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Speedy11(at)aol.com
Guest

Posted: Tue Aug 17, 2010 6:10 am Post subject: RV Speeds

I've done multiple GPS speed calculations and all of the TAS calculations  came within one knot of the EFIS TAS numbers, so if I have a CAS error, it is  not very large.

 My A is less draggy than a neighbors 390 powered A and we've used WOT side  by side and I pull away from him.  I'm also working on reducing drag before  painting in the fall.  I'm working on winglets, I'm fairing the aileron  hinges and fuel drains, I'm working on cooling air drag, I'm making mods to the  wheel pants, I have straight exhaust pipes for "jet effect," and other speed  mods.

 The best I can do right now is 184 KIAS at 1K" - WOT and 2680 RPM.  My  goal, with mods, is to indicate 188.  I just can't seem to get the numbers  that others are getting.

 Stan Sutterfield

  

   	  Quote: 	
		  Airspeed    calibration error .... or drag?



BIll

Matt,

I must be    doing something wrong because my IO-390 powered RV-8A numbers 

aren't even    close to yours.

At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2    GPH and turn 

2450 RPM.  I can get 3000 FPM climb, but only to pattern    altitude.  

Enroute climb at 145-150 KIAS produces only 600 FPM.     I've climbed to 

15.5K' and I'm planning a test flight to FL240 - to see if    it will make 

it.

I have Bower's ram air and a MT 3 blade - both of    which should help with 

high altitude performance.

I'm planning a trip    from FL to VT in 2 weeks, so I'll see how my cruise 

numbers are after that    flight.

But, with the numbers I have now, I'm nowhere near your    numbers.

I wonder why?

Stan Sutterfield

rv-8a.net

On the way home,    I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

2200 RPM and 204    MPH True at 8.8 GPH.  Earlier in the week I took it to    

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at)    6.5 GPH, 

and

202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about    a 1300 mile range less 

reserves.

Coupled with the 3000+ FPM climb    solo

	


  [quote][b]

wpaulin(at)usa.net
Guest

Posted: Tue Aug 17, 2010 8:28 am Post subject: RV Speeds

Sorry to act like an expert when I am only an obsolete aerodynamisist but:



1.  If you are relatively sure of your weight, airspeed, altitude and engine calibrations (i.e., sure you are pretty close to lift, speed, altitude and thrust measures), then

2.  Since T= D & L=W in unaccelerated flight,

3.  Either your D is higher than the others (due to W --> L --> D ... or just D items), or they are wrong in their airplane performance measures.

4.  If you believe their claims (I'd be careful here), then you have more W, less T or more D than you think.

But since you pull away from your friend (and assuming his calibrations are OK), then my personal guess is that you have to doubt the other's claims / calibrations.  

If you don't, then my personal guess would be that since you probably know your engine (T) and W pretty well (but I am not an engine expert), the airframe D is the problem (out of rig, bad airfoils, etc., etc.) ... but your problem then becomes endless.  Flying side by side seems the simplest way to get at differing "calibrations."

But again, I am just guessing and probably no help at all.

Bill



On Aug 17, 2010, at 7:08 AM, Speedy11(at)aol.com (Speedy11(at)aol.com) wrote:

   

 I've done multiple GPS speed calculations and all of the TAS calculations  came within one knot of the EFIS TAS numbers, so if I have a CAS error, it is  not very large.

 My A is less draggy than a neighbors 390 powered A and we've used WOT side  by side and I pull away from him.  I'm also working on reducing drag before  painting in the fall.  I'm working on winglets, I'm fairing the aileron  hinges and fuel drains, I'm working on cooling air drag, I'm making mods to the  wheel pants, I have straight exhaust pipes for "jet effect," and other speed  mods.

 The best I can do right now is 184 KIAS at 1K" - WOT and 2680 RPM.  My  goal, with mods, is to indicate 188.  I just can't seem to get the numbers  that others are getting.

 Stan Sutterfield

  

   	  Quote: 	
		  Airspeed    calibration error .... or drag?



BIll

Matt,

I must be    doing something wrong because my IO-390 powered RV-8A numbers 

aren't even    close to yours.

At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2    GPH and turn 

2450 RPM.  I can get 3000 FPM climb, but only to pattern    altitude.  

Enroute climb at 145-150 KIAS produces only 600 FPM.     I've climbed to 

15.5K' and I'm planning a test flight to FL240 - to see if    it will make 

it.

I have Bower's ram air and a MT 3 blade - both of    which should help with 

high altitude performance.

I'm planning a trip    from FL to VT in 2 weeks, so I'll see how my cruise 

numbers are after that    flight.

But, with the numbers I have now, I'm nowhere near your    numbers.

I wonder why?

Stan Sutterfield

rv-8a.net

On the way home,    I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

2200 RPM and 204    MPH True at 8.8 GPH.  Earlier in the week I took it to    

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at)    6.5 GPH, 

and

202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about    a 1300 mile range less 

reserves.

Coupled with the 3000+ FPM climb    solo

	


   	  Quote: 	
		  



href="http://www.matronics.com/Navigator?RV8-List">http://www.matronics.com/Navigator?RV8-List

href="http://forums.matronics.com/">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	


 ***********************************

William & Sandra Paulin

1575 South Forest Drive

Prescott, AZ 86303



Bill

  Cell         +1 858 722 2905

  Office      +1 760 720 2905

  Europe  +358 40 720 4047



  wpaulin(at)usa.net (wpaulin(at)usa.net)

Sandy

  Cell           +1 858 349 1729

  Office        +1 928 443 7739 





 

 



 [quote][b]

bifft(at)xmission.com
Guest

Posted: Tue Aug 17, 2010 9:33 am Post subject: RV Speeds

On Tue, 17 Aug 2010, Speedy11(at)aol.com wrote:



 	  Quote: 	
		   The best I can do right now is 184 KIAS at 1K" - WOT and 2680 RPM.  My  goa

 l, with mods, is to indicate 188.  I just can't seem to get the numbers

 that others are getting.


	




  I wonder how much of the difference is knots indicated vs mph true?

184 knots indicated would be 212 mph at sea level, about the same as Van's

180hp numbers.

 	  Quote: 	
		   On the way home,  I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

 2200 RPM and 204  MPH True at 8.8 GPH.  Earlier in the week I took it to


	


This calculator:



http://www.newbyte.co.il/calc.html



shows 204 TAS at 7000' (standard atmosphere) to be 184 mph CAS, or 160

KIAS.



  Brian Huffaker, DSWL (bifft(at)xmission.com)

  RV-8A 80091  Fitting wings

  1/4 Starduster II N23UT flying

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 26320
Location: Livermore CA USA

Posted: Tue Aug 17, 2010 9:52 am Post subject: RV Speeds

On multiple occasions, I have seen a top speed of 229-230 mph true at about 2000 msl, full throttle, and 2700 rpm, and gently leaned.  This was confirmed by the GPS GS from both the EFIS GPS and the Kenwood GPS.  The autopilot was on to assure no ascending/descending error.  These were on cool evenings (70-75f).



That being said, there are other days when it won't go much above 222-225 mph.



I will rig up the cockpit HD video camera again to verify my readings...

-

Matt Dralle

RV-8 #82880 N998RV

http://www.mattsrv8.com - Matt's RV-8 Construction Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 90+ Hours TTSN - Enjoying Every Minute...

 



At 07:08 AM 8/17/2010  Tuesday, you wrote:

 	  Quote: 	
		   

I've done multiple GPS speed calculations and all of the TAS calculations came within one knot of the EFIS TAS numbers, so if I have a CAS error, it is not very large.

My A is less draggy than a neighbors 390 powered A and we've used WOT side by side and I pull away from him.  I'm also working on reducing drag before painting in the fall.  I'm working on winglets, I'm fairing the aileron hinges and fuel drains, I'm working on cooling air drag, I'm making mods to the wheel pants, I have straight exhaust pipes for "jet effect," and other speed mods.

The best I can do right now is 184 KIAS at 1K" - WOT and 2680 RPM.  My goal, with mods, is to indicate 188.  I just can't seem to get the numbers that others are getting.

Stan Sutterfield

 

Airspeed calibration error .... or drag?



BIll

Matt,

I must be doing something wrong because my IO-390 powered RV-8A numbers 

aren't even close to yours.

At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2 GPH and turn 

2450 RPM.  I can get 3000 FPM climb, but only to pattern altitude.  

Enroute climb at 145-150 KIAS produces only 600 FPM.  I've climbed to 

15.5K' and I'm planning a test flight to FL240 - to see if it will make 

it.

I have Bower's ram air and a MT 3 blade - both of which should help with 

high altitude performance.

I'm planning a trip from FL to VT in 2 weeks, so I'll see how my cruise 

numbers are after that flight.

But, with the numbers I have now, I'm nowhere near your numbers.

I wonder why?

Stan Sutterfield

rv-8a.net

On the way home, I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

2200 RPM and 204 MPH True at 8.8 GPH.  Earlier in the week I took it to 

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at) 6.5 GPH, 

and

202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about a 1300 mile range less 

reserves.

Coupled with the 3000+ FPM climb solo

_________________
Matt Dralle
Matronics Email List Administrator

tcone1(at)comcast.net
Guest

Posted: Tue Aug 17, 2010 10:16 am Post subject: RV Speeds

Matt,



The National Test Pilot School has a nice excel spreadsheet for removing the 

effects of wind in determining true airspeed.



http://www.ntps.edu/images/stories/documents/gps-pec.XLS



Tim

---

Speedy11(at)aol.com
Guest

Posted: Tue Aug 17, 2010 7:42 pm Post subject: RV Speeds

Well, I had to see what my IO-390 RV-8A would do at 18K, so today  I climbed to 17,500 (couldn't get ATC clearance higher) and had the following  numbers:

 15.4" MP - 2400 RPM - 8.5 GPH - KIAS 124 - KTAS 166 (191 MPH)

 15.4" MP - 2310 RPM - 9.0 GPH - KIAS 120 - KTAS 162 (186 MPH)

 Fuel pump was out of service, so I'll confirm the actual fuel burn  next week.

 I'm simply not getting your numbers, Matt.  Must be my ham fisted  flying.  I can't imagine that the engines are that much different.

 Scratching my cranium.

 Stan Sutterfield

   	  Quote: 	
		  Matt,

I must be doing something wrong because my IO-390 powered    RV-8A numbers  

aren't even close to yours.

At 7K', to get 177 KTAS    (204 MPH TAS) I have to burn 10.2 GPH and turn 2450 

RPM.  I can get    3000 FPM climb, but only to pattern altitude.  Enroute  

climb at    145-150 KIAS produces only 600 FPM.  I've climbed  to 15.5K' and I'm    

planning a test flight to FL240 - to see if it will make  it.

I    have Bower's ram air and a MT 3 blade - both of which should help with     

high altitude performance.

I'm planning a trip from FL to VT in 2    weeks, so I'll see how my cruise  

numbers are after that    flight.

But, with the numbers I have now, I'm nowhere near your    numbers.

I wonder why?

Stan Sutterfield

rv-8a.net



On the     way home, I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

2200    RPM  and 204 MPH True at 8.8 GPH.  Earlier in the week I took it    to  

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH,    192 MPH (at) 6.5  GPH, and

202 MPG (at) 7 GPH.    At the 5.5 GPH,    that's about a 1300  mile range less 

reserves.

Coupled with the    3000+ FPM climb  solo 	


  [quote][b]

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 26320
Location: Livermore CA USA

Posted: Tue Aug 17, 2010 8:03 pm Post subject: RV Speeds

Looks to me like your RPMs are WAY too high!  At 5.5gph I was at 2000 RPM.  Lowering the RPM is how you get the flow rates down.  Bigger bite might make you go faster too.



I want to say that at 5.5/2000/18000/170mph I was at about 12.5" MP.  I think that I took still pictures of the EFIS's in all the various configurations I did.  I'll download them from the Camera and double check my numbers.



Matt

At 08:36 PM 8/17/2010  Tuesday, you wrote:

 	  Quote: 	
		   

Well, I had to see what my IO-390 RV-8A would do at 18K, so today I climbed to 17,500 (couldn't get ATC clearance higher) and had the following numbers:

15.4" MP - 2400 RPM - 8.5 GPH - KIAS 124 - KTAS 166 (191 MPH)

15.4" MP - 2310 RPM - 9.0 GPH - KIAS 120 - KTAS 162 (186 MPH)

Fuel pump was out of service, so I'll confirm the actual fuel burn next week.

I'm simply not getting your numbers, Matt.  Must be my ham fisted flying.  I can't imagine that the engines are that much different.

Scratching my cranium.

Stan Sutterfield

Matt,

I must be doing something wrong because my IO-390 powered RV-8A numbers  

aren't even close to yours.

At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2 GPH and turn 2450 

RPM.  I can get 3000 FPM climb, but only to pattern altitude.  Enroute  

climb at 145-150 KIAS produces only 600 FPM.  I've climbed  to 15.5K' and I'm 

planning a test flight to FL240 - to see if it will make  it.

I have Bower's ram air and a MT 3 blade - both of which should help with  

high altitude performance.

I'm planning a trip from FL to VT in 2 weeks, so I'll see how my cruise  

numbers are after that flight.

But, with the numbers I have now, I'm nowhere near your numbers.

I wonder why?

Stan Sutterfield

rv-8a.net



On the  way home, I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

2200 RPM  and 204 MPH True at 8.8 GPH.  Earlier in the week I took it to  

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at) 6.5  GPH, and

202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about a 1300  mile range less 

reserves.

Coupled with the 3000+ FPM climb  solo




	


Matt G Dralle | Matronics | 581 Jeannie Way | Livermore | CA | 94550

925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email

http://www.matronics.com/ WWW | Featuring Products For Aircraft

_________________
Matt Dralle
Matronics Email List Administrator

gcomfo(at)tc3net.com
Guest

Posted: Wed Aug 18, 2010 3:16 am Post subject: RV Speeds

You have different props, right?  

Gordon Comfort





--

Speedy11(at)aol.com
Guest

Posted: Wed Aug 18, 2010 5:22 pm Post subject: RV Speeds

Those are amazing numbers.   230 true MPH would be 200  KTAS.  That is 6 knots more than I am getting.

 The only thing I can think of is that my Barrett IO-390 is not producing  full power.  If my engine were producing only 190 HP at sea level and yours  were producing 210 HP, then that would likely make the difference in  speeds.

 Maybe I should talk to Allen about the engine.  The original dyno  run was low on power but that was attributed to high density altitude at the  time.  It should be producing a solid 210 HP since I asked them to  mill .015 off the cylinder bases to increase compression a bit.

 I also have an oil leak (since new) directly over the alternator.  I  haven't yet discovered the source.

 Maybe I should fly the plane to OK and talk to Allen and Monty about the  engine.  Might be a good reason for a nice flight.

 Stan Sutterfield

  

  	  Quote: 	
		  On    multiple occasions, I have seen a top speed of 229-230 mph true at about    2000

msl, full throttle, and 2700 rpm, and gently leaned.  This was    confirmed by

the GPS GS from both the EFIS GPS and the Kenwood GPS.     The autopilot was on to

assure no ascending/descending error.  These    were on cool evenings (70-75f).



That being said, there are other days    when it won't go much above 222-225 mph. 	


 

  

  [quote][b]

martinaerodrome(at)gmail.
Guest

Posted: Thu Aug 19, 2010 10:23 am Post subject: RV Speeds

Stan,

 I hate to tell you this, but your inability to achieve the higher speeds is to sell your 3 blade MT to some one you do not like, and use the proceeds to buy either the New blended airfoil blade Hartzell from Vans AC, or better yet, buy a Aerocomposites 2 blade 72 or 74 inch propeller.   Also, you could contact Same James and consider one of his cowlings and plenum chambers (proven speed prudecers).  Good luck.

  Dick Martin

 RV8 N233M

 the fast one

 On Tue, Aug 17, 2010 at 10:36 PM, <Speedy11(at)aol.com (Speedy11(at)aol.com)> wrote:

 [quote]   

 Well, I had to see what my IO-390 RV-8A would do at 18K, so today I climbed to 17,500 (couldn't get ATC clearance higher) and had the following numbers:

 15.4" MP - 2400 RPM - 8.5 GPH - KIAS 124 - KTAS 166 (191 MPH)

 15.4" MP - 2310 RPM - 9.0 GPH - KIAS 120 - KTAS 162 (186 MPH)

 Fuel pump was out of service, so I'll confirm the actual fuel burn next week.

 I'm simply not getting your numbers, Matt.  Must be my ham fisted flying.  I can't imagine that the engines are that much different.

 Scratching my cranium.

 Stan Sutterfield

   	  Quote: 	
		  Matt,

I must be doing something wrong because my IO-390 powered RV-8A numbers  

 aren't even close to yours.

At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2 GPH and turn 2450 

RPM.  I can get 3000 FPM climb, but only to pattern altitude.  Enroute  

climb at 145-150 KIAS produces only 600 FPM.  I've climbed  to 15.5K' and I'm 

 planning a test flight to FL240 - to see if it will make  it.

I have Bower's ram air and a MT 3 blade - both of which should help with  

high altitude performance.

I'm planning a trip from FL to VT in 2 weeks, so I'll see how my cruise  

 numbers are after that flight.

But, with the numbers I have now, I'm nowhere near your numbers.

I wonder why?

Stan Sutterfield

rv-8a.net



On the  way home, I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

 2200 RPM  and 204 MPH True at 8.8 GPH.  Earlier in the week I took it to  

18,000ft

(on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at) 6.5  GPH, and

202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about a 1300  mile range less 

 reserves.

Coupled with the 3000+ FPM climb  solo 	


 	  Quote: 	
		  



et="_blank">http://www.matronics.com/Navigator?RV8-List

ttp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

robin(at)PaintTheWeb.com
Guest

Posted: Thu Aug 19, 2010 11:04 am Post subject: RV Speeds

Dick,  

            I take exception to your usually EXCELLENT advice regarding the James cowl & plenum combination. I am placing one on my 8A (yet to fly) strictly for looks but I have also installed one on my RV-10 to near disastrous results. Significantly higher CHT’s and oil temps, poor airflow top to bottom and slower TAS. There is absolutely no engineering associated with the RV-10 James cowl & plenum regardless of what one hears or is told. And much like the two place James cowls that require a modification including additional fill for even a basic proper fit the James Plenum for the -10 does not even align with the cowl inlet openings. Speaking of the inlet openings on the -10 cowl they are the same 4.5” openings used in the two place RV’s. This MAY be the source of the temp issues as one builder has modified the cowl for custom made 6” inlet rings to apparent success in cooling. Think of the effort required to hack out the 4.5” rings and replace with 6” rings. Both the upper & lower cowl have to be mutilated to make room for this mod. Then one has to rework the baffles, inlet ramps etc… You are truly in the experimental world a that point. The -10 cowl has cost me well over $14K in R&D, modifications (oil coolers, turbo injectors…), wasted fuel and I still have not properly resolved the issues. Who knows what damage the extra heat has caused to my new $45K engine. If I were to do it again I would absolutely NOT install the James Cowl on my -10. I am pretty sure the stock cowl is faster too. I knowingly installed the James cowl on my 8A because there are many more success stories with the 4 cylinder versions.  

   

Good luck,  

Robin  

Do Not Archive  

     

From: owner-rv8-list-server(at)matronics.com (owner-rv8-list-server(at)matronics.com) [mailto:owner-rv8-list-server(at)matronics.com (owner-rv8-list-server(at)matronics.com)] On Behalf Of Richard Martin

 Sent: Thursday, August 19, 2010 11:15 AM

 To: rv8-list(at)matronics.com (rv8-list(at)matronics.com)

 Subject: Re: Re: RV Speeds  

  

     

Stan,  

    

I hate to tell you this, but your inability to achieve the higher speeds is to sell your 3 blade MT to some one you do not like, and use the proceeds to buy either the New blended airfoil blade Hartzell from Vans AC, or better yet, buy a Aerocomposites 2 blade 72 or 74 inch propeller.   Also, you could contact Same James and consider one of his cowlings and plenum chambers (proven speed prudecers).  Good luck.  

    

Dick Martin  

    

RV8 N233M  

    

the fast one  

    

On Tue, Aug 17, 2010 at 10:36 PM, <Speedy11(at)aol.com (Speedy11(at)aol.com)> wrote:      

   

    

Well, I had to see what my IO-390 RV-8A would do at 18K, so today I climbed to 17,500 (couldn't get ATC clearance higher) and had the following numbers:  

    

15.4" MP - 2400 RPM - 8.5 GPH - KIAS 124 - KTAS 166 (191 MPH)  

    

15.4" MP - 2310 RPM - 9.0 GPH - KIAS 120 - KTAS 162 (186 MPH)  

    

Fuel pump was out of service, so I'll confirm the actual fuel burn next week.  

    

I'm simply not getting your numbers, Matt.  Must be my ham fisted flying.  I can't imagine that the engines are that much different.  

    

Scratching my cranium.  

    

Stan Sutterfield  

     	  Quote: 	
		    

Matt,

 I must be doing something wrong because my IO-390 powered RV-8A numbers  

 aren't even close to yours.

 At 7K', to get 177 KTAS (204 MPH TAS) I have to burn 10.2 GPH and turn 2450 

 RPM.  I can get 3000 FPM climb, but only to pattern altitude.  Enroute  

 climb at 145-150 KIAS produces only 600 FPM.  I've climbed  to 15.5K' and I'm 

 planning a test flight to FL240 - to see if it will make  it.

 I have Bower's ram air and a MT 3 blade - both of which should help with  

 high altitude performance.

 I'm planning a trip from FL to VT in 2 weeks, so I'll see how my cruise  

 numbers are after that flight.

 But, with the numbers I have now, I'm nowhere near your numbers.

 I wonder why?

 Stan Sutterfield

 rv-8a.net

 

 On the  way home, I had the IO-390 engine dialed in at 7000ft, 22.4" MP /

 2200 RPM  and 204 MPH True at 8.8 GPH.  Earlier in the week I took it to  

 18,000ft

 (on oxygen) and was seeing 170 MPH True at 5.5 GPH, 192 MPH (at) 6.5  GPH, and

 202 MPG (at) 7 GPH.    At the 5.5 GPH, that's about a 1300  mile range less 

 reserves.

 Coupled with the 3000+ FPM climb  solo    et="_blank">http://www.matronics.com/Navigator?RV8-List 	
    	  Quote: 	
		   ttp://forums.matronics.com_blank">http://www.matronics.com/contribution  	


  

  

  

    	  Quote: 	
		   

 Use the Matronics List Features Navigator to browse[/b]  	
0 Day Browse, Chat, FAQ,[/b] [/quote]1 	  Quote: 	
		    	
2 	  Quote: 	
		    	
3 m">http://forums.matronics.com[/b] [/quote]4 	  Quote: 	
		    	
5                    -Matt Dralle, List A; http://www.matronics.com/contribution[/b][/quote] =======================[/b] [/quote]6

      [quote][b]

bjudge(at)gmail.com
Guest

Posted: Fri Aug 20, 2010 6:02 am Post subject: RV Speeds

Does anyone have a comparison of the Aerocomposites vs Whirlwind on

the same airframe?  I've heard that the WW is faster/more efficient

but I'm biased.



I've got a WW 200RV, RV-8, Superior Airparts IO-360 w/ Ryton exploding

sump, lightspeed II ignition and I generally run 160 knots TAS 10,000

feet, 6.5 gph, WOT, LOP, 1950 RPM.  Everything else about the airframe

is pretty much standard.  I'm very confident in that 6.5 GPH (at) 160

knots TAS figure.  I'm not as confident in other power setting since I

generally just run in the econo cruise (at) 160.  As the fuel burns off I

generally pick up 2-3 knots from the reduced weight.



I know that for keeping the efficiency up the low RPM is key.



Thanks,

Bill judge, RV-8, N84WJ 515 Hrs

rv-8.blogspot.com



 	  Quote: 	
		  

 Time: 11:23:12 AM PST US

 Subject: Re: Re: RV Speeds

 From: Richard Martin <martinaerodrome(at)gmail.com>



 Stan,

 I hate to tell you this, but your inability to achieve the higher speeds is

 to sell your 3 blade MT to some one you do not like, and use the proceeds to

 buy either the New blended airfoil blade Hartzell from Vans AC, or better

 yet, buy a Aerocomposites 2 blade 72 or 74 inch propeller.   Also, you could

 contact Same James and consider one of his cowlings and plenum chambers

 (proven speed prudecers).  Good luck.

 Dick Martin

 RV8 N233M

 the fast one

Speedy11(at)aol.com
Guest

Posted: Fri Aug 20, 2010 6:24 pm Post subject: RV Speeds

Dick,

 You gave me the same advice standing in my hangar last Jan.  Told you  then I don't plan to change the prop.  I'm going to experiment with  reducing the size of the Van's inlets (ala Dave Anders) to see if I can gain  anything.  But, I'm not willing to toss my cowling and put on the James  cowling.  My homemade plenum is working great.  CHTs are well under  control and Oil temp is perfect at 180.

 I did take your advice to straighten out the exhaust pipes for some jet  effect.  I don't notice any difference.  Except the exhaust is hitting  the bottom of the plane.

 Are you coming to FL for the winter?

 Stan Sutterfield

   	  Quote: 	
		  I hate    to tell you this, but your inability to achieve the higher speeds is

to    sell your 3 blade MT to some one you do not like, and use the proceeds    to

buy either the New blended airfoil blade Hartzell from Vans AC, or    better

yet, buy a Aerocomposites 2 blade 72 or 74 inch    propeller.   Also, you could

contact Same James and consider one    of his cowlings and plenum chambers

(proven speed prudecers).  Good    luck.

Dick Martin

	


  [quote][b]

Speedy11(at)aol.com
Guest

Posted: Sat Aug 21, 2010 6:58 pm Post subject: RV Speeds

Bill,

 Thanks for your input.  Each data point is valuable and  informative.

 160 KTAS is impressive for 1950 RPM.  I'll try the same parameters  next time I go flying and report back.

 Stan Sutterfield

   	  Quote: 	
		  I've got    a WW 200RV, RV-8, Superior Airparts IO-360 w/ Ryton exploding

sump,    lightspeed II ignition and I generally run 160 knots TAS 10,000

feet, 6.5    gph, WOT, LOP, 1950 RPM.  Everything else about the airframe

is pretty    much standard.  I'm very confident in that 6.5 GPH (at) 160

knots TAS    figure.  I'm not as confident in other power setting since I

generally    just run in the econo cruise (at) 160.  As the fuel burns off I

generally    pick up 2-3 knots from the reduced  weight.

	


  [quote][b]

tracy(at)rotaryaviation.c
Guest

Posted: Sun Aug 22, 2010 4:03 am Post subject: RV Speeds

 Mine aren't quite that good but in the same ballpark.  Typical cruise conditions are 12,500 ft, 172 mph, 1965 RPM (at the prop) burning 6.5 gph.  That's with one of those presumably gas hungry Mazda rotary engines. 

 

Tracy Crook



On Sat, Aug 21, 2010 at 10:55 PM,  <Speedy11(at)aol.com (Speedy11(at)aol.com)> wrote:

 	  Quote: 	
		         

 Bill,

 Thanks for your input.  Each data point is valuable and  informative.

 160 KTAS is impressive for 1950 RPM.  I'll try the same parameters  next time I go flying and report back.

 Stan Sutterfield

   	  Quote: 	
		  I've got    a WW 200RV, RV-8, Superior Airparts IO-360 w/ Ryton exploding

sump,    lightspeed II ignition and I generally run 160 knots TAS 10,000

feet, 6.5    gph, WOT, LOP, 1950 RPM.  Everything else about the airframe

is pretty    much standard.  I'm very confident in that 6.5 GPH (at) 160

knots TAS    figure.  I'm not as confident in other power setting since I

generally    just run in the econo cruise (at) 160.  As the fuel burns off I

generally    pick up 2-3 knots from the reduced  weight.

	


   	  Quote: 	
		  



et="_blank">http://www.matronics.com/Navigator?RV8-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


	


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Speedy11(at)aol.com
Guest

Posted: Sun Aug 22, 2010 3:23 pm Post subject: RV Speeds

Well, some new numbers today.

 I filed IFR to FL200 and then continued the climb to FL240.  It  took awhile to get up there, but I made it.  As it turns out, FL200 is the  more comfortable (for aircraft handling) and fuel efficient  altitude.

 FL200   WOT (13.8")   2400 RPM   about  6.3 GPH   IAS - 113K   TAS - 160K  Peak EGT    OAT - 40F

 FL240   WOT (11.5")   2300 RPM   about  6.3 GPH   IAS - 92K   TAS - 139K   40  LOP   OAT - 28F

 CHTs and Oil Temp were no problem at all altitudes.

 I didn't have time to do a 10K' run to compare with Bill's  numbers, but I'll try that in the AM if possible.

 Stan Sutterfield



  [quote][b]

martinaerodrome(at)gmail.
Guest

Posted: Mon Aug 23, 2010 5:19 am Post subject: RV Speeds

Bill< 

 I have raced against Whirlwinds and find them to be good performers, however I can usually outrun them by an average 5 knot difference, 

 Good Luck.

 Dick Martin

 RV8 N233M

 the fast one

 On Fri, Aug 20, 2010 at 8:32 AM, Bill Judge <bjudge(at)gmail.com (bjudge(at)gmail.com)> wrote:

 [quote]--> RV8-List message posted by: Bill Judge <bjudge(at)gmail.com (bjudge(at)gmail.com)>

 

Does anyone have a comparison of the Aerocomposites vs Whirlwind on

the same airframe?  I've heard that the WW is faster/more efficient

but I'm biased.



I've got a WW 200RV, RV-8, Superior Airparts IO-360 w/ Ryton exploding

 sump, lightspeed II ignition and I generally run 160 knots TAS 10,000

feet, 6.5 gph, WOT, LOP, 1950 RPM.  Everything else about the airframe

is pretty much standard.  I'm very confident in that 6.5 GPH (at) 160

 knots TAS figure.  I'm not as confident in other power setting since I

generally just run in the econo cruise (at) 160.  As the fuel burns off I

generally pick up 2-3 knots from the reduced weight.



I know that for keeping the efficiency up the low RPM is key.

 

Thanks,

Bill judge, RV-8, N84WJ 515 Hrs

rv-8.blogspot.com



 	  Quote: 	
		  

 Time: 11:23:12 AM PST US

 Subject: Re: Re: RV Speeds

 > From: Richard Martin <martinaerodrome(at)gmail.com (martinaerodrome(at)gmail.com)>
	


 	  Quote: 	
		  

 Stan,

 I hate to tell you this, but your inability to achieve the higher speeds is

 to sell your 3 blade MT to some one you do not like, and use the proceeds to

 > buy either the New blended airfoil blade Hartzell from Vans AC, or better
	


 	  Quote: 	
		   yet, buy a Aerocomposites 2 blade 72 or 74 inch propeller.   Also, you could

 contact Same James and consider one of his cowlings and plenum chambers

 > (proven speed prudecers).  Good luck.
	


 	  Quote: 	
		   Dick Martin

 RV:

 -List" target="_blank">http://www.matronics.com/Navigator?RV8-Listh
	


 a href="http://www.matronics.com/contribution" target="_blank">http://www.matronics.com/contribution

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