X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ew0-f167.google.com ([209.85.219.167] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3576487 for flyrotary@lancaironline.net; Fri, 10 Apr 2009 10:39:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.167; envelope-from=msteitle@gmail.com Received: by ewy11 with SMTP id 11so1644179ewy.19 for ; Fri, 10 Apr 2009 07:39:21 -0700 (PDT) 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=p+c3rwA234fro6tjC+nm4WX79TVJjpkxCCpnNbntTQg=; b=P109elbXaSZFl7+hnvcDa7wpV//aexDDg1z7lR36Vs0TKQMGkadwcU6MaCU4Uj0D4/ 8QrrwSmDmk3u9+5ltmyhychvv2PHR2r5yIWBd0G9QUFbCkjrIZzQa/oWeFKNkxDsnsI9 /ik9rL3xcUwpljv20v+OU/7iWT4shFoDbydO4= 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=n/i4DVwfG/P+ShI2Eu77RLjLEm63DEagCHN0b78Xp/4SQyVaCbJEyBEVnWioO6jymm E8V8E3VhEuovt+D82QGbzEcXWZLEKXxqME+awiPLqJdj6iO2BtcxYStk/RpajWw2GyhY RgzoshCB+C1AGFHmkq6b0n9BaDfO73+9FaznE= MIME-Version: 1.0 Received: by 10.210.82.13 with SMTP id f13mr2285206ebb.59.1239374359698; Fri, 10 Apr 2009 07:39:19 -0700 (PDT) In-Reply-To: References: Date: Fri, 10 Apr 2009 09:39:19 -0500 Message-ID: <5cf132c0904100739he6095fbn3acfd5ad4baf82e0@mail.gmail.com> Subject: Re: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174c17b4741f4e046734546b --0015174c17b4741f4e046734546b Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Thanks Ed. The Lancair bunch tend to be pretty conservative when it comes to their choice of engines. They can think of a hundred reasons why it is better to go with a certified engine, all of them based on the past 100 years. ;-) Gary is a very sharp engineer, so I need to be careful what claims I make because he will be checking to see if I'm embellishing the facts, not that = I would ever do that, mind you. Are you planning on attending the Texas roundup in May? It would be good to talk to you again. Bobby hopes to have his supercharged RV-10 flying by then (dependent on Tracy getting the mods finished to his EC-2). I plan to be there as will Dennis H. and a number of others. It should be fun. Mark On Fri, Apr 10, 2009 at 9:29 AM, Ed Anderson wro= te: > Good run down, Mark. > > > > Gary does mention the numerous parts on the rotor itself =96 and while e= ach > rotor does have a high part count, *you have to consider that each rotor > is the equivalent of 3 pistons* =96 so in that context the parts count is > actually lower, not higher =96 its very seldom you ever hear of any failu= re of > rotor parts other than the occasional apex seal =96 wear yes, failure = =96 > seldom. plus I have never heard of a rotor coming through the block {:>= ) > So, good questions and good answers from you. > > > > One saying does come to mind =96 from our good friend, Tracy Crook. *=93= =85If > you=92re asking if you should do it, you probably shouldn=92t. If you sho= uld be > doing it, nobody can talk you out of it..=94.* For 90% of homebuilders, = its > probably not appropriate. > > > > 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] *O= n > 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 > > > > Gary, > > > > Thanks for adding a more technical tone to this discussion. Yes, I was n= ot > accounting for all the misc pieces needed to make the rotary run, but the= n 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. ;-) > > > > 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 cool= ant > 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 s= ame > risk with an air-cooled engine. > > As for the bsfc, do your numbers reflect the modern EFI systems, or > carbureted engines. Tracy Crook realized a significant improvement in bs= fc > when he switched from carburetors to EFI. The new "Renesis" rotary engin= e > 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 cos= t > savings for purchasing and maintaining a rotary engine over a certified > engine, and that the rotary runs happily (prefers) on 89 UL fuel (half th= e > 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. > > > > 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 follo= w > the KISS principle and go N/A. But there's a little voice in my head tha= t > keeps whispering "turbo-charge". With the rotary's high energy exhaust > gasses, turbo's are a natural solution. Yes they add weight, but not muc= h > more than my current exhaust system. Stay tuned... > > > > 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. > > > > 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. > > > > Mark S. > > > > P.S. I've CC'd the Fly Rotary group as they need something to talk about > (the list has been rather quiet lately). > > > > > > > > > > On Fri, Apr 10, 2009 at 7:13 AM, Gary Casey wrote: > > > > 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 sys= tem > has essentially no moving parts, unless you count the vernitherm. Yes, t= he > 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 mor= e > aggressive pressure pulses, which have to be taken care of by some sort o= f > muffling. The ideal muffler is probably a turbocharger, which can work v= ery > 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 rot= ary > 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 w= as > 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. > > > > 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 > > > ------------------------------ > > *From:* Mark Steitle > *To:* Lancair_ES@yahoogroups.com > *Sent:* Thursday, April 9, 2009 2:27:21 PM > *Subject:* Re: [Lancair_ES] Rotary Engines > > Dave, > > > > Since there were no other replies, I figured I would give my 2-cents > worth. > > > > I have been flying a 3-rotor Lancair ES for almost 2 years now with a tot= al > of 110 hrs on the Hobbs. While it hasn't been without some teething pain= s, > all-in-all, it has been a very positive experience and I would choose a > rotary again if/when the opportunity presents itself. > > > > 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 t= he > Mistral 3-rotor. The Mistral folks have taken much of the rotary > engine technology, and refined and pakaged it into a (soon to be) certifi= ed > product. > > 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 i= n 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. > > > > 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 -1= 2 > 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 rp= m > in economy cruise.) I can run either 100LL or mogas (w/o alcohol) withou= t > 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-injecte= d, > it will start cold, hot, or anywhere in between. What's not to love? > > > > I mentioned some teething pains... those consisted of an early cooling > problem which was solved with an auxilary water-to-oil exchanger and a co= wl > flap. I have also had a series of oil leaks, all from the oil pan not be= ing > 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 su= re > 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. > > > > Hopes this helps answer your question(s). > > > > Mark S. > > > > > > > > __._,_.___ > > Messages in this topic > > (*5*) *Reply *(via web post) > | > *Start a new topic * > > Messages| > Files| > Photos| > Links| > Database| > Polls| > Members| > Calendar > > 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 > > [image: Yahoo! Groups] > Change settings via the Web(Yahoo! ID requir= ed) > Change settings via email: Switch delivery to Daily Digest| Switch > format to Traditional > Visit Your Group > | > Yahoo! Groups Terms of Use | Unsubscri= be > > > *Recent Activity* > > Visit Your Group > > > *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. > > . > > __,_._,___ > > > --0015174c17b4741f4e046734546b Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Thanks Ed.=A0 The Lancair bunch tend to be pretty conservative when it= comes to their choice of engines.=A0 They can think of a hundred reasons w= hy it is better to go with a certified engine, all of them based on the pas= t 100 years.=A0 ;-)
=A0
Gary is a very sharp engineer, so I need to be careful what claims I m= ake because he will be checking to see if I'm embellishing the facts, n= ot that I would ever do that, mind you.
=A0
Are you=A0planning on attending=A0the Texas roundup in May?=A0 It woul= d be good to=A0talk to you again.=A0=A0Bobby hopes to have his supercharged= RV-10 flying by then (dependent on Tracy getting the mods finished to his = EC-2).=A0 I plan to be there as will Dennis H. and a number of others.=A0 I= t should be fun.
=A0
Mark

On Fri, Apr 10, 2009 at 9:29 AM, Ed Anderson <eanderson@c= arolina.rr.com> wrote:

Good run down, Mark.<= /p>

=A0

Gary does mention the numerous part= s on the rotor =A0itself =96 and while each rotor does have a high part cou= nt, you have to consider that each rot= or is the equivalent of 3 pistons =96 so in that context the par= ts count is actually lower, not higher =96 its very seldom you ever hear of= any failure of rotor parts other than the occasional apex seal =A0=96 wear= yes, failure =96 seldom.=A0 =A0plus I have never heard of a rotor coming t= hrough the block {:>)=A0=A0 So, good questions and good answers from you= .

=A0

One saying does come to mind =96 fr= om our good friend, Tracy Crook.=A0 =93=85If you=92re asking if you should do it, you prob= ably shouldn=92t. If you should be doing it, nobody can talk you out of it.= .=94.=A0 For 90% of homebuilders, its probably not appropria= te.

=A0

Ed

From: Rota= ry motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Friday, April 10, 200= 9 9:26 AM
To: Rotary mot= ors in aircraft
Subject:= [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines

casey.gary@yahoo.com> wrote:=

=A0

I'll certainly have to commend Mark on th= e great work with the rotary engine. =A0I agree with his comments on almost= every count. =A0But...

You probably should count ALL the parts in an= d around the engine to have a fair comparison. =A0For example, the air-cool= ed aircraft engine cooling system has essentially no moving parts, unless y= ou count the vernitherm. =A0Yes, the 3-rotor engine has only 4 MAJOR moving= parts, but each rotor has about 50 components. =A0While that's not nec= essarily good or bad, it's not an inherently simple solution. =A0It rej= ects more heat to the coolant and more of that to the oil (rotors are oil-c= ooled), making the cooling system larger and potentially more complex. =A0A= nd the exhaust is hotter and contains more aggressive pressure pulses, whic= h have to be taken care of by some sort of muffling. =A0The ideal muffler i= s probably a turbocharger, which can work very well on account of the press= ure pulses, but it probably takes a special high-temperature turbo that can= tolerate the up-to 2000 degree exhaust. =A0The turbo adds weight and compl= exity, but perhaps not more weight than an effective muffler. =A0The fact t= hat 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 o= ne in front of the fuselage. =A0The rotary engine almost requires a speed r= eduction unit to make the power/weight come out favorable, and I was not im= pressed with the design of the then-currently available units, although the= y seem to work okay in practice. =A0One big thing that bothered me is that = the efficiency is inherently lower than that of a good piston engine, partl= y because the compression ratio is limited to less than about 9 and the sur= face-volume ratio the combustion chamber is higher. =A0This penalty is prob= ably 5 to 10%. =A0All that being said, the big attraction to me was, as Mar= k said, the rotary will rarely completely fail, even if the coolant is lost= . =A0The apex seals might disintegrate and parts warp, but it will most lik= ely continue to produce power for some time, unlike a piston engine. =A0A l= ong time ago we were testing many rotaries and occasionally we would see a = loss in power. =A0When the engine was shut down it welded itself together e= ven though it was still producing power. =A0And the very things that make i= t less efficient contribute to the fact that it can tolerate a variety of f= uels. =A0And with boosting it can be made to produce a lot of reliable powe= r.

=A0

I seriously looked at 3 different approaches = - a standard aircraft engine, a direct-drive automotive piston engine, and = a rotary. =A0The eventual deciding factors were that the automotive engine = came out heavy and the rotary engine burned more fuel. =A0I really do like = the rotary, though.

Gary

=A0

From: Mark Steitle <msteitle@gmail.com>
To: Lancair_ES@yahoogroups.com
= Sent: Thursday, April 9, 20= 09 2:27:21 PM
Subject: Re: [Lancair_ES] R= otary Engines

Dave,

=A0

Since there were no other replies, I figured = I would give my 2-cents worth.=A0

=A0

I have been flying a 3-rotor Lancair ES for a= lmost 2 years now with a total of 110 hrs on the Hobbs.=A0 While it hasn= 9;t been without some teething pains, all-in-all, it has been a very positi= ve experience and I would choose a rotary again if/when the opportunity pre= sents itself.=A0

=A0

While I did the FWF myself,=A0my installation= and the=A0Mistral are both closely related.=A0 As an example, I could bolt= a Mistral intake and/or exhaust directly=A0to my engine, and probably inte= rchange many parts with the Mistral 3-rotor.=A0 The Mistral folks have take= n much of the=A0rotary engine=A0technology, and refined and=A0pakaged it in= to a (soon to be) certified product.=A0 =A0=A0=A0

My reasoning is based on my belief that the r= otary is inheretly a stronger=A0engine (pistons are cast iron vs. aluminum)= ,=A0with=A0 only 4=A0moving parts.=A0 If you read the recent AOPA story abo= ut 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.=A0 Like the c= hap in the AOPA story, we too just=A0barely made it to the nearest airport,= with oil pouring out from the cowl onto the runway.=A0 Since that incident= , I have been very leery of all conventional=A0 piston engines.=A0 Hence my= decision to go with a rotary.=A0=A0

=A0

Gross weight on my ES was 2060 lbs.=A0 I typi= cally climb out at 7000 - 7200 rpm (2400 - 2500 prop rpm), climbing at=A0be= tween 1000 fpm and 1300 fpm, burning 16 - 18=A0gph, 15 gph in regular cruis= e (6000 rpm) and=A0around 10 -12 gph in economy cruise (5100 rpm).=A0 (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.)=A0=A0I can run eithe= r 100LL or mogas (w/o alcohol) without worry and can lean the=A0mixture agg= ressively without worry of hurting the engine (no exhaust valves to burn).= =A0 I can pull the throttle to idle=A0whenever=A0 and not=A0risk shock cool= ing the engine.=A0=A0Being fuel-injected, it will start cold, hot, or anywh= ere in between.=A0 What's not to love?=A0

=A0

I mentioned some teething pains... those cons= isted of an early cooling problem which was solved with an auxilary water-t= o-oil exchanger and a cowl flap.=A0 I have also had a series of oil leaks, = all from the oil pan not being properly sealed.=A0 I finally pulled the pan= , cleaned=A0and=A0resealed=A0 it.=A0 Problem solved.=A0 The toughest issue = to resolve has been finding a muffler that could withstand the pounding of = the rotary's exhaust.=A0=A0I'm pretty sure that=A0issue has been=A0= resolved=A0 by switching to a DNA racing muffler, but I don't have enou= gh hours on it yet to state for certain.

=A0

Hopes this helps answer your question(s).

=A0

Mark S.

=A0

=A0=A0

=A0

__._,_.___

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