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 3577033 for flyrotary@lancaironline.net; Fri, 10 Apr 2009 18:17:18 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.167; envelope-from=msteitle@gmail.com Received: by ewy11 with SMTP id 11so1859011ewy.19 for ; Fri, 10 Apr 2009 15:16:41 -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=oBrnDAjZh7gvq8nEf2n0lWMiAhOeWlu0v6g/x83R6Q4=; b=Jzk/XvtmGskF2eDYiHmQWhl4YatKuOGpKhertUp25OJv6RBVeCsze2tjv6vZMV1Cip apLjj4cRq0Vla1cP+3j0zZa23nJr5jj6Xad+IFf9E8KjkZ/ndSSjHYR6tTBvLSqkHXJx SCANaMez0Vqe/l/M05kQEU3YJNJpb8KKKkUSM= 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=gQiwubfESTyudauaz9tnDsSrKRUK3K9WkftAWou/RYcQcQtGGzwAm8hZIgOuKtDU/+ ejTzw6Wqls2X+i39Ey60BqtxAM+baXbVDtp+l8N4lSnMc2GEWHxQ6Rt+Iwszmr1tpR33 GzjIbsvKjKw0UsUywl/s5BBrG79VzCUqBY2Hw= MIME-Version: 1.0 Received: by 10.210.120.7 with SMTP id s7mr3524ebc.79.1239401801639; Fri, 10 Apr 2009 15:16:41 -0700 (PDT) In-Reply-To: References: Date: Fri, 10 Apr 2009 17:16:41 -0500 Message-ID: <5cf132c0904101516p1a792b1cyd0cc28d373382507@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=0015174bdf2e1ee93004673ab887 --0015174bdf2e1ee93004673ab887 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Ed, That's one award I can just as well do without. Mark On Fri, Apr 10, 2009 at 4:31 PM, Ed Anderson wro= te: > Ok, Mark, > > > > Yes, engineers can get anal about details. But, they sometimes forget th= e > rotary is not a piston engine {:>) Looks like my fame has preceded me, y= es, > so long as its cold, hot, or luke warm {:>). > > > > The Hobbs reads 530 hrs but flying hour are around 450 or so. Had about > 160 hrs on the original N/A 86 13B before I decided to switch to the curr= ent > 1991 turbo block. So around 290 hrs on the turbo block =96 this was the = one I > put the high compression rotors with the worn apex seal slots in and had = one > fail on way to Sun & Fun in 2005. Did a hasty (too hasty) rebuild and got= an > apex seal part jammed between rotor and side housing leading to localized > overheating and coolant =93O=94 ring failure in that area (due to way hig= h temps > =96 the metal turned blue) which resulted in a rebuild in Louisiana in Su= mmer > 2005 after the brake fire. But did it correctly that time in my brother = in > laws abandon garage with Tracy and Laura shipping parts to rotary > =96no-man-land. > > > > Yes, I still hold the record (will it never be broken?) for the most > mishaps =96 or almost mishaps with a flying rotary. Got the award from R= WS to > prove it {:>) > > > > > > 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 3:07 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines > > > > Ed, > > > > His point was that there are more than four moving parts in a 3-rotor > engine. If I had known that an engineer would be responding, I would hav= e > been more precise. ;-) > > > > And thanks for pointing out that while a single rotor has many small > pieces, it does the work of three pistons. Next time I will mention that > fact. > > > > How many "rotary hours" do you have on your RV now, and how many hours on > the newest engine? How's it running? > > > > Glad to hear you're planning on attending the fly-in. I'd ask you what > brand of beer you drink, but I've heard that you'll pretty much drink > anything as long as it is cold. ;-) > > > > Mark S. > > > > > > On Fri, Apr 10, 2009 at 1:56 PM, Ed Anderson > wrote: > > Hi Mark, > > > > I can understand being conservative =96 particularly in a Lancair =96 dea= d > sticking an RV into a field is one thing, doing it with a Lancair is not > something I would care to do. > > > > Well, being an engineer then Gary can pretty much see the advantages of t= he > rotary =96 but, as I noted his claim of =93more parts on a rotor than a p= iston=94 > needs to be seen in the context of a rotor really being equivalent of thr= ee > pistons =96 then the part difference is not what it first appears. > > > > Yes, my plans are to attend, hopefully everything will work out and I=92l= l > see you there again. > > > > 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 10:39 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines > > > > Thanks Ed. The Lancair bunch tend to be pretty conservative when it come= s > to their choice of engines. They can think of a hundred reasons why it i= s > 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 tha= t 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 > wrote: > > 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. > > . > > __,_._,___ > > > > > > > --0015174bdf2e1ee93004673ab887 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Ed,

That's one award I can just as well do without.

Mark<= br>
On Fri, Apr 10, 2009 at 4:31 PM, Ed Ander= son <eand= erson@carolina.rr.com> wrote:

Ok, Mark,

=A0

Yes, engineers can get anal about = details.=A0 But, they sometimes forget the rotary is not a piston engine {:>)=A0 Looks like my fame has preceded me, yes, so long as its cold, hot, or luke = warm {:>).

=A0

The Hobbs reads 530 hrs but flying= hour are around 450 or so.=A0 Had about 160 hrs on the original N/A 86 13B befor= e I decided to switch to the current 1991 turbo block.=A0 So around 290 hrs o= n the turbo block =96 this was the one I put the high compression rotors with the worn apex seal slots in and had one fail on way to Sun & Fun in 200= 5. Did a hasty (too hasty) rebuild and got an apex seal part jammed between ro= tor and side housing leading to localized overheating and coolant =93O=94 ring failure in that area (due to way high temps =96 the metal turned blue) which resulted in a rebuild in Louisiana in Summer 2005 after the brake fir= e.=A0 But did it correctly that time in my brother in laws abandon garage with Tr= acy and Laura shipping parts to rotary =96no-man-land.

=A0

=A0Yes, I still hold the record (w= ill it never be broken?) for the most mishaps =96 or almost mishaps with a flying rotary.=A0 Got the award from RWS to prove it {:>)<= /p>

=A0

=A0

Ed

=A0

From: Ro= tary motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Friday, April 10, 20= 09 3:07 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines

=A0

Ed,

=A0

His point was that there are more than four moving parts in a 3-rotor engine.=A0 If I had known that an engineer would be responding, I would hav= e been more precise.=A0 ;-)

=A0

And thanks for pointing out that while a single rotor has many small pieces, it does the work of three pistons.=A0=A0Next time=A0I will mention that fact.=A0

=A0

How many "rotary hours" do you have on your RV now, and how many hours on the newest engine?=A0 How's it running?=A0 =

=A0

Glad to hear you're planning on attending the fly-in.=A0 I'd ask= you what brand of beer you drink, but I've heard that you'll pretty muc= h drink anything as long as it is cold.=A0 ;-)

=A0

Mark S.



=A0

On Fri, Apr 10, 2009 at 1:56 PM, Ed Anderson <eanderson@carolina.rr.com> wrote:

Hi Mark,

=A0

I can understand being conservativ= e =96 particularly in a Lancair =96 dead sticking an RV into a field is one thing, doing it with a Lancair is not something I would care to do.

=A0

Well, being an engineer then Gary = can pretty much see the advantages of the rotary =96 but, as I noted his claim of =93more parts on a rotor than a piston=94 needs to be seen in the context of a rotor really being equivalent of three pistons =96 then the part difference is not what it first appears.

=A0

Yes, my plans are to attend, hopef= ully everything will work out and I=92ll see you there again.

=A0

Ed

From: Ro= tary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle<= br> Sent: Friday, April 10, 20= 09 10:39 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines

=A0

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 why it is better to go with a certified engine, all of them based on the past 100 years.=A0 ;-)

=A0

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.

=A0

Are you=A0planning on attending=A0the Texas roundup in May?=A0 It would 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 Denni= s H. and a number of others.=A0 It should be fun.

=A0

Mark

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

Good run down, Mark.=

=A0

Gary does mention the numerous par= ts on the rotor =A0itself =96 and while each rotor does have a high part count, you have to consider that each rotor is the equi= valent 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 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 through the block {:>)=A0=A0 So, good questions and good answers from you.

=A0

One saying does come to mind =96 f= rom our good friend, Tracy Crook.=A0 =A0

Ed

From: Ro= tary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle<= br> Sent: Friday, April 10, 20= 09 9:26 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: [Lancair_ES] Re: Rotary Engines

=A0

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, but then = I wasn't considering all the little pieces needed to make a conventional = piston engine run either.=A0 Of the pieces that normally fail and end up poking ou= t through the engine case, I think you'll agree that the rotary has signi= ficantly 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=A0anything that can't be overcome with good engineering.=A0 For coolant lines on my installation I used aluminum tubing connected to the engine and radiator=A0via "Wiggins" couplings.=A0 I monitor=A0coolant pressure, coolant level, and coolant temperature. =A0Of course, if I catch = a Canadian goose in the radiator, it will likely loose its ability to cool th= e engine, 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, or carbureted engines.=A0=A0Tracy Crook realized a significant improvement in 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=A0maintaining a rotary engine over a certified engine, and that the rotary runs happily (prefers)=A0on 89 UL fue= l (half the cost of avgas), the cost per mile tips significantly=A0in favor o= f the rotary.=A0=A0(Reading the recent post about the $2300.00 oil pan practically brought tears to my eyes.)=A0 I guess 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 initially 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 voice in my head that keeps whispering "turbo-charge".=A0 With th= e rotary's high energy exhaust gasses, turbo's=A0are a natural soluti= on.=A0 Yes they add weight, but not much more than my current exhaust system. =A0Stay tuned...

=A0

One thing that I hadn't mentioned that could be considered a negative for the rot= ary engine is that very few A&P's know anything about rotary engines.= =A0 Heck, very few auto mechanics know how to work on a rotary engine.=A0 But, if I'm there with my repairman's certificate in hand, who needs an A&P?=A0 Also, rotary parts are less plentiful if you get stuck in some hole-in-the-wall town.=A0 But there is always UPS overnight.=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:

=A0

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

You probably should count ALL the parts in and ar= ound the engine to have a fair comparison. =A0For example, the air-cooled aircraft engine cooling 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 has about 50 components. =A0While that's not necessarily good or bad, it's not an inherently simple solution. =A0It 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. =A0And the exhaust is hotter and contains more aggressive pressure pulses, which have to be taken care of 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 probably takes a special high-temperature turbo tha= t can tolerate the up-to 2000 degree exhaust. =A0The turbo adds weight and complexity, but perhaps not more weight than an effective muffler. =A0The fact that the engine is inherently round and concentric with the output sha= ft is a good thing, but probably more attractive for a wing-mounted engine tha= n one in front of the fuselage. =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 of the then-currently available units, although t= hey seem to work okay in practice. =A0One big thing that bothered me is that th= e 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. =A0This penalty is probably 5 to 10%. =A0All that being said, the big attraction to me was, as Mark said, the rotary will rarely completely fail, even if the coolant is l= ost. =A0The apex seals might disintegrate and parts warp, but it will most likel= y continue to produce power for some time, unlike a piston engine. =A0A long 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 even though it was still producing power. =A0And the very things that make it less efficient contribute to the fact that it can tolerate a variety of fue= ls. =A0And with boosting it can be made to produce a lot of reliable power.

=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 <msteitl= e@gmail.com>

Sent: Th= ursday, April 9, 2009 2:27:21 PM
Subject: Re: [Lancair_ES] = Rotary Engines

Dave,

=A0

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

=A0

I have been flying a 3-rotor Lancair ES for almos= t 2 years now with a total of 110 hrs on the Hobbs.=A0 While it hasn't been without some teething pains, all-in-all, it has be= en 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 both 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 the Mistral 3-rotor.=A0 The Mistral folks have taken much of the=A0rotary engine=A0technology, and refined and=A0pakaged it into a (soon to be) certified product.=A0 =A0=A0=A0

My reasoning is based on my belief that the rotar= y 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 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 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 typicall= y climb out at 7000 - 7200 rpm (2400 - 2500 prop rpm), climbing at=A0between 1000 fpm and 1300 fpm, burning 16 - 18=A0gph, 15 gph in regular cruise (600= 0 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 alcohol) without worry and can lean the=A0mixture aggressivel= y 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 cooling the engine.=A0=A0Being fuel-injected, it will start cold, hot, or anywhere in between.=A0 What's not to love?=A0

=A0

I mentioned some teething pains... those consiste= d of an early cooling problem which was solved with an auxilary water-to-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 t= he 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 state for certain.

=A0

Hopes this helps answer your question(s).<= /font>

=A0

Mark S.

=A0

=A0=A0

=A0

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