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 5.2.12) with ESMTP id 3527951 for flyrotary@lancaironline.net; Wed, 04 Mar 2009 22:28:23 -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.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090305032745.PJEE16134.fed1rmmtao104.cox.net@fed1rmimpo02.cox.net> for ; Wed, 4 Mar 2009 22:27:45 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo02.cox.net with bizsmtp id PFTj1b00L1CvZmk04FTlFM; Wed, 04 Mar 2009 22:27:46 -0500 X-Authority-Analysis: v=1.0 c=1 a=RgAroyKy78wA:10 a=U1ZaYnf293oA:10 a=kviXuzpPAAAA:8 a=EkCloD1j5JAarSoAPvEA:9 a=gmh5ZduZ7Y5GFGpYpCUA:7 a=eTv_FFaywphtDWj3Oyr2Xg6_OkQA:4 a=vNGxQsTWjH8A:10 a=4vB-4DCPJfMA:10 a=cx5sD7YXV02LjAeN:21 a=PmwuFp0ydJY5sYy-:21 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=pBLPPKk9mhAAtBuG5CkA:9 a=Jdfk7kC2J__DqID9eXwA:7 a=mukuemy62kpJXDg9_cdkS2yhm7gA:4 a=AfD3MYMu9mQA:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 Message-ID: <004601c99d42$58da3e70$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Questions on buying a rotary plane Date: Wed, 4 Mar 2009 19:27:43 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0043_01C99CFF.4A6CFD20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_0043_01C99CFF.4A6CFD20 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Mark, All of them can burn it if installed in an Experimental. They could = burn bio-diesel if they choose to. And that's the point. You choose to = burn Mogas, they choose not to. Its the same risk averse attitude that = makes them shake their heads at your choice to fly a car engine. I dont = think its fair to claim that as a rotary advantage because you are less = risk averse than the average Lyc/Cont flyer. Cant quantify the different aspect. I have a bad habit of doing things = that are different - sometimes it works out, sometimes not. In this = particular case it seems to be working. I agree that in some ways the = rotary is better. The basic engine is rock solid. Its all the stuff that = gets bolted to it thats a question mark. Some of the installations I've = seen (or seen pictures of) are outstanding. Some not so much. I think my = own installation is pretty well engineered but there are some things I'd = do differently and I dont think I'll really know until I have a lot more = hours. I know there's an awful high percentage of guys on this list = currently flying that have had at least one in-flight engine failure = (you know who you are). So I'd say that at least during the early test = flight hours (where i am right now) the rotary is statistically worse. Mike Wills RV-4 N144MW=20 ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Wednesday, March 04, 2009 5:21 AM Subject: [FlyRotary] Re: Questions on buying a rotary plane Mike, I agree with you that some of the Lycomings can burn mogas, but few = actually do it. I belong to the Lancair list and they are constantly = debating how to (or not to) run their engines so as to not damage them. = Most are just plain scared to run their engines lean of peak where they = are able to get close to the "advertised" bsfc. They're willing to burn = more fuel in order to sleep better at night. But the rotary is designed = to run on mogas. So, why not do it? Alcohol and possible vapor lock = are the only issues I know of, and with a properly designed EFI fuel = system, vapor lock isn't an issue. As long as they don't start blending = alcohol in the fuel in my neck of the woods, I'll keep burning mogas and = pocketing the difference. =20 You stated, "But really the biggest motivation was to do something a = little different." As for that statement... I couldn't agree more, but = how do you quantify something like that? And I believe that it isn't = just different, but in a lot of ways the rotary is definitely better. = Mark S. On Tue, Mar 3, 2009 at 9:55 PM, Mike Wills wrote: Glad I woke you guys up! :-) While it may appear from my post that I was trying to discourage = this guy and am not happy with my rotary powered airplane that is not = the case. I'm very happy with it. Will be even happier once I get all of = the little glitches fixed so I can just fly it. I simply wanted to make sure William understands what he's getting = into. What appears to be a fairly straight forward mod is a lot more = complicated than it appears and there are potential pitfalls that are = not necessarily obvious. My bad on the misread regarding fuel efficiency - he was talking = about homebuilt aircraft versus factory built planes, not rotaries = versus certified engines. I think he's still way off base here which was = why I replied to his post. Al, I dont know anyone who actually KNOWS what BSFC they acheive = with their Lyc/Cont. I know that low .40s is a published number that is = stuck in my head. I know what kind of fuel consumption I got with my Lyc = powered RV-6A at cruise and I know there are certainly enough flying Lyc = powered RVs to pretty firmly establish a cruise performance baseline. = Since there are more flying rotary powered RVs than other types, seems = like we should be able to get at least an idea of how they compare. Lets = challenge the rotary RV fliers here to post real cruise performance = (altitude, TAS, fuel consumption) and answer the question. Or give me a = year and 100 hours and I'll let you know how my RV-4 stacks up against = the -6A for a data point. As for your performance against conventional powered Velocities, = thats great news. I think thats one of the significant short comings of = our little group here. Common perception is that rotaries are gas hogs = and we dont do anything to accurately document and advertise our = performance. Mark, I agree that burning Mogas definitely makes a big difference = economy-wise. But that's a red herring. You could legally burn Mogas in = a Lyc/Cont also - just that most guys who are too conservative to choose = an auto conversion are also too conservative to burn Mogas. Burning = Mogas isnt the exclusive territory of the rotary. I personally know a = guy with a 200HP Lyc in an RV-8 who has burned Mogas exclusively for = years. Really what it comes down to is convenience and comfort. Lets be = fair, compare apples to apples, and while we're at it throw in the = additional cost and hassle of having to pour in 2 stroke oil for your = rotary (assuming you do that as most seem to do). I do totally agree with you on the price of parts. And that was one = of my huge motivations for going this route. But really the biggest = motivation was to do something a little different. When my RV-4 finally = makes it's appearance at a fly-in (hopefully this year) it's not going = to be lost in the sea of belly button RVs that show up. Mike Wills RV-4 N144MW ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Monday, March 02, 2009 9:51 PM Subject: [FlyRotary] Re: Questions on buying a rotary plane I dont know where you got the idea that rotaries are more fuel = efficient. Lycosaurs/Continentals typically have BSFCs in the low .40s. = The commonly accepted number for a rotary is about .50. Some here seem = to do better, others worse.=20 Mike; I=92m not disagreeing with the points in your message; but I am = wondering if you know anybody actually flying a Lyc/Cont and achieving = BSFC in the low 40=92s. I see numbers like .43 or .45 bandied about, = but I guess no one leans enough when flying to get that for fear of = burning out a valve =96 or worse. I=92ve yet to hear from anyone flying = a Velocity like mine with a Lyc who can surpass the speed/fuel burn that = I get with the 20B. I don=92t know why =96 it surprised me; but there it = is. I think in the real world operation the BSFCs are comparable. I = may have a bit lower drag because of smaller cowl; or other factors. Al =20 ------=_NextPart_000_0043_01C99CFF.4A6CFD20 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Mark,
 
 All of them can burn it if = installed in an=20 Experimental. They could burn bio-diesel if they choose to. And that's = the=20 point. You choose to burn Mogas, they choose not to. Its the same risk = averse=20 attitude that makes them shake their heads at your choice to fly a car = engine. I=20 dont think its fair to claim that as a rotary advantage because you are = less=20 risk averse than the average Lyc/Cont flyer.
 
 Cant quantify the different = aspect. I have a=20 bad habit of doing things that are different - sometimes it works out, = sometimes=20 not. In this particular case it seems to be working. I agree that in = some ways=20 the rotary is better. The basic engine is rock solid. Its all the stuff = that=20 gets bolted to it thats a question mark. Some of the installations I've = seen (or=20 seen pictures of) are outstanding. Some not so much. I think my own = installation=20 is pretty well engineered but there are some things I'd do differently = and I=20 dont think I'll really know until I have a lot more hours. I know = there's an=20 awful high percentage of guys on this list currently flying that have = had at=20 least one in-flight engine failure (you know who you are). So I'd say = that at=20 least during the early test flight hours (where i am right now) the = rotary is=20 statistically worse.
 
Mike Wills
RV-4 N144MW 
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Wednesday, March 04, 2009 = 5:21=20 AM
Subject: [FlyRotary] Re: = Questions on=20 buying a rotary plane

Mike,
 
I agree with you that some of the Lycomings = can burn=20 mogas, but few actually do it.  I belong to the Lancair = list=20 and they are constantly debating how to (or not to) run their engines = so as to=20 not damage them.  Most are just plain scared to run their engines = lean of=20 peak where they are able to get close to the = "advertised" bsfc. =20 They're willing to burn more fuel in order to sleep better at = night.  But=20 the rotary is designed to run on mogas.  So, why not do it?  = Alcohol and possible vapor lock are the only issues I know = of,=20 and with a properly designed EFI fuel system, vapor lock isn't an = issue.  As long as they don't start blending alcohol in the=20 fuel in my neck of the woods, I'll keep burning mogas and = pocketing=20 the difference. 
 
You stated, "But really the biggest motivation was to do = something a=20 little different."  As for that statement... I couldn't agree = more, but=20 how do you quantify something like that?  And I believe that it = isn't=20 just different, but in a lot of ways the rotary is=20 definitely better.   
Mark S.
On Tue, Mar 3, 2009 at 9:55 PM, Mike Wills = <rv-4mike@cox.net>=20 wrote:
Glad I woke you guys up! = :-)
 
While it may appear from my post = that I was=20 trying to discourage this guy and am not happy with my rotary = powered=20 airplane that is not the case. I'm very happy with it. Will be even = happier=20 once I get all of the little glitches fixed so I can just fly=20 it.
 
 I simply wanted to make sure = William=20 understands what he's getting into. What appears to be a fairly = straight=20 forward mod is a lot more complicated than it appears and there are=20 potential pitfalls that are not necessarily obvious.
 
 My bad on the misread = regarding fuel=20 efficiency - he was talking about homebuilt aircraft = versus=20 factory built planes, not rotaries versus certified engines. = I think=20 he's still way off base here which was why I replied to his=20 post.
 
 Al, I dont know anyone = who actually=20 KNOWS what BSFC they acheive with their Lyc/Cont. I know that low = .40s is a=20 published number that is stuck in my head. I know what kind of = fuel=20 consumption I got with my Lyc powered RV-6A at cruise and I = know there=20 are certainly enough flying Lyc powered RVs to pretty firmly = establish=20 a cruise performance baseline. Since there are more flying = rotary=20 powered RVs than other types, seems like we should be able to get at = least=20 an idea of how they compare. Lets challenge the rotary RV = fliers here=20 to post real cruise performance (altitude, TAS, fuel consumption) = and answer=20 the question. Or give me a year and 100 hours and I'll let you know = how my=20 RV-4 stacks up against the -6A for a data point.
 
 As for your performance = against=20 conventional powered Velocities, thats great news. I think thats one = of the=20 significant short comings of our little group here. Common = perception is=20 that rotaries are gas hogs and we dont do anything to accurately = document=20 and advertise our performance.
 
 Mark, I agree that burning = Mogas=20 definitely makes a big difference economy-wise. But that's a red = herring.=20 You could legally burn Mogas in a Lyc/Cont also - just that most = guys who=20 are too conservative to choose an auto conversion are also too = conservative=20 to burn Mogas. Burning Mogas isnt the exclusive territory of the=20 rotary. I personally know a guy with a 200HP Lyc in an RV-8 who = has=20 burned Mogas exclusively for years. Really what it comes down to is=20 convenience and comfort. Lets be fair, compare apples to = apples,=20 and while we're at it throw in the additional cost and hassle of = having to=20 pour in 2 stroke oil for your rotary (assuming you do that as most = seem to=20 do).
 
 I do totally agree with you = on the price=20 of parts. And that was one of my huge motivations for going this = route. But=20 really the biggest motivation was to do something a little = different. When=20 my RV-4 finally makes it's appearance at a fly-in (hopefully this = year) it's=20 not going to be lost in the sea of belly button RVs that show=20 up.
 
Mike Wills
RV-4 N144MW
 
 
----- Original Message ----- =
From: = Al=20 Gietzen
To: Rotary = motors in=20 aircraft
Sent: Monday, March 02, = 2009 9:51=20 PM
Subject: [FlyRotary] Re: = Questions on=20 buying a rotary plane

 I dont know = where you=20 got the idea that rotaries are more fuel efficient.=20 Lycosaurs/Continentals typically have BSFCs in the low .40s. The = commonly accepted number for a rotary is about .50. Some here = seem to do=20 better, others worse.

 

Mike;

 

I=92m not=20 disagreeing with the points in your message; but I am wondering = if you=20 know anybody actually flying a Lyc/Cont and achieving BSFC in = the low=20 40=92s.  I see numbers like .43 or .45 bandied about, but I = guess no=20 one leans enough when flying to get that for fear of burning out = a valve=20 =96 or worse.  I=92ve yet to hear from anyone flying a=20 Velocity = like mine=20 with a Lyc who can surpass the speed/fuel burn that I get with = the 20B.=20 I don=92t know why =96 it surprised me; but there it = is.

 

I = think in=20 the real world operation the BSFCs are comparable.  I may = have a=20 bit lower drag because of smaller cowl; or other=20 factors.

 

Al=20 =  


------=_NextPart_000_0043_01C99CFF.4A6CFD20--