X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qmta11.emeryville.ca.mail.comcast.net ([76.96.27.211] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4552923 for flyrotary@lancaironline.net; Tue, 02 Nov 2010 19:40:11 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.27.211; envelope-from=hoursaway1@comcast.net Received: from omta05.emeryville.ca.mail.comcast.net ([76.96.30.43]) by qmta11.emeryville.ca.mail.comcast.net with comcast id SLW81f0030vp7WLABPfdZl; Tue, 02 Nov 2010 23:39:37 +0000 Received: from sz0081.ev.mail.comcast.net ([76.96.26.137]) by omta05.emeryville.ca.mail.comcast.net with comcast id SPfd1f0012xV6SL8RPfdLH; Tue, 02 Nov 2010 23:39:37 +0000 Date: Tue, 2 Nov 2010 23:39:37 +0000 (UTC) From: hoursaway1@comcast.net To: Rotary motors in aircraft Message-ID: <756088973.583936.1288741177006.JavaMail.root@sz0081a.emeryville.ca.mail.comcast.net> In-Reply-To: <1091156679.583772.1288740954824.JavaMail.root@sz0081a.emeryville.ca.mail.comcast.net> Subject: Re: [FlyRotary] Re: EM2 Numbers MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_583935_315389167.1288741177005" X-Originating-IP: [68.61.190.35] X-Mailer: Zimbra 6.0.5_GA_2431.RHEL5_64 (ZimbraWebClient - IE8 (Win)/6.0.5_GA_2427.RHEL4) ------=_Part_583935_315389167.1288741177005 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Ed, Mark, manifold absolute pressure should be measured from the intake man= ifold as close to throttle plate as possible, this is your controlling auth= ority for MAP & we all know with the rotary eng. strong pulses are generate= d & 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 need= le at the diff. positions, shaking violently near housing, shimmering sligh= tly at t-body.=C2=A0=C2=A0 David R. Cook=C2=A0 RV6A Rotary.=20 ----- Original Message -----=20 From: "Mark Steitle" =20 To: "Rotary motors in aircraft" =20 Sent: Tuesday, November 2, 2010 11:03:12 AM=20 Subject: [FlyRotary] Re: EM2 Numbers=20 Ed,=C2=A0=20 I measure the manifold pressure at the unused oil injection ports in the ro= tor housings. =C2=A0The EM-2 MAP reads in the upper 20's while at WOT, so I= don't think I have a problem with this. =C2=A0The MCT was as received, whi= ch was set up for Tracy's injectors. =C2=A0I assume they were 460cc, but th= at's just a guess. =C2=A0I'm running 60# DEKA IV injectors. =C2=A0Could the= re possibly be an impedance mismatch between the two types? =C2=A0=20 Mark=20 On Tue, Nov 2, 2010 at 9:09 AM, Ed Anderson < eanderson@carolina.rr.com > w= rote:=20 Hi Mark,=20 Injectors are certainly large enough - six=C2=A0 injectors at 60 lb/hr woul= d give you a max flow rate capacity of around 58 gallons/hour - far more th= an you are reporting fuel burn wise.=20 I guess what I am wondering is how your manifold pressure is registering at= WOT.=C2=A0 The PP as I recall can have a problem providing reliable/consis= tent manifold pressure - no good source?=C2=A0 So exactly how is your EC2/3= getting its manifold pressure signal ?=C2=A0=C2=A0 What comes to mind is t= hat if there is a problem getting a good consistent manifold pressure readi= ng at WOT - could that possibly result in your injectors injecting less tha= n you would expect.=20 In other words, if manifold pressure was low relative to what you would exp= ect 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.=20 Ed=20 Edward L. Anderson=20 Anderson Electronic Enterprises LLC=20 305 Reefton Road=20 Weddington, NC 28104=20 http://www.andersonee.com=20 http://www.eicommander.com=20 From: stevei@carey.asn.au=20 Sent: Tuesday, November 02, 2010 8:24 AM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers=20 Hi Mark=20 Are you in a position to confirm your fuel rail pressure?=20 Fuel injected =3D Pulse width AND injector size AND fuel pressure.=20 Cheers=20 Steve Izett=20 On 02/11/2010, at 4:42 AM, Mark Steitle wrote:=20 Tracy,=20 As I recall the low end numbers are around -50ish.=C2=A0 So there is still= =C2=A0room for adjustment.=C2=A0 When running WOT, turning the mixture knob= full CW doesn't get the mixture bar to show up on the EM-2 screen.=C2=A0 I= find this odd as I'm running 60# injectors.=C2=A0 I guess that's why the l= ow end numbers are in the -50 range.=C2=A0=20 I'll post a question on the Lancair list=C2=A0regarding the most efficient = cruise speed for the=C2=A0Lancair ES airframe.=20 Mark=20 =C2=A0=20 On Mon, Nov 1, 2010 at 3:03 PM, Tracy < tracy@rotaryaviation.com > wrote:= =20 "So, if it is going LOP in those addresses, which it is,=C2=A0it would expl= ain why power drops off as I open the throttle to WOT. "=20 That's new data to me.=C2=A0 Yes, that would certainly cause a loss of powe= r.=C2=A0=C2=A0=C2=A0 Are you able to compensate by turning up the mixture c= ontrol?=C2=A0 Are the MAP table values at the low end above minimum value?= =C2=A0 The right thing to do depends on these answers.=C2=A0=C2=A0 If answe= r is yes to the 2nd one, then you should bump up the value in Mode 3.=20 The most efficient point on most airframes is the point where the induced d= rag curve crosses the parasitic drag curve.=C2=A0 On RV's that happens at a= round an indicated airspeed of 135 mph.=C2=A0 It will probably be higher th= an that on a Lancair but I've never seen the curves on that airplane.=20 Tracy=20 On Mon, Nov 1, 2010 at 3:34 PM, Mark Steitle < msteitle@gmail.com > wrote:= =20 Tracy wrote:=20 Having said that, I think there is still a good possibility that your drop = in power above 6000 is not due to runner length. =C2=A0=20 Tracy,=20 I suspect it could be tuning as I've hit the max adjustment=C2=A0(+127) on = the EC-2 MCT for the addresses in the upper 20" range, so it looks like I n= eed to adjust the injector pulse width and then start over on the tuning.= =C2=A0=C2=A0So, if it is going LOP in those addresses, which it is,=C2=A0it= would explain why power drops off as I open the throttle to WOT.=C2=A0 I'l= l do more tuning when I get my updated EC-2 back.=C2=A0 (will go out in tod= ay's mail)=C2=A0=20 Where does one find the "most efficient operationg point" for a particular = airframe?=C2=A0 Is this the same as=C2=A0LDmax?=20 Mark=20 On Mon, Nov 1, 2010 at 1:28 PM, Tracy < tracy@rotaryaviation.com > wrote:= =20 "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.=C2=A0 The VE is optimum.=C2=A0 In other words it is the mo= st efficient operating point for the engine."=C2=A0=20 Mark,=20 =C2=A0That is the point of minimum pumping losses in the engine, NOT the mo= st overall efficient point of operation.=C2=A0=C2=A0=C2=A0 It ignores the m= any other factors that affect BSFC.=C2=A0=C2=A0 If you look at Mazda's data= on BSFC, the best point is usually around 5000 rpm.=C2=A0=20 It also ignores the most efficient operating point of your airframe.=C2=A0 = If you tune the engine for a higher rpm torque peak you WILL make more HP,= =C2=A0 you will fly faster but you will burn a lot more fuel.=20 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=20 On Mon, Nov 1, 2010 at 11:54 AM, Mark Steitle < msteitle@gmail.com > wrote:= =20 Al,=20 Isn't the formula HP=3D (torque x rpm)/5252.=C2=A0=20 I'm more focused on peak Volumetric Efficiency (VE).=C2=A0 According to Fun= damentals of Intake System Design , (ACRE)=C2=A0"The lowest fuel burn per H= P generated always occurs at the torque peak as that is where the engine ta= kes in the most amount of air for each revolution of the engine.=C2=A0 The = VE is optimum.=C2=A0 In other words it is the most efficient operating poin= t for the engine."=C2=A0=20 So, I will be good=C2=A0tuning for=C2=A0peak torque.=C2=A0 Do you have a dy= no chart on your 20B that you will share?=C2=A0 I find it interesting that = your intake runners are only 13".=C2=A0=20 Mark=20 On Mon, Nov 1, 2010 at 11:10 AM, Al Gietzen < ALVentures@cox.net > wrote:= =20 Keep in mind that the graph is peak torque (T)); not peak HP. =C2=A0The pea= k HP (which is what you=E2=80=99re after would be at higher rpm.=C2=A0 HP = =3D T x RPM=20 =C2=A0=20 Al=20 =C2=A0=20 -----Original Message-----=20 From: Rotary motors in aircraft [mailto: flyrotary@lancaironline.net ] On B= ehalf Of stevei@carey.asn.au=20 Sent: Monday, November 01, 2010 1:09 AM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers=20 =C2=A0=20 Hi Mark=20 =C2=A0=20 I have attached the Leman intake dimensions from Paul L.=20 Hope this is helpful. Can't remember whether this measurement was to the ro= tor face or manifold face.=20 =C2=A0=20 Steve Izett=20 Perth Western Australia=C2=A0=20 =20 On 01/11/2010, at 8:40 AM, Mark Steitle wrote:=20 Bill,=20 =C2=A0=20 I understand the sausage illustration.=C2=A0 But if=C2=A0what you propose= =C2=A0were true, then why did Mazda=C2=A0make such a major effort to design= and implement=C2=A0the variable intake on their LeMans 26B p-port motor?= =C2=A0 That tells me that=C2=A0runner length=C2=A0does make a significant d= ifference on the p-port motor.=C2=A0 Also, if tuned runners didn't matter f= or peripheral ports, then why do they tune the exhaust runners on the 13B's= ?=C2=A0 Somewhere I have a chart showing the effect of runner length, but I= 'm not sure that=C2=A0the data=C2=A0is from a=C2=A0p-port motor.=20 =C2=A0=20 Mark=20 On Sun, Oct 31, 2010 at 7:27 PM, Bill Bradburry < bbradburry@bellsouth.net = > wrote:=20 Mark,=20 I don=E2=80=99t think that will work with the PP.=C2=A0 You never actually = block the inlet.=C2=A0 You just cut off the end of the flow of air as the a= pex flies by and it starts to fill the next chamber.=C2=A0 Think of the flo= w as a long sausage that is going through a propeller made of a strand of w= ire 2 or 3 MM thick and being cut into sections.=C2=A0 It is never blocked.= =C2=A0I doubt that there are any reflections and if there are, they would = be very small and of little benefit to enhance.=20 =C2=A0=20 I think that is why the PP is so much stronger than the side port.=20 =C2=A0=20 Bill B=20 =C2=A0=20 From: Rotary motors in aircraft [mailto: flyrotary@lancaironline.net ] On B= ehalf Of Mark Steitle=20 Sent: Sunday, October 31, 2010 8:01 PM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 George,=20 =C2=A0=20 Sorry for the delayed reply, but I had to go to the hangar and measure the = runner length to be sure.=C2=A0 It is 24" bellmouth to rotor face, 2" OD.= =C2=A0 Exhaust is 2" OD also, running the stock 20b exhaust splitters.=20 =C2=A0=20 So, my power seems to peak around 6000 rpm.=C2=A0 What length intake runner= length would it take to bring=C2=A0peak power=C2=A0up to around 6500 rpm?= =C2=A0=20 =C2=A0=20 Mark=C2=A0=20 On Sat, Oct 30, 2010 at 3:53 PM, George Lendich < lendich@aanet.com.au > wr= ote:=20 =C2=A0=C2=A0 Mark,=20 =C2=A0=C2=A0=C2=A0 That's interesting; can you tell me what is your PP size= , runner length and exhaust header ID=C2=A0size.=20 =C2=A0=C2=A0=C2=A0=C2=A0George (down under)=C2=A0=20 =C2=A0=20 From: Mark Steitle=20 Sent: Saturday, October 30, 2010 7:38 PM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 Numbers=20 =C2=A0=20 Bill,=C2=A0=20 =C2=A0=20 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. =C2=A0My old engine did best aroun= d 6500-6600 running the same prop. =C2=A0So, I feel there is something that= isn't quite right on the new P-Port motor... maybe intake runners too shor= t, intake or exhaust too restrictive, timing off a bit, etc. =C2=A0It defin= itely makes more hp than the old motor did in the 5000-6000 range, but I fe= el that it should be producing more hp than I'm seeing in the 6000-7000 ran= ge. =C2=A0=20 =C2=A0=20 So, things are still developing. =C2=A0Yesterday, I reinstalled the old air= -filter box which has a ram-air feature incorporated into the design. =C2= =A0I haven't flown it yet to see if there is any improvement, but I hope to= see at least a little improvement.=20 =C2=A0=20 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. =C2=A0I= have an optical tach that I will be using to determine which one is in err= or. =C2=A0=C2=A0=20 =C2=A0=20 Stay tuned (no pun intended),=20 Mark=20 =C2=A0=20 =C2=A0=20 On Fri, Oct 29, 2010 at 8:30 PM, Bill Bradburry < bbradburry@bellsouth.net = > wrote:=20 Mark,=20 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.=C2= =A0 Conversely, it seems that if you increased the prop pitch, the engine r= pms would decrease, but the airspeed would increase up to some point and th= en after that, an increase in pitch would cause a decrease in airspeed beca= use you are taking too big a bite and the engine just can not pull it.=C2= =A0 Somewhere in there is a =E2=80=9CSweet Spot=E2=80=9D of propeller rpm t= hat gives the highest airspeed.=C2=A0 Lets say that this question assumes t= hat you are at WOT and 8500 feet, which should give you roughly a 75% power= output.=C2=A0 Do you know where that sweet spot is with your propeller?=20 =C2=A0=20 Bill B=20 =C2=A0=20 From: Rotary motors in aircraft [mailto: flyrotary@lancaironline.net ] On B= ehalf Of Mark Steitle=20 Sent: Thursday, October 28, 2010 10:00 PM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] EM2 Numbers=20 =C2=A0=20 Rotarians,=20 =C2=A0=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 Lockha= rt, TX (50R) yesterday. =C2=A0I was level at 8500msl when taking the pictur= e. =C2=A0A/C is a Lancair ES (4-place), engine is a n/a p-ported 20b. =C2= =A0=20 =C2=A0=20 Please disregard the oil temp as the reading on the EM-2 is measured after = the first cooler and before the second cooler. =C2=A0Oil temp readings out = of the second cooler (measured at the oil filter pad) track water temps wit= hin a few degrees.=20 =C2=A0=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. =C2=A0You pay dear= ly for that 15 mph but sometimes it is just too much fun to slow down.=20 =C2=A0=20 Mark S.=20 ---------- Forwarded message ----------=20 From: Mark < msteitle@gmail.com >=20 Date: Thu, Oct 28, 2010 at 8:50 PM=20 Subject:=20 To: msteitle@gmail.com=20 Sent from my iPhone=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 =C2=A0=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 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= .=20 ------=_Part_583935_315389167.1288741177005 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <= div style=3D'font-family: Arial; font-size: 12pt; color: #000000'>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 &am= p; 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 t= he needle at the diff. positions, shaking violently near housing, shimmerin= g slightly at t-body.   David R. Cook  RV6A Rotary.
-----= Original Message -----
From: "Mark Steitle" <msteitle@gmail.com><= BR>To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
S= ent: Tuesday, November 2, 2010 11:03:12 AM
Subject: [FlyRotary] Re: EM2 = Numbers

Ed, =20

I measure the manifold pressure at the unused oil injection ports in t= he 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, b= ut that's just a guess.  I'm running 60# DEKA IV injectors.  Coul= d there 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> wrote:
Hi Mark,
 
Injectors are certainly large enough - six  in= jectors at 60 lb/hr would give you a max flow rate capacity of around 58 ga= llons/hour - far more than you are reporting fuel burn wise.
 
I guess what I am wondering is how your manifold pr= essure is registering at WOT.  The PP as I recall can have a problem p= roviding reliable/consistent manifold pressure - no good source?  So e= xactly 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 inje= ctors injecting less than you would expect.
 
In other words, if manifold pressure was low relati= ve to what you would expect at WOT (near ambient) then turning up the manua= l mixture control would only provide adjustment against the smaller target = pulse duration for that lower Manifold pressure rather than WOT manifold pr= essure.
 
Ed
 
Edward L. Anderson
Anderson Electronic Enterpris= es LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com=
 
 
 
 

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,
 
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@r= otaryaviation.com> wrote:
"So, if it is going LOP in thos= e addresses, which it is, it would explain why power drops off as I op= en the throttle to WOT."

That's new data to me.  Yes, that = would certainly cause a loss of power.    Are you able to co= mpensate 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 airfr= ames is the point where the induced drag curve crosses the parasitic drag c= urve.  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 se= en the curves on that airplane.

Tracy


On Mon, Nov 1, 2010 at 3:34 PM, Mark Steitle <msteit= le@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@r= otaryaviation.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 i= gnores the many other 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.&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 <mstei= tle@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 <ALVentu= res@cox.net> wrote:

Keep in mind that t= he graph is peak torque (T)); not peak HP.  The peak HP (which is what= you=E2=80=99re after would be at higher rpm.  HP =3D T x RPM


 

Al


 

-----Original Mess= age-----
From: Rotary mo= tors 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

<= SPAN style=3D"FONT-SIZE: 12pt">
 

Hi Mark

<= SPAN style=3D"FONT-SIZE: 12pt">
 

I have attached the Leman in= take dimensions from Paul L.

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

<= SPAN style=3D"FONT-SIZE: 12pt">
 

Steve Izett

Perth Western Australia = ;

<image001.gif>

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



Bill,

<= SPAN style=3D"FONT-SIZE: 12pt">
 

I understand the sausage ill= ustration.  But if what you propose were true, then why did = Mazda make such a major effort to design and implement the variab= le intake on their LeMans 26B p-port motor?  That tells me that r= unner length does make a significant difference on the p-port motor.&n= bsp; 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&n= bsp;is from a p-port motor.

<= SPAN style=3D"FONT-SIZE: 12pt">
 

Mark

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

Mark,

I don=E2=80=99t think that will work with the PP.  You never a= ctually 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 str= and 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, the= y would be very small and of little benefit to enhance.

=
 

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

=
 

Bill B

=
 

From: Rotary motors in aircraft [mailto:flyrotary@lancairo= nline.net] On Behalf Of Mark Steitle
Sent: Sund= ay, October 31, 2010 8:01 PM


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

<= SPAN style=3D"FONT-SIZE: 12pt">
 
<= SPAN style=3D"FONT-SIZE: 12pt">
 
<= SPAN style=3D"FONT-SIZE: 12pt">
 

George,

<= SPAN style=3D"FONT-SIZE: 12pt">
 

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

<= SPAN style=3D"FONT-SIZE: 12pt">
 

So, my power seems to peak a= round 6000 rpm.  What length intake runner length would it take to bri= ng peak power up to around 6500 rpm? 

<= SPAN style=3D"FONT-SIZE: 12pt">
 

Mark&nb= sp;

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

   Mar= k,

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

  &nbs= p; George (down under) 


 

<= B>From: Mark Steitle

<= B>Sent: Saturday, Octobe= r 30, 2010 7:38 PM

<= B>Subject: [FlyRotary]= Re: EM2 Numbers

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Bill, 

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With the current setup, it a= ppears 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 ne= w P-Port motor... maybe intake runners too short, intake or exhaust too res= trictive, 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 produci= ng more hp than I'm seeing in the 6000-7000 range.  

=
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So, things are still develop= ing.  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 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 deter= mined 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.   

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Stay tuned (no pun intended)= ,

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.  Conversely, it seems that if you increased the prop pitch, the e= ngine 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 airspe= ed because you are taking too big a bite and the engine just can not pull i= t.  Somewhere in there is a =E2=80=9CSweet Spot=E2=80=9D of propeller = rpm that gives the highest airspeed.  Lets say that this question assu= mes 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 propelle= r?

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Bill B

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


Sent: Thursday, October 28, 2010 10:00 PM=
To: Rotary motors in ai= rcraft
Subject: [FlyRota= ry] EM2 Numbers

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Rotarians,

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Things have been a bit quiet= on the list lately, so I thought I would post this picture of my EM-2 take= n on a trip from Galveston, TX (KGLS) to Lockhart, TX (50R) yesterday. &nbs= p;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.  

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Please disregard the oil tem= p 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 (measur= ed at the oil filter pad) track water temps within a few degrees.

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Leaned to "Economy Cruise" a= nd 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 somet= imes it is just too much fun to slow down.

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Mark S.=

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


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








Sent from = my iPhone

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