X-Virus-Scanned: clean according to Sophos on Logan.com From: "James R. Osborn" Received: from mail-pa0-f49.google.com ([209.85.220.49] verified) by logan.com (CommuniGate Pro SMTP 6.1.6) with ESMTPS id 8116194 for flyrotary@lancaironline.net; Fri, 30 Oct 2015 17:53:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.220.49; envelope-from=rxcited@gmail.com Received: by pasz6 with SMTP id z6so85255677pas.2 for ; Fri, 30 Oct 2015 14:52:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-type:message-id:mime-version:subject:date:references :to:in-reply-to; bh=KnB/c4ZqZU8f6DgAcndZfBD8hrNJU3aKyFRIJa2y4fU=; b=UBO5GjRQS0z3XHyy9TE3+wNeLtw6uwqysXVwFTOUEAnLuc46QjZdarW7DbGZS+fmO1 /ZJ/Y76PjzmEG3LZQYJWohm3QD1xs+kKTiD17IQxOAffHavUoNdF4wCFVLBYHjPnW6XO zhRi4aXWJFJGEyTPwCfENFV2cpEXiUbeSCdE9ln6GEBdwExlos8N5NzUlzlC/Dl5Gcxg t0N2ikdzFe6Aql+B0vxpjbJ7qJN8B7YJVpAdOsT0N1dSZYF1nvipXjD+7j1K+zbgWaXQ 6nCW/A34A0vi/kvd9jV1u1XJu/JKdGRBQYqKl+eezIGx2vBPuhIdDwzMZXkVteWFQVnL jeaA== X-Received: by 10.66.241.35 with SMTP id wf3mr11282157pac.53.1446241975157; Fri, 30 Oct 2015 14:52:55 -0700 (PDT) Return-Path: Received: from ?IPv6:2620:83:8001:24::1:1c35? ([2620:83:8001:24::1:1c35]) by smtp.gmail.com with ESMTPSA id fb1sm10044719pab.9.2015.10.30.14.52.54 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 30 Oct 2015 14:52:54 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_F1F0306F-7100-4ECB-8E9A-DB1A619465D4" Message-Id: <79A6B5A4-028C-4C0B-AC0B-9F7177CA4856@gmail.com> Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Subject: Re: [FlyRotary] 20B with RD-1C Prop Options Date: Fri, 30 Oct 2015 14:52:49 -0700 References: To: Rotary motors in aircraft In-Reply-To: X-Mailer: Apple Mail (2.2104) --Apple-Mail=_F1F0306F-7100-4ECB-8E9A-DB1A619465D4 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 HI Bill, I guess there is disagreement about what is attainable! I have no doubt = PP is the way to go based on the recent rehash. I have decided however = to let the motor decide. If it checks out as a healthy side port, I = will probably leave it that way. It seems there are some side port = intakes out there that others are willing to part with. If I had to = start from scratch though, the ease of the PP intake would weigh in its = favor certainly. =E2=80=94 James > On Oct 30, 2015, at 2:20 PM, William Jepson = wrote: >=20 > James, a side port 20B with a good intake and exhaust can reasonably = expect to see about 300 HP at 7000. Mistral's 3 rotor was right there. A = peripheral port version quite a bit more. For an aircraft I suggest the = p-port. There is almost no down side. My biggest reason is the intake is = sooo much easier. They are more efficient in the range we use in = aircraft anyway. >=20 > Bill Jepson >=20 > On Oct 30, 2015 8:13 AM, "James R. Osborn" = > = wrote: > Hi Bill, >=20 > Yeah after I sent that I realized slip was a much smaller difference. = The difference between top speed and standing still is 100% slip! >=20 > I don=E2=80=99t really know what to expect for HP. I threw those = numbers out there for feedback. So what numbers say for unported site = port, medium street port side port, and peripheral port on a 20B can we = reasonably achieve? >=20 > Thanks for more input and numbers. It will be interesting to try to = work it out on the ground and the more I think about it, adjustability = will be a real big help. I did recall correctly that a friend has an = old dyno I can borrow. So I guess I will move in that direction first = and set the prop selection aside for now. >=20 > My plan is to buy an in progress RV-10, hopefully way past 50%. I = really don=E2=80=99t want to start from scratch; we have only one = lifetime - 22000 days as the song goes (maybe more like 28000 days now = days :). >=20 > =E2=80=94 James >=20 > P.S. Thanks to you Charlie too and for the invite. Alas I am pretty = far West in the SF Bay area. Someday I hope to make it to some of the = rotary gatherings back East and South. >=20 > > On Oct 29, 2015, at 9:33 PM, Bill Bradburry = > = wrote: > > > > James, > > There could be some slip involved, but it is mostly the change in = angle of > > attack as the prop disc is moved forward thru the air. > > > > If you can stand the expense, I recommend you get some kind of in = flight > > adjustable prop. The rotary power output is really affected by rpm = and > > being able to adjust it in flight is very helpful. > > I also recommend you set a max take off rpm target of 2500 prop and = 7125 > > engine. There are several good reasons for this not the least of = which is > > that the EC-2/3 has a cutoff at 7500 rpm. (Tracy can straighten me = out here > > if needed) > > If you dyno the engine be sure and let us know what you get. I = don't think > > you will be anywhere near those HP numbers you quote. Also when you = get up > > to altitude and cut the rpm back to 48-5200, you will really be = reducing the > > output. If you leave the engine at 7125 rpm and climb to 8000 ft, = you will > > be producing 75%, if you then reduce the rpm to 4800, I don't know = what your > > percent power might be...but a heck of a lot lower than 75%. > > > > Do you plan to try and buy a completed airframe? It sometimes takes = a > > surprising length of time to build one. Ask me how I know. :>) > > > > Bill > > > > -----Original Message----- > > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net = ] > > Sent: Thursday, October 29, 2015 9:20 PM > > To: Rotary motors in aircraft > > Subject: [FlyRotary] Re: 20B with RD-1C Prop Options > > > > Thanks for the input Tracy! So is the difference between top speed = rpm and > > static rpm the "slip"? > > > >> On Oct 29, 2015, at 6:32 PM, Tracy > wrote: > >> > >> Hi James, > >> HP targets sound doable, but those rpm numbers are probably off. > > Remember that with a fixed pitch prop, hp varies as the CUBE of rpm. = Would > > recommend propping for a max power at top speed rpm of about 7000. = That > > will give you a static rpm of around 6000. > >> > >> Will get those instruction manuals you asked about to you next time = I'm in > > the office. > >> > >> Tracy > >> > >> Sent from my iPad > >> > >>> On Oct 29, 2015, at 16:22, James R. Osborn = > > > wrote: > >>> > >>> Hi guys, > >>> > >>> So I am going to be building an RV-10. I sourced Bobby's spare = 20B / > > RD-1C combo and my plan is to work on the motor first, kind of = bass-ackward > > but that is what I am doing. My plan is to build a motor/mount test = stand > > and work everything out on the ground before I ever put it in an = airframe. > > I plan to set it up NA using the existing side port configuration. = I don't > > know if it is ported - I am going to attempt to determine this by = inspection > > without cracking it open and doing a dynamic compression test to = evaluate > > the health of the motor. If it is necessary to entirely rebuild the = motor, > > I would probably go PP. So I am thinking the target HP as it is = would be in > > the 275 HP range and probably 325 HP if it ends up being a PP. How = do these > > numbers sound to you all? > >>> > >>> I will be looking for a way to dyno it, hopefully borrow one to = get some > > data. But I was also thinking about just getting an appropriate = fixed pitch > > prop and working through the bugs based on static run ups. I like = the idea > > of a three blade prop. I like the idea of optimizing for cruise at = 75%, say > > 5800 rpm which would put full throttle at 7733 rpm on the 20B. At = 5800 rpm, > > the prop would be spinning 2035 rpm and at full throttle 2713 rpm = (using the > > 2.85 ratio RD-1C PSRU). Do all these numbers sound about right? > >>> > >>> If so, then how do I choose a prop that will result in 2713 rpm = static > > run up at full throttle, but be tuned for efficiency at 2035 rpm = cruise? I > > am assuming at these reasonable RPMs that it will be a larger swing = and the > > three blade makes sense - what do you think? Is there a convenient = way to > > find props out there that will work at the target full throttle HP = of 275 or > > 325? Also if you guys have any good resources to learn about how to = figure > > these things out (books, web pages, online calculators, etc.) that = would be > > great! > >>> > >>> Another option might be to go with something like the IVOPROP = Magnum, > > either ground adjustable or electric inflight adjustable. What do = you guys > > think of these? Would the adjustability really help me adapt to = however my > > power plant turns out? Would the extra complexity be worth it? For = the > > ground adjustable one, I am thinking the process would be: 1. = select the > > "correct" swing (how?) and go for three blades, 2) use ground = adjustability > > and work up to THE pitch while I tune the motor until I achieve full > > throttle static run up around 7700 RPM. Will this result in a = reasonably > > efficient setting for 75% cruise? Am I thinking about this clearly? = All > > opinions are welcome. > >>> > >>> There's a lot for you to chew on! > >>> > >>> - James > >>> > >>> > >>> -- > >>> Homepage: http://www.flyrotary.com/ > >>> Archive and UnSub: > > http://mail.lancaironline.net:81/lists/flyrotary/List.html = > >> > >> -- > >> Homepage: http://www.flyrotary.com/ > >> Archive and UnSub: > > http://mail.lancaironline.net:81/lists/flyrotary/List.html = > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: > > http://mail.lancaironline.net:81/lists/flyrotary/List.html = > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html = >=20 >=20 > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html = --Apple-Mail=_F1F0306F-7100-4ECB-8E9A-DB1A619465D4 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 HI Bill,

I = guess there is disagreement about what is attainable!  I have no = doubt PP is the way to go based on the recent rehash.  I have = decided however to let the motor decide.  If it checks out as a = healthy side port, I will probably leave it that way.  It seems = there are some side port intakes out there that others are willing to = part with.  If I had to start from scratch though, the ease of the = PP intake would weigh in its favor certainly.

=E2=80=94 James

On Oct 30, 2015, at 2:20 PM, William Jepson <flyrotary@lancaironline.net> wrote:

James, a side port 20B with a good intake and exhaust can = reasonably expect to see about 300 HP at 7000. Mistral's 3 rotor was = right there. A peripheral port version quite a bit more. For an aircraft = I suggest the p-port. There is almost no down side. My biggest reason is = the intake is sooo much easier. They are more efficient in the range we = use in aircraft anyway.

Bill Jepson

On Oct 30, 2015 8:13 AM, "James R. Osborn" = <flyrotary@lancaironline.net> wrote:
Hi Bill,

Yeah after I sent that I realized slip was a much smaller = difference.  The difference between top speed and standing still is = 100% slip!

I don=E2=80=99t really know what to expect for HP.  I threw those = numbers out there for feedback.  So what numbers say for unported = site port, medium street port side port, and peripheral port on a 20B = can we reasonably achieve?

Thanks for more input and numbers.  It will be interesting to try = to work it out on the ground and the more I think about it, = adjustability will be a real big help.  I did recall correctly that = a friend has an old dyno I can borrow.  So I guess I will move in = that direction first and set the prop selection aside for now.

My plan is to buy an in progress RV-10, hopefully way past 50%.  I = really don=E2=80=99t want to start from scratch; we have only one = lifetime - 22000 days as the song goes (maybe more like 28000 days now = days :).

=E2=80=94 James

P.S.  Thanks to you Charlie too and for the invite.  Alas I am = pretty far West in the SF Bay area.  Someday I hope to make it to = some of the rotary gatherings back East and South.

> On Oct 29, 2015, at 9:33 PM, Bill Bradburry <flyrotary@lancaironline.net> wrote:
>
> James,
> There could be some slip involved, but it is mostly the change in = angle of
> attack as the prop disc is moved forward thru the air.
= >
> If you can stand the expense, I recommend you get some kind of in = flight
> adjustable prop.  The rotary power output is really affected = by rpm and
> being able to adjust it in flight is very helpful.
> I also recommend you set a max take off rpm target of 2500 prop and = 7125
> engine.  There are several good reasons for this not the least = of which is
> that the EC-2/3 has a cutoff at 7500 rpm. (Tracy can straighten me = out here
> if needed)
> If you dyno the engine be sure and let us know what you get.  = I don't think
> you will be anywhere near those HP numbers you quote.  Also = when you get up
> to altitude and cut the rpm back to 48-5200, you will really be = reducing the
> output.  If you leave the engine at 7125 rpm and climb to 8000 = ft, you will
> be producing 75%, if you then reduce the rpm to 4800, I don't know = what your
> percent power might be...but a heck of a lot lower than 75%.
>
> Do you plan to try and buy a completed airframe?  It sometimes = takes a
> surprising length of time to build one.  Ask me how I = know.  :>)
>
> Bill
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
> Sent: Thursday, October 29, 2015 9:20 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: 20B with RD-1C Prop Options
>
> Thanks for the input Tracy!  So is the difference between top = speed rpm and
> static rpm the "slip"?
>
>> On Oct 29, 2015, at 6:32 PM, Tracy <flyrotary@lancaironline.net> wrote:
>>
>> Hi James,
>>  HP targets sound doable, but those rpm numbers are = probably off.
> Remember that with a fixed pitch prop, hp varies as the CUBE of = rpm.  Would
> recommend propping for a max power at top speed rpm of about = 7000.  That
> will give you a static rpm of around 6000.
>>
>> Will get those instruction manuals you asked about to you next = time I'm in
> the office.
>>
>> Tracy
>>
>> Sent from my iPad
>>
>>> On Oct 29, 2015, at 16:22, James R. Osborn <flyrotary@lancaironline.net>
> wrote:
>>>
>>> Hi guys,
>>>
>>> So I am going to be building an RV-10.  I sourced = Bobby's spare 20B /
> RD-1C combo and my plan is to work on the motor first, kind of = bass-ackward
> but that is what I am doing.  My plan is to build a = motor/mount test stand
> and work everything out on the ground before I ever put it in an = airframe.
> I plan to set it up NA using the existing side port = configuration.  I don't
> know if it is ported - I am going to attempt to determine this by = inspection
> without cracking it open and doing a dynamic compression test to = evaluate
> the health of the motor.  If it is necessary to entirely = rebuild the motor,
> I would probably go PP.  So I am thinking the target HP as it = is would be in
> the 275 HP range and probably 325 HP if it ends up being a = PP.  How do these
> numbers sound to you all?
>>>
>>> I will be looking for a way to dyno it, hopefully borrow = one to get some
> data.  But I was also thinking about just getting an = appropriate fixed pitch
> prop and working through the bugs based on static run ups.  I = like the idea
> of a three blade prop.  I like the idea of optimizing for = cruise at 75%, say
> 5800 rpm which would put full throttle at 7733 rpm on the = 20B.  At 5800 rpm,
> the prop would be spinning 2035 rpm and at full throttle 2713 rpm = (using the
> 2.85 ratio RD-1C PSRU).  Do all these numbers sound about = right?
>>>
>>> If so, then how do I choose a prop that will result in 2713 = rpm static
> run up at full throttle, but be tuned for efficiency at 2035 rpm = cruise?  I
> am assuming at these reasonable RPMs that it will be a larger swing = and the
> three blade makes sense - what do you think?  Is there a = convenient way to
> find props out there that will work at the target full throttle HP = of 275 or
> 325?  Also if you guys have any good resources to learn about = how to figure
> these things out (books, web pages, online calculators, etc.) that = would be
> great!
>>>
>>> Another option might be to go with something like the = IVOPROP Magnum,
> either ground adjustable or electric inflight adjustable.  = What do you guys
> think of these?  Would the adjustability really help me adapt = to however my
> power plant turns out?  Would the extra complexity be worth = it?  For the
> ground adjustable one, I am thinking the process would be:  1. = select the
> "correct" swing (how?) and go for three blades, 2) use ground = adjustability
> and work up to THE pitch while I tune the motor until I achieve = full
> throttle static run up around 7700 RPM.  Will this result in a = reasonably
> efficient setting for 75% cruise?  Am I thinking about this = clearly?  All
> opinions are welcome.
>>>
>>> There's a lot for you to chew on!
>>>
>>> - James
>>>
>>>
>>> --
>>> Homepage:  http://www.flyrotary.com/
>>> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br class=3D""> >>
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br class=3D""> >
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br class=3D""> >
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br class=3D"">

--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html<= br class=3D"">

= --Apple-Mail=_F1F0306F-7100-4ECB-8E9A-DB1A619465D4--