X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4120345 for flyrotary@lancaironline.net; Wed, 10 Feb 2010 21:21:08 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao104.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100211022031.OSUW16123.fed1rmmtao104.cox.net@fed1rmimpo02.cox.net> for ; Wed, 10 Feb 2010 21:20:31 -0500 Received: from willsPC ([68.105.86.80]) by fed1rmimpo02.cox.net with bizsmtp id gSLX1d00B1k005Q04SLYea; Wed, 10 Feb 2010 21:20:32 -0500 X-VR-Score: -200.00 X-Authority-Analysis: v=1.1 cv=zS9SgV63hfBKgCfMNmcWTXDxxMKGbBeTgNVRdCpsi3s= c=1 sm=1 a=TWlVO4UZOuUA:10 a=XruvlouZCDbGUgEaRUiNZQ==:17 a=Ia-xEzejAAAA:8 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=8fvOh1mKAAAA:8 a=nUuTZ29dAAAA:8 a=Bp5r7WCVgQtJHD9-1hUA:9 a=LbokP2Yv-t51-fKLkcoA:7 a=BYkBxszrTZgmR1_JLfeZjcDcxsIA:4 a=5zrLeAV0Z70A:10 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=SVqzirnCOXUA:10 a=sT9W5Lx-gic9e9A4:21 a=WyK-awKyVAD5oDOy:21 a=4PR2P7QzAAAA:8 a=ytPPjj4hfvNuLyGkfKMA:9 a=OLDz2vHMk5QUNh8uQOAA:7 a=rkwlPI-F4lrKUCq0hg7_QV0XgS4A:4 a=djSSOgbfo6cA:10 a=xqPrIgXkO304g4pK:21 a=-36naLc5jRkfG0E7:21 a=XruvlouZCDbGUgEaRUiNZQ==:117 X-CM-Score: 0.00 Message-ID: <3DDF2D9D63DE49A0974D4632107DA739@willsPC> From: "Mike Wills" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to turbo Date: Wed, 10 Feb 2010 18:20:30 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008E_01CAAA7D.BA35C380" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_008E_01CAAA7D.BA35C380 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I feel better now. That lines up pretty well with the 191 true I = measured at 8500'. Still would like to duplicate that 2000+fpm though. Mike From: Dennis Haverlah=20 Sent: Wednesday, February 10, 2010 2:36 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. = Renesis to turbo Jeff, I have seen 194 mph true air speed on the EM-2. My GPS also was showing = the same number. I only went full throttle for about 5 minutes = traveling both north and south. I believe this was at around 7,000' = alt. I have never tried to get max. speed at 500' - I guess I am a = little chicken to run full out down low. Maybe I'll do it this spring. Dennis H. Jeff Luckey wrote: Dennis, =20 What is your top speed? =20 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Dennis Haverlah Sent: Tuesday, February 09, 2010 14:50 To: Rotary motors in aircraft Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: = N.A. Renesis to turbo =20 Ed, did you trim your propeller to less than 76 in. dia? I thought = you or Tracy had trimmed one to 74 in. =20 I've been flying my Renesis RV-7A for almost 3 years. My static is = about 5200 rpm and top end in flight is around 6300 rpm. I have the = 2.85:1 drive on my Renesis a Catto 76 in dia. and 88 in pitch composite = and a very quiet exhaust on a Van's RV-7A. I had fabricated the intake = using the original Renesis 4 port intake. I cut it off just above the = secondaries and added a plunum with a Mustang throttle body. Last = spring I replaced the intake with a new intake designed with Ed = Anderson's much needed assistance. The new intake really improved the = take-off, climb and top end performance. The new intake uses dynamic = ram effect - the reflected pulse from the closing of one rotor intake = causes a compression wave to bounce off the side of the rotor and the = tube lengths are such that the pulse arrives at the other rotors intake = port just before it closes. My top end RPM increased from about = 5800-5900 to 6300 with the new intake. I now see climb rates above 2000 = fpm at 100 kts. See attached photos of the old and new intake. Ron, you mentioned temperatures of water - 185F and oil 205F at 8000' = I normally see 20 deg. delta. between oil and water with oil hotter like = yours - but I don't see oil temp. above 200 in the summer. If you are = getting 205 oil in the winter it will probably be much too hot in the = summer. Temps are about linear with outside temp - a 25 deg increase in = outside temp will add about 25 to both oil and water! Also with your = prop turning 2450 rpm, the engine would be turning 6980 rpm. I'd think = you would be going much faster than 174 mph at that rpm with the same = prop, engine and gear drive as I have. Tracy, if you have the data = could you give us the RPMs you saw at the 205 and 217.5 air speeds? Dennis H.=20 Renesis RV-7A Austin, Tx. Ed Anderson wrote: Good point, Tracy =20 I had one instance where I my static and top end rpm were essentially = the same. I had a static of 6000 rpm and a top end in flight of around = 6100 rpm. But, in my case, the cause was very obvious - my muffler of = the time was limiting the top end to my static rpm. Once I changed the = muffler - top end rpm was again up around 6800 rpm. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Tracy Crook Sent: Tuesday, February 09, 2010 8:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: = N.A. Renesis to turbo =20 Ed's experience pretty much matches my own when changing gear drive = ratios. A little more top end. (Sun 100 results were 209 mph w/ 2.176 = drive vs 217.5 mph the next year with 2.85 drive.) Takeoff & climb = performance improved dramatically though. It's not an inexpensive = change though. What does mystify me is the small difference between Mike's static & = top end rpm. I got an 1100 rpm difference. 5200 vs 6300 with a 68 - 81 = Performance prop. Another detail I'm not certain about is whether Mike's manifold = pressure is or is not increasing during that last 1/3 - 1/2 throttle = travel with no power increase. Seems like he said it did go up but I'm = not sure. If it is going up, there is still something unexplained going = on. What was the MP doing Mike? Was it at full ambient at the point = where the rpm stopped increasing? Tracy On Tue, Feb 9, 2010 at 12:12 AM, Ed Anderson = wrote: Well, Mike, just for comparison, when I had a 2.17:1 and a 68 x72 Performance prop, 5200 -5400 rpm on a nominal 70deg day was what I got = for static. While I don't claim my set up was the best in the land, I think it was = a pretty fair set up. So I would say you are doing just fine. It does not matter how large a throttle body you have when the = manifold air density hits ambient or as close as it can given any losses in the = induction system - that's it. You can continue to open the throttle body, but = you will not get any more power. However, there is a way! Looking at some of the variables in the power equation we have: Power(HP) =3D Torque * rpm/ 5250, swapping some variables around we = get: RPM =3D Power/torque. So this indicates the rpm can increase if = either the power is increased or the torque is decreased. Well, it's difficult to increase the power by itself(unless you go to forced induction or = nitrous oxide) But one way to get more rpm (and ultimately more power) is to lower = the Torque load on the engine. Decreasing the Torque permits more engine = rpm even if power did not increase. However we know that more rpm =3D = more air =3D more power. The torque load on the engine caused by the prop decreases = as your gear ratio increases. By going to a 2.85:1 gear ratio that would reduce the load on the = engine by approx 25% (assuming the same prop at the same static rpm). Now the = rpm power relationship were linear (which it is not with a prop as the = load) then I should have gotten around 6650 rpm with the new gear box - well = not really - due to the cube root relationship between prop rpm and power, = it will be much less of an increase and due to the fact I put on a larger diameter prop. But in any case, all this theory aside, with the 2.85 and 74 x88 prop = I now get engine 6000 - 6200 rpm static or about an 13% increase in rpm. = So that's using use the same intake, throttle body and engine for both. = But now because the engine can turn faster (lesser prop load at any = specific rpm). Now the fact the engine is turning faster means it takes more airflow = to maintain the same (ambient) air density in the manifold. This is = because the higher engine rpm can "suck" that manifold volume (which didn't = change) down faster than it did before. This in turn means that the throttle = position has to be more open to let a sufficient increase in air flow need to = achieve and maintain that (hopefully) ambient air density in the manifold. So from what you are reporting, I really don't see anything poor about = your performance with your set up. In fact, it's pretty good. The new set up gave a noticeable benefit in take off performance (and = I do mean noticeable). However, the top end was relatively unaffected - = although I did measure an approx 4 mph increase in top aircraft speed. In any case, that is my experience. FWIW Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mike Wills Sent: Monday, February 08, 2010 10:36 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Throttle limits was Re: N.A. Renesis to turbo Thanks Ed. Mentioned this a few months ago and was convinced at least = for the moment, to just fly the plane as is. So that's what I have been = doing. To recap, my engine is an NA 13B built by Bruce Turrentine. It is a = second gen engine with Turbo rotor housings (no exhaust splitter) and high compression NA rotors. The exhaust uses 1 3/4" x 32" primaries into a = Burns merge collector, 2 1/2" outlet directly into my "muffler". My = "muffler" is essentially a 4 1/2" x 30" tube with some spiral baffles and 2 1/2" inlet/outlet. The intake uses a modified 87 lower manifold casting = port matched to the engine. The upper manifold uses 4 tubes (1 1/2" and 1 = 1/4" dia) over the top of the engine to a small dynamic chamber/plenum = directly over the oil filler port in the center iron housing. The throttle body copies Tracy's original - a stock second gen 3 throat TB cut down to = just 2 ports. The gearbox is Tracy's first RD-1 with 2.17 gears. Prop is a Warnke 68 = x 80 (not sure the pitch number is meaningful - everyone seems to measure = it differently). On the ground static RPM is about 5350 and is reached at = about 2/3 throttle opening. In flight max RPM I've seen is about 5750. The Warnke prop is unique due to the shape. The appearance gets a lot = of comments. I'm really hesitant to mess with it and screw it up = unless/until I can say with certainty that there isnt something else I can do with = tweaking (I'm thinking on the intake side) to improve airflow through the = engine. Hard to believe that there isnt more HP to be had when a hacked 2 = barrel TB is only 2/3 open and I've hit the limit. But like you say there are a = lot of variables. Mike -------------------------------------------------- From: "Ed Anderson" Sent: Monday, February 08, 2010 5:06 AM To: "Rotary motors in aircraft" Subject: [FlyRotary] Throttle limits was Re: N.A. Renesis to turbo > Hi Mike, > > Several things could be causing the situation you see in advancing = your > throttle but getting no increased engine rpm. This is not an = uncommon > situation. Ok assuming we are talking naturally aspired engine (no = forced > induction), fixed pitch prop and assuming your engine is basically = OK (not > weak on compression, etc), > > then the most likely cause is you have simply reach the point at = which > where the engine is producing all the power it can - given the prop = load > it > sees at that moment. Once that point is reached, then advancing the > throttle more does not result in more air flow through the engine = and > therefore no increase in power nor rpm. In fact, it can cause the = engine > to > run leaner and actually produce less power than a partial closed = throttle. > > It's sort of the chicken and the egg in that you need more power to > produce > more rpm, but power is dependent on air flow - which is dependent on = rpm > which dependent on power produced, etc. {:>). But to try to be a = bit more > helpful, look at it this way. > > > Basically for every throttle position (at a constant altitude, temp, = air > density, etc) there is one associated manifold pressure(air = density). > This > manifold pressure is a product of a number of variables, but the = most > dominating ones involving the engine are volumetric efficiency, = throttle > position and engine rpm. Now your volumetric efficiency is more or = less > fixed by the intake/exhaust design so we'll eliminate that for the = moment. > That leaves throttle position and rpm as controllable variables and = your > ambient air density as a fixed (for this discussion). > > > We know the engine is a positive displacement pump which displaces = the > same > volume once each engine cycle. The power the engine produces in that = cycle > is limited by the density of the air in the combustion chamber as = the > volume > is always a constant (fixed by size of your combustion chamber). = The air > density into the combustion chamber is dependent on the air density = in the > intake manifold. > > So that leaves us with: More throttle =3D higher manifold air = density =3D > =3D more oxygen + More fuel(permits more fuel to be burnt) =3D more = power =3D > more rpm. That is until you hit the limit - what limit you say? > > The limit is that once you have opened the throttle plate = sufficiently > that > the air density in the intake manifold is equal to ambient air = density (or > as close as its going to get- given intake losses) - then it will = not make > any difference (in power) to advance the throttle further. Once you = have > reached that limit, then advancing the throttle further does not = further > increase the air density in the manifold and therefore limits the = amount > of > fuel you can burn/power you can make. > > Clearly if you have a large throttle body you can reach that point = with a > smaller opening of the throttle plate than if you have a small = throttle > body. > > As I said - there can be other causes, but this is the one I think = most > folks run into. You can find the same situation even on the ground, = where > again once the manifold air density =3D ambient air density (or as = close as > your engine Ve will permit) you stop producing power increase even = if you > have throttle travel left. > > Therefore if your throttle body is sized so you get max power at = 100% > throttle opening a sea level, then with every increase in altitude, = you > will > find you have additional throttle travel that produces no increase = in > power. > The higher you go in altitude the more throttle travel will be = available > that results in no power increase. This is because the ultimate = limit is > based on the ambient air density. > > Hope this helped. > > Ed > > > > > Ed Anderson > > Rv-6A N494BW Rotary Powered > > Matthews, NC > > eanderson@carolina.rr.com > > http://www.andersonee.com > > http://www.dmack.net/mazda/index.html > > http://www.flyrotary.com/ > > http://members.cox.net/rogersda/rotary/configs.htm#N494BW > > http://www.rotaryaviation.com/Rotorhead%20Truth.htm > > -----Original Message----- > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On > Behalf Of Mike Wills > Sent: Sunday, February 07, 2010 12:51 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: N.A. Renesis to turbo > > Don, > > I'm at about 23 hours and am seeing roughly the same performance on = my > RV-4 > with a Bruce T built gen 2 13B. My temps are a little cooler. I'm = pretty > happy with the performance, but like you say, its not possible to = have too > much power. But I don't have room for a turbo and intercooler. > > I think there's more power in my NA engine. I'm still a little = mystified > by > the fact that at about 1/2 - 2/3 throttle the engine stops making = any more > power. But I decided to take several people's advice and just fly it = for a > while. I also think there's more speed in it via some drag = reduction. A > turbo would be nice to tame the noise though. > > I'll be interested in seeing how the Burns muffler works out for = you. I'm > not willing to dive into any more muffler experiments for the moment = since > my failed trial with the DNA muffler. But sooner or later, and one = way or > another I have to quiet this thing down. > > Mike Wills > RV-4 N144MW > > -------------------------------------------------- > From: "Don Wallker" > Sent: Saturday, February 06, 2010 6:21 PM > To: "Rotary motors in aircraft" > Subject: [FlyRotary] N.A. Renesis to turbo > >> Dear list, Turbo flyers and especially David Leonard, >> I've 16 flying hours on my RV-8 with a Renesis and all of = Tracy's >> stuff > >> and a Catto 76/88. The airplane flys great, just like an RV, no = gliding >> time, and about 36 hours on the ground. SPECS >> Full throttle 8,000' 174 mph indicated, 2450 on the prop, water = 185, >> oil > >> 205, >> Climb out 110 mph, rate of climb, 1250'/min. Field elevation 5046. >> >> These are not bad numbers, but I would like better. I've been = influenced >> by some of the the local jet jocks who say that there is no such = thing as >> too much horsepower and they are right! N113BR seems to be = performing >> about like a 160-170 HP RV. So I am investigating turboing it! = The idea >> is to have a little better than sea level performance on take off >> (designed for 210HP N.A.) and turbo normalizing at cruise. Up to = 12000' >> would be nice. >> During the air races this year, Dave Leonard showed up and I was = very >> impressed by his airplane. He was able to turbo and inter cool it = and >> have it all inside an RV cowl, so I'll likely base my installation = on >> his. Plus, he has been through the learning curve of 3 or so = turbos so >> he > >> knows what to do, what not to do and what would be better if he = were to >> do > >> it all over again. >> >> I've spent the afternoon looking through the archives, reading as = much as >> I can find about turbos, and downloading all the photos I can. = Here is >> what I am tentatively planning on doing. >> Get one of Techwelding's Renesis exhaust flanges made from 304 SS = and >> have > >> my local waterjet guy copy it and make one out of 321SS. I'll weld = 321 >> SS > >> and manifold it together and run it into the bottom of the turbo = that >> will sit right in front of the exhaust. The turbo will have = additional >> support. Run the turbo outlet air from it through a stock RX-7 = inter >> cooler sitting in front of the left cheek opening and then out to = the >> right side of the engine, probably routing it under the PSRU and = then up >> to a throttle body and manifold. Then four al tubes over the top = of the >> engine into a cut down and welded up stock RX-8 intake manifold. = The >> exhaust out of the turbo will run down and out in the usual center = of the >> back of the cowl opening. I am thinking of trying one of Burns = Stainless >> all SS mufflers. It is basically a glass pack, but instead of = glass, >> they > >> are using stainless steel wool and they say it is holding up for = the >> rotary racers. They make it any length you want and is about 4 lbs = with >> their SS vs 9 lbs with the hushpower 2 I'm using now. The = combustion air >> intake to the turbo will be on the aft left side of the cowl via an = NACA >> duct opening as Dave's is. >> The oil cooler will have to be moved to under the engine. I will = build >> up > >> a fiberglass scoop, probably based on Van's scoop and modify it to = have a >> bigger opening and be farther forward, closer to the prop. I will >> probably have the oil cooler made a little larger (Techwelding) = than the >> one I have now. >> >> That's the basic idea at this point. I'll finalize my plan, = prebuild as >> much as possible before tearing the airplane apart and try for as = little >> down time as possible. I'm looking for the list's critique here, = plus >> questions that I will have missed. The following are a list of = questions >> that I have. >> 1. Which turbo should I use, which orientation and who should I use = to do >> the work, plus what is the approximate price? TO4 hybrid? Dave = and >> Steve Brooks mention BNR turbo as a modifier. Who manufactures the >> turbo? >> 2. What is the ideal situation with a waste gate? Full open or = not, or, >> or? >> 3. I read about a N.O.oil line solenoid to the turbo bearings. I = assume >> that if the Turbo fails, you turn it on to the N.C. position to = prevent >> oil from being pumped down your exhaust? I assume the oil that is = used >> is > >> routed back to the sump. >> 4. What size exhaust is optimum? It seems Dave is running 2.5 = inch. >> 5. What size throttle body should I use and what would be a good = one? >> One > >> throttle body or two? 4. What size injectors should I use, and = where >> should the secondaries be placed? Dave is using 480cc and staging = is at >> 32 inches. Are you using the same for the primaries and is there = an idle >> problem with the larger injectors? >> 5. Anyone out there turboing a Renesis? Anyone flying one? >> 6. My compression is 9.7 to 1. Any problems with this higher >> compression ratio as long as I use an inter cooler and keep the = boost no >> higher than 35"? >> And lot more questions, but that's all I can think of now. >> So If any of you can add any thought, let me know. >> >> Don Walker >> >> -- >> 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 > > __________ Information from ESET NOD32 Antivirus, version of virus > signature > database 3267 (20080714) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > -- > 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 __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html =20 ------=_NextPart_000_008E_01CAAA7D.BA35C380 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I feel better now. That lines up pretty well = with the=20 191 true I measured at 8500'. Still would like to duplicate that = 2000+fpm=20 though.
 
Mike

Sent: Wednesday, February 10, 2010 2:36 PM
Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits = was Re:=20 N.A. Renesis to turbo

Jeff,

I have seen 194 mph true air speed on the = EM-2. My=20 GPS also was showing the same number.  I only went  full = throttle for=20 about 5 minutes traveling both north and south.  I believe this was = at=20 around 7,000' alt.   I have never tried to get max. speed at=20 500'  - I guess I am a little chicken to run full out down = low.  Maybe=20 I'll do it this spring.

Dennis H.

Jeff Luckey wrote:
=

Dennis,

 

What is = your top=20 speed?

 

From: = Rotary motors=20 in aircraft [mailto:flyrotary@lancaironlin= e.net]=20 On Behalf Of Dennis=20 Haverlah
Sent: = Tuesday,=20 February 09, 2010 14:50
To:=20 Rotary motors in aircraft
Subject: [FlyRotary] Re: rpm vs = Power was=20 : Throttle limits was Re: N.A. Renesis to turbo

 



Ed, did you trim your propeller to = less than=20 76 in. dia?  I thought you or Tracy had trimmed one to 74 = in. =20

I've been flying my Renesis RV-7A for almost 3 = years.   My=20 static is  about  5200 rpm and top end in flight is around = 6300=20 rpm.  I have the  2.85:1 drive on my Renesis a Catto 76 in = dia. and=20 88 in pitch composite and a very quiet exhaust on a Van's RV-7A.  = I had=20 fabricated  the intake using the original Renesis 4 port = intake.  I=20 cut it off just above the secondaries and added a plunum with a = Mustang=20 throttle body.  Last spring I replaced the intake with a new = intake=20 designed with Ed Anderson's much needed assistance.  The new = intake=20 really improved the take-off, climb and top end performance.  The = new=20 intake uses dynamic ram effect - the reflected pulse from the closing = of one=20 rotor intake causes a compression wave to bounce off the side of the = rotor and=20 the tube lengths are such that the pulse arrives at the other rotors = intake=20 port just before it closes.   My top end RPM increased from about = 5800-5900 to 6300 with the new intake.  I now see climb rates = above 2000=20 fpm at 100 kts.  See attached photos of the old and new=20 intake.

Ron, you mentioned temperatures of water - 185F and oil = 205F at=20 8000'  I normally see 20 deg. delta. between oil and water with = oil=20 hotter like yours - but I don't see oil temp. above 200 in the = summer. =20 If you are getting 205 oil in the winter it will probably be much = too=20 hot in the summer.  Temps are about linear with = outside temp -=20 a 25 deg increase in outside temp will add about 25 to both oil and=20 water!  Also with your prop turning 2450 rpm, the engine would be = turning=20 6980 rpm.  I'd think you would be going much faster than 174 mph = at that=20 rpm with the same prop, engine and gear drive as I have.  = Tracy, if = you have the=20 data could you give us the  RPMs you saw at the 205 and 217.5 air = speeds?

Dennis H.
Renesis RV-7A
Austin, Tx.

Ed Anderson=20 wrote:

Good=20 point, Tracy

 

I had one = instance=20 where I my static and top end rpm were essentially the same.  I = had a=20 static of 6000 rpm and a top end in flight of around 6100 rpm.  = But, in=20 my case, the cause was very obvious =96 my muffler of the time was = limiting the=20 top end to my static rpm.  Once I changed the muffler - top end = rpm was=20 again up around 6800 rpm.

 

Ed

 

Ed=20 Anderson

Rv-6A N494BW=20 Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com=

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

<= /DIV>

From:=20 Rotary motors in = aircraft [mailto:flyrotary@lancaironlin= e.net]=20 On Behalf Of Tracy=20 Crook
Sent: = Tuesday, February=20 09, 2010 8:21 AM
To:=20 Rotary motors in=20 aircraft
Subject: [FlyRotary] Re: rpm vs = Power was=20 : Throttle limits was Re: N.A. Renesis to=20 turbo

 

Ed's = experience pretty=20 much matches my own when changing gear drive ratios.  A little = more top=20 end.  (Sun 100 results were 209 mph w/ 2.176 drive vs 217.5 mph = the next=20 year with 2.85 drive.)   Takeoff & climb performance improved = dramatically though.  It's not an inexpensive change = though.

What=20 does mystify me is the small difference between Mike's static & = top end=20 rpm.  I got an 1100 rpm difference.  5200 vs 6300 with a 68 = - 81=20 Performance prop.

Another detail I'm not certain about is = whether=20 Mike's manifold pressure is or is not increasing during that last 1/3 = - 1/2=20 throttle travel with no power increase.  Seems like he said it = did go up=20 but I'm not sure.  If it is going up, there is still something=20 unexplained going on.  What was the MP doing Mike?  Was it = at full=20 ambient at the point where the rpm stopped = increasing?

Tracy


On Tue, Feb 9, 2010 at 12:12 AM, Ed Anderson = <eanderson@carolina.rr.com&g= t;=20 wrote:

Well, Mike, just for comparison, when I had = a 2.17:1=20 and a 68 x72
Performance prop, 5200 -5400 rpm on a nominal 70deg = day was=20 what I got for
static.

While I don't claim my set up was the = best in=20 the land, I think it was a
pretty fair set up.  So I would say = you are=20 doing just fine.

It does not matter how large a throttle body = you have=20 when the manifold air
density hits ambient or as close as it can = given any=20 losses in the induction
system - that's it.  You can continue = to open=20 the throttle body, but you
will not get any more power. However, = there is a=20 way!

Looking at some of the variables in the power equation we=20 have:

Power(HP) =3D Torque * rpm/ 5250, swapping some variables = around we=20 get:

RPM =3D Power/torque.  So this indicates the rpm can = increase=20 if either the
power is increased or the torque is decreased. Well, = it's=20 difficult to
increase the power by itself(unless you go to forced = induction=20 or nitrous
oxide)

But one way to get more rpm (and = ultimately more=20 power)  is to lower the
Torque load on the engine. =  Decreasing=20 the Torque permits more engine rpm
even if power did not increase.=20  However we know that more rpm =3D more air =3D
more power. = The torque=20 load on the engine caused by the prop decreases as
your gear ratio=20 increases.


By going to a 2.85:1 gear ratio that would = reduce the=20 load on the engine by
approx 25% (assuming the same prop at the = same static=20 rpm).  Now the rpm
power relationship were linear (which it is = not=20 with a prop as the load)
then I should have gotten around 6650 rpm = with the=20 new gear box - well not
really - due to the cube root relationship = between=20 prop rpm and power, it
will be much less of an increase and due to = the fact=20 I put on a larger
diameter prop.

But in any case, all this = theory=20 aside,  with the 2.85 and 74 x88 prop I now
get engine 6000 - = 6200 rpm=20 static or about an 13% increase in rpm.   So
that's using use = the same=20 intake, throttle body and engine for both.  But
now because = the engine=20 can turn faster (lesser prop load at any specific
rpm).

Now = the fact=20 the engine is turning faster means it takes more airflow = to
maintain the=20 same (ambient) air density in the manifold. This is because = the
higher=20 engine rpm can "suck" that manifold volume (which didn't change)=20 down
faster than it did before.  This in turn means that the = throttle=20 position
has to be more open to let a sufficient increase in air = flow need=20 to achieve
and maintain that (hopefully) ambient air density in the = manifold.

So from what you are reporting, I really don't see = anything=20 poor about your
performance with your set up. In fact, it's pretty=20 good.

The new set up gave a noticeable benefit in take off = performance=20 (and I do
mean noticeable).  However, the top end was = relatively=20 unaffected - although
I did measure an approx 4 mph increase in top = aircraft speed.

In any case, that is my=20 experience.

FWIW

Ed Anderson

Rv-6A N494BW Rotary=20 Powered

Matthews, NC

eanderson@carolina.rr.com
http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW=

http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original=20 Message-----
From: Rotary motors in=20 aircraft [mailto:flyrotary@lancaironline.net]=20 On
Behalf Of Mike Wills
Sent: Monday, February 08, 2010 10:36 = PM
To:=20 Rotary motors in=20 aircraft
Subject: [FlyRotary] Re: Throttle limits = was Re:=20 N.A. Renesis to turbo

Thanks Ed. Mentioned this a few months = ago and=20 was convinced at least for
the moment, to just fly the plane as is. = So=20 that's what I have been doing.

To recap, my engine is an NA 13B = built=20 by Bruce Turrentine. It = is a=20 second
gen engine with Turbo rotor housings (no exhaust splitter) = and=20 high
compression NA rotors. The exhaust uses 1 3/4" x 32" primaries = into a=20 Burns
merge collector, 2 1/2" outlet directly into my "muffler". My = "muffler" is
essentially a 4 1/2" x 30" tube with some spiral = baffles and 2=20 1/2"
inlet/outlet. The intake uses a modified 87 lower manifold = casting=20 port
matched to the engine. The upper manifold uses 4 tubes (1 1/2" = and 1=20 1/4"
dia) over the top of the engine to a small dynamic = chamber/plenum=20 directly
over the oil filler port in the center iron housing. The = throttle=20 body
copies Tracy's = original - a=20 stock second gen 3 throat TB cut down to just 2
ports.

The = gearbox=20 is Tracy's = first = RD-1=20 with 2.17 gears. Prop is a Warnke 68 x 80
(not sure the pitch = number is=20 meaningful - everyone seems to measure it
differently). On the = ground=20 static RPM is about 5350 and is reached at about

2/3 throttle = opening.=20 In flight max RPM I've seen is about 5750.

The Warnke prop is = unique=20 due to the shape. The appearance gets a lot of
comments. I'm really = hesitant to mess with it and screw it up unless/until I

can say = with=20 certainty that there isnt something else I can do with = tweaking

(I'm=20 thinking on the intake side) to improve airflow through the=20 engine.

Hard to believe that there isnt more HP to be had when = a hacked=20 2 barrel TB
is only 2/3 open and I've hit the limit. But like you = say there=20 are a lot=20 = of

variables.

Mike

---------------------------------= -----------------
From:=20 "Ed Anderson" <eanderson@carolina.rr.com&g= t;
Sent:=20 Monday, February 08, 2010 5:06 AM
To: "Rotary=20 motors in aircraft" <flyrotary@lancaironline.net>
Subject:=20 [FlyRotary] Throttle limits was  Re: N.A. Renesis to = turbo

> Hi=20 Mike,
>
> Several things could be causing the situation = you see in=20 advancing your
> throttle but getting no increased engine rpm.=20  This is not an uncommon
> situation. Ok assuming we are = talking=20 naturally aspired engine (no forced
> induction), fixed pitch = prop and=20 assuming your engine is basically OK (not
> weak on compression, = etc),
>
> then the most  likely cause is you have = simply=20 reach the point at which
> where the engine is producing all the = power=20 it can - given the prop load
> it
> sees at that moment.=20  Once that point is reached, then advancing the
> throttle = more=20 does not result in more air flow through the engine and
> = therefore no=20 increase in power nor rpm.  In fact, it can cause the = engine
>=20 to
> run leaner and actually produce less power than a partial = closed=20 throttle.
>
> It's sort of the chicken and the egg in that = you=20 need more power to
> produce
> more rpm, but power is = dependent on=20 air flow - which is dependent on rpm
> which dependent on power=20 produced, etc. {:>).  But to try to be a bit more
> = helpful,=20 look at it this way.
>
>
> Basically for every = throttle=20 position (at a constant altitude, temp, air
> density, etc) = there is one=20 associated manifold pressure(air density).
> This
> = manifold=20 pressure is a product of a number of variables, but the most
>=20 dominating ones involving the engine are volumetric efficiency,=20  throttle
> position and engine rpm.  Now your = volumetric=20 efficiency is more or less
> fixed by the intake/exhaust design = so we'll=20 eliminate that for the moment.
> That leaves throttle position = and rpm=20 as controllable variables and your
> ambient air density as a = fixed (for=20 this discussion).
>
>
> We know the engine is a = positive=20 displacement pump which displaces the
> same
> volume once = each=20 engine cycle. The power the engine produces in that cycle
> is = limited=20 by the density of the air in the combustion chamber as the
>=20 volume
> is always a constant (fixed by size of your combustion=20 chamber).  The air
> density into the combustion chamber is = dependent on the air density in the
> intake = manifold.
>
>=20 So that leaves us with:  More throttle =3D higher manifold air = density=20 =3D
>  =3D more oxygen + More fuel(permits more fuel to be = burnt) =3D=20 more power =3D
> more rpm.  That is until you hit the limit = - what=20 limit you say?
>
> The limit is that once you have opened = the=20 throttle plate sufficiently
> that
> the air density in = the intake=20 manifold is equal to ambient air density (or
> as close as its = going to=20 get- given intake losses) - then it will not make
> any = difference (in=20 power) to advance the throttle further.  Once you have
> = reached=20 that limit, then advancing the throttle further does not = further
>=20 increase the air density in the manifold and therefore limits the=20 amount
> of
> fuel you can burn/power you can=20 make.
>
> Clearly if you have a large throttle body you = can reach=20 that point with a
> smaller opening of the throttle plate than = if you=20 have a small throttle
> body.
>
> As I said - there = can be=20 other causes, but this is the one I think most
> folks run into. = You can=20 find the same situation even on the ground, where
> again once = the=20 manifold air density =3D ambient air density (or as close as
> = your engine=20 Ve will permit) you stop producing power increase even if you
> = have=20 throttle travel left.
>
> Therefore if your throttle body = is sized=20 so you get max power at 100%
> throttle opening a sea level, = then with=20 every increase in altitude, you
> will
> find you have = additional=20 throttle travel that produces no increase in
> power.
> = The higher=20 you go in altitude the more throttle travel will be available
> = that=20 results in no power increase.  This is because the ultimate limit = is
> based on the ambient air density.
>
> Hope this = helped.
>
> Ed
>
>
>
>
> Ed=20 Anderson
>
> Rv-6A N494BW Rotary Powered
>
> = Matthews,=20 NC
>
> eanderson@carolina.rr.com>
>=20 http://www.andersonee.com
>
> http://www.dmack.net/mazda/index.html
>
>= http://www.flyrotary.com/
>
> http://members.cox.net/rogersda/rotary/configs.htm#N494BW=
>
>=20 http://www.rotaryaviation.com/Rotorhead%20Truth.htm>
>=20 -----Original Message-----
> From: Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net]=20 On
> Behalf Of Mike Wills
> Sent: Sunday, February 07, = 2010 12:51=20 PM
> To: Rotary motors in=20 aircraft
> Subject: [FlyRotary] Re: N.A. = Renesis to=20 turbo
>
> Don,
>
> I'm at about 23 hours and = am seeing=20 roughly the same performance on my
> RV-4
> with a Bruce T = built=20 gen 2 13B. My temps are a little cooler. I'm pretty
> happy with = the=20 performance, but like you say, its not possible to have too
> = much=20 power. But I don't have room for a turbo and = intercooler.
>
> I=20 think there's more power in my NA engine. I'm still a little = mystified
>=20 by
> the fact that at about 1/2 - 2/3 throttle the engine stops = making=20 any more
> power. But I decided to take several people's advice = and just=20 fly it for a
> while. I also think there's more speed in it via = some=20 drag reduction. A
> turbo would be nice to tame the noise=20 though.
>
> I'll be interested in seeing how the Burns = muffler=20 works out for you. I'm
> not willing to dive into any more = muffler=20 experiments for the moment since
> my failed trial with the DNA = muffler.=20 But sooner or later, and one way or
> another I have to quiet = this thing=20 down.
>
> Mike Wills
> RV-4 N144MW
>
>=20 --------------------------------------------------
> From: "Don = Wallker"=20 <drwalker@gbis.com>
> = Sent:=20 Saturday, February 06, 2010 6:21 PM
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>=20 Subject: [FlyRotary] N.A. Renesis to turbo
>
>> Dear = list,=20 Turbo flyers and especially David=20 Leonard,
>>    I've 16 flying = hours on my=20 RV-8 with a Renesis and all of Tracy's
>= >=20 stuff
>
>> and a Catto 76/88.  The airplane flys = great,=20 just like an RV, no gliding
>> time, and about 36 hours on = the=20 ground. SPECS
>> Full throttle 8,000'   174 mph = indicated, 2450=20 on the prop, water 185,
>> oil
>
>> = 205,
>>=20 Climb out 110 mph, rate of climb, 1250'/min.  Field elevation=20 5046.
>>
>> These are not bad numbers, but I would = like=20 better.  I've been influenced
>> by some of the the = local jet=20 jocks who say that there is no such thing as
>> too much = horsepower=20 and they are right!   N113BR seems to be performing
>> = about=20 like a 160-170 HP RV.  So I am investigating turboing it! =  The=20 idea
>> is to have a little better than sea level performance = on take=20 off
>> (designed for 210HP N.A.) and turbo normalizing at = cruise.=20  Up to 12000'
>> would be nice.
>> During the = air races=20 this year, Dave Leonard = showed up=20 and I was very
>> impressed by his airplane.  He was = able to=20 turbo and inter cool it and
>> have it all inside an RV cowl, = so I'll=20  likely base my installation on
>> his.  Plus, he = has been=20 through the learning curve of 3 or so turbos so
>>=20 he
>
>> knows what to do, what not to do and what would = be=20 better if he were to
>> do
>
>> it all over=20 again.
>>
>> I've spent the afternoon looking = through the=20 archives, reading as much as
>> I can find about turbos, and=20 downloading all the photos I can.  Here is
>> what I am=20 tentatively planning  on doing.
>> Get one of = Techwelding's=20 Renesis exhaust flanges made from 304 SS and
>>=20 have
>
>> my local waterjet guy copy it and make one = out of=20 321SS.  I'll weld 321
>> SS
>
>> and=20  manifold it together and run it into the bottom of the turbo=20 that
>> will sit right in front of the exhaust.  The = turbo will=20 have additional
>> support.  Run the turbo outlet air = from it=20 through a stock RX-7 inter
>> cooler sitting in front of the = left=20 cheek opening and then out to the
>> right side of the = engine,=20 probably routing it under the PSRU and then up
>> to a = throttle body=20 and manifold.  Then four al tubes over the top of the
>> = engine=20 into a cut down and welded up stock RX-8  intake manifold.=20  The
>> exhaust out of the turbo will run down and out = in the=20 usual center of the
>> back of the cowl opening.  I am = thinking=20 of trying one of Burns Stainless
>> all SS mufflers.  It = is=20 basically a glass pack, but instead of glass,
>>=20 they
>
>> are using stainless steel wool and they say = it is=20 holding up for the
>> rotary racers.  They make it any = length=20 you want and is about 4 lbs with
>> their SS vs 9 lbs with = the=20 hushpower 2 I'm using now.  The combustion air
>> intake = to the=20 turbo will be on the aft left side of the cowl via an NACA
>> = duct=20 opening as Dave's is.
>> The oil cooler will have to be moved = to=20 under the engine.  I will build
>> = up
>
>> a=20 fiberglass scoop, probably based on Van's scoop and modify it to have=20 a
>> bigger opening and be farther forward, closer to the = prop.=20  I will
>> probably  have the oil cooler made a = little=20 larger (Techwelding) than the
>> one I have=20 now.
>>
>> That's the basic idea at this point. =  I'll=20 finalize my plan, prebuild as
>> much as possible before = tearing the=20 airplane apart and try for as little
>> down time as = possible.=20  I'm looking for the list's critique here, plus
>> = questions=20 that I will have missed.  The following are a list of=20 questions
>> that I have.
>> 1. Which turbo should I = use,=20 which orientation and who should I use to do
>> the work, = plus what=20 is the approximate price?   TO4 hybrid?  Dave = and
>> Steve=20 Brooks mention BNR turbo as a modifier.  Who manufactures = the
>>=20 turbo?
>> 2. What is the ideal situation with a waste gate?=20  Full open or not, or,
>> or?
>> 3. I read = about a=20 N.O.oil line solenoid to the turbo bearings.  I = assume
>> that=20 if the Turbo fails, you turn it on to the N.C. position to = prevent
>>=20 oil from being pumped down your exhaust?  I assume the oil that = is=20 used
>> is
>
>> routed back to the = sump.
>>=20 4. What size exhaust is optimum?  It seems Dave is running 2.5=20 inch.
>> 5.  What size throttle body should I use and = what would=20 be a good one?
>> One
>
>> throttle body or = two? 4.=20  What size injectors should I use, and where
>> should = the=20 secondaries be placed?   Dave is using 480cc and staging is=20 at
>> 32 inches.  Are you using the same for the = primaries and=20 is there an idle
>> problem with the larger = injectors?
>> 5.=20  Anyone out there turboing a Renesis?  Anyone flying=20 one?
>> 6.  My compression is 9.7 to 1.   Any = problems with=20 this higher
>> compression ratio as long as I use an inter = cooler and=20 keep the boost no
>> higher than 35"?
>> And lot = more=20 questions, but that's all I can think of now.
>> So If any of = you can=20 add any thought, let me know.
>>
>> Don=20 Walker
>>
>> --
>> Homepage:  http://www.flyrotary.com/
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>
>
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