X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from relais.videotron.ca ([24.201.245.36] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3576513 for flyrotary@lancaironline.net; Fri, 10 Apr 2009 11:00:46 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.201.245.36; envelope-from=geryvon@videotron.ca MIME-version: 1.0 Content-type: multipart/alternative; boundary="Boundary_(ID_tuSRxICedbuyqtkfVzK59Q)" Received: from yvon ([66.130.84.106]) by VL-MH-MR001.ip.videotron.ca (Sun Java(tm) System Messaging Server 6.3-4.01 (built Aug 3 2007; 32bit)) with SMTP id <0KHW004F74C0G740@VL-MH-MR001.ip.videotron.ca> for flyrotary@lancaironline.net; Fri, 10 Apr 2009 11:00:05 -0400 (EDT) Message-id: <9133169426714826BBCC1C72568B1E83@yvon> From: Yvon Cournoyer To: Rotary motors in aircraft References: Subject: Re: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines Date: Fri, 10 Apr 2009 10:59:25 -0400 X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. --Boundary_(ID_tuSRxICedbuyqtkfVzK59Q) Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: quoted-printable Please elaborate on the meaning of Tracy Crook's quotation, as I do not = understand its meaning, but then, my primary language is French. Thank = you Yvon Cournoyer ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, April 10, 2009 10:29 AM Subject: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines Good run down, Mark. =20 Gary does mention the numerous parts on the rotor itself - and while = each rotor does have a high part count, you have to consider that each = rotor is the equivalent of 3 pistons - so in that context the parts = count is actually lower, not higher - its very seldom you ever hear of = any failure of rotor parts other than the occasional apex seal - wear = yes, failure - seldom. plus I have never heard of a rotor coming = through the block {:>) So, good questions and good answers from you. =20 One saying does come to mind - from our good friend, Tracy Crook. = ".If you're asking if you should do it, you probably shouldn't. If you = should be doing it, nobody can talk you out of it..". For 90% of = homebuilders, its probably not appropriate. =20 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 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mark Steitle Sent: Friday, April 10, 2009 9:26 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines =20 Gary,=20 =20 Thanks for adding a more technical tone to this discussion. Yes, I = was not accounting for all the misc pieces needed to make the rotary = run, but then I wasn't considering all the little pieces needed to make = a conventional piston engine run either. Of the pieces that normally = fail and end up poking out through the engine case, I think you'll agree = that the rotary has significantly fewer of those. In fact, I have never = seen a rotary with a thrown connecting rod. ;-) =20 Having a liquid cooling system is a two-edged sword, but its not = anything that can't be overcome with good engineering. For coolant = lines on my installation I used aluminum tubing connected to the engine = and radiator via "Wiggins" couplings. I monitor coolant pressure, = coolant level, and coolant temperature. Of course, if I catch a = Canadian goose in the radiator, it will likely loose its ability to cool = the engine, but then you have the same risk with an air-cooled engine. =20 As for the bsfc, do your numbers reflect the modern EFI systems, or = carbureted engines. Tracy Crook realized a significant improvement in = bsfc when he switched from carburetors to EFI. The new "Renesis" rotary = engine has a better bsfc due to the side exhaust ports. Anyway, I = prefer to consider it in "dollars per air-mile". By the time you factor = in the cost savings for purchasing and maintaining a rotary engine over = a certified engine, and that the rotary runs happily (prefers) on 89 UL = fuel (half the cost of avgas), the cost per mile tips significantly in = favor of the rotary. (Reading the recent post about the $2300.00 oil = pan practically brought tears to my eyes.) I guess its the German in me = that caused me to seek out something better, or different. =20 =20 Ahhhh... you mentioned the magic word, "turbo-charger". I built my = engine with the intention of turbo-charging as it was initially = turbo-charged in its former life. After much thought, I decided to = follow the KISS principle and go N/A. But there's a little voice in my = head that keeps whispering "turbo-charge". With the rotary's high = energy exhaust gasses, turbo's are a natural solution. Yes they add = weight, but not much more than my current exhaust system. Stay tuned... =20 One thing that I hadn't mentioned that could be considered a negative = for the rotary engine is that very few A&P's know anything about rotary = engines. Heck, very few auto mechanics know how to work on a rotary = engine. But, if I'm there with my repairman's certificate in hand, who = needs an A&P? Also, rotary parts are less plentiful if you get stuck in = some hole-in-the-wall town. But there is always UPS overnight. =20 =20 Gary, thanks again for your thoughtful post. I'm not trying to = convert anyone to a rotary engine, I only want to see it get a fair = shake. =20 =20 Mark S. =20 P.S. I've CC'd the Fly Rotary group as they need something to talk = about (the list has been rather quiet lately). =20 =20 =20 =20 On Fri, Apr 10, 2009 at 7:13 AM, Gary Casey = wrote: =20 I'll certainly have to commend Mark on the great work with the rotary = engine. I agree with his comments on almost every count. But... You probably should count ALL the parts in and around the engine to = have a fair comparison. For example, the air-cooled aircraft engine = cooling system has essentially no moving parts, unless you count the = vernitherm. Yes, the 3-rotor engine has only 4 MAJOR moving parts, but = each rotor has about 50 components. While that's not necessarily good = or bad, it's not an inherently simple solution. It rejects more heat to = the coolant and more of that to the oil (rotors are oil-cooled), making = the cooling system larger and potentially more complex. And the exhaust = is hotter and contains more aggressive pressure pulses, which have to be = taken care of by some sort of muffling. The ideal muffler is probably a = turbocharger, which can work very well on account of the pressure = pulses, but it probably takes a special high-temperature turbo that can = tolerate the up-to 2000 degree exhaust. The turbo adds weight and = complexity, but perhaps not more weight than an effective muffler. The = fact that the engine is inherently round and concentric with the output = shaft is a good thing, but probably more attractive for a wing-mounted = engine than one in front of the fuselage. The rotary engine almost = requires a speed reduction unit to make the power/weight come out = favorable, and I was not impressed with the design of the then-currently = available units, although they seem to work okay in practice. One big = thing that bothered me is that the efficiency is inherently lower than = that of a good piston engine, partly because the compression ratio is = limited to less than about 9 and the surface-volume ratio the combustion = chamber is higher. This penalty is probably 5 to 10%. All that being = said, the big attraction to me was, as Mark said, the rotary will rarely = completely fail, even if the coolant is lost. The apex seals might = disintegrate and parts warp, but it will most likely continue to produce = power for some time, unlike a piston engine. A long time ago we were = testing many rotaries and occasionally we would see a loss in power. = When the engine was shut down it welded itself together even though it = was still producing power. And the very things that make it less = efficient contribute to the fact that it can tolerate a variety of = fuels. And with boosting it can be made to produce a lot of reliable = power. =20 I seriously looked at 3 different approaches - a standard aircraft = engine, a direct-drive automotive piston engine, and a rotary. The = eventual deciding factors were that the automotive engine came out heavy = and the rotary engine burned more fuel. I really do like the rotary, = though. Gary =20 -------------------------------------------------------------------------= ----- From: Mark Steitle To: Lancair_ES@yahoogroups.com Sent: Thursday, April 9, 2009 2:27:21 PM Subject: Re: [Lancair_ES] Rotary Engines Dave,=20 =20 Since there were no other replies, I figured I would give my 2-cents = worth. =20 =20 I have been flying a 3-rotor Lancair ES for almost 2 years now with a = total of 110 hrs on the Hobbs. While it hasn't been without some = teething pains, all-in-all, it has been a very positive experience and I = would choose a rotary again if/when the opportunity presents itself. =20 =20 While I did the FWF myself, my installation and the Mistral are both = closely related. As an example, I could bolt a Mistral intake and/or = exhaust directly to my engine, and probably interchange many parts with = the Mistral 3-rotor. The Mistral folks have taken much of the rotary = engine technology, and refined and pakaged it into a (soon to be) = certified product. =20 My reasoning is based on my belief that the rotary is inheretly a = stronger engine (pistons are cast iron vs. aluminum), with only 4 = moving parts. If you read the recent AOPA story about the Cessna 400 = blowing an engine over Pennsylvania in the night, well, I had a similar = experience in a Cessna 152, only not at night. Like the chap in the = AOPA story, we too just barely made it to the nearest airport, with oil = pouring out from the cowl onto the runway. Since that incident, I have = been very leery of all conventional piston engines. Hence my decision = to go with a rotary. =20 =20 Gross weight on my ES was 2060 lbs. I typically climb out at 7000 - = 7200 rpm (2400 - 2500 prop rpm), climbing at between 1000 fpm and 1300 = fpm, burning 16 - 18 gph, 15 gph in regular cruise (6000 rpm) and around = 10 -12 gph in economy cruise (5100 rpm). (Keep in mind that the pistons = (rotors) turn at 1/3 the speed of the crankshaft, so they are only = turning 1733 rpm in economy cruise.) I can run either 100LL or mogas = (w/o alcohol) without worry and can lean the mixture aggressively = without worry of hurting the engine (no exhaust valves to burn). I can = pull the throttle to idle whenever and not risk shock cooling the = engine. Being fuel-injected, it will start cold, hot, or anywhere in = between. What's not to love? =20 =20 I mentioned some teething pains... those consisted of an early cooling = problem which was solved with an auxilary water-to-oil exchanger and a = cowl flap. I have also had a series of oil leaks, all from the oil pan = not being properly sealed. I finally pulled the pan, cleaned and = resealed it. Problem solved. The toughest issue to resolve has been = finding a muffler that could withstand the pounding of the rotary's = exhaust. I'm pretty sure that issue has been resolved by switching to = a DNA racing muffler, but I don't have enough hours on it yet to state = for certain. =20 Hopes this helps answer your question(s). =20 Mark S. =20 =20 =20 __._,_.___ Messages in this topic (5) Reply (via web post) | Start a new topic=20 Messages | Files | Photos | Links | Database | Polls | Members | = Calendar=20 To Post a message to the group, send it to: Lancair_ES@YahooGroups.com To Unsubscribe, send a blank message to: Lancair_ES-unsubscribe@YahooGroups.com If you have questions for the group administrator, send it to: Lancair_ES-owner@YahooGroups.com=20 Change settings via the Web (Yahoo! ID required)=20 Change settings via email: Switch delivery to Daily Digest | Switch = format to Traditional=20 Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe=20 Recent Activity Visit Your Group=20 Give Back Yahoo! for Good Get inspired by a good cause. Y! Toolbar Get it Free! easy 1-click access to your groups. Yahoo! Groups Start a group in 3 easy steps. Connect with others. . __,_._,___ =20 --Boundary_(ID_tuSRxICedbuyqtkfVzK59Q) Content-type: text/html; charset=iso-8859-1 Content-transfer-encoding: quoted-printable
Please elaborate on the meaning = of Tracy=20 Crook's quotation, as I do not understand its meaning, but then, my = primary=20 language is French. Thank you
Yvon = Cournoyer
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Friday, April 10, 2009 = 10:29=20 AM
Subject: [FlyRotary] Re: = [Lancair_ES] Re:=20 Rotary Engines

Good run = down,=20 Mark.

 

Gary does = mention the=20 numerous parts on the rotor  itself =96 and while each rotor does = have a=20 high part count, you have to = consider that=20 each rotor is the equivalent of 3 pistons =96 so in that = context the=20 parts count is actually lower, not higher =96 its very seldom you ever = hear of=20 any failure of rotor parts other than the occasional apex seal =  =96 wear=20 yes, failure =96 seldom.   plus I have never heard of a = rotor coming=20 through the block {:>)   So, good questions and good = answers from=20 you.

 

One saying = does come=20 to mind =96 from our good friend, Tracy Crook.  =93=85If you=92re = asking if you should=20 do it, you probably shouldn=92t. If you should be doing it, nobody can = talk you=20 out of it..=94.  For 90% of homebuilders, its = probably not=20 appropriate.

 

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

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Mark Steitle
Sent: Friday, April 10, 2009 = 9:26=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = [Lancair_ES] Re:=20 Rotary Engines

 

Gary,=20

 

Thanks for adding a more technical tone to = this=20 discussion.  Yes, I was not accounting for all the misc pieces = needed to=20 make the rotary run, but then I wasn't considering all the little = pieces=20 needed to make a conventional piston engine run either.  Of the = pieces=20 that normally fail and end up poking out through the engine case, I = think=20 you'll agree that the rotary has significantly fewer of those.  = In fact,=20 I have never seen a rotary with a thrown connecting rod. =20 ;-)

 

Having a liquid cooling system is a = two-edged sword,=20 but its not anything that can't be overcome with good = engineering. =20 For coolant lines on my installation I used aluminum tubing connected = to the=20 engine and radiator via "Wiggins" couplings.  I = monitor coolant=20 pressure, coolant level, and coolant temperature.  Of course, if = I catch=20 a Canadian goose in the radiator, it will likely loose its ability to = cool the=20 engine, but then you have the same risk with an air-cooled = engine. =20

As for the bsfc, do your numbers = reflect the=20 modern EFI systems, or carbureted engines.  Tracy Crook = realized a=20 significant improvement in bsfc when he switched from carburetors to=20 EFI.  The new "Renesis" rotary engine has a better bsfc = due to=20 the side exhaust ports.  Anyway, I prefer to = consider it=20 in "dollars per air-mile".  By the time you factor in the = cost=20 savings for purchasing and maintaining a rotary engine over a = certified=20 engine, and that the rotary runs happily (prefers) on 89 UL fuel = (half=20 the cost of avgas), the cost per mile tips significantly in favor = of the=20 rotary.  (Reading the recent post about the = $2300.00=20 oil pan practically brought tears to my eyes.)  I guess its the = German in=20 me that caused me to seek out something better, or = different. =20

 

Ahhhh... you mentioned the magic word,=20 "turbo-charger".  I built my engine with the intention=20 of turbo-charging as it was initially turbo-charged in its = former=20 life.  After much thought, I decided to follow the = KISS=20 principle and go N/A.  But there's a little voice in my head = that=20 keeps whispering "turbo-charge".  With the rotary's high energy = exhaust=20 gasses, turbo's are a natural solution.  Yes they add = weight, but=20 not much more than my current exhaust system.  Stay=20 tuned...

 

One thing that I hadn't mentioned that could = be=20 considered a negative for the rotary engine is that very few A&P's = know=20 anything about rotary engines.  Heck, very few auto mechanics = know how to=20 work on a rotary engine.  But, if I'm there with my repairman's=20 certificate in hand, who needs an A&P?  Also, rotary parts = are less=20 plentiful if you get stuck in some hole-in-the-wall town.  But = there is=20 always UPS overnight. 

 

Gary, = thanks=20 again for your thoughtful post.  I'm not trying to convert=20 anyone to a rotary engine, I only want to see it get a fair=20 shake.  

 

Mark S.

 

P.S.  I've CC'd the Fly Rotary group as = they need=20 something to talk about (the list has been rather quiet=20 lately).

 

 

 

 

On Fri, Apr 10, 2009 at 7:13 AM, Gary Casey = <casey.gary@yahoo.com>=20 wrote:

 

I'll = certainly have to=20 commend Mark on the great work with the rotary engine.  I agree = with his=20 comments on almost every count.=20  But...

You probably = should count=20 ALL the parts in and around the engine to have a fair comparison. =  For=20 example, the air-cooled aircraft engine cooling system has essentially = no=20 moving parts, unless you count the vernitherm.  Yes, the 3-rotor = engine=20 has only 4 MAJOR moving parts, but each rotor has about 50 components. =  While that's not necessarily good or bad, it's not an inherently = simple=20 solution.  It rejects more heat to the coolant and more of that = to the=20 oil (rotors are oil-cooled), making the cooling system larger and = potentially=20 more complex.  And the exhaust is hotter and contains more = aggressive=20 pressure pulses, which have to be taken care of by some sort of = muffling.=20  The ideal muffler is probably a turbocharger, which can work = very well=20 on account of the pressure pulses, but it probably takes a special=20 high-temperature turbo that can tolerate the up-to 2000 degree = exhaust.=20  The turbo adds weight and complexity, but perhaps not more = weight than=20 an effective muffler.  The fact that the engine is inherently = round and=20 concentric with the output shaft is a good thing, but probably more = attractive=20 for a wing-mounted engine than one in front of the fuselage.  The = rotary=20 engine almost requires a speed reduction unit to make the power/weight = come=20 out favorable, and I was not impressed with the design of the = then-currently=20 available units, although they seem to work okay in practice. =  One big=20 thing that bothered me is that the efficiency is inherently lower than = that of=20 a good piston engine, partly because the compression ratio is limited = to less=20 than about 9 and the surface-volume ratio the combustion chamber is = higher.=20  This penalty is probably 5 to 10%.  All that being said, = the big=20 attraction to me was, as Mark said, the rotary will rarely completely = fail,=20 even if the coolant is lost.  The apex seals might disintegrate = and parts=20 warp, but it will most likely continue to produce power for some time, = unlike=20 a piston engine.  A long time ago we were testing many rotaries = and=20 occasionally we would see a loss in power.  When the engine was = shut down=20 it welded itself together even though it was still producing power. =  And=20 the very things that make it less efficient contribute to the fact = that it can=20 tolerate a variety of fuels.  And with boosting it can be made to = produce=20 a lot of reliable power.

 

I seriously = looked at 3=20 different approaches - a standard aircraft engine, a direct-drive = automotive=20 piston engine, and a rotary.  The eventual deciding factors were = that the=20 automotive engine came out heavy and the rotary engine burned more = fuel.=20  I really do like the rotary, = though.

Gary

 

From: Mark=20 Steitle <msteitle@gmail.com>
To: Lancair_ES@yahoogroups.com
Sent: Thursday, April 9, 2009 = 2:27:21=20 PM
Subject: Re: = [Lancair_ES]=20 Rotary Engines

Dave,=20

 

Since there = were no other=20 replies, I figured I would give my 2-cents worth. =20

 

I have been = flying a=20 3-rotor Lancair ES for almost 2 years now with a total of 110 hrs on = the=20 Hobbs. =20 While it hasn't been without some teething pains, all-in-all, it has = been a=20 very positive experience and I would choose a rotary again if/when the = opportunity presents itself. 

 

While I did = the FWF=20 myself, my installation and the Mistral are both closely=20 related.  As an example, I could bolt a Mistral intake and/or = exhaust=20 directly to my engine, and probably interchange many parts with = the=20 Mistral 3-rotor.  The Mistral folks have taken much of = the rotary=20 engine technology, and refined and pakaged it into a (soon = to be)=20 certified product.     =20

My reasoning = is based on=20 my belief that the rotary is inheretly a stronger engine (pistons = are=20 cast iron vs. aluminum), with  only 4 moving = parts.  If=20 you read the recent AOPA story about the Cessna 400 blowing an engine = over=20 Pennsylvania=20 in the night, well, I had a similar experience in a Cessna 152, only = not at=20 night.  Like the chap in the AOPA story, we too just barely = made it=20 to the nearest airport, with oil pouring out from the cowl onto the=20 runway.  Since that incident, I have been very leery of all=20 conventional  piston engines.  Hence my decision to go with = a=20 rotary.  

 

Gross weight = on my ES was=20 2060 lbs.  I typically climb out at 7000 - 7200 rpm (2400 - 2500 = prop=20 rpm), climbing at between 1000 fpm and 1300 fpm, burning 16 -=20 18 gph, 15 gph in regular cruise (6000 rpm) and around 10 = -12 gph in=20 economy cruise (5100 rpm).  (Keep in mind that the pistons = (rotors) turn=20 at 1/3 the speed of the crankshaft, so they are only turning 1733 rpm = in=20 economy cruise.)  I can run either 100LL or mogas (w/o = alcohol)=20 without worry and can lean the mixture aggressively without worry = of=20 hurting the engine (no exhaust valves to burn).  I can pull the = throttle=20 to idle whenever  and not risk shock cooling the=20 engine.  Being fuel-injected, it will start cold, hot, or = anywhere=20 in between.  What's not to love? =20

 

I mentioned = some teething=20 pains... those consisted of an early cooling problem which was solved = with an=20 auxilary water-to-oil exchanger and a cowl flap.  I have also had = a=20 series of oil leaks, all from the oil pan not being properly = sealed.  I=20 finally pulled the pan, cleaned and resealed  it.  = Problem=20 solved.  The toughest issue to resolve has been finding a muffler = that=20 could withstand the pounding of the rotary's exhaust.  I'm = pretty=20 sure that issue has been resolved  by switching to a = DNA racing=20 muffler, but I don't have enough hours on it yet to state for=20 certain.

 

Hopes this = helps answer=20 your question(s).

 

Mark=20 S.

 

  

 

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