X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wa-out-1112.google.com ([209.85.146.182] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3528007 for flyrotary@lancaironline.net; Wed, 04 Mar 2009 23:16:03 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.146.182; envelope-from=fluffysheap@gmail.com Received: by wa-out-1112.google.com with SMTP id v33so2195242wah.3 for ; Wed, 04 Mar 2009 20:15:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=7EnLORkpJkAGA+gGshjYTQGUPTumF+dthSzn8Gu6Eyo=; b=iopsBSqSVnF+Qeh2yxnwsbdDVfUORVilopgf0OcUm2vaCXzTZB0n6ydooYLw3NylOB Tc4SFp/JRL/0MDurctFUGONgsVaH6t9+9HRDkmoX/WxndQ0ZUeBa+dhgdbaFPsLKt25H y59d5t11eX9xLze7co2hgj+N0N0k6EPEcW0L4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=on3FXu+jEc+0e49Jva6WJbQli94f20+nmFXs7XhOW1wlp+/nwKzfQ2ll0v1M6lHhR5 pwClKiQk9nkpjizpdO6jcXItqPmGsvVWzInXEGRjJsw7um91YmDlcJK7Dgn8//KEsYa1 5MDc5qK7xXGh5wY3aXjzh5vxBBlqxyy1OM1W8= MIME-Version: 1.0 Received: by 10.115.106.18 with SMTP id i18mr385123wam.213.1236226526101; Wed, 04 Mar 2009 20:15:26 -0800 (PST) In-Reply-To: References: Date: Wed, 4 Mar 2009 20:15:26 -0800 Message-ID: Subject: Re: [FlyRotary] Re: Questions on buying a rotary plane From: William Wilson To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00163646c222f340710464576a30 --00163646c222f340710464576a30 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable I won't dispute that ethanol does have an affinity for water. That doesn't mean that the water is likely to freeze. The key is that the ethanol will keep the water in solution. This is why alcohol is used to clear gas tanks in cars that have been contaminated with water (though they usually use rubbing alcohol, not ethanol, but the principle is the same). The water is actually dissolved in the fuel. The water cannot freeze until the entire solution freezes. This will not happen at any temperature you are plausibl= y going to encounter, even at high altitude. Of course, keeping your tanks full and flying more often will minimize the chance for water to accumulate, and that can only be a good thing. But the biggest problem with having ethanol in the fuel is that it, or water it attracts, may be chemically incompatible with the fuel system parts (anothe= r rumor I haven't actually heard coming true, but which I can't deny because every fuel system is different and there is a lot more chemistry involved). But it is not going to freeze. On Wed, Mar 4, 2009 at 7:35 PM, Mike Wills wrote: > 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 actuall= y > 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 condensatio= n > 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 ne= ver > noticed it during all the ground running over the past year). Or somethin= g > is coming apart. I'm going to drain the MOGAS and run 100LL for a while j= ust > to see if the contamination issues clear up. If so I'll switch back and s= ee > if it starts again. > > Mike Wills > RV-4 N144MW > > ----- Original Message ----- > *From:* William Wilson > *To:* Rotary motors in aircraft > *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 wh= ere > alcohol is not required in fuel, it can be easier for them to just sell i= t > 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 ther= e > is alcohol even if your state doesn't mandate it. Would be good to doubl= e > check. > > Since the rotary runs perfectly fine in cars with alcohol, so long as you= r > 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 f= uel > 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. Ethano= l > 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 mor= e >> fuel in order to sleep better at night. But the rotary is designed to r= un >> on mogas. So, why not do it? Alcohol and possible vapor lock are the o= nly >> issues I know of, and with a properly designed EFI fuel system, vapor lo= ck >> isn't an issue. As long as they don't start blending alcohol in the fue= l in >> my neck of the woods, I'll keep burning mogas and pocketing the differen= ce. >> >> >> 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 g= uy >>> 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 int= o. >>> What appears to be a fairly straight forward mod is a lot more complica= ted >>> than it appears and there are potential pitfalls that are not necessari= ly >>> obvious. >>> >>> My bad on the misread regarding fuel efficiency - he was talking >>> about homebuilt aircraft versus factory built planes, not rotaries vers= us >>> 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 stuc= k 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 powere= d RVs >>> to pretty firmly establish a cruise performance baseline. Since there a= re >>> more flying rotary powered RVs than other types, seems like we should b= e >>> able to get at least an idea of how they compare. Lets challenge the ro= tary >>> RV fliers here to post real cruise performance (altitude, TAS, fuel >>> consumption) and answer the question. Or give me a year and 100 hours a= nd >>> I'll let you know how my RV-4 stacks up against the -6A for a data poin= t. >>> >>> As for your performance against conventional powered Velocities, thats >>> great news. I think thats one of the significant short comings of our l= ittle >>> 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 2= 00HP >>> 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 o= f >>> 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 motiva= tion >>> 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 ----- >>> *From:* Al Gietzen >>> *To:* Rotary motors in aircraft >>> *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 d= o >>> better, others worse. >>> >>> >>> >>> Mike; >>> >>> >>> >>> I=92m not disagreeing with the points in your message; but I am wonderi= ng >>> if you know anybody actually flying a Lyc/Cont and achieving BSFC in th= e low >>> 40=92s. I see numbers like .43 or .45 bandied about, but I guess no on= e leans >>> enough when flying to get that for fear of burning out a valve =96 or w= orse. >>> I=92ve yet to hear from anyone flying a Velocity like mine with a Lyc w= ho >>> 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 ha= ve >>> a bit lower drag because of smaller cowl; or other factors. >>> >>> >>> >>> Al >>> >>> >> > --00163646c222f340710464576a30 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable I won't dispute that ethanol does have an affinity for water.=A0 That d= oesn't mean that the water is likely to freeze.=A0 The key is that the = ethanol will keep the water in solution.=A0 This is why alcohol is used to = clear gas tanks in cars that have been contaminated with water (though they= usually use rubbing alcohol, not ethanol, but the principle is the same).= =A0 The water is actually dissolved in the fuel.=A0 The water cannot freeze= until the entire solution freezes.=A0 This will not happen at any temperat= ure you are plausibly going to encounter, even at high altitude.

Of course, keeping your tanks full and flying more often will minimize = the chance for water to accumulate, and that can only be a good thing.=A0 B= ut the biggest problem with having ethanol in the fuel is that it, or water= it attracts, may be chemically incompatible with the fuel system parts (an= other rumor I haven't actually heard coming true, but which I can't= deny because every fuel system is different and there is a lot more chemis= try involved).=A0 But it is not going to freeze.

On Wed, Mar 4, 2009 at 7:35 PM, Mike Wills <= span dir=3D"ltr"><rv-4mike@cox.net> wrote:
William,
=A0
=A0No 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=A0are 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.
=A0
=A0I know in my case I've found co= ntamination 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 t= he=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.
=A0
Mike Wills
RV-4 N144MW
Sent: Wedn= esday, March 04, 2009 11:33=20 AM
Subject: [Norton AntiSpam] [FlyRot= ary]=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 ev= erything,=20 even where alcohol is not required in fuel, it can be easier for them to = just=20 sell it anyway.=A0 Of course if you have an airport selling mogas it won&= #39;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.=A0 Would be g= ood to=20 double check.

Since the rotary runs perfectly fine in cars with=20 alcohol, so long as your fuel tanks and plumbing can handle it without fa= lling=20 apart, you shouldn't have a problem.=A0 Alcohol may have a bit less p= ower=20 but not enough to be unsafe.=A0 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.=A0 No one has ever seen it happ= en=20 and the chemistry does not make it particularly likely.=A0 Ethanol freeze= s=20 at -114C!

On Wed, Mar 4, 2009 at= 5:21 AM, Mark Steitle <msteitle@gmail.com> wrote:
Mike,
=A0
I agree with you that=A0some of the=A0Lycomings can=A0burn=20 mogas,=A0but=A0few actually do it.=A0 I belong to the Lancair list=20 and they are constantly debating how to (or not to) run their engines s= o as=20 to not damage them.=A0 Most are just plain scared to run their engines= =20 lean of peak where they are able to get close to the=20 "advertised"=A0bsfc.=A0 They're willing to burn more fuel= in order to=20 sleep better at night.=A0 But the rotary is designed to run on=20 mogas.=A0 So, why not do it?=A0 Alcohol=A0and possible vapor=20 lock=A0are the only issues I know of, and=A0with a properly designed=20 EFI fuel system, vapor lock isn't an issue.=A0=A0As long as they do= n't=20 start blending alcohol in the fuel=A0in my neck of the woods, I'll= =20 keep=A0burning mogas and pocketing the difference.=A0
=A0
You stated, "But really the biggest motivation was to do some= thing a=20 little different."=A0 As for that statement... I couldn't agre= e more, but=20 how do you quantify something like that?=A0 And I believe that it isn&#= 39;t=20 just different, but in a lot of ways=A0the rotary is=20 definitely=A0better.=A0 =A0
Mark S.
On Tue, Mar 3, 2009 at 9:55 PM, Mike Wills <= span dir=3D"ltr"><= rv-4mike@cox.net> wrote:
Glad I woke you guys up! :-)
=A0
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 ev= en=20 happier once I get all of the little glitches fixed so=A0I can just f= ly=20 it.
=A0
=A0I simply wanted to make sure = William=20 understands what he's getting into. What appears to be a fairly s= traight=20 forward mod is a lot more complicated than it appears and there are= =20 potential pitfalls that are not necessarily obvious.
=A0
=A0My bad on the misread regardi= ng fuel=20 efficiency - he=A0was talking about=A0homebuilt aircraft versus=20 factory built planes, not rotaries versus certified engines. I=A0thin= k=20 he's still way off base here which was why I=A0replied to his=20 post.
=A0
=A0Al, I dont=A0know anyone who= =20 actually KNOWS what BSFC they acheive with their Lyc/Cont. I know tha= t low=20 .40s is a published number that is stuck in my head.=A0I know what ki= nd=20 of fuel consumption I got with my Lyc powered RV-6A at cruise=A0and I= =20 know there are certainly enough flying Lyc powered RVs to pretty firm= ly=20 establish a=A0cruise performance baseline. Since there are more flyin= g=20 rotary powered RVs than other types, seems like we should be able to = get=20 at least an idea of how they compare.=A0Lets 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 dat= a=20 point.
=A0
=A0As for your performance again= st=20 conventional powered Velocities, thats great news. I think thats one = of=20 the significant short comings of our little group here. Common percep= tion=20 is that rotaries are gas hogs and we dont do anything to accurately= =20 document and advertise our performance.
=A0
=A0Mark, I agree that burning Mo= gas=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 territor= y of=20 the rotary.=A0I 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.=A0Lets be fair,=A0compare 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 se= em to=20 do).
=A0
=A0I do totally agree with you o= n the=20 price of parts. And that was one of my huge motivations for going thi= s=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 bel= ly button=20 RVs that show up.
=A0
Mike Wills
RV-4 N144MW
=A0
=A0
-----=20 Original Message -----
From:=20 Al Gietzen
Sent:=20 Monday, March 02, 2009 9:51 PM
Subject:=20 [FlyRotary] Re: Questions on buying a rotary plane

= =A0I 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 see= m to=20 do better, others worse.

=A0<= /p>

Mike;

=A0<= /p>

I=92m not=20 disagreeing with the points in your message; but I am wondering i= f you=20 know anybody actually flying a Lyc/Cont and achieving BSFC in the= low=20 40=92s.=A0 I see numbers like .43 or .45 bandied about, but I gue= ss=20 no one leans enough when flying to get that for fear of burning o= ut a=20 valve =96 or worse.=A0 I=92ve yet to hear from anyone flying a=20 Velocity<= /span> like mine=20 with a Lyc who can surpass the speed/fuel burn that I get with th= e=20 20B. I don=92t know why =96 it surprised me; but there it=20 is.

=A0<= /p>

I think in=20 the real world operation the BSFCs are comparable.=A0 I may have = a=20 bit lower drag because of smaller cowl; or other=20 factors.

=A0<= /p>

Al=20 =A0




--00163646c222f340710464576a30--