X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=PbaBeRpd c=1 sm=1 tr=0 a=9ckEMGzu87BYN+04MSaxJg==:117 a=o1vJpwMMYvDUKScKAq5SIg==:17 a=IkcTkHD0fZMA:10 a=x7bEGLp0ZPQA:10 a=CKeqCrOqW6IA:10 a=y4yBn9ojGxQA:10 a=3oc9M9_CAAAA:8 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=0qqORytXAAAA:8 a=7g1VtSJxAAAA:8 a=AfZtqGWxQ81NGzkqnYoA:9 a=4_69wdvq_JUFYMTP:21 a=6ub5Djv037VfcxN9:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=Urk15JJjZg1Xo0ryW_k8:22 a=Nj1bhqyGrdl6Az3_ctNx:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Stephen Izett stephen.izett@gmail.com" Received: from mail-pf1-f169.google.com ([209.85.210.169] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 617287 for flyrotary@lancaironline.net; Fri, 07 Aug 2020 20:29:37 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.210.169; envelope-from=stephen.izett@gmail.com Received: by mail-pf1-f169.google.com with SMTP id a79so2002494pfa.8 for ; Fri, 07 Aug 2020 17:29:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:content-transfer-encoding:mime-version:subject:date:references :to:in-reply-to:message-id; bh=7drws68t41rseOFw6FN3EFgA6ZH5kosaTKDw1OsfAh0=; b=fqbxzI37njoegcSamHhICqSmcZJgsuUTooS5guFztwTa+EUjaAFIdv3u2wxpOHWcjU nQyQCdjCbG7edWmLxq7Av/QGi+UERJd91miYekHfa475nwtnCwhYa/aW0XaPKblFfaus j3NEIE0Twv4xrNIJk88XcleKcJ6xMjcLn3PXn7UrQIAsfo3026G0SQ72R8e5Zy/YF1Nf EdECUxEw2zIaYGUT+0Fmywj47kBombO7PUBws251E58Hu80EtzqUdyDdgzbFY8E/QXf3 X7ir+RESzDJbyK7cnJg3673XnfGs9LyR6hc89VqMq6XHPXxpJOlI9ifSzuvKQEvObDB9 MAHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:content-transfer-encoding:mime-version :subject:date:references:to:in-reply-to:message-id; bh=7drws68t41rseOFw6FN3EFgA6ZH5kosaTKDw1OsfAh0=; b=Mh8mteWF6LTPXtEgKx7017Oerap5RAu8TkCevjJ27P+Vzh0qYLrX/SPI4ZTN0yMhVY 6fox8i3mPToROQMKKupRpcfP65qUWXbAcy8NHzLKK5Mh43ZS7P6Pk+WHe0OgBx6pmYij R8hSash7cHh6bn9wSP6AxOTvtEaD4pOxV8BNiFM4H7zrSeDggM6t2QQwBwwQBOA/dRFC zmENwnbHnDCdxHbQExnxJFDYPT3SGg80Enu0xvDMY4omb8kN0I2oX7ADwPdEaFGkeY3o BQTTqRYHY+3/kzSq02egzSsPmVrJ02jjunlV3TGk4AcYna5mWt/JFgvQR369upQYIBq8 z4Hg== X-Gm-Message-State: AOAM533UzpWcF36ePOnm0K+9l+kcbE87phQDsirYu1He52V7hHYRMXyS 8jr6xs5ChcrFkXpVIQ/et++2wqnp X-Google-Smtp-Source: ABdhPJydBrSYQ951sThivzEXz+jfqF7cOFutiEWtCkcmQPsF+1RH9W0ev1NtTzSbTpi04mjF8LVDjg== X-Received: by 2002:a62:1a49:: with SMTP id a70mr16185292pfa.297.1596846559564; Fri, 07 Aug 2020 17:29:19 -0700 (PDT) Return-Path: Received: from macbook-pro.lan (220-235-83-233.dyn.iinet.net.au. [220.235.83.233]) by smtp.gmail.com with ESMTPSA id w130sm15720726pfd.104.2020.08.07.17.29.17 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Aug 2020 17:29:19 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Subject: Re: [FlyRotary] Re: Dyno Sheet Date: Sat, 8 Aug 2020 08:29:15 +0800 References: To: Rotary motors in aircraft In-Reply-To: Message-Id: <40C11827-1F35-4852-A770-3711F8966FD8@gmail.com> X-Mailer: Apple Mail (2.3445.104.11) Sorry Lynn. My apologies those figures @ 9500, 7500,6000 and 4500 are = altitude. Didn=E2=80=99t click that they could also be read as RPM. = Sorry! Again thanks for the expertise, those things you mention re flow make = sense of the anomalies. Please excuse my ignorance - SAE tables?=20 Right, so convert those numbers back to sea level. Can you explain this = for me Lynn? Much appreciated.=20 Steve > On 8 Aug 2020, at 8:08 am, lehanover lehanover@aol.com = wrote: >=20 > The impossible is possible................ >=20 > Along the way to tuning success you will find that a specific = combination of facts may appear and disappear within a few RPM. Such as = induction tube length VS exhaust system harmonics/back pressure. Every = RPM would suggest that a specific tuned intake length would be ideal. = See the Mazda winning 4 rotor and its adjustable length intake runners. = Exhaust back pressure may be high at one RPM and nonexistent at another. = 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 reduce combustion temps and pull back Oxides of Nitrogen. I = have seen movies of fuel air flowing backwards in an intake runner. = When you record what appears to be faulty data do not discard it and = then see it again the next day. When you make a change....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 steep learning = curve......but it will come to you. I had a fabulous Stuska dyno in my = shop for years. > and a flow bench. I never did learn all I should have. >=20 > Fixed pitch props (In effect) reduce pitch as air speed through the = disc increases. The suggestion that you turned up 9,500 RPM gives me = chills. What would the tip speeds be then? >=20 > You can get above 10,000 RPM with 13-B rotors but they 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 two = different diameters to allow for that standing sign wave that forms in = the crank. Nobody uses Fram filters or lets friends turn over 8,000 RPM > Lynn E. Hanover >=20 > In a message dated 8/7/2020 6:48:47 PM Eastern Standard Time, = flyrotary@lancaironline.net writes: >=20 > Hi Charlie and all >=20 > On the four runs - Speeds were: > 147 KIAS 21.6=E2=80=9D @ 9500 WOT > 136 KIAS 18.2=E2=80=9D @ 7500 (Not WOT) > 160 KIAS 24.8=E2=80=9D @ 6000 WOT > 165 KIAS 26.2=E2=80=9D @ 4500 WOT >=20 > Prop hub is Airmaster 3 blade electric with Aerotek Blades >=20 > On looking over the 4500 ft run: > As RPM steps up from 5500-7250 (in 250rpm inc) over 9 mins (OAT = 49) > Temps gradually build from 172/154 to 198/171 (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 ending at 166 >=20 > We probably haven=E2=80=99t allowed enough time between changes for = full settling of the numbers, but the trends seem consistent. >=20 > 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 increasing, but if torque is decreasing faster than rpm is = rising, power will be decreasing. >=20 > 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. >=20 > What science could I do to discover this? > Rightly or wrongly, thats why I value 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 best power (torque peek) RPM being somewhere around the 6750rpm = setting. > We had been spinning her up 600+RPM higher, perhaps for no advantage. >=20 > On another note about the Intake manifold. We shortened the OEM unit = to lift peak torque from Mazda's 5000rpm documented curve, hoping for = something in 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 producing a pleasing amount of hp at = that 6750rpm. >=20 > On Takeoff with a mixture at a Lambda of 0.9 / 13.2 AFR she is burning = 17 Gal of our Premium Unleaded fuel using 1 Ounce / Gal of two stroke = oil, whatever hp that equates too. >=20 > Is my logic OK here or am I just dreaming? >=20 > Cheers >=20 > Steve >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 >=20 > =20 >=20 > =20 >=20 >=20 > > On 7 Aug 2020, at 10:34 pm, Charlie England ceengland7@gmail.com = wrote: > > > > That's curious. Are you saying that fuel flow *decreased* as rpm = *increased* above 6750 rpm? And airspeed decreased, as well? The 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 absorb the HP) as = you get faster? Is the airframe hitting a drag wall 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 'airplane as dyno' thing: If rpm continues 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 increasing, and = so must fuel flow. Simple math; (torque*rpm)/5252. So, was the plane = 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.izett@gmail.com = 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 rpm 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 WOT at Takeoff = the 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 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 pitch adjustment. > > A Constant Speed Controller would be nice! > > > > I=E2=80=99m now thinking we have enough data to tune the Mixture = Correction 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 Super IIRG will be playing with = the cowl flaps and cooling drag. Presently the flaps are wide open and = draggy. > > I=E2=80=99m in the process of completing a little box of 5 = differential pressure transducers (MPX10DP=E2=80=99s) mounted under the = cowl. > > 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 Skyview 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=E2=80=99ve 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 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 Super 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 cruise RPM = should be 6000. Mazda did many instrumented runs and found that 6000 rpm = was a sweet spot where the dynamics balanced perfectly. At 6000 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 wrote: > > > Hi Guys > > > > > > Thanks for all the feedback. > > > I think I didn=E2=80=99t explain my objective clearly 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 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 trying to use the = flight as a dyne - I didn=E2=80=99t 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=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 identified by = best miles per gallon. > > > > > > I thought our Renesis with our modified OEM (shortened) manifold = but no variable intake valves etc. would have a distinctive peak at = ~6400-6600rpm. > > > > > > 2. I=E2=80=99m finding tuning the EC2 (objective being 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, say a cruise of = 18=E2=80=9D AND 5000 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 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. If I then choose ab > > > > > > > On 7 Aug 2020, at 6:16 am, lehanover lehanover@aol.com = wrote: > > > > > > > > Your thinking is correct. Control full throttle 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 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+for+stock+rx-7+engines&s_= it=3Dimg-ans&v_t=3Dloki-keyword&fr=3Dloki-keyword&imgurl=3Dhttp%3A%2F%2Fww= w.rx7club.com%2Fattachments%2Ftime-slips-dyno-128%2F346326d1243952257-anyo= ne-have-stock-turbo-ii-dyno-graph-stock-s4-t2.jpg#id=3D19&iurl=3Dhttp%3A%2= F%2Fwww.rx7club.com%2Fattachments%2Ftime-slips-dyno-128%2F346326d124395225= 7-anyone-have-stock-turbo-ii-dyno-graph-stock-s4-t2.jpg&action=3Dclick > > > > > > > > > -- > > > Homepage: http://www.flyrotary.com/ > > > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html >=20 >=20 > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html