Return-Path: Received: from [65.54.169.164] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3117954 for flyrotary@lancaironline.net; Wed, 24 Mar 2004 11:01:53 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 24 Mar 2004 08:01:52 -0800 Received: from 64.159.104.62 by bay3-dav134.adinternal.hotmail.com with DAV; Wed, 24 Mar 2004 16:01:52 +0000 X-Originating-IP: [64.159.104.62] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Renesis & RD-1Cdrivetesting Date: Wed, 24 Mar 2004 11:01:45 -0500 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0002_01C4118F.65A58B80" Message-ID: X-OriginalArrivalTime: 24 Mar 2004 16:01:52.0451 (UTC) FILETIME=[52886930:01C411B9] ------=_NextPart_001_0002_01C4118F.65A58B80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Charlie's observations are right in line with what I have seen so far. = Still, I would not want to give up the ability to do wheel landings comfo= rtably. 74" is at the limit for my -4. The -8 or the -4 with the update= d longer gear would not have this problem. The -8 I'm building will hav= e nothing less than 76" prop and more if I can get it. As I accumulate more hours I clearly see the trend. Huge advantage at lo= w speeds (acceleration & climb) but advantage diminishes as speed approac= hed maximum. With the IVO prop (72" dia) I saw the same thing but the a= dvantage diminished to zero at about 140 mph and then became negative abo= ve that. =20 I still have not run the new drive & prop to top speed. I attempted to = yesterday evening but the dreaded SAG (Sparkplug Attention Getter as Ed c= alls it) struck as I was approaching 220 MPH. My best guess is that the= zero point (same performance as with -B drive) is right at this speed. = Things may improve after I get the cuffs built (today's project). BTW, this -C drive stuff is very encouraging but it's way too early to cl= ose the books on this. One week of testing does not prove anything about= long term effects. It's always the unexpected things that are the bane= of the experimenters' life. The 13B tension bolt problem took over 1000= hours to show up. I'll be flying on "Orange Alert" status for hundreds = of hours before I feel as comfortable as I did with the -B drive. =20 Tracy Crook ----- Original Message ----- From: Charlie & Tupper England Sent: Tuesday, March 23, 2004 9:21 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: C mounting on a B plate?? Renesis & RD-1Cdrivete= sting You guys with nose wheels shouldn't get too excited. One of the reasons =20 that almost all bush planes use tailwheels is that the nose gear is just =20 too fragile for rough field operation. Guess what the other reason is. FWIW, I've flown a short-legged RV-4 with a 76" dia. prop. I didn't do =20 it very much (long story) but it can be managed by doing all takeoffs & =20 landings tail low. RE: Tracy's radically improved performance, I'm now flying Chuck =20 Dunlap's old Lyc powered RV-4 (Hi Chuck). It's got a 62" dia 3 blade =20 climb prop because he flew out of high altitude gravel strips. Down here =20 in the lowlands of Mississippi, it turns about 2450 static & will turn =20 over 3000 rpm in level flight. I recently tried a prop originally made =20 for a 180 hp engine, originally 72", cut down to 68" dia., a very bad =20 prop because of the 'surgery'. It was about 5 mph faster at full =20 throttle & turned not quite as high an rpm as the 3 blade, but the =20 takeoff performance was radically different. The extra 6" of diameter =20 probably cut at least 30% off the takeoff roll. Vance Jaqua (sp?) posted =20 a prop efficiency chart on the 'other list' comparing optimized props of =20 various diameters. Bigger (dia.) was always better until speed got over =20 200, at which time the smaller props became as efficient as the larger =20 ones. I'm pretty excited that Tracy will have the Renesis & big prop =20 debugged by the time my -7 is ready for an engine. (Go for a 76" dia on =20 the RV-8. :-) ) Charlie Ed Anderson wrote: > Sounds like all around great news on the new gearbox and prop. Keep =20 > the reports coming. =20 > =20 > If such a "retrofit" of a B shell to C internals is possible and =20 > economical then that could move the trend toward the 2.85 even quicker.= =20 > =20 > Shucks, if you used NA rotor housings it sounds like you wouldn't even =20 > need a muffler {:>). =20 > =20 > I am somewhat surprised that you can get the same airspeed with only =20 > about a 5% difference in rpm - sounds like my initial assumption that =20 > a higher rpm (and fuel burn)would be required to get the same =20 > airspeed is not valid. Perhaps the much greater pitch gets more work =20 > done per revolution. I wonder if possibly the fact that at higher =20 > rpm you not only get the benefit of more power strokes per second, but =20 > at the higher rpm the airflow in your manifold (assuming you are using =20 > the same dia tubes as before) is at a higher velocity and therefore =20 > great inertia for stuffing even more air/fuel mixture into the =20 > combustion chamber when the port opens. =20 > =20 > In any case, sounds like all pluses for us guys with nose gears {:>) > =20 > =20 > =20 > Ed > =20 > Ed Anderson > RV-6A N494BW Rotary Powered > Matthews, NC > > ----- Original Message ----- > From: Tracy Crook > To: Rotary motors in aircraft > Sent: Monday, March 22, 2004 11:02 AM > Subject: [FlyRotary] Re: C mounting on a B plate?? Renesis & RD-1C > drivetesting > > The -C drive has very different internals but I will look at the > feasibility of reworking the -B housing to receive the -C guts. I > think it can be done. Yes, the -C bolts right up to the same > adapter plate. I think you are right about the 2.85 becoming the > preferred ratio, but only if you can handle the longer prop. You > nose draggers have the advantage here. > =20 > The more I fly it the better I like this setup. The higher rpm > was very disconcerting at first but I acclimated rapidly. And > now that I have digested the fact that the actual rpm difference > at normally used throttle settings is only about 5%, I absolutely > love it. Another good sign is that the manifold pressure is now > more than 5% lower at any given airspeed that I've tested so far. =20 > Even if the wear rate is up 5% or so it would be a non issue. =20 > =20 > One more plus for the 2.85 is something I hesitate to mention. =20 > It's kind of like the "engine making oil so I have to drain some > out" thing, kind of unbelievable. It makes sense that there > would be less prop noise but I'm also getting less engine noise. =20 > =20 > I was getting tired of the increased noise with the Hushpower II > muffler and was almost ready to put the Spintech back on even > though it costs at least 5 - 6 mph in drag. But with the -C drive > things have quieted down substantially. I think part of the > credit for this goes to the difference in RPM moving the > vibrations away from the resonance point of the sheet metal panels > in my RV-4 but even observers on the ground have mentioned > that the engine sounds quieter. > =20 > I better shut-up now, this is starting to sound too good to be true= > =20 > Tracy > =20 > > ----- Original Message ----- > From: Ed Anderson > Sent: Monday, March 22, 2004 8:30 AM > To: Rotary motors in aircraft > Subject: [FlyRotary] C mounting on a B plate?? Renesis & RD-1C > drivetesting > =20 > Sounds great thus far, Tracy > =20 > Imagine having so much thrust that you can't hold the > aircraft still for maximum static, must be tough {:>). If you > initial observations hold regarding fuel consumption and > performance, then I predict the 285 will soon become the > standard. If the fuel burn/performance is a wash then only > engine wear from higher rpm might be a factor, but since the > rotary seems to only have no/ minimum wear in any case, that > probably will not be a significant factor. > =20 > So how much are you given for 2.17:1 trade ins? Seriously, > will the B model mounting plate accommodate the C model gear > box housing (looks like you mount it the same way). I presume > it would not be so simple as swapping out the internals as I > am certain the internal mounting/housing is different in the > two. Third, in case you consider getting rid of that old > performance prop, put me on top of your list. > =20 > Ed > >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_001_0002_01C4118F.65A58B80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Charlie's obse= rvations are right in line with what I have seen so far.   Stil= l, I would not want to give up the ability to do wheel landings comfortab= ly.  74" is at the limit for my -4.  The -8 or the -4 with the = updated longer gear would not have this problem.   The -8 I'm b= uilding will have nothing less than 76" prop and more if I can get it.
 
As I accumulate more hours I clearly see the t= rend.  Huge advantage at low speeds (acceleration & climb) but a= dvantage diminishes as speed approached maximum.   With the IVO= prop (72" dia) I saw the same thing but the advantage diminished to zero= at about 140 mph and then became negative above that. 
&= nbsp;
 I still have not run the new drive & prop to t= op speed.  I attempted to yesterday evening but the dreaded SAG (Spa= rkplug Attention Getter as Ed calls it) struck as I was approaching 220 M= PH.   My best guess is that the zero point (same performance as= with -B drive) is right at this speed.   Things may improve af= ter I get the cuffs built (today's project).
 
BTW, this -C drive stuff is very encouraging but it's way too early to c= lose the books on this.  One week of testing does not prove anything= about long term effects.   It's always the unexpected thi= ngs that are the bane of the experimenters' life.  The 13B tension b= olt problem took over 1000 hours to show up.  I'll be flying on "Ora= nge Alert" status for hundreds of hours before I feel as comfortable as I= did with the -B drive. 
 
Tracy Crook
 
----- Original Message -----
=
Fro= m: Charlie & Tupper England
Sent: Tuesday, March 23, 2004 9:21 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: C mounting on a B plate?? Re= nesis & RD-1Cdrivetesting
 
You guys with nose w= heels shouldn't get too excited.  One of the reasons
that almost= all bush planes use tailwheels is that the nose gear is just
too fra= gile for rough field operation. Guess what the other reason is.

FW= IW, I've flown a short-legged RV-4 with a 76" dia. prop.  I didn't d= o
it very much (long story) but it can be managed by doing all takeof= fs &
landings tail low.

RE: Tracy's radically improved per= formance, I'm now flying Chuck
Dunlap's old Lyc powered RV-4 (Hi Chuc= k). It's got a 62" dia 3 blade
climb prop because he flew out of high= altitude gravel strips. Down here
in the lowlands of Mississippi, it= turns about 2450 static & will turn
over 3000 rpm in level fligh= t. I recently tried a prop originally made
for a 180 hp engine, origi= nally 72", cut down to 68" dia., a very bad
prop because of the 'surg= ery'. It was about 5 mph faster at full
throttle & turned not qui= te as high an rpm as the 3 blade, but the
takeoff performance was rad= ically different. The extra 6" of diameter
probably cut at least 30% = off the takeoff roll. Vance Jaqua (sp?) posted
a prop efficiency char= t on the 'other list' comparing optimized props of
various diameters.= Bigger (dia.) was always better until speed got over
200, at which t= ime the smaller props became as efficient as the larger
ones. I'm pre= tty excited that Tracy will have the Renesis & big prop
debugged = by the time my -7 is ready for an engine. (Go for a 76" dia on
the RV= -8. :-) )

Charlie


Ed Anderson wrote:

> Sounds= like all around great news on the new gearbox and prop.  Keep
&= gt; the reports coming.
> 
> If such a "retrofit" of a= B shell to C internals is possible and
> economical then that cou= ld move the trend toward the 2.85 even quicker.
> 
> S= hucks, if you used NA rotor housings it sounds like you wouldn't even > need a muffler {:>).
> 
> I am somewhat surpr= ised that you can get the same airspeed with only
> about a 5% dif= ference in rpm - sounds like my initial assumption that
>  a = higher rpm (and fuel burn)would be required to get the same
> airs= peed is not valid. Perhaps the much greater pitch gets more work
>= done per revolution.   I wonder if possibly the fact that at h= igher
> rpm you not only get the benefit of more power strokes per= second, but
> at the higher rpm the airflow in your manifold (ass= uming you are using
> the same dia tubes as before)  is at a = higher velocity and therefore
> great inertia for stuffing even mo= re air/fuel mixture into the
> combustion chamber when the port op= ens.
> 
> In any case, sounds like all pluses for us g= uys with nose gears {:>)
> 
> 
>  <= BR>> Ed
> 
> Ed Anderson
> RV-6A N494BW Rotary= Powered
> Matthews, NC
>
>     ---= -- Original Message -----
>     From: Tracy Cro= ok <mailto:lors01@msn.com>
>     To: Rota= ry motors in aircraft <mailto:flyrotary@lancaironline.net>
>&= nbsp;    Sent: Monday, March 22, 2004 11:02 AM
>&nbs= p;    Subject: [FlyRotary] Re: C mounting on a B plate?? R= enesis & RD-1C
>     drivetesting
>>     The -C drive has very different internals = but I will look at the
>     feasibility of rew= orking the -B housing to receive the -C guts.  I
>  =    think it can be done.   Yes, the -C bolts right up= to the same
>     adapter plate.  I think= you are right about the 2.85 becoming the
>    = ; preferred ratio, but only if you can handle the longer prop.  = ; You
>     nose draggers have the advantage he= re.
>     
>    = ; The more I fly it the better I like this setup.   The higher = rpm
>     was very disconcerting at first but I= acclimated rapidly.   And
>     now = that I have  digested the fact that the actual rpm difference
>= ;     at normally used throttle settings is only abou= t 5%, I absolutely
>     love it. Another good = sign is that the manifold pressure is now
>    = more than 5% lower at any given airspeed that I've tested so far.
&g= t;     Even if the wear rate is up 5% or so it would = be a non issue.
>     
> &nbs= p;   One more plus for the 2.85 is something I hesitate to ment= ion.
>     It's kind of like the "engine makin= g oil so I have to drain some
>     out" thing,= kind of unbelievable.   It makes sense that there
> = ;    would be less prop noise but I'm also getting less en= gine noise.
>     
>  &n= bsp;  I was getting tired of the increased noise with the Hushpower = II
>     muffler and was almost ready to put th= e Spintech back on even
>     though it costs a= t least 5 - 6 mph in drag.  But with the -C drive
>  = ;   things have quieted down substantially.  I think part = of the
>     credit for this goes to the differ= ence in RPM moving the
>     vibrations away fr= om the resonance point of the sheet metal panels
>   = ;  in my RV-4 but even observers on the ground have mentioned
>= ;     that the engine sounds quieter.
> &n= bsp;   
>     I better shut-up = now, this is starting to sound too good to be true.
>  &n= bsp;  
>     Tracy
> &nbs= p;   
>
>      =    ----- Original Message -----
>    =      From: Ed Anderson
>    = ;     Sent: Monday, March 22, 2004 8:30 AM
>&nb= sp;        To: Rotary motors in aircra= ft
>         Subject: [FlyR= otary] C mounting on a B plate?? Renesis & RD-1C
>  &= nbsp;      drivetesting
>   = ;      
>    &nb= sp;    Sounds great thus far, Tracy
>  &nb= sp;      
>    &= nbsp;        Imagine having so much th= rust that you can't hold the
>      &= nbsp;  aircraft still for maximum static, must be tough {:>).&nbs= p; If you
>         initial= observations hold regarding fuel consumption and
>  &nbs= p;      performance, then I predict the 285 will= soon become the
>         = standard.  If the fuel burn/performance is a wash then only
>&= nbsp;        engine wear from higher r= pm might be a factor, but since the
>     =     rotary seems to only have no/ minimum wear in any case= , that
>         probably w= ill not be a significant factor.
>     &nb= sp;   
>       &= nbsp;   So how much are you given for 2.17:1 trade ins?  S= eriously,
>         will th= e B model mounting plate accommodate the C model gear
>  =        box housing (looks like you mount it= the same way).  I presume
>     &nbs= p;   it would not be so simple as swapping out the internals as= I
>         am certain the= internal mounting/housing is different in the
>   &= nbsp;     two.   Third, in case you conside= r getting rid of that old
>      &nbs= p;  performance prop, put me on top of your list.
>  = ;       
>   &nb= sp;     Ed
>



>>  Home= page:  http://www.flyrotary.com/
>>  Archive: &nb= sp; http://lancaironline.net/lists/flyrotary/List.html
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