X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qw-out-2122.google.com ([74.125.92.25] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3525508 for flyrotary@lancaironline.net; Tue, 03 Mar 2009 14:17:47 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.92.25; envelope-from=msteitle@gmail.com Received: by qw-out-2122.google.com with SMTP id 8so2247148qwh.25 for ; Tue, 03 Mar 2009 11:17:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=QzZrLMscJcu8/pPColswf2YKPjXP6NQqyjziTcir2Mk=; b=SiRrZ4RdIW+aFJ9gZz5Q/7DPf7t9dV7BGpwn6wEpqvBzjiH/ca/AyVEj2O1a5izEOj xZXYeEVKewNXK0bVsAoG82zHqkXbMuuiEuBFLTGFNHDhw+R1Gm90PQ4dudBbKw2g0eXY +OHGH/Me0STQHujMuVRHy8vvluhaw36PP671s= 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=jQonNGWUHcXKQN5SxLWeblhHIqQ6UTaAo/VE52yqfNCxsi0UOZirR9f2LkRXbhuo1c YMc/sqjZEqHFi1+G1kuXGFhZa0HNGgzaUh48nT+1tCROstC/VHai7rpSvJiduYZMl42F uovx3PzZLub236iWg/5e73/Xi1p3ZLl+XCT1E= MIME-Version: 1.0 Received: by 10.224.6.136 with SMTP id 8mr10195242qaz.212.1236107831938; Tue, 03 Mar 2009 11:17:11 -0800 (PST) In-Reply-To: References: Date: Tue, 3 Mar 2009 13:17:11 -0600 Message-ID: <5cf132c0903031117h322cc7ccm70797a1be121cc4f@mail.gmail.com> Subject: Re: [FlyRotary] Re: Questions on buying a rotary plane From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015175ce0c63a0d8904643bc8af --0015175ce0c63a0d8904643bc8af Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable ... and in the price of parts (rarely necessary), ... and that I can work on the engine myself (rarely required), ...plus it runs smooth as silk, ...and starts when hot. Mark S. _I_ ------{0}------ On Tue, Mar 3, 2009 at 12:45 PM, Patrick Panzera < panzera@experimental-aviation.com> wrote: > Hi Mark, > > > > I know you are saying that you are not overly concerned with BSFC, but wh= at > you=92ve described is exactly that. > > > > If the IO-540 and the rotary both have similar BSFC, then equal fuel > consumption will net equal power. > > > > That is to say, if you are burning 10.5 GPH @ 20=94 MP, you are making ab= out > 123 HP figuring .51 lbs per hp/hr. BSFC > > If the IO-540 is making only 123 HP and its BSFC is also .51, then it too > will burn only 10.5 GPH > > > > If your BSFC is as good as .49 lbs per hp/hr then 10.5 GPH would yield a > little over 128 HP. > > 128 HP with the IO-540 with a BSFC of only .51 would net 10.88 GPH. > > > > The difference between mogas and 100LL is where the real savings might be= . > > > > Pat > > > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Mark Steitle > *Sent:* Tuesday, March 03, 2009 5:24 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Questions on buying a rotary plane > > > > William, > > > > I'll throw my 2 cents worth in here. Regardinging fuel burn, I'm not > overly concerned with bsfc, although its not that bad if you're running > EFI. What we're really interested in is cost per mile. I have burned > nothing but mogas in my 3-rotor Lancair. The last time I purchased fuel,= it > was $1.65/gallon. My N/A 3-rotor burns between 10 and 11 gph at around 2= 0" > MAP. So, it will cost me somewhere around $16.50 - $18.15/hr to fly. Ot= her > Lancair ES's are running IO-540's, or some derivative of the "540". From > what I hear, they burn between 12 - 15 gph. With the cost of 100LL runni= ng > around $4/gallon, that would cost between $48 - $60/hr in fuel. So, > figuring cost per mile, I don't see how a Lycoming could come close to > matching a rotary. The fuel savings alone will more than cover the cost = of > an overhaul. > > > > And hope the Lycoming doesn't burn a valve, or any number of other common > ailments which can take a serious bite out of your checkbook. Most of th= e > things that break on a piston engine aren't even present on the rotary. = If > it ain't there, it can't break. > > > > So, would I use a rotary if I were to do it over, yes, absolutely! > > > Mark S. > > On Mon, Mar 2, 2009 at 11:31 PM, William Wilson > wrote: > > I have not found an accomodating A&P but I attribute that to the fact tha= t > I have not looked yet. Given that I live in Seattle I am pretty sure I c= an > find one. Seattle is crawling (fluttering?) with homebuilt planes. If > anyone has suggestions, I am listening, but I had not started searching y= et. > > Plan is not to take apart a perfectly good flying plane to change the > engine, but ideally to get one with a rotary in it already, or replace on= ly > at overhaul time. In each case I save as much on the cheaper engine as I > would lose on resale value... and if the plane has the rotary in it to st= art > with, I get to pay the lower price up front too, which makes price > difference just plain better. > > For efficiency what I said was that homebuilt planes are more efficient > than factory built, not that rotary are more efficient than Lycoming, tho= ugh > in that case it should be quite close. Bad fuel economy of rotary engine= is > overstated, economy is comparatively bad at low power & RPM but at high > power it is not bad at all. As long as you are not turbocharged, you can > run much leaner than a piston engine, making up for less efficient > combustion chamber shape. Rotary BSFC in the lab has gone as low as .375 > (for renesis), and .44-.46 measured in real world racing applications eve= n > with traditional type engine. So I think I would not see a significant > difference in fuel economy between rotary and piston. Weight & drag of t= he > plane it is in will matter more. > > In any case all advice is welcome, even dissenting opinions ;) > > On Mon, Mar 2, 2009 at 8:12 PM, Mike Wills wrote: > > William, > > > > I highly recommend you check around to make sure you can find an A&P who > will do a condition inspection with the rotary engine installed BEFORE yo= u > commit. Many A&Ps I've talked to dont want anything to do with Experiment= als > let alone an engine that looks nothing like what they are used to. There'= s > simply too much potential liability (real or perceived) to go out on a li= mb > like that. The A&P who used to do the condition inspection on the RV-6A I > used to own (Lycoming powered) was willing to do it because the RV struct= ure > is similar to typical spam cans. He wont have anything to do with wet lay= up > homebuilts (EZs, Cozys, etc...). He doesnt even like doing annuals on > Diamond aircraft with the Rotax 912/914 and they are certified. > > > > If you buy a flying homebuilt that is Lyc or Continental powered, before > you convert it to rotary power seriously think about what you are doing t= o > the resale value - if you could ever sell it that is. My guess is that > you'll give up at least $10,000 in resale value, maybe much more. No big > deal if you plan on keeping it for life. > > > > I dont know where you got the idea that rotaries are more fuel efficient= . > Lycosaurs/Continentals typically have BSFCs in the low .40s. The commonly > accepted number for a rotary is about .50. Some here seem to do better, > others worse. With a grand total of 2 hours on my rotary I cant say what = my > experience will be but hope its close to the Lyc I used to fly. > > > > Finally dont underestimate the effort required to make the change. I > started building my RV-4 in late 1995. The airframe was essentially done= in > 2000. My first flight was last month. Granted I took longer than many and > much of the trouble came from my desire to eliminate the cowl cheeks on a= n > already cramped engine compartment. But thats eight years of tinkering to > get the engine installed and running to the point where I had enough > confidence in it to fly it. > > > > Not trying to discourage you, but go into this with eyes wide open. > > > > Mike Wills > > RV-4 N144MW > > - Show quoted text - > > > > > > ----- Original Message ----- > > *From:* William Wilson > > *To:* Rotary motors in aircraft > > *Sent:* Sunday, March 01, 2009 7:46 PM > > *Subject:* [Norton AntiSpam] [FlyRotary] Re: Questions on buying a rotary > plane > > > > This is great news. Thanks Charlie and Bob :) > > On Sun, Mar 1, 2009 at 7:34 PM, Charlie England > wrote: > > William Wilson wrote: > > I am in the market for a plane and would prefer a rotary-powered, as I ha= ve > lots of experience working with rotary engines. As a bonus, homebuilt > planes all seem to get about twice as much fuel economy as factory built > planes. So that is nice too. I know there are a few rotary powered plan= es > available for sale, but not too many. > > I have neither the time nor desire to build my own plane, so my question = is > more about maintenance and inspections. I'm not an official A&P and I do= n't > know if I will be able to find an A&P to work on a home built plane with = a > car engine in it! I am happy to do engine maintenance, but am not entire= ly > clear on the legality of it, since I would not be the original builder. > > Similarly when it is eventually time for an engine rebuild, would I be ab= le > to remove the engine, take it down to Atkins (who are not far from me) an= d > have them rebuild it, or rebuild it myself, and then reinstall it, and fi= nd > an A&P to just sign off on the work? > > Plan B is to buy whatever plane even if it has a Lycosaurus, but when tim= e > for overhaul comes, get rid of the Lycoming and replace it with a rotary. > Thought in this case is to get the rotary tuned, a little broken in and > running on a stand in the hangar in advance, so that when the time comes = to > do the swap it can be done with a minimum of downtime. (I know it cannot > really be tuned for altitude in this way but it is better than nothing!). > But again, the fact that I would not be the original builder makes me wo= rry > about legalities. I have heard that this has been done so question is mo= re > about the how. > > I do not really understand all the law involved and hopefully somebody he= re > can help. Thanks! > > > > I can't speak with authority, but I can speak from experience. > > Experimental homebuilts can be maintained or modified by anyone. No FAA > blessings required. Annual condition inspections must be performed by eit= her > the holder of the 'repairman's certificate' (only available to the builde= r > of record) or by the holder of an A&P ticket (no IA required). > > Once the airworthiness certificate is awarded, *anyone* can do any > maintenance, repairs, modifications etc desired. The post-modification > requirements vary somewhat from plane to plane depending on when the a/w = was > issued, but in general terms, you notify the FAA in writing that major mo= ds > were made, ask for a defined test area, make a log entry detailing the > return to 'phase one' testing, fly test flights for (typically) 5 hours, > then make another log entry saying that the plane has been tested with th= e > mods & is being returned to 'phase two' (normal operational) status. > > 'Major modification' isn't clearly defined, but if you have to ask, it's > major. :-) > > The availability of an A&P to sign off condition inspections is all over > the map (literally). It's never been a problem for me, but in some parts = of > the country people can't find an A&P who will sign off *any* homebuilt, = no > matter what engine. If you have that problem, get to know the guys who s= ign > off the crop dusters in your area. > > Hope that helps.... > > Charlie > > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > > > > > > --0015175ce0c63a0d8904643bc8af Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
... and in the price of parts (rarely necessary),
... and that I can work on the engine myself (rarely required),
...plus it runs smooth as silk,
...and starts when hot.
=A0
Mark S.=A0
=A0=A0=A0=A0=A0=A0 _I_
=A0------{0}------
=A0=A0=A0=A0=A0=A0
On Tue, Mar 3, 2009 at 12:45 PM, Patrick Panzera= <panzera@experimental-aviation.com> wrote:

Hi Mark,

=A0

I know you are saying that you are = not overly concerned with BSFC, but what you=92ve described is exactly that= .

=A0

If the IO-540 and the rotary both h= ave similar BSFC, then equal fuel consumption will net equal power.<= /font>

=A0

That is to say, if you are burning = 10.5 GPH @ 20=94 MP, you are making about 123 HP figuring .51 lbs per hp/hr= . BSFC

If the IO-540 is making only 123 HP= and its BSFC is also .51, then it too will burn only 10.5 GPH

=A0

If your BSFC is as good as .49 lbs = per hp/hr then 10.5 GPH would yield a little over 128 HP.

128 HP with the IO-540 with a BSFC = of only .51 would net 10.88 GPH.

=A0

The difference between mogas and 10= 0LL is where the real savings might be.

=A0

Pat

=A0

=A0

From: Rota= ry motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Tuesday, March 03, 20= 09 5:24 AM
To: Rotary mo= tors in aircraft
Subject: [FlyRotary] Re: Questions on buying a rotary plane

fluffysheap@gmail.com> wrote:<= /span>

= I have not found an accomodating A&P bu= t I attribute that to the fact that I have not looked yet.=A0 Given that I = live in Seattle I am pretty sure I can find one.=A0 Seattle is crawling (fl= uttering?) with homebuilt planes.=A0 If anyone has suggestions, I am listen= ing, but I had not started searching yet.

Plan is not to take apart a perfectly good flying plane to change the e= ngine, but ideally to get one with a rotary in it already, or replace only = at overhaul time.=A0 In each case I save as much on the cheaper engine as I= would lose on resale value... and if the plane has the rotary in it to sta= rt with, I get to pay the lower price up front too, which makes price diffe= rence just plain better.

For efficiency what I said was that homebuilt planes are more efficient= than factory built, not that rotary are more efficient than Lycoming, thou= gh in that case it should be quite close.=A0 Bad fuel economy of rotary eng= ine is overstated, economy is comparatively bad at low power & RPM but = at high power it is not bad at all.=A0 As long as you are not turbocharged,= you can run much leaner than a piston engine, making up for less efficient= combustion chamber shape.=A0 Rotary BSFC in the lab has gone as low as .37= 5 (for renesis), and .44-.46 measured in real world racing applications eve= n with traditional type engine.=A0 So I think I would not see a significant= difference in fuel economy between rotary and piston.=A0 Weight & drag= of the plane it is in will matter more.

In any case all advice is welcome, even dissenting opinions ;)

rv-4mike@cox.net> wrote:

William,

=A0I highly recommend you check around to make sure you can fin= d an A&P who will do a condition inspection with the rotary engine inst= alled BEFORE you commit. Many A&Ps I've talked to dont want anythin= g to do with Experimentals let alone an engine that looks nothing like what= they are used to. There's simply too much potential liability (real or= perceived) to go out on a limb like that. The A&P who used to do the c= ondition inspection on the RV-6A I used to own (Lycoming powered) was willi= ng to do it because the RV structure is similar to typical spam cans. He wo= nt have anything to do with wet layup homebuilts (EZs, Cozys, etc...). He d= oesnt even like doing annuals on Diamond aircraft with the Rotax 912/914 an= d they are certified.

=A0If you buy a flying homebuilt that is Lyc or Continental pow= ered, before you convert it to rotary power seriously think about what you = are doing to the resale value - if you could ever sell it that is. My guess= is that you'll give up at least $10,000 in resale value, maybe much mo= re. No big deal if you plan on keeping it for life.

=A0I dont know where you got the idea that rotaries are more fu= el efficient. Lycosaurs/Continentals typically have BSFCs in the low .40s. = The commonly accepted number for a rotary is about .50. Some here seem to d= o better, others worse. With a grand total of 2 hours on my rotary I cant s= ay what my experience will be but hope its close to the Lyc I used to fly.<= /span>

=A0Finally dont underestimate the effort required to make the c= hange. I started building my RV-4=A0 in late 1995. The airframe was essenti= ally done in 2000. My first flight was last month. Granted I took longer th= an many and much of the trouble came from my desire to eliminate the cowl c= heeks on an already cramped engine compartment. But thats eight years of ti= nkering to get the engine installed and running to the point where I had en= ough confidence in it to fly it.

=A0Not trying to discourage you, but go into this with eyes wid= e open.

Mike Wills

RV-4 N144MW

=

----- Original Message -----

Sent: Sunday, = March 01, 2009 7:46 PM

Subject: [Nort= on AntiSpam] [FlyRotary] Re: Questions on buying a rotary plane

= This is great news.=A0 Thanks Charlie and B= ob :)

ceengland@bellsouth.net> wro= te:


Charlie

http://www.flyrotary.com/
Archive and UnSub: =A0 <= a href=3D"http://mail.lancaironline.net:81/lists/flyrotary/List.html" targe= t=3D"_blank">http://mail.lancaironline.net:81/lists/flyrotary/List.html=