X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=PbaBeRpd c=1 sm=1 tr=0 a=GWsEYdmQbN9pH0Hr6y0L/Q==:117 a=x7bEGLp0ZPQA:10 a=Fee85h93u3AA:10 a=y4yBn9ojGxQA:10 a=8IjSFGYmQxEA:10 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=3oc9M9_CAAAA:8 a=0qqORytXAAAA:8 a=7g1VtSJxAAAA:8 a=CIHQPls3ZoHDGkFpQm4A:9 a=EmePap7aGrHp7Q9O:21 a=9fQGFIVrAkiEladJ:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=d7OJ2h0JwCJzZ7hYkB0A:9 a=m5RO3KczhqOlx4qA:21 a=jfyJAC5rzl20HtO5:21 a=KYV_YWSQjDUz36dj:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=Nj1bhqyGrdl6Az3_ctNx:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "lehanover lehanover@aol.com" Received: from sonic304-10.consmr.mail.bf2.yahoo.com ([74.6.128.33] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 617143 for flyrotary@lancaironline.net; Fri, 07 Aug 2020 20:09:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.6.128.33; envelope-from=lehanover@aol.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1596845343; bh=dvXIYESMSygEzcmI4gsr0cTbY1YfWXVOBRLJ1vbTEPE=; h=Date:From:To:In-Reply-To:References:Subject:From:Subject; b=GDrlBZIQVuOuyaPCjQnfoudK4jska+z9+P2gaKfBneXhZT+HGvS4oXjmCoRTS4oMt1Cni6S8GNzmRmRtHpM0bKVbN60V804SuoPdxT0o1YBEbdXo4tjrg39mnt1T9zYQm1j4OPlwQGvNq1Q5Hb8qUAYeUoRZF1/pXDtyqZG4fnVys25pMtgK4xD33IbV9nml8WpIcud/sp72zfo1Ou41XkKTLNcF5nnsmWhdGjP5sjU92XuVTdH3cfmNIi0YZLlgZvUlKWEfd2BWAl4oZ60viByDoToDdcVXXIEt2f1RJqGn1aNJPYnu+WR/K0qNC0xBI+nbTFX3nKl9CAnXTepnPQ== X-YMail-OSG: lAQwi8UVM1lHBFOX9VdN0MZaQUORfDYuBxGX.3p2C_YIJ5DZB_7lhQvTiGCIHci LHtqXCQ4mfWiDm1p3GFnoYz1Cen5ct8pP6EtKOuL7kXl5zPvMnBqMfCnZelbsCNs6DBlBtKcWtib cpOl3_MOouX_r._b4ZDabbM7QsKtlcd2xALuMXYUSjkbHW3oDuUkPiHkPsOjKKAtm_Ghf6AZ0Fit MQHaLWDKFZv87_FSNH.T8cPZ.d1nAzN8r0UEaHPlVArvFBPrOVHE5XhXEfpBU3FmSNvUCiZ_kbR. YD_S7Emv78c_oPZiUTDrQ10xOq.ZFhkqpg33rgBWeA1NdGWUVBqY4RyEhRLrmZeU1AXp1X8q1vSC oug9vevxhlYHqpN3rUKYV7Lx93X._KIyghgm6R4C3kFxPWUAC9zfhOYJsWWUWkGDlFCll8Sr2S4I vepQ6isiGMmMCrg.JW6k1qA5gqA.7WKOmhrl2RGWn8e2LwZKQzW4nPVemPgjhXYNM06dUrFajSX4 eRd8xslE61zMlf4wcYCDIKs0av.wa.WJLSJrUJQZrJDRcq1dkqff0WF27Iwn3RAf1KMgiS75catk eIjCwwjBjDZq3I.fX_9VC3_PT8j.ey5COSIbc4bcIbJjcatAodeId1qO7KFdH6W.EQaqJbvjzIZj TGUYhDF8IiV4R7F09gb2ykRK1TfOr31hck655UzXIQfA_WZ2GtzdYp3zj2ZM2uv3.3Z.ImtP4zhk ACIoFwN97NgvcJbnjK_g0rQ.5o_bZc_OFboukhKM_WwFrABGpLwDz1zsdxWLw1RUc_xOJtrcZC5N JPs9Xrz2ugG8_DBNPViW5ffZ2dKOyR3rKjMtAuqqNKXV4Ll6l4NKXZDe_q2Gk5IQ2p9hFGicbr3g OU_g3EbgaaAC.wt5u5ohbvrLsyXPQHCaSoYGGqgemqI8DmKyLIocJ8S0QjR2dfxLteUIL2XTkozH 23WDLPiD7uo0zWwI8bYZilksbHhb0euuXhp6ZNwDgzBGFNFZ7fqjK98G.a3sFHUY.hglXDScsnUw _htO4krtMfkmmHzsoYGmQ828ekZZGs2vR6EtTF.UA5bz0EQ15Cm1obm_PrZYV3tuSER4Cluxqafz 3G8ZD0DIClyuPRLallIQBw2xvBEyFyjgnzOe2x29kyu63cu163SrYqsM0GckmNMQyYposztUxYsk JxULXVAJPxkX0qhXLjV0L7JlQXbWPAVmUP3FBuHNltj4zLpIKDwGi2DQuqNr0cu4riWJUBCE7zcl 7VV44m_pqpsndFPApZoWfsJ5sqk0pzsFTHosrYohJ59icmX7nzUNSk_yOKvMI0_Dh7_sD0qmAifJ cYVySECaFtiwPEOkDDBDj6nr9C5CFOeI9ZuJF6DMgSPkHIOWlak9oXWtyGDQhBL.jIKOi Received: from sonic.gate.mail.ne1.yahoo.com by sonic304.consmr.mail.bf2.yahoo.com with HTTP; Sat, 8 Aug 2020 00:09:03 +0000 Date: Sat, 8 Aug 2020 00:08:58 +0000 (UTC) To: flyrotary@lancaironline.net Message-ID: <1903928607.1207174.1596845338842@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: Dyno Sheet MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_1207173_1360906795.1596845338836" X-Mailer: WebService/1.1.16436 aolloki Apache-HttpClient/4.5.7 (Java/1.8.0_252) Content-Length: 33884 ------=_Part_1207173_1360906795.1596845338836 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable The impossible is possible................ Along the way to tuning success you will find that a specific combination o= f facts may appear and disappear within a few RPM.=C2=A0 Such as induction = tube length VS exhaust system harmonics/back pressure. Every RPM would sugg= est that a specific tuned intake length would be ideal. See the Mazda winni= ng 4 rotor and its adjustable length intake runners.=C2=A0 Exhaust back pre= ssure may be high at one RPM and nonexistent at another. The whole reason f= or disconnecting the intake and exhaust=C2=A0 in the Renesis among other th= ings is to get the tuning down to some form of normal (Meet California UHC)= . Having no overlap is a giant step in that direction. The poor exhaust sha= pes help pollute the incoming charge a bit so as to reduce combustion temps= and pull back Oxides of Nitrogen. I have seen movies of fuel air flowing b= ackwards in an intake runner.=C2=A0 =C2=A0 When you record what appears to = be faulty data do not discard it and then see it again the next day.=C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0When you make a change....make it a big o= ne so you can see which way that one took you. Never make more than one cha= nge.=C2=A0 Use the SAE tables to take all of the data down to sea level. Be= fore you compare two data sets.=C2=A0 =C2=A0It is a steep learning curve...= ...but it will come to you.=C2=A0 I had a fabulous Stuska dyno in my shop f= or years.and a flow bench. I never did learn all I should have. Fixed pitch props (In effect) reduce pitch as air speed through the disc in= creases.=C2=A0 The suggestion that you turned up 9,500 RPM gives me chills.= What would the tip speeds be then? You can get above 10,000 RPM with 13-B rotors but they must be very light a= nd you must look inside after every race because the tend to crack when tha= t light. Note that the Renesis rear main bearing is two different diameters= to allow for that standing sign wave that forms in the crank.=C2=A0 Nobody= uses Fram filters or lets friends turn over 8,000 RPMLynn E. Hanover In a message dated 8/7/2020 6:48:47 PM Eastern Standard Time, flyrotary@lan= caironline.net writes: Hi Charlie and all On the four runs - Speeds were: 147 KIAS 21.6=E2=80=9D @ 9500 WOT136 KIAS 1= 8.2=E2=80=9D @ 7500 (Not WOT)160 KIAS 24.8=E2=80=9D @ 6000 WOT165 KIAS 26.2= =E2=80=9D @ 4500 WOT Prop hub is Airmaster 3 blade electric with Aerotek Blades=20 On looking over the 4500 ft run:=C2=A0=C2=A0=C2=A0 As RPM steps up from 550= 0-7250 (in 250rpm inc) over 9 mins (OAT 49)=C2=A0=C2=A0=C2=A0 Temps gradual= ly build from 172/154 to 198/171 (Oil/Water)=C2=A0=C2=A0=C2=A0 Fuel Flow go= es from 14.5 peaking at 16.2 (6750) before ending at 15.8=C2=A0=C2=A0=C2=A0= KIAS 160 peaking at 168 (7000) before ending at 166 We probably haven=E2=80=99t allowed enough time between changes for full se= ttling of the numbers, but the trends seem consistent. Not sure I agree with your thoughts re engine rpm rising and drag constant = or rising =3D power must be increasing.Torque x RPM =3D Power RPM is increa= sing, but if torque is decreasing faster than rpm is rising, power will be = decreasing. What I was interested in discovering was the max power RPM.My logic is, eve= n if power is constant after 6750rpm (ie. rpm increasing matches torque dec= reasing) there is no value in spinning her above that rpm. What science could I do to discover this?Rightly or wrongly, thats why I va= lue this list, I was looking for the peek in Fuel Flow AND IAS (I=E2=80=99m= relying on the wideband O2 being accurate and keeping mixture constant)Its= not anything like dramatic, but I think I can maybe see evidence of that b= est power (torque peek) RPM being somewhere around the 6750rpm setting.We h= ad been spinning her up 600+RPM higher, perhaps for no advantage. On another note about the Intake manifold. We shortened the OEM unit to lif= t peak torque from Mazda's 5000rpm documented curve, hoping for something i= n the low 6000=E2=80=99s.We also kept the VDI valve that opens at high RPM = to provide Mazda=E2=80=99s Renesis intake shockwave charging, but presently= I cant activate the valve in flight.And to be honest it seems to be produc= ing a pleasing amount of hp at that 6750rpm. On Takeoff with a mixture at a Lambda of 0.9 / 13.2 AFR she is burning 17 G= al of our Premium Unleaded fuel using 1 Ounce / Gal of two stroke oil, what= ever hp that equates too. Is my logic OK here or am I just dreaming? Cheers Steve =C2=A0=C2=A0 =20 =C2=A0=C2=A0 =20 > On 7 Aug 2020, at 10:34 pm, Charlie England ceengland7@gmail.com wrote:> > That's curious. Are you saying that fuel fl= ow *decreased* as rpm *increased* above 6750 rpm? And airspeed decreased, a= s well? The only way fuel flow should decrease as rpm increases is if the l= oad on the engine is going down.> > Is the prop running out of pitch (or ab= ility to absorb the HP) as you get faster? Is the airframe hitting a drag w= all due to cooling drag (still shouldn't show a reduction in fuel flow; it = just wouldn't go any faster)?> > What actual speeds are you achieving when = this is happening?> > Refresh my memory; who's prop (what blades) is it? > = > Do engine temps go up as you get above 6750 rpm?> > Think about the 'airp= lane as dyno' thing: If rpm continues to go up, and the drag (our substitut= e for torque on the engine brake in a real dyno) stays the same or increase= s, then power *must* be increasing, and so must fuel flow. Simple math; (to= rque*rpm)/5252. So, was the plane going downhill, or was the prop unable to= absorb the additional power and decoupling, unloading the engine?> > Charl= ie> > On Fri, Aug 7, 2020 at 9:01 AM Stephen Izett stephen.izett@gmail.com = wrote:> Hi Guys.> > Today we did some engine = data analysis at 9500, 7500, 6000 and 4500 feet agl.> WOT with constant bes= t power mixture of 0.9 Lambda.> We looked at Fuel Flow and IAS at 5500,5750= ,6000,6250,6500,6750 & 7000rpm.> The data revealed a very slight peak in bo= th IAS and Fuel Flow at the 6750rpm point at basically all altitudes.> I th= ink what this is suggesting is that increasing rpm beyond 6750 is only incr= easing wear and has no benefit given the current intake/exhaust configurati= on.> > With the current Prop Fine Pitch Limit, on initial WOT at Takeoff th= e engine consistently hits 6900rpm within ~6 seconds and 7000rpm by liftoff= at 70 KIAS.> It then generally builds to 7400rpm (With no pitch adjustment= - We presently don't have a Constant Speed Controller) before throttling b= ack as we turn downwind.> > I think this would suggest we ought adjust the = props fine limit marginally so that takeoff WOT yields approx 6700rpm and k= eeping the rpm as close to 6750rpm as > possible when seeking maximum power= by manual prop pitch adjustment.> A Constant Speed Controller would be nic= e!> > I=E2=80=99m now thinking we have enough data to tune the Mixture Corr= ection Table of the EC2=E2=80=99s computers for climbing at 6750rpm and as = Bill suggested cruising at 6000rpm.> > Next step in tuning in the Glasair S= uper IIRG will be playing with the cowl flaps and cooling drag. Presently t= he flaps are wide open and draggy.> I=E2=80=99m in the process of completin= g a little box of 5 differential pressure transducers (MPX10DP=E2=80=99s) m= ounted under the cowl.> I worked out that they interface quite nicely witho= ut any other circuitry with the Dynon Skyview's surplus EGT inputs via a ne= w Polynomial in the sensor config settings.> So hoping in the next few week= s to ascertain how the inlets, diffusers and outlets are functioning or not= .> What I like about the MPX10 interface with the Skyview EFIS is the simpl= icity of displaying the pressure data inflight while its all logged along w= ith engine and flight data > for analysis on the ground.> > I=E2=80=99ve go= t 7 more hours of Phase #1 testing.> So far both aircraft and engine are re= ally great.> > My friend and test pilot Dawie also demonstrated at the end = of todays flight - a Lazy Eight, a Roll and Wingover. > I felt sick for the= next 3 hours. I don't think aerobatics will be in my future.> > Thanks for= all the help you guys.> > Steve Izett> Perth Western Australia> Glasair Su= per IIRG Renesis 4 port RD1C EC2 EM3> > > > > > > > > > On 7 Aug 2020, at 2= :25 pm, William Jepson wrjjrs@gmail.com wrote= :> > > > Stephen, > > The answer to one of your questions is easy. A fast c= ruise RPM should be 6000. Mazda did many instrumented runs and found that 6= 000 rpm was a sweet spot where the dynamics balanced perfectly. At 6000 the= re is almost no load on the bearings. The rotary would run at that RPM inde= finitely. If you have more power at higher speeds you can use that for maxi= mum speed. Those RPMs are eshaft RPMs not propeller.> > Bill> > > > On Thu,= Aug 6, 2020 at 4:15 PM Stephen Izett stephen.izett@gmail.com wrote:> > Hi Guys> > > > Thanks for all the feedback.> > I= think I didn=E2=80=99t explain my objective clearly enough.> > > > Some qu= estions:> > 1. Given I have variable pitch, what combination of MAP and RPM= should I climb or cruise at? With fixed pitch I dont suppose you think in = these terms.> > So should I be Climbings at WOT & 7000rpm OR WOT & 6300rpm = Best Power Mixture.> > > > I think Lynn best understood my intention of try= ing to use the flight as a dyne - I didn=E2=80=99t realise the complexity o= f the relationship of mixture and timing at various settings, thanks Lynn.>= > I thought by keeping WOT and mixture constant I might ascertain a maximu= m efficiency combination for MAP/RPM.> > > > I=E2=80=99d like a combination= for max power. I=E2=80=99m thinking identified by higher fuel burn and IAS= for the climb, and > > a max efficiency/ecconomy combination for cruise id= entified by best miles per gallon.> > > > I thought our Renesis with our mo= dified OEM (shortened) manifold but no variable intake valves etc. would ha= ve a distinctive peak at ~6400-6600rpm.> > > > 2. I=E2=80=99m finding tunin= g the EC2 (objective being EC provides constant mixture across the flight e= nvelope) is dependant on the combination I choose to tune it at. > > Eg. Tu= ne EC2 MCT for one MAP/RPM combination, say a cruise of 18=E2=80=9D AND 500= 0 rpm, then the EC will not be able to provide a constant mixture if I then= choose 18=E2=80=9D at 6000rpm.> > My EC2 has Tracy=E2=80=99s 8 table setup= but fueling requirements given the extra permutations provided by the vari= able pitch prop (climbing that hill - which gear should I use - 3rd 4th or = 5th??) > > appears to stretch its inherent capabilities. So I want a plan f= or what MAP/RPM I will use and then adjust/tune the EC MCT for that combina= tion.> > > > Thanks again guys.> > > > Steve Izett> > > > > >=C2=A0 all is = nice if you fly that combination. If I then choose ab> > > > > On 7 Aug 202= 0, at 6:16 am, lehanover lehanover@aol.com wr= ote:> > > > > > Your thinking is correct. Control full throttle RPM with lo= ad. Then experiment always at that particular RPM until you have whatever d= ata point you were after. Everything affects everything so it may be that (= for example) advancing ignition timing at one RPM adds power but at another= RPM reduces power. A rich mixture at one RPM may increase power but reduce= power at another RPM. To recover even similar data on consecutive days is = difficult. The SAE has some charts that produce a multiplier to account for= density temperature and so on. Required to compare results day to day. It = takes a long time to collect good data..........> > > > > > Lynn E. Hanover > > > > > > > > > > > > https://search.aol.com/aol/image?p=3Ddyno+sheets+f= or+stock+rx-7+engines&s_it=3Dimg-ans&v_t=3Dloki-keyword&fr=3Dloki-keyword&i= mgurl=3Dhttp%3A%2F%2Fwww.rx7club.com%2Fattachments%2Ftime-slips-dyno-128%2F= 346326d1243952257-anyone-have-stock-turbo-ii-dyno-graph-stock-s4-t2.jpg#id= =3D19&iurl=3Dhttp%3A%2F%2Fwww.rx7club.com%2Fattachments%2Ftime-slips-dyno-1= 28%2F346326d1243952257-anyone-have-stock-turbo-ii-dyno-graph-stock-s4-t2.jp= g&action=3Dclick> > > > > > --> > Homepage:=C2=A0 http://www.flyrotary.com/= > > Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrota= ry/List.html> > > --> Homepage:=C2=A0 http://www.flyrotary.com/> Archive an= d UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrotary/List.html --Homepage:=C2=A0 http://www.flyrotary.com/Archive and UnSub:=C2=A0 http://= mail.lancaironline.net:81/lists/flyrotary/List.html ------=_Part_1207173_1360906795.1596845338836 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The impossible is possible................

Along the way to tuning success you will find that a = specific combination of facts may appear and disappear within a few RPM.&nb= sp; Such as induction tube length VS exhaust system harmonics/back pressure= . Every RPM would suggest that a specific tuned intake length would be idea= l. See the Mazda winning 4 rotor and its adjustable length intake runners.&= nbsp; Exhaust back pressure may be high at one RPM and nonexistent at anoth= er. The whole reason for disconnecting the intake and exhaust  in the = Renesis among other things is to get the tuning down to some form of normal= (Meet California UHC). Having no overlap is a giant step in that direction= . The poor exhaust shapes help pollute the incoming charge a bit so as to r= educe combustion temps and pull back Oxides of Nitrogen. I have seen movies= of fuel air flowing backwards in an intake runner.    When you r= ecord what appears to be faulty data do not discard it and then see it agai= n the next day.           When you make a cha= nge....make it a big one so you can see which way that one took you. Never = make more than one change.  Use the SAE tables to take all of the data= down to sea level. Before you compare two data sets.   It is a s= teep learning curve......but it will come to you.  I had a fabulous St= uska dyno in my shop for years.
and a flow bench. I never did learn all I should have= .

Fixed pitch props (In effect) reduce pitch as air spe= ed through the disc increases.  The suggestion that you turned up 9,50= 0 RPM gives me chills. What would the tip speeds be then?

You can get above 10,000 RPM with 13-B rotors but the= y must be very light and you must look inside after every race because the = tend to crack when that light. Note that the Renesis rear main bearing is t= wo different diameters to allow for that standing sign wave that forms in t= he crank.  Nobody uses Fram filters or lets friends turn over 8,000 RP= M
Lynn E. Hanover

In a message dated 8/7/2020 6:48:47 PM Eastern Standard Time, flyrotary@lan= caironline.net writes:

Hi Charlie and all

On the four runs - Speeds were:
147 KIAS 21.6” @ 9500 WOT
136 KIAS 18.2” @ 7500 (Not WOT)
160 KIAS 24.8” @ 6000 WOT
165 KIAS 26.2” @ 4500 WOT

Prop hub is Airmaster 3 blade electric with Aerotek Blades=

On looking over the 4500 ft run:
    As RPM steps up from 5500-7250 (in 250r= pm inc) over 9 mins (OAT 49)
    Temps gradually build from 172/154 to 1= 98/171 (Oil/Water)
    Fuel Flow goes from 14.5 peaking at 16.= 2 (6750) before ending at 15.8
    KIAS 160 peaking at 168 (7000) before e= nding at 166

We probably haven’t allowed enough time between chan= ges for full settling of the numbers, but the trends seem consistent.

Not sure I agree with your thoughts re engine rpm rising a= nd drag constant or rising =3D power must be increasing.
Torque x RPM =3D Power
RPM is increasing, but if torque is decreasing faster than= rpm is rising, power will be decreasing.

What I was interested in discovering was the max power RPM= .
My logic is, even if power is constant after 6750rpm (ie. = rpm increasing matches torque decreasing) there is no value in spinning her= above that rpm.

What science could I do to discover this?
Rightly or wrongly, thats why I value this list, I was loo= king for the peek in Fuel Flow AND IAS (I’m relying on the wideband O= 2 being accurate and keeping mixture constant)
Its not anything like dramatic, but I think I can maybe se= e evidence of that best power (torque peek) RPM being somewhere around the = 6750rpm setting.
We had been spinning her up 600+RPM higher, perhaps for no= advantage.

On another note about the Intake manifold. We shortened th= e OEM unit to lift peak torque from Mazda's 5000rpm documented curve, hopin= g for something in the low 6000’s.
We also kept the VDI valve that opens at high RPM to provi= de Mazda’s Renesis intake shockwave charging, but presently I cant ac= tivate the valve in flight.
And to be honest it seems to be producing a pleasing amoun= t of hp at that 6750rpm.

On Takeoff with a mixture at a Lambda of 0.9 / 13.2 AFR sh= e is burning 17 Gal of our Premium Unleaded fuel using 1 Ounce / Gal of two= stroke oil, whatever hp that equates too.

Is my logic OK here or am I just dreaming?

Cheers

Steve





















  

  


> On 7 Aug 2020, at 10:34 pm, Charlie England ceengland7@gma= il.com <flyrotary@lancaironline.net> wrote:
>
> That's curious. Are you saying that fuel flow *decrea= sed* as rpm *increased* above 6750 rpm? And airspeed decreased, as well? Th= e only way fuel flow should decrease as rpm increases is if the load on the= engine is going down.
>
> Is the prop running out of pitch (or ability to absor= b the HP) as you get faster? Is the airframe hitting a drag wall due to coo= ling drag (still shouldn't show a reduction in fuel flow; it just wouldn't = go any faster)?
>
> What actual speeds are you achieving when this is hap= pening?
>
> Refresh my memory; who's prop (what blades) is it?
>
> Do engine temps go up as you get above 6750 rpm?
>
> Think about the 'airplane as dyno' thing: If rpm cont= inues to go up, and the drag (our substitute for torque on the engine brake= in a real dyno) stays the same or increases, then power *must* be increasi= ng, and so must fuel flow. Simple math; (torque*rpm)/5252. So, was the plan= e going downhill, or was the prop unable to absorb the additional power and= decoupling, unloading the engine?
>
> Charlie
>
> On Fri, Aug 7, 2020 at 9:01 AM Stephen Izett stephen.ize= tt@gmail.com <flyrotary@lancaironline.net> wrote:
> Hi Guys.
>
> Today we did some engine data analysis at 9500, 7500,= 6000 and 4500 feet agl.
> WOT with constant best power mixture of 0.9 Lambda.
> We looked at Fuel Flow and IAS at 5500,5750,6000,6250= ,6500,6750 & 7000rpm.
> The data revealed a very slight peak in both IAS and = Fuel Flow at the 6750rpm point at basically all altitudes.
> I think what this is suggesting is that increasing rp= m beyond 6750 is only increasing wear and has no benefit given the current = intake/exhaust configuration.
>
> With the current Prop Fine Pitch Limit, on initial WO= T at Takeoff the engine consistently hits 6900rpm within ~6 seconds and 700= 0rpm by liftoff at 70 KIAS.
> It then generally builds to 7400rpm (With no pitch ad= justment - We presently don't have a Constant Speed Controller) before thro= ttling back as we turn downwind.
>
> I think this would suggest we ought adjust the props = fine limit marginally so that takeoff WOT yields approx 6700rpm and keeping= the rpm as close to 6750rpm as
> possible when seeking maximum power by manual prop pi= tch adjustment.
> A Constant Speed Controller would be nice!
>
> I’m now thinking we have enough data to tune th= e Mixture Correction Table of the EC2’s computers for climbing at 675= 0rpm and as Bill suggested cruising at 6000rpm.
>
> Next step in tuning in the Glasair Super IIRG will be= playing with the cowl flaps and cooling drag. Presently the flaps are wide= open and draggy.
> I’m in the process of completing a little box o= f 5 differential pressure transducers (MPX10DP’s) mounted under the c= owl.
> I worked out that they interface quite nicely without= any other circuitry with the Dynon Skyview's surplus EGT inputs via a new = Polynomial in the sensor config settings.
> So hoping in the next few weeks to ascertain how the = inlets, diffusers and outlets are functioning or not.
> What I like about the MPX10 interface with the Skyvie= w EFIS is the simplicity of displaying the pressure data inflight while its= all logged along with engine and flight data
> for analysis on the ground.
>
> I’ve got 7 more hours of Phase #1 testing.
> So far both aircraft and engine are really great.
>
> My friend and test pilot Dawie also demonstrated at t= he end of todays flight - a Lazy Eight, a Roll and Wingover.
> I felt sick for the next 3 hours. I don't think aerob= atics will be in my future.
>
> Thanks for all the help you guys.
>
> Steve Izett
> Perth Western Australia
> Glasair Super IIRG Renesis 4 port RD1C EC2 EM3
>
>
>
>
>
>
>
>
> > On 7 Aug 2020, at 2:25 pm, William Jepson wrjjrs@gmail.com<= /a> <flyrotary@lancaironline.net> wrote:
> >
> > Stephen,
> > The answer to one of your questions is easy. A f= ast cruise RPM should be 6000. Mazda did many instrumented runs and found t= hat 6000 rpm was a sweet spot where the dynamics balanced perfectly. At 600= 0 there is almost no load on the bearings. The rotary would run at that RPM= indefinitely. If you have more power at higher speeds you can use that for= maximum speed. Those RPMs are eshaft RPMs not propeller.
> > Bill
> >
> > On Thu, Aug 6, 2020 at 4:15 PM Stephen Izett stephen= .izett@gmail.com <flyrotary@lancaironline.net> wrote:
> > Hi Guys
> >
> > Thanks for all the feedback.
> > I think I didn’t explain my objective clea= rly enough.
> >
> > Some questions:
> > 1. Given I have variable pitch, what combination= of MAP and RPM should I climb or cruise at? With fixed pitch I dont suppos= e you think in these terms.
> > So should I be Climbings at WOT & 7000rpm OR= WOT & 6300rpm Best Power Mixture.
> >
> > I think Lynn best understood my intention of try= ing to use the flight as a dyne - I didn’t realise the complexity of = the relationship of mixture and timing at various settings, thanks Lynn.
> > I thought by keeping WOT and mixture constant I = might ascertain a maximum efficiency combination for MAP/RPM.
> >
> > I’d like a combination for max power. I&rs= quo;m thinking identified by higher fuel burn and IAS for the climb, and
> > a max efficiency/ecconomy combination for cruise= identified by best miles per gallon.
> >
> > I thought our Renesis with our modified OEM (sho= rtened) manifold but no variable intake valves etc. would have a distinctiv= e peak at ~6400-6600rpm.
> >
> > 2. I’m finding tuning the EC2 (objective b= eing EC provides constant mixture across the flight envelope) is dependant = on the combination I choose to tune it at.
> > Eg. Tune EC2 MCT for one MAP/RPM combination, sa= y a cruise of 18” AND 5000 rpm, then the EC will not be able to provi= de a constant mixture if I then choose 18” at 6000rpm.
> > My EC2 has Tracy’s 8 table setup but fueli= ng requirements given the extra permutations provided by the variable pitch= prop (climbing that hill - which gear should I use - 3rd 4th or 5th??)
> > appears to stretch its inherent capabilities. So= I want a plan for what MAP/RPM I will use and then adjust/tune the EC MCT = for that combination.
> >
> > Thanks again guys.
> >
> > Steve Izett
> >
> >
> >  all is nice if you fly that combination. I= f I then choose ab
> >
> > > On 7 Aug 2020, at 6:16 am, lehanover lehanover@aol.co= m <flyrotary@lancaironline.net> wrote:
> > >
> > > Your thinking is correct. Control full thro= ttle RPM with load. Then experiment always at that particular RPM until you= have whatever data point you were after. Everything affects everything so = it may be that (for example) advancing ignition timing at one RPM adds powe= r but at another RPM reduces power. A rich mixture at one RPM may increase = power but reduce power at another RPM. To recover even similar data on cons= ecutive days is difficult. The SAE has some charts that produce a multiplie= r to account for density temperature and so on. Required to compare results= day to day. It takes a long time to collect good data..........
> > >
> > > Lynn E. Hanover
> > >
> > >
> > >
> >
> >
> > --
>
>
> --


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