X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3527939 for flyrotary@lancaironline.net; Wed, 04 Mar 2009 22:36:31 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090305033554.MBNQ22254.fed1rmmtao106.cox.net@fed1rmimpo01.cox.net> for ; Wed, 4 Mar 2009 22:35:54 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo01.cox.net with bizsmtp id PFbr1b00X1CvZmk03Fbt9l; Wed, 04 Mar 2009 22:35:54 -0500 X-Authority-Analysis: v=1.0 c=1 a=RgAroyKy78wA:10 a=U1ZaYnf293oA:10 a=pGLkceISAAAA:8 a=kviXuzpPAAAA:8 a=VjNX197Mgd2jSfnUUP0A:9 a=5PpgVv_1UFfxhrGgQkEA:7 a=2YVRcoIUycETozqjs8r7wQGmRCIA:4 a=MInBT2ynV54A:10 a=MSl-tDqOz04A:10 a=4vB-4DCPJfMA:10 a=2oBgR5sZBl-Taqob:21 a=GWSVy7HqN-eiQl8x:21 a=Ia-xEzejAAAA:8 a=xG-MqPz_Ck2FlQyWutMA:9 a=1ok8mbBZRnR6HYkG-zgA:7 a=0DhkSmDe7WQ3WbL-5gzuoJoXDsIA:4 a=AfD3MYMu9mQA:10 a=-K1qMbr-rfkA:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 Message-ID: <004f01c99d43$7bc04e60$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Date: Wed, 4 Mar 2009 19:35:51 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004C_01C99D00.6D50C320" 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 Subject: Re: [FlyRotary] Re: Questions on buying a rotary plane This is a multi-part message in MIME format. ------=_NextPart_000_004C_01C99D00.6D50C320 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable William, No claims I've ever read about alcohol or fuel freezing. But its a fact = that ethanol has an affinity for water. And there's no doubt that water = freezes. I have no idea if there are any documented cases of this = actually happening in flight and causing an engine failure. In any case = I think it might be wise to keep tanks full if running MOGAS to minimize = condensation in the tanks. I know in my case I've found contamination in my fuel twice in the past = month. The second time happened after carefully filtering the MOGAS as = it went in the tank. It's either residual from the construction (though = I never noticed it during all the ground running over the past year). Or = something is coming apart. I'm going to drain the MOGAS and run 100LL = for a while just to see if the contamination issues clear up. If so I'll = switch back and see if it starts again. Mike Wills RV-4 N144MW ----- Original Message -----=20 From: William Wilson=20 To: Rotary motors in aircraft=20 Sent: Wednesday, March 04, 2009 11:33 AM Subject: [Norton AntiSpam] [FlyRotary] Re: Questions on buying a = rotary plane More car gas is polluted with alcohol nowadays because the = distributors don't always want to maintain separate facilities for = everything, even where alcohol is not required in fuel, it can be easier = for them to just sell it anyway. Of course if you have an airport = selling mogas it won't have alcohol but if you self fuel from the local = gas station you may find there is alcohol even if your state doesn't = mandate it. Would be good to double check. Since the rotary runs perfectly fine in cars with alcohol, so long as = your fuel tanks and plumbing can handle it without falling apart, you = shouldn't have a problem. Alcohol may have a bit less power but not = enough to be unsafe. Important thing for combustion properties is the = octane of the fuel which alcohol does not reduce. Rumors of alcohol causing frozen fuel are just FUD. No one has ever = seen it happen and the chemistry does not make it particularly likely. = Ethanol freezes at -114C! On Wed, Mar 4, 2009 at 5:21 AM, Mark Steitle = wrote: 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_004C_01C99D00.6D50C320 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
William,
 
 No claims I've ever read about = alcohol or=20 fuel freezing. But its a fact that ethanol has an affinity for water. = And=20 there's no doubt that water freezes. I have no idea if there are = any=20 documented cases of this actually happening in flight and causing an = engine=20 failure. In any case I think it might be wise to keep tanks full if = running=20 MOGAS to minimize condensation in the tanks.
 
 I know in my case I've found = contamination in=20 my fuel twice in the past month. The second time happened after = carefully=20 filtering the MOGAS as it went in the tank. It's either residual from = the=20 construction (though I never noticed it during all the ground running = over the=20 past year). Or something is coming apart. I'm going to drain the MOGAS = and run=20 100LL for a while just to see if the contamination issues clear up. If = so I'll=20 switch back and see if it starts again.
 
Mike Wills
RV-4 N144MW
----- Original Message -----
From:=20 William=20 Wilson
Sent: Wednesday, March 04, 2009 = 11:33=20 AM
Subject: [Norton AntiSpam] = [FlyRotary]=20 Re: Questions on buying a rotary plane

More car gas is polluted with alcohol nowadays because = the=20 distributors don't always want to maintain separate facilities for = everything,=20 even where alcohol is not required in fuel, it can be easier for them = to just=20 sell it anyway.  Of course if you have an airport selling mogas = it won't=20 have alcohol but if you self fuel from the local gas station you may = find=20 there is alcohol even if your state doesn't mandate it.  Would be = good to=20 double check.

Since the rotary runs perfectly fine in cars with = alcohol, so long as your fuel tanks and plumbing can handle it without = falling=20 apart, you shouldn't have a problem.  Alcohol may have a bit less = power=20 but not enough to be unsafe.  Important thing for combustion = properties=20 is the octane of the fuel which alcohol does not reduce.

Rumors = of=20 alcohol causing frozen fuel are just FUD.  No one has ever seen = it happen=20 and the chemistry does not make it particularly likely.  Ethanol = freezes=20 at -114C!

On Wed, Mar 4, 2009 at 5:21 AM, Mark Steitle = <msteitle@gmail.com> = wrote:
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=20 to not damage them.  Most are just plain scared to run their = engines=20 lean of peak where they are able to get close to the=20 "advertised" bsfc.  They're willing to burn more fuel in = order to=20 sleep better at night.  But the rotary is designed to run on=20 mogas.  So, why not do it?  Alcohol and possible = vapor=20 lock are the only issues I know of, and with a properly = designed=20 EFI fuel system, vapor lock isn't an issue.  As long as = they don't=20 start blending alcohol in the fuel in my neck of the woods, = I'll=20 keep burning mogas and pocketing 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> 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=20 happier 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=20 actually KNOWS what BSFC they acheive with their Lyc/Cont. I know = that low=20 .40s is a published number that is stuck in my head. I know = what kind=20 of fuel consumption I got with my Lyc powered RV-6A at = cruise and I=20 know there are certainly enough flying Lyc powered RVs to pretty = firmly=20 establish a cruise performance baseline. Since there are more = flying=20 rotary powered RVs than other types, seems like we should be able = to get=20 at least an idea of how they compare. Lets challenge the = rotary RV=20 fliers here to post real cruise performance (altitude, TAS, fuel=20 consumption) and answer the question. Or give me a year and 100 = hours and=20 I'll let you know how my 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=20 the significant short comings of our little group here. Common = perception=20 is that rotaries are gas hogs and we dont do anything to = accurately=20 document 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=20 conservative to burn Mogas. Burning Mogas isnt the exclusive = territory of=20 the rotary. I personally know a guy with a 200HP Lyc in an = RV-8 who=20 has 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=20 price of parts. And that was one of my huge motivations for going = this=20 route. But really the biggest motivation was to do something a = little=20 different. When my RV-4 finally makes it's appearance at a fly-in=20 (hopefully this year) it's not going to be lost in the sea of = belly button=20 RVs that show up.
 
Mike Wills
RV-4 N144MW
 
 
-----=20 Original Message -----
From:=20 Al Gietzen
To:=20 Rotary motors in=20 aircraft
Sent:=20 Monday, March 02, 2009 9:51 PM
Subject:=20 [FlyRotary] Re: Questions on buying a rotary plane

 I dont = know where=20 you got the idea that rotaries are more fuel efficient.=20 Lycosaurs/Continentals typically have BSFCs in the low .40s. = The=20 commonly accepted number for a rotary is about .50. Some here = seem to=20 do 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=20 no one leans enough when flying to get that for fear of = burning out a=20 valve =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=20 20B. I don=92t know why =96 it surprised me; but there it=20 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 =  



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