X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omta2.toronto.rmgopenwave.com ([4.59.182.100] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4552218 for flyrotary@lancaironline.net; Tue, 02 Nov 2010 11:55:09 -0400 Received-SPF: pass receiver=logan.com; client-ip=4.59.182.100; envelope-from=lacombr@nbnet.nb.ca Received: from torspm04.toronto.rmgopenwave.com ([142.167.183.254]) by tormtz02.toronto.rmgopenwave.com (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20101102155433.RXZR13337.tormtz02.toronto.rmgopenwave.com@torspm04.toronto.rmgopenwave.com> for ; Tue, 2 Nov 2010 11:54:33 -0400 Received: from PCdeRita ([142.167.183.254]) by torspm04.toronto.rmgopenwave.com with SMTP id <20101102155431.BBQE1920.torspm04.toronto.rmgopenwave.com@PCdeRita> for ; Tue, 2 Nov 2010 11:54:31 -0400 Message-ID: From: "Rino" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: EM2 Numbers Date: Tue, 2 Nov 2010 12:54:15 -0300 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0038_01CB7A8D.0E295BC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18263 X-Opwv-CommTouchExtSvcRefID: str=0001.0A020205.4CD03439.02E1,ss=1,fgs=0 This is a multi-part message in MIME format. ------=_NextPart_000_0038_01CB7A8D.0E295BC0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable I use a small manifold to smooth out the induction pulses, before that = the pulses would affect the pressure reading and probably the computer = also. Rino ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Tuesday, November 02, 2010 12:03 PM Subject: [FlyRotary] Re: EM2 Numbers Ed,=20 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 was 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? =20 Mark On Tue, Nov 2, 2010 at 9:09 AM, Ed Anderson = wrote: 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 than 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/consistent manifold pressure - no good source? So exactly how = is your EC2/3 getting its manifold pressure signal ? What comes 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 = injecting less than you would expect. 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=20 Sent: Tuesday, November 02, 2010 8:24 AM To: Rotary motors in aircraft=20 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,=20 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. =20 I'll post a question on the Lancair list regarding the most = efficient cruise speed for the Lancair ES airframe. Mark =20 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 thing to do depends 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 drag 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.=20 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.=20 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 like 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 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) =20 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 the most efficient operating point for the engine." =20 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 you look at Mazda's data on = BSFC, the best point is usually around 5000 rpm. =20 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 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,=20 Isn't the formula HP=3D (torque x rpm)/5252. =20 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 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." =20 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". =20 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 =20 Al =20 -----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 =20 Hi Mark=20 =20 I have attached the Leman intake dimensions from Paul L. Hope this is helpful. Can't remember whether this = measurement was to the rotor face or manifold face. =20 Steve Izett Perth Western Australia=20 On 01/11/2010, at 8:40 AM, Mark Steitle wrote: Bill,=20 =20 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 variable intake on their LeMans 26B p-port motor? = That tells me that runner length does make a significant difference on = the p-port 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. =20 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 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 long sausage that is going through a propeller made of a = strand of wire 2 or 3 MM thick and being 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 little benefit to enhance. =20 I think that is why the PP is so much stronger than the = side port. =20 Bill B =20 ---------------------------------------------------------------- From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Sunday, October 31, 2010 8:01 PM=20 To: Rotary motors in aircraft Subject: [FlyRotary] Re: EM2 Numbers =20 =20 =20 George,=20 =20 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. =20 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 = rpm? =20 =20 Mark =20 On Sat, Oct 30, 2010 at 3:53 PM, George Lendich = wrote: Mark,=20 That's interesting; can you tell me what is your PP = size, runner length and exhaust header ID size. George (down under)=20 =20 From: Mark Steitle=20 Sent: Saturday, October 30, 2010 7:38 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers =20 Bill, =20 =20 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 something that isn't quite 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 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 range. =20 =20 So, things are still developing. Yesterday, I = reinstalled the old air-filter 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 least a little improvement. =20 On a side note, I have 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 tach that I will be using to = determine which one is in error. =20 =20 Stay tuned (no pun intended), Mark =20 =20 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 start to slow down because the prop was just not = taking a big enough bite. Conversely, it seems 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 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 gives 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 know where that sweet spot = is with your propeller? =20 Bill B =20 ---------------------------------------------------------------- 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 =20 Rotarians, =20 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) 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. =20 =20 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 the second cooler (measured at the oil filter pad) = track water temps within a few degrees. =20 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 for that 15 mph but sometimes it is just too = much fun to slow down. =20 Mark S. ---------- Forwarded message ---------- From: Mark Date: Thu, Oct 28, 2010 at 8:50 PM Subject:=20 To: msteitle@gmail.com Sent from my iPhone =20 =20 =20 =20 =20 =20 ---------------------------------------------------------------- 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 the sender immediately and then = delete/destroy the e-mail and any printed copies. All liability for = viruses is excluded to the fullest extent of the law. ------=_NextPart_000_0038_01CB7A8D.0E295BC0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
I use a small manifold to smooth out = the induction=20 pulses, before that the pulses would affect the pressure reading and = probably=20 the computer also.
 
Rino
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Tuesday, November 02, = 2010 12:03=20 PM
Subject: [FlyRotary] Re: EM2=20 Numbers

Ed, 

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

Mark

On Tue, Nov 2, 2010 at 9:09 AM, Ed Anderson = <eanderson@carolina.rr.com&g= t;=20 wrote:
Hi Mark,
 
Injectors are certainly large enough - = six =20 injectors at 60 lb/hr would give you a max flow rate capacity of = around 58=20 gallons/hour - far more than you are reporting fuel burn = wise.
 
I guess what I am wondering is how your = manifold=20 pressure is registering at WOT.  The PP as I recall can have a = problem=20 providing reliable/consistent manifold pressure - no good = source?  So=20 exactly how is your EC2/3 getting its manifold pressure signal = ?  =20 What comes to mind is that if there is a problem getting a good = consistent=20 manifold pressure reading at WOT - could that possibly result in = your=20 injectors injecting less than you would expect.
 
In other words, if manifold pressure was low = relative=20 to what you would expect at WOT (near ambient) then turning up the = manual=20 mixture control would only provide adjustment against the smaller = target=20 pulse duration for that lower Manifold pressure rather than WOT = manifold=20 pressure.
 
Ed
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
 
 
 
 

From: stevei@carey.asn.au=20
Sent: Tuesday, November 02, 2010 8:24 AM
To: Rotary = motors in=20 aircraft
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,
 
As I recall the low end numbers are around -50ish.  So = there is=20 still room for adjustment.  When running WOT, turning = the=20 mixture knob full CW doesn't get the mixture bar to show up on the = EM-2=20 screen.  I find this odd as I'm running 60# injectors.  = I guess=20 that's why the low end numbers are in the -50 range. 
 
I'll post a question on the Lancair list regarding the = most=20 efficient cruise speed for the Lancair ES airframe.
 
Mark


 
On Mon, Nov 1, 2010 at 3:03 PM, Tracy = <tracy@rotaryaviation.com> wrote:
"So, if it is going LOP in those addresses, = which=20 it is, it would explain why power drops off as I open the = throttle=20 to WOT."

That's new data to me.  Yes, that would = certainly cause a loss of power.    Are you able = to=20 compensate by turning up the mixture control?  Are the MAP = table=20 values at the low end above minimum value?  The right thing = to do=20 depends on these answers.   If answer is yes to the = 2nd one,=20 then you should bump up the value in Mode 3.

The most = efficient=20 point on most airframes is the point where the induced drag = curve=20 crosses the parasitic drag curve.  On RV's that happens at = around=20 an indicated airspeed of 135 mph.  It will probably be = higher than=20 that on a Lancair but I've never seen the curves on that = airplane.=20

Tracy


On Mon, Nov 1, 2010 at 3:34 PM, Mark = Steitle=20 <msteitle@gmail.com> wrote:
Tracy wrote:
Having said that, I think there is still a good = possibility=20 that your drop in power above 6000 is not due to runner=20 length. 
 
Tracy,
I suspect it could be tuning as I've hit the max=20 adjustment (+127) on the EC-2 MCT for the addresses in = the upper=20 20" range, so it looks like I need to adjust the injector = pulse width=20 and then start over on the tuning.  So, if it is = going LOP=20 in those addresses, which it is, it would explain why = power drops=20 off as I open the throttle to WOT.  I'll do more tuning = when I=20 get my updated EC-2 back.  (will go out in today's = mail) =20
 
Where does one find the "most efficient operationg point" = for a=20 particular 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=20 torque peak as that is where the engine takes in the most = amount of=20 air for each revolution of the engine.  The VE is=20 optimum.  In other words it is the most efficient = operating=20 point for the engine."  =

Mark,
 That=20 is the point of minimum pumping losses in the engine, NOT = the most=20 overall efficient point of operation.    It = ignores=20 the many other factors that affect BSFC.   If you = look at=20 Mazda's data on BSFC, the best point is usually around 5000=20 rpm. 

It also ignores the most efficient = operating=20 point of your airframe.  If you tune the engine for a = higher=20 rpm torque peak you WILL make more HP,  you will fly = faster but=20 you will burn a lot more fuel.

Having said that, I = think=20 there is still a good possibility that your drop in power = above 6000=20 is not due to runner length.

Tracy



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

On Mon, Nov 1, 2010 at 11:10 AM, = Al Gietzen=20 <ALVentures@cox.net> = wrote:

Keep=20 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=20 rpm.  HP =3D T x RPM


 

Al


 

-----Original=20 Message-----
From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of stevei@carey.asn.au
Sent: Monday, = November 01,=20 2010 1:09 AM
To: Rotary motors = in=20 aircraft
Subject: = [FlyRotary] Re:=20 EM2 Numbers


 

Hi Mark=20


 

I have=20 attached the Leman intake dimensions from Paul=20 L.

Hope this=20 is helpful. Can't remember whether this measurement was = to the=20 rotor face or manifold face.


 

Steve=20 Izett

Perth=20 Western Australia 

<image001.gif>

On=20 01/11/2010, at 8:40 AM, Mark Steitle=20 wrote:



Bill,=20


 

I=20 understand the sausage illustration.  But = if what you=20 propose were true, then why did Mazda make = such a=20 major effort to design and implement the variable = intake on=20 their LeMans 26B p-port motor?  That tells me=20 that runner length does make a significant = difference=20 on the p-port motor.  Also, if tuned runners didn't = matter=20 for peripheral ports, then why do they tune the exhaust = runners=20 on the 13B's?  Somewhere I have a chart showing the = effect=20 of runner length, but I'm not sure that the = data is=20 from a p-port motor.


 
Mark

On Sun, Oct=20 31, 2010 at 7:27 PM, Bill Bradburry <bbradburry@bellsouth.net>=20 wrote:

Mark,

I don=92t=20 think that will work with the PP.  You never = actually block=20 the inlet.  You just cut off the end of the flow of = air as=20 the apex flies by and it starts to fill the next = chamber. =20 Think of the flow as a long sausage that is going = through a=20 propeller made of a strand of wire 2 or 3 MM thick and = being cut=20 into sections.  It is never blocked.  I doubt = that=20 there are any reflections and if there are, they would = be very=20 small and of little benefit to = enhance.


 

I think=20 that is why the PP is so much stronger than the side=20 port.


 

Bill=20 B


 

From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mark = Steitle
Sent:=20 Sunday, October 31, 2010 8:01 PM


To: Rotary motors = in=20 aircraft
Subject: = [FlyRotary] Re:=20 EM2 Numbers


 

 

 

George,=20


 

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


 

So, my=20 power seems to peak around 6000 rpm.  What length = intake=20 runner length would it take to bring peak = power up to=20 around 6500 rpm? 


 

Mark  =

On Sat, Oct=20 30, 2010 at 3:53 PM, George Lendich <lendich@aanet.com.au>=20 wrote:

   Mark,=20

   =20 That's interesting; can you tell me what is your PP = size, runner=20 length and exhaust header = ID size.

    George=20 (down under) 


 

From: Mark = Steitle=20

Sent: = Saturday, October=20 30, 2010 7:38 PM

To: Rotary=20 motors in aircraft

Subject: = [FlyRotary] Re:=20 EM2 Numbers


 

Bill, =20


 

With the=20 current setup, it appears to be around 6000-6100, but = I'm still=20 tuning on the upper addresses of the EC-2.  My old = engine=20 did best around 6500-6600 running the same prop. =  So, I=20 feel there is something that isn't quite right on the = new P-Port=20 motor... maybe intake runners too short, intake or = exhaust too=20 restrictive, timing off a bit, etc.  It definitely = makes=20 more hp than the old motor did in the 5000-6000 range, = but I=20 feel that it should be producing more hp than I'm seeing = in the=20 6000-7000 range.  


 

So, things=20 are still developing.  Yesterday, I reinstalled the = old=20 air-filter box which has a ram-air feature incorporated = into the=20 design.  I haven't flown it yet to see if there is = any=20 improvement, but I hope to see at least a little=20 improvement.


 

On a side=20 note, I have determined that there is a 250 rpm = discrepancy=20 between the rpm readout of the EM-2 and that of the M/T = prop=20 controller.  I have an optical tach that I will be = using to=20 determine which one is in error.=20   


 

Stay tuned=20 (no pun intended),

Mark


 

 

On Fri, Oct=20 29, 2010 at 8:30 PM, Bill Bradburry <bbradburry@bellsouth.net>=20 wrote:

Mark,

It=20 would seem that if you flattened the pitch of the prop, = the=20 engine rpms would increase, but at some point, you would = begin=20 to lose airspeed and start to slow down because the prop = was=20 just not taking a big enough bite.  Conversely, it = seems=20 that if you increased the prop pitch, the engine rpms = would=20 decrease, but the airspeed would increase up to some = point and=20 then after that, an increase in pitch would cause a = decrease in=20 airspeed because you are taking too big a bite and the = engine=20 just can not pull it.  Somewhere in there is a = =93Sweet Spot=94=20 of propeller rpm that gives the highest airspeed.  = Lets say=20 that this question assumes that you are at WOT and 8500 = feet,=20 which should give you roughly a 75% power output.  = Do you=20 know where that sweet spot is with your=20 propeller?


 

Bill=20 B


 

From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mark = Steitle


Sent: Thursday, = October 28,=20 2010 10:00 PM
To: Rotary motors = in=20 aircraft
Subject: = [FlyRotary] EM2=20 Numbers


 

Rotarians,


 

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


 

Please=20 disregard the oil temp as the reading on the EM-2 is = measured=20 after the first cooler and before the second cooler. =  Oil=20 temp readings out of the second cooler (measured at the = oil=20 filter pad) track water temps within a few=20 degrees.


 

Leaned to=20 "Economy Cruise" and dial the prop down to 1800 rpm and = the=20 speed drops down about 15 mph and fuel burn drops to 9.1 = gph.=20  You pay dearly for that 15 mph but sometimes it is = just=20 too much fun to slow down.


 

Mark S.

----------=20 Forwarded message ----------


From:=20 Mark = <msteitle@gmail.com>
Date: Thu, = Oct 28,=20 2010 at 8:50 PM
Subject:
To: msteitle@gmail.com







Sent=20 from my iPhone


 

 

 

 

 

 

The=20 contents of this email are confidential and intended = only for=20 the named recipients of this e-mail. If you have = received this=20 e-mail in error, you are hereby notified that any use,=20 reproduction, disclosure or distribution or the = information=20 contained in this e-mail is prohibited. Please notify = the sender=20 immediately and then delete/destroy the e-mail and any = printed=20 copies. All liability for viruses is excluded to the = fullest=20 extent of the=20 = law.





=



------=_NextPart_000_0038_01CB7A8D.0E295BC0--