut into sections. It is never blocked. I doubt that th= ere are >>>>>>> any reflections and if there are, they would be very small and of l= ittle >>>>>>> benefit to enhance. >>>>>>> >>>>>>> >>>>>>> >>>>>>> I think that is why the PP is so much stronger than the side port. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Bill B >>>>>>> >>>>>>> >>>>>>> ------------------------------ >>>>>>> >>>>>>> *From:* Rotary motors in aircraft [mailto: >>>>>>> flyrotary@lancaironline.net] *On Behalf Of *Mark Steitle >>>>>>> *Sent:* Sunday, October 31, 2010 8:01 PM >>>>>>> >>>>>>> >>>>>>> *To:* Rotary motors in aircraft >>>>>>> *Subject:* [FlyRotary] Re: EM2 Numbers >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> George, >>>>>>> >>>>>>> >>>>>>> >>>>>>> Sorry for the delayed reply, but I had to go to the hangar and >>>>>>> measure the runner length to be sure. It is 24" bellmouth to rotor= face, 2" >>>>>>> OD. Exhaust is 2" OD also, running the stock 20b exhaust splitters= . >>>>>>> >>>>>>> >>>>>>> >>>>>>> So, my power seems to peak around 6000 rpm. What length intake >>>>>>> runner length would it take to bring peak power up to around 6500 r= pm? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Mark >>>>>>> >>>>>>> On Sat, Oct 30, 2010 at 3:53 PM, George Lendich < >>>>>>> lendich@aanet.com.au> wrote: >>>>>>> >>>>>>> Mark, >>>>>>> >>>>>>> That's interesting; can you tell me what is your PP size, runne= r >>>>>>> length and exhaust header ID size. >>>>>>> >>>>>>> George (down under) >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From:* Mark Steitle >>>>>>> >>>>>>> *Sent:* Saturday, October 30, 2010 7:38 PM >>>>>>> >>>>>>> *To:* Rotary motors in aircraft >>>>>>> >>>>>>> *Subject:* [FlyRotary] Re: EM2 Numbers >>>>>>> >>>>>>> >>>>>>> >>>>>>> Bill, >>>>>>> >>>>>>> >>>>>>> >>>>>>> With the current setup, it appears to be around 6000-6100, but I'm >>>>>>> still tuning on the upper addresses of the EC-2. My old engine did= best >>>>>>> around 6500-6600 running the same prop. So, I feel there is someth= ing that >>>>>>> isn't quite right on the new P-Port motor... maybe intake runners t= oo short, >>>>>>> intake or exhaust too restrictive, timing off a bit, etc. It defin= itely >>>>>>> makes more hp than the old motor did in the 5000-6000 range, but I = feel that >>>>>>> it should be producing more hp than I'm seeing in the 6000-7000 ran= ge. >>>>>>> >>>>>>> >>>>>>> >>>>>>> So, things are still developing. Yesterday, I reinstalled the old >>>>>>> air-filter box which has a ram-air feature incorporated into the de= sign. I >>>>>>> haven't flown it yet to see if there is any improvement, but I hope= to see >>>>>>> at least a little improvement. >>>>>>> >>>>>>> >>>>>>> >>>>>>> On a side note, I have determined that there is a 250 rpm discrepan= cy >>>>>>> between the rpm readout of the EM-2 and that of the M/T prop contro= ller. I >>>>>>> have an optical tach that I will be using to determine which one is= in >>>>>>> error. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Stay tuned (no pun intended), >>>>>>> >>>>>>> Mark >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Fri, Oct 29, 2010 at 8:30 PM, Bill Bradburry < >>>>>>> bbradburry@bellsouth.net> wrote: >>>>>>> >>>>>>> Mark, >>>>>>> >>>>>>> It would seem that if you flattened the pitch of the prop, the engi= ne >>>>>>> rpms would increase, but at some point, you would begin to lose air= speed and >>>>>>> start to slow down because the prop was just not taking a big enoug= h bite. >>>>>>> Conversely, it seems that if you increased the prop pitch, the engi= ne rpms >>>>>>> would decrease, but the airspeed would increase up to some point an= d then >>>>>>> after that, an increase in pitch would cause a decrease in airspeed= because >>>>>>> you are taking too big a bite and the engine just can not pull it. >>>>>>> Somewhere in there is a =93Sweet Spot=94 of propeller rpm that give= s the highest >>>>>>> airspeed. Lets say that this question assumes that you are at WOT = and 8500 >>>>>>> feet, which should give you roughly a 75% power output. Do you kno= w where >>>>>>> that sweet spot is with your propeller? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Bill B >>>>>>> >>>>>>> >>>>>>> ------------------------------ >>>>>>> >>>>>>> *From:* Rotary motors in aircraft [mailto: >>>>>>> flyrotary@lancaironline.net] *On Behalf Of *Mark Steitle >>>>>>> >>>>>>> >>>>>>> *Sent:* Thursday, October 28, 2010 10:00 PM >>>>>>> *To:* Rotary motors in aircraft >>>>>>> *Subject:* [FlyRotary] EM2 Numbers >>>>>>> >>>>>>> >>>>>>> >>>>>>> Rotarians, >>>>>>> >>>>>>> >>>>>>> >>>>>>> Things have been a bit quiet on the list lately, so I thought I wou= ld >>>>>>> post this picture of my EM-2 taken on a trip from Galveston, TX (KG= LS) to >>>>>>> Lockhart, TX (50R) yesterday. I was level at 8500msl when taking t= he >>>>>>> picture. A/C is a Lancair ES (4-place), engine is a n/a p-ported 2= 0b. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Please disregard the oil temp as the reading on the EM-2 is measure= d >>>>>>> after the first cooler and before the second cooler. Oil temp read= ings out >>>>>>> of the second cooler (measured at the oil filter pad) track water t= emps >>>>>>> within a few degrees. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Leaned to "Economy Cruise" and dial the prop down to 1800 rpm and t= he >>>>>>> speed drops down about 15 mph and fuel burn drops to 9.1 gph. You = pay >>>>>>> dearly for that 15 mph but sometimes it is just too much fun to slo= w down. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Mark S. >>>>>>> >>>>>>> ---------- Forwarded message ---------- >>>>>>> >>>>>>> >>>>>>> From: *Mark* >>>>>>> Date: Thu, Oct 28, 2010 at 8:50 PM >>>>>>> Subject: >>>>>>> To: msteitle@gmail.com >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Sent from my iPhone >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> ------------------------------ >>>>>>> >>>>>>> The contents of this email are confidential and intended only for t= he >>>>>>> named recipients of this e-mail. If you have received this e-mail i= n error, >>>>>>> you are hereby notified that any use, reproduction, disclosure or >>>>>>> distribution or the information contained in this e-mail is prohibi= ted. >>>>>>> Please notify the sender immediately and then delete/destroy the e-= mail and >>>>>>> any printed copies. All liability for viruses is excluded to the fu= llest >>>>>>> extent of the law. >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >> >> > --0015174be5ec9e5f2a04941a93b7 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable David,=A0

Mark S. (Colorado) had problems getting a good= steady MAP signal with his slide throttle p-port engine. =A0He ended up us= ing the oil injection ports for MAP. =A0Worked out well for him, so I copie= d his approach. =A0The slide throttle is very close to the housing, so ther= e is just a couple of inches of runner between it and the rotor port. =A0 = =A0

Mark S. (Austin)

On Tue, Nov 2, 2010 at 6:39 PM, <hoursaway1@comcast.net> wrote:
Ed, Mark= , manifold absolute pressure should be measured from the intake manifold as= close to throttle plate as possible, this is your controlling authority fo= r MAP & we all know with the rotary eng. strong pulses are generated &a= mp; the t-body is where they are dampened the most, you can check this with= a cheap vac. gauge connected near housing & near t-body & monitor = the needle at the diff. positions, shaking violently near housing, shimmeri= ng slightly at t-body.=A0=A0 David R. Cook=A0 RV6A Rotary.
----- Original Message -----
From: "Mark Steitle" <msteitle@gmail.com>=
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>=
Sent: Tuesday, November 2, 2010 11:03:12 AM
Subject: [FlyRotary] Re: EM2= Numbers

Ed,=A0=20

I measure the manifold pressure at the unused oil injection ports in t= he rotor housings. =A0The EM-2 MAP reads in the upper 20's while at WOT= , so I don't think I have a problem with this. =A0The MCT was as receiv= ed, which was set up for Tracy's injectors. =A0I assume they were 460cc= , but that's just a guess. =A0I'm running 60# DEKA IV injectors. = =A0Could there possibly be an impedance mismatch between the two types? =A0=

Mark

On Tue, Nov 2, 2010 at 9:09 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
Hi Mark,
=A0
Injectors are certainly large enough - six=A0 inj= ectors at 60 lb/hr would give you a max flow rate capacity of around 58 gal= lons/hour - far more than you are reporting fuel burn wise.
=A0
I guess what I am wondering is how your manifold = pressure is registering at WOT.=A0 The PP as I recall can have a problem pr= oviding reliable/consistent manifold pressure - no good source?=A0 So exact= ly how is your EC2/3 getting its manifold pressure signal ?=A0=A0 What come= s to mind is that if there is a problem getting a good consistent manifold = pressure reading at WOT - could that possibly result in your injectors inje= cting less than you would expect.
=A0
In other words, if manifold pressure was low rela= tive to what you would expect at WOT (near ambient) then turning up the man= ual mixture control would only provide adjustment against the smaller targe= t pulse duration for that lower Manifold pressure rather than WOT manifold = pressure.
=A0
Ed
=A0
Edward L. Anderson
Anderson Electronic Enterpr= ises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommande= r.com
=A0
=A0
=A0
=A0

Sent: Tuesday, November 02, 2010 8:24 AM
Subject: [FlyRotary] Re: EM2 Numbers

Hi Mark=20

Are you in a position to confirm your fuel rail pressure?
Fuel injected =3D Pulse width AND injector size AND fuel pressure.
Cheers

Steve Izett


On 02/11/2010, at 4:42 AM, Mark Steitle wrote:

Tracy,
=A0
As I recall the low end numbers are around -50ish.=A0 So there is stil= l=A0room for adjustment.=A0 When running WOT, turning the mixture knob full= CW doesn't get the mixture bar to show up on the EM-2 screen.=A0 I fin= d this odd as I'm running 60# injectors.=A0 I guess that's why the = low end numbers are in the -50 range.=A0
=A0
I'll post a question on the Lancair list=A0regarding the most effi= cient cruise speed for the=A0Lancair ES airframe.
=A0
Mark


=A0
On Mon, Nov 1, 2010 at 3:03 PM, Tracy <= tracy@rotaryaviation.com> wrote:
"So, if it is going LOP in th= ose addresses, which it is,=A0it would explain why power drops off as I ope= n the throttle to WOT."

That's new data to me.=A0 Yes, that would certainly cause a loss of= power.=A0=A0=A0 Are you able to compensate by turning up the mixture contr= ol?=A0 Are the MAP table values at the low end above minimum value?=A0 The = right thing to do depends on these answers.=A0=A0 If answer is yes to the 2= nd one, then you should bump up the value in Mode 3.

The most efficient point on most airframes is the point where the induc= ed drag curve crosses the parasitic drag curve.=A0 On RV's that happens= at around an indicated airspeed of 135 mph.=A0 It will probably be higher = than that on a Lancair but I've never seen the curves on that airplane.=

Tracy


On Mon, Nov 1, 2010 at 3:34 PM, Mark Steitle <= msteitle@gmail.com> wrote:
Tracy wrote:
Having said that, I think there is still a good possibility that yo= ur drop in power above 6000 is not due to runner length.=A0
=A0
Tracy,
I suspect it could be tuning as I've hit the max adjustment=A0(+12= 7) on the EC-2 MCT for the addresses in the upper 20" range, so it loo= ks like I need to adjust the injector pulse width and then start over on th= e tuning.=A0=A0So, if it is going LOP in those addresses, which it is,=A0it= would explain why power drops off as I open the throttle to WOT.=A0 I'= ll do more tuning when I get my updated EC-2 back.=A0 (will go out in today= 's mail)=A0
=A0
Where does one find the "most efficient operationg point" fo= r a particular airframe?=A0 Is this the same as=A0LDmax?
=A0
Mark

On Mon, Nov 1, 2010 at 1:28 PM, Tracy <= tracy@rotaryaviation.com> wrote:
"The lowest fuel burn per HP generated always occurs at the to= rque peak as that is where the engine takes in the most amount of air for e= ach revolution of the engine.=A0 The VE is optimum.=A0 In other words it is= the most efficient operating point for the engine."=A0

Mark,
=A0That is the point of minimum pumping losses in th= e engine, NOT the most overall efficient point of operation.=A0=A0=A0 It ig= nores the many other factors that affect BSFC.=A0=A0 If you look at Mazda&#= 39;s data on BSFC, the best point is usually around 5000 rpm.=A0

It also ignores the most efficient operating point of your airframe.=A0= If you tune the engine for a higher rpm torque peak you WILL make more HP,= =A0 you will fly faster but you will burn a lot more fuel.

Having sa= id that, I think there is still a good possibility that your drop in power = above 6000 is not due to runner length.

Tracy



On Mon, Nov 1, 2010 at 11:54 AM, Mark Steitle <msteitle@gmail.com> wrote:
Al,
=A0
Isn't the formula HP=3D (torque x rpm)/5252.=A0
=A0
I'm more focused on peak Volumetric Efficiency (VE).=A0 According = to Fundamentals of Intake System Design, (ACRE)=A0"The lowest f= uel burn per HP generated always occurs at the torque peak as that is where= the engine takes in the most amount of air for each revolution of the engi= ne.=A0 The VE is optimum.=A0 In other words it is the most efficient operat= ing point for the engine."=A0
=A0
So, I will be good=A0tuning for=A0peak torque.=A0 Do you have a dyno c= hart on your 20B that you will share?=A0 I find it interesting that your in= take runners are only 13".=A0
=A0
Mark

On Mon, Nov 1, 2010 at 11:10 AM, Al Gietzen <A= LVentures@cox.net> wrote:

Keep in mind tha= t the graph is peak torque (T)); not peak HP. =A0The peak HP (which is what= you=92re after would be at higher rpm.=A0 HP =3D T x RPM


=A0

Al=


=A0

-----Original Me= ssage-----
From: Rotary m= otors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of stevei@carey.asn.au
Sent: Monday, November 01, 2= 010 1:09 AM
To: Rotary mo= tors in aircraft
Subject:= [FlyRotary] Re: EM2 Numbers

=
=A0

Hi Mark

=
=A0

I have attached the Leman = intake dimensions from Paul L.

Hope this is helpful. Can&= #39;t remember whether this measurement was to the rotor face or manifold f= ace.

=
=A0

Steve Izett<= /p>

Perth Western Australia=A0=

<image001.gif>=

On 01/11/2010, at 8:40 AM,= Mark Steitle wrote:



Bill,

=
=A0

I understand the sausage i= llustration.=A0 But if=A0what you propose=A0were true, then why did Mazda= =A0make such a major effort to design and implement=A0the variable intake o= n their LeMans 26B p-port motor?=A0 That tells me that=A0runner length=A0do= es make a significant difference on the p-port motor.=A0 Also, if tuned run= ners didn't matter for peripheral ports, then why do they tune the exha= ust runners on the 13B's?=A0 Somewhere I have a chart showing the effec= t of runner length, but I'm not sure that=A0the data=A0is from a=A0p-po= rt motor.

=
=A0

Mark

On Sun, Oct 31, 2010 at 7:= 27 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

I don=92t think that will work with the PP.=A0 You never actually b= lock the inlet.=A0 You just cut off the end of the flow of air as the apex = flies by and it starts to fill the next chamber.=A0 Think of the flow as a = long sausage that is going through a propeller made of a strand of wire 2 o= r 3 MM thick and being cut into sections.=A0 It is never blocked. =A0I doub= t that there are any reflections and if there are, they would be very small= and of little benefit to enhance.


=A0

I think that is why the PP is so much stronger than the side port.<= /span>


=A0

Bill B


=A0

From: Rotary motors in aircraft [mailto:flyrotary@lanca= ironline.net] On Behalf Of <= /b>Mark Steitle
Sent: Sunday, October 31, 20= 10 8:01 PM


To: Rotary motors in aircraft
Subject: [FlyRotary] Re: EM2 Number= s

=
=A0
=
=A0
=
=A0

George,

=
=
=A0

Sorry for the delayed repl= y, but I had to go to the hangar and measure the runner length to be sure.= =A0 It is 24" bellmouth to rotor face, 2" OD.=A0 Exhaust is 2&quo= t; OD also, running the stock 20b exhaust splitters.

=
=A0

So, my power seems to peak= around 6000 rpm.=A0 What length intake runner length would it take to brin= g=A0peak power=A0up to around 6500 rpm?=A0

=
=A0

Mark=A0=

On Sat, Oct 30, 2010 at 3:= 53 PM, George Lendich <lendich@aanet.com.au> wrote:

=A0=A0 Mark, <= /span>

=A0=A0=A0 That= 's interesting; can you tell me what is your PP size, runner length and= exhaust header ID=A0size.

=A0=A0=A0=A0Ge= orge (down under)=A0


=A0
<= /div>

From: Mark Steitle

Sent: Saturday, October= 30, 2010 7:38 PM

Subject: [FlyRotary] = Re: EM2 Numbers

=
=A0

Bill,=A0

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=A0

With the current setup, it= appears to be around 6000-6100, but I'm still tuning on the upper addr= esses of the EC-2. =A0My old engine did best around 6500-6600 running the s= ame prop. =A0So, I feel there is something that isn't quite right on th= e new P-Port motor... maybe intake runners too short, intake or exhaust too= restrictive, timing off a bit, etc. =A0It definitely makes more hp than th= e old motor did in the 5000-6000 range, but I feel that it should be produc= ing more hp than I'm seeing in the 6000-7000 range. =A0

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So, things are still devel= oping. =A0Yesterday, I reinstalled the old air-filter box which has a ram-a= ir feature incorporated into the design. =A0I haven't flown it yet to s= ee if there is any improvement, but I hope to see at least a little improve= ment.

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On a side note, I have det= ermined that there is a 250 rpm discrepancy between the rpm readout of the = EM-2 and that of the M/T prop controller. =A0I have an optical tach that I = will be using to determine which one is in error. =A0=A0

=
=A0

Stay tuned (no pun intende= d),

Mark

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On Fri, Oct 29, 2010 at 8:= 30 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

It would seem that if you flattened the pitch of the prop, the engi= ne rpms would increase, but at some point, you would begin to lose airspeed= and start to slow down because the prop was just not taking a big enough b= ite.=A0 Conversely, it seems that if you increased the prop pitch, the engi= ne rpms would decrease, but the airspeed would increase up to some point an= d then after that, an increase in pitch would cause a decrease in airspeed = because you are taking too big a bite and the engine just can not pull it.= =A0 Somewhere in there is a =93Sweet Spot=94 of propeller rpm that gives th= e highest airspeed.=A0 Lets say that this question assumes that you are at = WOT and 8500 feet, which should give you roughly a 75% power output.=A0 Do = you know where that sweet spot is with your propeller?

=
=A0

Bill B

=
=A0

From: Rotary motors in aircraft [mailto:flyrotary@lanca= ironline.net] On Behalf Of <= /b>Mark Steitle


Sent: Thursday, October 28, 2010 10:00 P= M
To: Rotary motors in ai= rcraft
Subject: [FlyRotary] EM2 Num= bers

=
=A0

Rotarians,

=
=A0

Things have been a bit qui= et on the list lately, so I thought I would post this picture of my EM-2 ta= ken on a trip from Galveston, TX (KGLS) to Lockhart, TX (50R) yesterday. = =A0I was level at 8500msl when taking the picture. =A0A/C is a Lancair ES (= 4-place), engine is a n/a p-ported 20b. =A0

=
=A0

Please disregard the oil t= emp as the reading on the EM-2 is measured after the first cooler and befor= e the second cooler. =A0Oil temp readings out of the second cooler (measure= d at the oil filter pad) track water temps within a few degrees.

=
=A0

Leaned to "Economy Cr= uise" and dial the prop down to 1800 rpm and the speed drops down abou= t 15 mph and fuel burn drops to 9.1 gph. =A0You pay dearly for that 15 mph = but sometimes it is just too much fun to slow down.

=
=A0

Mark S.=

---------- Forwarded messa= ge ----------


From: Mark <msteitle@gmail.com>
Date: Thu, Oct 28, 2010 at 8:50 PM
Subject:
To: msteitle@gmail.com



<= br>



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