X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 69 [XX] (34%) BODY: contains URL text "unsubscribe" (20%) HTML: contains clickable image tag (14%) URL: contains "unsubscribe" text (14%) BODY: text/html email has no html tag (-20%) BODY: image URL adjustment 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 3576390 for flyrotary@lancaironline.net; Fri, 10 Apr 2009 09:26:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.167; envelope-from=msteitle@gmail.com Received: by ewy11 with SMTP id 11so1606552ewy.19 for ; Fri, 10 Apr 2009 06:26:15 -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:cc:content-type; bh=fSSiuKUmpbbH0a2ifDsF3gOuuMbF3ErtvIW1iD4lDmc=; b=L0nFAn085x+A5ICGdHApJT1UiRYs4qdtx487UkE0h0iXtoFNndHIFxx8QgnqiogcZh CfNlITHwcUazyGujHo+8ow4t/1Ondtgwpa6zHLcDVPusMEC1U2Sj4h3kRi5otZVriqWi prsiDUwe5/zrUxXqEBfd9zfw/mYH3/pMfnXdM= 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 :cc:content-type; b=UZgo8azN+YLOJ+Y5x0ESXSOY+1wiY5okUZR4sBqyN4CgAvluWTkkEbK6Tis05hl6a1 ZZX9iNOnEzBeBzQM9LzZI8ng8UlVc/dyTQcickYMUHxLKtVI2I64ZCxgJrPjkWm+ldDv T8SW+CWsFX+GQ4PbppQw8Qi3CpSnUcl4xsOac= MIME-Version: 1.0 Received: by 10.210.20.17 with SMTP id 17mr215770ebt.61.1239369975650; Fri, 10 Apr 2009 06:26:15 -0700 (PDT) In-Reply-To: <694027.93356.qm@web57501.mail.re1.yahoo.com> References: <20090408013640.DASS28131.ispmxaamta08-gx.windstream.net@dave> <5cf132c0904091427t11122457m9085664e1a9f26fe@mail.gmail.com> <694027.93356.qm@web57501.mail.re1.yahoo.com> Date: Fri, 10 Apr 2009 08:26:15 -0500 Message-ID: <5cf132c0904100626l7ac12e2fm87a5521f8df3b1a0@mail.gmail.com> Subject: Re: [Lancair_ES] Re: Rotary Engines From: Mark Steitle To: Lancair_ES@yahoogroups.com Cc: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015174be73224daa00467334f7e --0015174be73224daa00467334f7e Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Gary, 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. ;-) 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. 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. 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... 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 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. > > 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 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. > > 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. > 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. > > 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? > > 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. > > 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 required) > Change settings via email: Switch delivery to Daily Digest| Switch > format to Traditional > Visit Your Group > | > Yahoo! Groups Terms of Use | Unsubscribe > > 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. > . > > __,_._,___ > --0015174be73224daa00467334f7e Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Gary,
=A0
Thanks for adding a more technical tone to this discussion.=A0 Yes, I = was not accounting for all the misc pieces needed to make the rotary run, b= ut then I wasn't considering all the little pieces needed to make a con= ventional piston engine run either.=A0 Of the pieces that normally fail and= end up poking out through the engine case, I think you'll agree that t= he rotary has significantly fewer of those.=A0 In fact, I have never seen a= rotary with a thrown connecting rod.=A0 ;-)
=A0
Having a liquid cooling system is a two-edged sword, but its not=A0any= thing that can't be overcome with good engineering.=A0 For coolant line= s on my installation I used aluminum tubing connected to the engine and rad= iator=A0via "Wiggins" couplings.=A0 I monitor=A0coolant pressure,= coolant level, and coolant temperature. =A0Of course, if I catch a Canadia= n goose in the radiator, it will likely loose its ability to cool the engin= e, but then you have the same risk with an air-cooled engine.=A0
As for the bsfc,=A0do your numbers reflect=A0the modern EFI systems, o= r carbureted engines.=A0=A0Tracy Crook realized a significant improvement i= n bsfc when he switched from carburetors to EFI.=A0=A0The new "Renesis= " rotary=A0engine has a better bsfc due to the side exhaust ports.=A0= =A0Anyway, I=A0prefer to consider=A0it in=A0"dollars per air-mile"= ;.=A0 By the time you factor in the cost savings for purchasing and=A0maint= aining a rotary engine over a certified engine, and that the rotary runs ha= ppily (prefers)=A0on 89 UL fuel (half the cost of avgas), the cost per mile= tips significantly=A0in favor of the rotary.=A0=A0(Reading the recent post= about the $2300.00 oil pan practically brought tears to my eyes.)=A0 I gue= ss its the German in me that caused me to=A0seek out=A0something better, or= different.=A0
=A0
Ahhhh... you mentioned the magic word, "turbo-charger".=A0 I= built my engine=A0with the intention of=A0turbo-charging as=A0it was initi= ally turbo-charged in its former life.=A0=A0After much thought, I=A0decided= to=A0follow the KISS principle=A0and go N/A.=A0 But there's a little v= oice in my head that keeps whispering "turbo-charge".=A0 With the= rotary's high energy exhaust gasses, turbo's=A0are a natural solut= ion.=A0 Yes they add weight, but not much more than my current exhaust syst= em. =A0Stay tuned...
=A0
One thing that I hadn't mentioned that could be considered a negat= ive for the rotary engine is that very few A&P's know anything abou= t rotary engines.=A0 Heck, very few auto mechanics know how to work on a ro= tary engine.=A0 But, if I'm there with my repairman's certificate i= n hand, who needs an A&P?=A0 Also, rotary parts are less plentiful if y= ou get stuck in some hole-in-the-wall town.=A0 But there is always UPS over= night.=A0
=A0
Gary, thanks again for your thoughtful post.=A0 I'm not trying to= =A0convert anyone=A0to=A0a rotary engine, I only want to see it get a fair = shake.=A0=A0
=A0
Mark S.
=A0
P.S.=A0 I've CC'd the Fly Rotary group as they need something = to talk about (the list has been rather quiet lately).
=A0
=A0
=A0
=A0
On Fri, Apr 10, 2009 at 7:13 AM, Gary Casey <casey.gary@yahoo.= com> wrote:


I'll certainly have to commend Mark on the great work with the rot= ary engine. =A0I agree with his comments on almost every count. =A0But...
You probably should count ALL the parts in and around the engine to ha= ve a fair comparison. =A0For example, the air-cooled aircraft engine coolin= g system has essentially no moving parts, unless you count the vernitherm. = =A0Yes, the 3-rotor engine has only 4 MAJOR moving parts, but each rotor ha= s about 50 components. =A0While that's not necessarily good or bad, it&= #39;s not an inherently simple solution. =A0It rejects more heat to the coo= lant and more of that to the oil (rotors are oil-cooled), making the coolin= g system larger and potentially more complex. =A0And the exhaust is hotter = and contains more aggressive pressure pulses, which have to be taken care o= f by some sort of muffling. =A0The ideal muffler is probably a turbocharger= , which can work very well on account of the pressure pulses, but it probab= ly takes a special high-temperature turbo that can tolerate the up-to 2000 = degree exhaust. =A0The turbo adds weight and complexity, but perhaps not mo= re weight than an effective muffler. =A0The fact that the engine is inheren= tly round and concentric with the output shaft is a good thing, but probabl= y more attractive for a wing-mounted engine than one in front of the fusela= ge. =A0The rotary engine almost requires a speed reduction unit to make the= power/weight come out favorable, and I was not impressed with the design o= f the then-currently available units, although they seem to work okay in pr= actice. =A0One big thing that bothered me is that the efficiency is inheren= tly 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 com= bustion chamber is higher. =A0This penalty is probably 5 to 10%. =A0All tha= t being said, the big attraction to me was, as Mark said, the rotary will r= arely completely fail, even if the coolant is lost. =A0The apex seals might= disintegrate and parts warp, but it will most likely continue to produce p= ower for some time, unlike a piston engine. =A0A long time ago we were test= ing many rotaries and occasionally we would see a loss in power. =A0When th= e engine was shut down it welded itself together even though it was still p= roducing power. =A0And the very things that make it less efficient contribu= te to the fact that it can tolerate a variety of fuels. =A0And with boostin= g it can be made to produce a lot of reliable power.

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

From: Mark Steitle <msteitle@gmail.com&= gt;
To: Lancair_ES@yahoogroups.com<= /a>
Sent: Thursday, April 9, 20= 09 2:27:21 PM
Subject: R= e: [Lancair_ES] Rotary Engines

Dave,
=A0
Since there were no other replies, I figured I would give my 2-cents w= orth.=A0
=A0
I have been flying a 3-rotor Lancair ES for almost 2 years now with a = total of 110 hrs on the Hobbs.=A0 While it hasn't been without some tee= thing pains, all-in-all, it has been a very positive experience and I would= choose a rotary again if/when the opportunity presents itself.=A0
=A0
While I did the FWF myself,=A0my installation and the=A0Mistral are bo= th closely related.=A0 As an example, I could bolt a Mistral intake and/or = exhaust directly=A0to my engine, and probably interchange many parts with t= he Mistral 3-rotor.=A0 The Mistral folks have taken much of the=A0rotary en= gine=A0technology, and refined and=A0pakaged it into a (soon to be) certifi= ed product.=A0 =A0=A0=A0
My reasoning is based on my belief that the rotary is inheretly a stro= nger=A0engine (pistons are cast iron vs. aluminum),=A0with=A0 only 4=A0movi= ng parts.=A0 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.=A0 Like the chap in the AOPA story, we= too just=A0barely made it to the nearest airport, with oil pouring out fro= m 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 ro= tary.=A0=A0
=A0
Gross weight on my ES was 2060 lbs.=A0 I typically climb out at 7000 -= 7200 rpm (2400 - 2500 prop rpm), climbing at=A0between 1000 fpm and 1300 f= pm, burning 16 - 18=A0gph, 15 gph in regular cruise (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 either 100LL or mogas (w/o alc= ohol) without worry and can lean the=A0mixture aggressively without worry o= f hurting the engine (no exhaust valves to burn).=A0 I can pull the throttl= e to idle=A0whenever=A0 and not=A0risk shock cooling the engine.=A0=A0Being= fuel-injected, it will start cold, hot, or anywhere in between.=A0 What= 9;s not to love?=A0
=A0
I mentioned some teething pains... those consisted of an early cooling= problem which was solved with an auxilary water-to-oil exchanger and a cow= l 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=A0reseale= d=A0 it.=A0 Problem solved.=A0 The toughest issue to resolve has been findi= ng a muffler that could withstand the pounding of the rotary's exhaust.= =A0=A0I'm pretty sure that=A0issue has been=A0resolved=A0 by switching = to a DNA racing muffler, but I don't have enough hours on it yet to sta= te for certain.
=A0
Hopes this helps answer your question(s).
=A0
Mark S.
=A0
=A0=A0

__._,_.___
To Post a message = to the group, send it to:

Lancair_ES@YahooGroups.com

To Unsub= scribe, 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.c= om
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