X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from exchange.carey.wa.edu.au ([118.82.44.212] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTPS id 4551829 for flyrotary@lancaironline.net; Tue, 02 Nov 2010 08:25:06 -0400 Received-SPF: none receiver=logan.com; client-ip=118.82.44.212; envelope-from=stevei@carey.asn.au Received: from exchange.carey.local ([10.10.0.5]) by exchange.carey.local ([10.10.0.5]) with mapi; Tue, 2 Nov 2010 20:24:18 +0800 From: To: Date: Tue, 2 Nov 2010 20:24:25 +0800 Subject: Re: [FlyRotary] Re: EM2 Numbers Thread-Topic: [FlyRotary] Re: EM2 Numbers Thread-Index: Act6iN6qX43DC51TTemdNi2ERAwbOQ== Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_ABB71DA297724561B8DB245BC031BEF6careyasnau_" MIME-Version: 1.0 --_000_ABB71DA297724561B8DB245BC031BEF6careyasnau_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable 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 room = for adjustment. When running WOT, turning the mixture knob full CW doesn'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 the = -50 range. I'll post a question on the Lancair list regarding the most efficient cruis= e 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 w= hy 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 thing to do de= pends on these answers. If answer is yes to the 2nd one, then you should = bump up the value in Mode 3. The most efficient point on most airframes is the point where the induced d= rag curve crosses the parasitic drag curve. On RV's that happens at around= 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 E= C-2 MCT for the addresses in the upper 20" range, so it looks like I need t= o adjust the injector pulse width and then start over on the tuning. So, i= f it is going LOP in those addresses, which it is, it would explain why pow= er drops off as I open the throttle to WOT. I'll do more 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 revolutio= n of the engine. The VE is optimum. In other words it is the most efficie= nt operating point for the engine." Mark, That is the point of minimum pumping losses in the engine, NOT the most ov= erall efficient point of operation. It ignores the many other factors th= at affect BSFC. If you look at Mazda's data on BSFC, the best point is us= ually around 5000 rpm. It also ignores the most efficient operating point of your airframe. If yo= u tune the engine for a higher rpm torque peak you WILL make more 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 > wrote: Al, Isn't the formula HP=3D (torque x rpm)/5252. I'm more focused on peak Volumetric Efficiency (VE). According to Fundamen= tals of Intake System Design, (ACRE) "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 the most efficient operating point for the engine." So, I will be good tuning for peak torque. Do you have a dyno chart on you= r 20B that you will share? I find it interesting that your intake runners = are only 13". Mark On Mon, Nov 1, 2010 at 11:10 AM, Al Gietzen > wrote: 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 to the ro= tor 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 were true, = then why did Mazda make such a major effort to design and implement the var= iable intake on their LeMans 26B p-port motor? That tells me that runner l= ength does make a significant difference on the p-port motor. Also, if tun= ed runners didn't matter for peripheral ports, then why do they tune the ex= haust 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 > wrote: Mark, I don=92t think that will work with the PP. You never actually block the i= nlet. 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 long sausage t= hat is going through a propeller made of a strand of wire 2 or 3 MM thick a= nd being cut into sections. It is never blocked. I doubt that there are a= ny reflections and if there are, they would be very small and of little ben= efit 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. Exhau= st is 2" OD also, running the stock 20b exhaust splitters. So, my power seems to peak around 6000 rpm. What length intake runner leng= th would it take to bring peak power up to around 6500 rpm? Mark On Sat, Oct 30, 2010 at 3:53 PM, George Lendich > wrote: Mark, That's interesting; can you tell me what is your PP size, runner 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 tu= ning on the upper addresses of the EC-2. My old engine did best around 650= 0-6600 running the same prop. So, I feel there is something that isn't qui= te right on the new P-Port motor... maybe intake runners too short, intake = or exhaust too restrictive, timing off a bit, etc. It definitely makes mor= e hp than the old motor did in the 5000-6000 range, but I feel that it shou= ld be producing more hp than I'm seeing in the 6000-7000 range. So, things are still developing. Yesterday, I reinstalled the old air-filt= er box which has a ram-air feature incorporated into the design. I haven't= flown it yet to see if there is any improvement, but I hope to see at leas= t a little improvement. On a side note, I have determined that there is a 250 rpm discrepancy betwe= en the rpm readout of the EM-2 and that of the M/T prop controller. 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 > wrote: Mark, It would seem that if you flattened the pitch of the prop, the engine rpms = would increase, but at some point, you would begin to lose airspeed and sta= rt to slow down because the prop was just not taking a big enough bite. Co= nversely, it seems that if you increased the prop pitch, the engine rpms wo= uld decrease, but the airspeed would increase up to some point and then aft= er that, an increase in pitch would cause a decrease in airspeed because yo= u 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 gives the highest air= speed. Lets say that this question assumes that you are at WOT and 8500 fe= et, which should give you roughly a 75% power output. Do you know where th= at 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 would post = this picture of my EM-2 taken on a trip from Galveston, TX (KGLS) to Lockha= rt, TX (50R) yesterday. I was level at 8500msl when taking the picture. A= /C is a Lancair ES (4-place), engine is a n/a p-ported 20b. Please disregard the oil temp as the reading on the EM-2 is measured after = the first cooler and before the second cooler. Oil temp readings out of th= e second cooler (measured at the oil filter pad) track water temps within a= few degrees. Leaned to "Economy Cruise" and dial the prop down to 1800 rpm and the speed= drops down about 15 mph and fuel burn drops to 9.1 gph. You pay dearly fo= r that 15 mph but sometimes it is just too much fun to slow 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 the named= recipients of this e-mail. If you have received this e-mail in error, you = are hereby notified that any use, reproduction, disclosure or distribution = or the information contained in this e-mail is prohibited. Please notify th= e sender immediately and then delete/destroy the e-mail and any printed cop= ies. All liability for viruses is excluded to the fullest extent of the law= . --_000_ABB71DA297724561B8DB245BC031BEF6careyasnau_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Hi Mark

Are you in a position to confirm your fuel rail pressure?
Fuel i= njected =3D Pulse width AND injector size AND fuel pressure.
Chee= rs

Steve Izett


<= div>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 s= till room for adjustment.  When running WOT, turning the mixture = knob full CW doesn't get the mixture bar to show up on the EM-2 screen.&nbs= p; I find this odd as I'm running 60# injectors.  I guess that's why t= he low end numbers are in the -50 range. 
 
I'll post a question on the Lancair list regarding the most effic= ient cruise speed for the Lancair ES airframe.
 
Mark


 
On Mon, Nov 1, 2010 at 3:03 PM, Tracy <tracy@rotaryaviati= on.com> wrote:
"So, if it is going LOP in th= ose 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 mixtu= re control?  Are the MAP table values at the low end above minimum val= ue?  The right thing to do depends on these answers.   If an= swer is yes to the 2nd 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.  On RV's that happens = at around an indicated airspeed of 135 mph.  It will probably be highe= r than that on a Lancair but I've never seen the curves on that airplane. <= br>
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. 
 
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 tuni= ng.  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.  = I'll do more 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 partic= ular airframe?  Is this the same as LDmax?
 
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 torque = peak as that is where the engine takes in the most amount of air for each r= evolution of the engine.  The VE is optimum.  In other words it i= s the 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 other factors that affect BSFC.   If y= ou 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.&nb= sp; If you tune the engine for a higher rpm torque peak you WILL make more = HP,  you will fly faster but you will burn a lot more fuel.

Hav= ing 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 <msteitle@gmail.com> wrote:
Al,
 
Isn't the formula HP=3D (torque x rpm)/5252. 
 
I'm more focused on peak Volumetric Efficiency (VE).  According t= o Fundamentals of Intake System Design, (ACRE) "The lowest fuel= burn per HP generated always occurs at the torque peak as that is where th= e engine 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 ope= rating point for the engine." 
 
So, I will be good tuning for peak torque.  Do you have= a dyno chart on your 20B that you will share?  I find it interesting = that your intake runners are only 13". 
 
Mark

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

Keep i= n 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

 

-----Orig= inal 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:<= /b> [FlyRotary] Re: EM2 Numbers

 
<= p class=3D"MsoNormal" style=3D"MARGIN-LEFT: 0.5in">Hi Mark
 

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

Hope this is helpfu= l. Can't remember whether this measurement was to the rotor face or manifol= d face.

 

Steve Izett<= /font>

Perth Western Austr= alia 

<image001.= gif>

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



Bill,

 

I understand the sa= usage illustration.  But if what you propose were true, then= why did Mazda make such a major effort to design and implement t= he variable intake on their LeMans 26B p-port motor?  That tells me th= at runner length does make a significant difference on the p-port= motor.  Also, if tuned runners didn't matter for peripheral ports, th= en why do they tune the exhaust runners on the 13B's?  Somewhere I hav= e a chart showing the effect of runner length, but I'm not sure that t= he data is from a p-port motor.

 

Mark

On Sun, Oct 31, 201= 0 at 7:27 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

I don=92t think tha= t will work with the PP.  You never actually block the inlet.  Yo= u just cut off the end of the flow of air as the apex flies by and it start= s to fill the next chamber.  Think of the flow as a long sausage that = is going through a propeller made of a strand of wire 2 or 3 MM thick and b= eing cut into sections.  It is never blocked.  I doubt that there= are any reflections and if there are, they would be very small and of litt= le benefit to enhance.

 
<= p class=3D"MsoNormal" style=3D"MARGIN-LEFT: 0.5in">I think that is why the PP is so much stronger than the side p= ort.

 
<= p class=3D"MsoNormal" style=3D"MARGIN-LEFT: 0.5in">Bill B

 

= From: Rotary mot= ors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Sunday, October 31, 2= 010 8:01 PM


= To: Rotary motors in aircraft<= br>Subject: [FlyRotary] Re:= EM2 Numbers

 
 
 

George,

 

Sorry for the delay= ed 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 ta= ke to bring peak power up to around 6500 rpm? 

 

On Sat, Oct 30, 201= 0 at 3:53 PM, George Lendich <lendich@aanet.com.au> wrote:

 = ;  Mark,

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

 = ;   George (down under) 

<= span style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> 

From: <= a title=3D"mailto:msteitle@gmail.com CTRL + Click to follow link" href=3D"mailto:msteitle@gmail.com" target=3D"_= blank">Mark Steitle

Sent: S= aturday, October 30, 2010 7:38 PM

Subject: [FlyRotary] Re: EM2 Numbers

 

Bill, 

 

With the current se= tup, it appears to be around 6000-6100, but I'm still tuning on the upper a= ddresses of the EC-2.  My old engine did best around 6500-6600 running= the same prop.  So, I feel there is something that isn't quite right = on the new P-Port motor... maybe intake runners too short, intake or exhaus= t too restrictive, timing off a bit, etc.  It definitely makes more hp= than the old motor did in the 5000-6000 range, but I feel that it should b= e producing more hp than I'm seeing in the 6000-7000 range.  

 

So, things are stil= l developing.  Yesterday, I reinstalled the old air-filter box which h= as a ram-air feature incorporated into the design.  I haven't flown it= yet to see if there is any improvement, but I hope to see at least a littl= e improvement.

 

On a side note, I h= ave determined that there is a 250 rpm discrepancy between the rpm readout = of the EM-2 and that of the M/T prop controller.  I have an optical ta= ch that I will be using to determine which one is in error.   

 

Stay tuned (no pun = intended),

Mark<= /p>

 
 = ;

On Fri, Oct 29, 201= 0 at 8:30 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

It would seem that = if you flattened the pitch of the prop, the engine rpms would increase, but= at some point, you would begin to lose airspeed and start to slow down bec= ause the prop was just not taking a big enough bite.  Conversely, it s= eems that if you increased the prop pitch, the engine rpms would decrease, = but the airspeed would increase up to some point and then after that, an in= crease in pitch would cause a decrease in airspeed because you are taking t= oo big a bite and the engine just can not pull it.  Somewhere in there= is a =93Sweet Spot=94 of propeller rpm that gives the highest airspeed.&nb= sp; 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 know where t= hat sweet spot is with your propeller?

 

Bill B

 

= From: Rotary mot= ors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle


= Sent: Thursday, October 28, 20= 10 10:00 PM
To: Rotary motors in aircra= ft
Subject: [FlyRotary] = EM2 Numbers

 

Rotarians,

 

Things have been a = bit quiet on the list lately, so I thought I would post this picture of my = EM-2 taken on a trip from Galveston, TX (KGLS) to Lockhart, TX (50R) yester= day.  I was level at 8500msl when taking the picture.  A/C is a L= ancair ES (4-place), engine is a n/a p-ported 20b.  

 

Please disregard th= e oil temp as the reading on the EM-2 is measured after the first cooler an= d before the second cooler.  Oil temp readings out of the second coole= r (measured at the oil filter pad) track water temps within a few degrees.<= /span>

 

Leaned to "Economy = Cruise" and dial the prop down to 1800 rpm and the speed drops down about 1= 5 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 slow down.

 

---------- Forwarde= d message ----------


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



<= br>



Sent from my iPhone

 
 
 
 
 
 

The contents of this email are confident= ial and intended only for the named recipients of this e-mail. If you have = received this e-mail in error, you are hereby notified that any use, reprod= uction, disclosure or distribution or the information contained in this e-m= ail is prohibited. Please notify the sender immediately and then delete/des= troy the e-mail and any printed copies. All liability for viruses is exclud= ed to the fullest extent of the law.







= --_000_ABB71DA297724561B8DB245BC031BEF6careyasnau_--