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jacklockamy(at)verizon.ne
Guest

Posted: Wed Aug 23, 2006 5:15 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

Dan,  

   

You are RIGHT ON (as usual I might add....)!  This is EXACTLY what the guys at Van's and others told me:  "...a Lycoming 0-320 160HP engine in an RV-7/7A is NOT under powered and will actually extend your cross-country range....".  Since 95% or better of my flying is for cross-country purposes and fuel economy is at the top of my list, I chose the 0-320/160HP engine option.  

   

One last comment I will share from the same engineer at Van's I spoke with that day.  He said, "it has been their experience that an RV-7/7A  Lycoming 0-320 160 HP is the BEST engine/airframe combination...".  I've flown both a 180 HP RV-7A and my 160 HP model and the only difference I can tell is climb in the 160 HP airplane is about 200 FPM on average less than the 180 HP.  Oh.. and I burn about .5 to 1.0 gallons less per hour... thus extending my cross-country range.  I fly 4.0-4.5 hour cross country legs and always have an hour or better reserve when I land.  

   

Sorry Ron... I know you are an advocate for 180-HP or better in the RV-7/7A but I venture to same more of us live and fly from airports at/near mean sea level than 7KFT in the mountains...  I've flown my RV-7A from airports at 9KFT density altitude... no problem!  

   

Jack Lockamy  

RV-7A N174JL 210 hrs  

Lycoming 0-320/160HP/Constant Speed  

Camarillo, CA  

www.jacklockamy.com  

   

do not archive  

        [quote][b]

KBelue(at)drs-tem.com
Guest

Posted: Thu Aug 24, 2006 3:27 am Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

In my experience, an RV-x with 160hp and an RV-x with 180hp flying together at the same speed (both with the same prop: fixed pitch or CS, and both with the same induction: carb. or FI) consume almost exactly the same amount of fuel. The only variance seems to be the amount one might be able to lean over the other. If they both fly (at) 75% power, the 180hp uses more fuel, but is going faster (~10 mph).  

     

[b]Kevin D. Belue[/b]  

[b]RV-6A 700hrs.[/b]  

[b]RV-10 finish[/b]  

   

          

  

From: Jack Lockamy [mailto:jacklockamy(at)verizon.net] 

 Sent: Wednesday, August 23, 2006 8:15 PM

 To: rv-list(at)matronics.com

 Subject: Re: RV-7 or RV-9 ?RV-7 or RV-9 ?  

  

   

Dan,  

   

You are RIGHT ON (as usual I might add....)!  This is EXACTLY what the guys at Van's and others told me:  "...a Lycoming 0-320 160HP engine in an RV-7/7A is NOT under powered and will actually extend your cross-country range....".  Since 95% or better of my flying is for cross-country purposes and fuel economy is at the top of my list, I chose the 0-320/160HP engine option.  

   

One last comment I will share from the same engineer at Van's I spoke with that day.  He said, "it has been their experience that an RV-7/7A  Lycoming 0-320 160 HP is the BEST engine/airframe combination...".  I've flown both a 180 HP RV-7A and my 160 HP model and the only difference I can tell is climb in the 160 HP airplane is about 200 FPM on average less than the 180 HP.  Oh.. and I burn about .5 to 1.0 gallons less per hour... thus extending my cross-country range.  I fly 4.0-4.5 hour cross country legs and always have an hour or better reserve when I land.  

   

Sorry Ron... I know you are an advocate for 180-HP or better in the RV-7/7A but I venture to same more of us live and fly from airports at/near mean sea level than 7KFT in the mountains...  I've flown my RV-7A from airports at 9KFT density altitude... no problem!  

   

Jack Lockamy  

RV-7A N174JL 210 hrs  

Lycoming 0-320/160HP/Constant Speed  

Camarillo, CA  

www.jacklockamy.com  

   

do not archive  

  

      [quote][b]

Hopperdhh(at)aol.com
Guest

Posted: Thu Aug 24, 2006 6:50 am Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

In a message dated 8/24/2006 7:47:25 A.M. Eastern Daylight Time,  KBelue(at)drs-tem.com writes:

  	  Quote: 	
		     

In my    experience, an RV-x with 160hp and an RV-x with 180hp flying together at the    same speed (both with the same prop: fixed pitch or CS, and both with the same    induction: carb. or FI) consume almost exactly the same amount of fuel. The    only variance seems to be the amount one might be able to lean over the other.    If they both fly (at) 75% power, the 180hp uses more fuel, but is going faster    (~10 mph).   

       

[b]Kevin    D. Belue[/b]   

[b]RV-6A    700hrs.[/b]   

[b]RV-10    finish[/b]   

 

	


 

 I would think that the lower weight would give an advantage to the O-320  powered ship.

  

 Dan Hopper

 RV-7A 200 HP wishing it were lighter

  

  [quote][b]

rv6(at)grandecom.net
Guest

Posted: Thu Aug 24, 2006 2:43 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

Quoting Hopperdhh(at)aol.com:



Well said.

 	  Quote: 	
		  

 In a message dated 8/24/2006 7:47:25 A.M. Eastern Daylight Time,

 KBelue(at)drs-tem.com writes:



 In my  experience, an RV-x with 160hp and an RV-x with 180hp flying together

 at the  same speed (both with the same prop: fixed pitch or CS, and both with

 the same  induction: carb. or FI) consume almost exactly the same amount of

 fuel. The  only variance seems to be the amount one might be able to lean

 over

 the other.  If they both fly (at) 75% power, the 180hp uses more fuel, but is

 going faster  (~10 mph).



 Kevin  D. Belue

 RV-6A  700hrs.

 RV-10  finish





 I would think that the lower weight would give an advantage to the O-320

 powered ship.



 Dan Hopper

 RV-7A 200 HP wishing it were lighter

lifeofreiley2003(at)yahoo
Guest

Posted: Thu Aug 24, 2006 4:33 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

I will agree 100%, a 320 platform with a few accessory

mods would be the perfect power plant for the RV7. Use

Dan Checkoways leaning rules, a 320 with FI & EI will

be the efficient performer.



Darrell

--- rv6(at)grandecom.net wrote:



 	  Quote: 	
		   

 

 Quoting Hopperdhh(at)aol.com:

 

 Well said.

 

 

 >

 > In a message dated 8/24/2006 7:47:25 A.M. Eastern

 Daylight Time,

 > KBelue(at)drs-tem.com writes:

 >

 > In my  experience, an RV-x with 160hp and an RV-x

 with 180hp flying together

 > at the  same speed (both with the same prop: fixed

 pitch or CS, and both with

 > the same  induction: carb. or FI) consume almost

 exactly the same amount of

 > fuel. The  only variance seems to be the amount

 one might be able to lean

 > over

 > the other.  If they both fly (at) 75% power, the

 180hp uses more fuel, but is

 > going faster  (~10 mph).

 >

 > Kevin  D. Belue

 > RV-6A  700hrs.

 > RV-10  finish

 >

 >

 >

 >

 > I would think that the lower weight would give an

 advantage to the O-320

 > powered ship.

 >

 > Dan Hopper

 > RV-7A 200 HP wishing it were lighter

 >

 >

 

 

 

 

 



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 Admin.



 

 

 

 


	




__________________________________________________

khorton01(at)rogers.com
Guest

Posted: Thu Aug 24, 2006 4:45 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

On 24 Aug 2006, at 10:49, Hopperdhh(at)aol.com (Hopperdhh(at)aol.com) wrote:

 	  Quote: 	
		     In a message dated 8/24/2006 7:47:25 A.M. Eastern Daylight Time, KBelue(at)drs-tem.com (KBelue(at)drs-tem.com) writes:

  	  Quote: 	
		  

In my   experience, an RV-x with 160hp and an RV-x with 180hp flying together at the   same speed (both with the same prop: fixed pitch or CS, and both with the same   induction: carb. or FI) consume almost exactly the same amount of fuel. The   only variance seems to be the amount one might be able to lean over the other.   If they both fly (at) 75% power, the 180hp uses more fuel, but is going faster   (~10 mph).

   

[b]Kevin   D. Belue[/b]

[b]RV-6A   700hrs.[/b]

[b]RV-10   finish[/b]

 

	


 

 I would think that the lower weight would give an advantage to the O-320 powered ship.

  

 	




The speed change for a 10 to 20 lb weight reduction is negligible, as the vast majority of the drag at cruise speeds is profile drag, and it does not vary with weight.  The induced drag, which does vary with the square of weight, is less than 15% of the total drag at typical cruise speeds (data from the CAFE Foundation APR on the RV-6A) .  The CAFE foundation data suggests that it would take about a 100 lb weight reduction to realize a 1 mph speed increase, assuming everything else was equal.



 Kevin Horton         RV-8 (finishing kit)

Ottawa, Canada

http://www.kilohotel.com/rv8

 



 [quote][b]

ddcuster(at)wmv-co.us
Guest

Posted: Fri Aug 25, 2006 6:00 am Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

The 7 is a heavy plane -- stressed for aerobatics. The 9 is much lighter and 

has a modern wing while the 7 uses an old NACA airfoil. The 9 is thus more 

efficient: Less weight, better wing.



Still -- it all depends on the mission. Ask the guys at Vans who fly long 

distance cross country which plane they would rather take. I did. The 

agreement was unanimous -- take the 9 for cross country.



If you want to be upside down go with the 7.



Simple. Just look at Van's design goals with both the 7 and the 9. Van's 

designs are very successful based on which mission is going to be flown. If 

you get a plane designed for one mission and fly it on different missions 

regularly you are not going to be as satisfied as the guy who flies the 

plane on the mission for which it was designed.



Doc

---

jmsears(at)adelphia.net
Guest

Posted: Fri Aug 25, 2006 6:11 am Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

Well, the -9A may be lighter by design; but, I built a RV-6A and helped to 

build a -9A.  Amazingly, the two were within a couple of pounds of each 

other in weight.  Both were similarly equiped with power, prop, etc.  I 

think the -7A is pretty close to that, as well.  In fact, I'm still not sure 

why Van removed the 150hp engine from their list of powerplants for the -7x 

unless it was the fact that they don't sell them.  As for the mission, I 

agree.  I must say that my little -6A with 150hp engine isn't too bad on 

cross countries.  I fly VFR, though.



Anyway, the fellow who asked the original question to the thread has already 

decided to build a -7x; so, I guess this discussion could probably end.



Jim Sears in KY

do not archive



---

rv7(at)b4.ca
Guest

Posted: Fri Aug 25, 2006 8:28 am Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

On 6:59:10 2006-08-25 "Doc Custer" <ddcuster(at)wmv-co.us> wrote:

 	  Quote: 	
		   



 The 7 is a heavy plane -- stressed for aerobatics. The 9 is much

 lighter and has a modern wing while the 7 uses an old NACA airfoil.

 The 9 is thus more efficient: Less weight, better wing.


	


 	  Quote: 	
		  From the Van's website:


	


RV-9

Empty Weight   	1015 - 1057 lbs

Gross Weight  	1600 - 1750 lbs



RV-7

Empty Weight  	1061 - 1114 lbs 

Gross Weight 	1800 lbs



I don't think it's safe to say that the -7 is a "heavy" plane compared to

the -9.  AFter all, it uses the same fuselage, and probably the same gear

and engine mount.  The only difference is the horizontal stab and the wing.

 Beyond that, your choice of engine and avionics will determine your empty

weight more than your choice of airframe.



 	  Quote: 	
		   If you want to be upside down go with the 7.


	


That was my criteria.  



-Rob

Hopperdhh(at)aol.com
Guest

Posted: Fri Aug 25, 2006 2:27 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

Doc,

  

 Pretty sure the -7 and -9 have exactly the same fuselage, except for where  the wing brackets are for mounting the front of the wing, and possibly some  other very small differences.

  

 The reason the -9 is not aerobatic is mainly because of the longer wings,  and possibly because of a weaker horizontal stab.

  

 Weights are about the same for a given powerplant.  I was referring  earlier to the engine being lighter.

  

 Can't speak too much about how the -9 is to fly.  I have a friend who  has one, but I haven't flown it from the left seat, and not much from the right  seat.  But, I sure do like my -7A for any mission, except aerial  photography.  I can't imagine a better 2 place airplane.

  

 Dan Hopper

 RV-7A

  

  

 In a message dated 8/25/2006 10:02:21 A.M. Eastern Daylight Time,  ddcuster(at)wmv-co.us writes:

  	  Quote: 	
		  -->    RV-List message posted by: "Doc Custer" <ddcuster(at)wmv-co.us>



The    7 is a heavy plane -- stressed for aerobatics. The 9 is much lighter and    

has a modern wing while the 7 uses an old NACA airfoil. The 9 is thus more    

efficient: Less weight, better wing.



Still -- it all depends on the    mission. Ask the guys at Vans who fly long 

distance cross country which    plane they would rather take. I did. The 

agreement was unanimous -- take    the 9 for cross country.



If you want to be upside down go with the    7.



Simple. Just look at Van's design goals with both the 7 and the 9.    Van's 

designs are very successful based on which mission is going to be    flown. If 

you get a plane designed for one mission and fly it on different    missions 

regularly you are not going to be as satisfied as the guy who    flies the 

plane on the mission for which it was    designed.



Doc



	


 

  

  [quote][b]

Hopperdhh(at)aol.com
Guest

Posted: Fri Aug 25, 2006 2:47 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

In a message dated 8/24/2006 8:47:14 P.M. Eastern Daylight Time,  khorton01(at)rogers.com writes:

  	  Quote: 	
		         	  Quote: 	
		       I would think that the lower weight would give an advantage to the      O-320 powered ship.

      

	




   The speed change for a 10 to 20 lb weight reduction is negligible, as the    vast majority of the drag at cruise speeds is profile drag, and it does not    vary with weight.  The induced drag, which does vary with the square of    weight, is less than 15% of the total drag at typical cruise speeds (data from    the CAFE Foundation APR on the RV-6A) .  The CAFE foundation data    suggests that it would take about a 100 lb weight reduction to realize a 1 mph    speed increase, assuming everything else was equal.



      Kevin Horton         RV-8 (finishing    kit)

   Ottawa, Canada



	


 

 Kevin,

  

 The weight difference between a plane with a 200 HP angle valve IO-360 with  a constant speed prop and a O-320 with a wood prop would probably be close  to 100 pounds.  I'm glad to hear that even 100 pounds is not too  significant.  I would still like to experience a really light RV-7A.   Too bad it is soooooo much work to change engines!

  

 Dan Hopper

 RV-7A 200 HP

  

  [quote][b]

Mark Phillips in TN

Joined: 10 Jan 2006
Posts: 431
Location: Columbia, TN

Posted: Fri Aug 25, 2006 6:35 pm Post subject: RV-7 or RV-9 ?RV-7 or RV-9 ?

In a message dated 08/25/2006 9:13:21 AM Central Daylight Time, jmsears(at)adelphia.net writes:

  	  Quote: 	
		  I must say that my little -6A with 150hp engine isn't too bad on 

cross countries.  	


 >> Yaaaa Jim- been crossing the country for some time in mine and I couldn't agree more!  X-amples: either OSH or LAL to SYI (home base near Nashville) in about 4 hours, non-stop, less than 25 gallons!  Sho' 'nuff cain't be-atch about that!    

  

 Mark do not archive

  [quote][b]

_________________
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