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  #1  
Old 08-07-2008, 10:33 AM
rvnor rvnor is offline
 
Join Date: Aug 2008
Location: 70'N ENNA Norway
Posts: 14
Default REAL PERFORMANCE FOR THE RV-7

I'm planning too build one and how is the performance for the RV7???
207mph at 8000ft ~ 182 kts at 8000ft according too Van's.
This is true airspeed and indicated app. 160 kts???
What is the performance at sealevel ? 160-170 kts IAS at 75% with IO390 engnie 210hp+??? Fuelburn??
What is the VNE?
Is it possible to make a larger fuel tank?? 50 gallon...
Is this really the aircraft to build instead of the Glassair, Lancair etc...
Thanks
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  #2  
Old 08-07-2008, 11:36 AM
rv72004 rv72004 is offline
 
Join Date: Nov 2005
Posts: 452
Default

If you build according to Vans, the figures stated by Vans are true and correct.
If its the right plane for you?, only you can decide.
Good luck in your quest.
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  #3  
Old 08-07-2008, 04:00 PM
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frankh frankh is offline
 
Join Date: Jul 2006
Location: Corvallis Oregon
Posts: 3,547
Default Outboard fuel tanks

Yes there have been a number of airplanes built with this mod.

Some use aftermarket tip tanks abut others have built an extra tank in the outboard protion of the wing. Its more work of course but quite feasable.

Having found a number of occasions when i could have used an extra 30 gallons I wish I had.

Frank
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  #4  
Old 08-07-2008, 10:58 PM
yakdriver yakdriver is offline
 
Join Date: Aug 2006
Location: Twin Falls, ID
Posts: 683
Default

Finished mine in November. 180+hp C/S prop. 8000' 23" 2550 208mph 11GPH. More realistic cruise is 10,000' 21" 2350 190mph 8.2 gph LOP. Don
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  #5  
Old 08-08-2008, 05:23 AM
Pirkka Pirkka is offline
 
Join Date: Feb 2006
Location: Europe, Finland (EFTU)
Posts: 542
Default

Quote:
Originally Posted by rvnor View Post
I'm planning too build one and how is the performance for the RV7???
In that case you should probably meet Alf who just got his RV-7 fly in Norway... There is one 7 and one 7A in Sweden as well flying.
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  #6  
Old 08-08-2008, 02:14 PM
Nouj Nouj is offline
 
Join Date: Jun 2008
Location: England
Posts: 32
Default

I have fitted tip tanks to my RV7. It gives me an extra 22.2 us gallons. I used the original Vans tips laid a foam sandwich with carbon cloth on the inside and carbon foam transverse ribs and closed out with a carbon rib on the inside face. The original tips will certainly split with 1.5 psi pitot pressure hence the strengthening. The tanks gravity feed into the mains via a non return valve simple and straight forward but I reckon it added around 150 hours work. You need to be aware not to exceed the MTOW as well. It does however give me nearly 6 hours at 178 ktas which at least gives me the opportunity to buy some duty free fuel!! 100 LL in UK is now 13.15 USD a gallon . I may even use the range to emigrate to the US!!
Steve
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  #7  
Old 08-09-2008, 09:23 AM
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mick mick is offline
 
Join Date: Sep 2007
Location: Melbourne Australia
Posts: 76
Default Leading edge fuel tanks

50 gallons!. What about an extra 38.5 gallons ?

I have had an engineer design leading edge tanks for the 7 and 8. All load testing exceeded our original specs. We loaded the tanks to 7.7 G's with no deformation, we then tested for a 9 G impact which resulted in a very small leak at one joint. One thing to note when adding so much weight is the undercarriage was never designed for such loads. When we conducted a load test on the undercarriage of the 7A it was found to be marginal even without extra fuel. I Recommended you do not land full of fuel in long range tanks !! Some times you have no choice..

I am not aware if any load testing has been done on these tip tanks. The problem that was pointed out to me is 1: The attachment at the tip is inadequate for such loads, and there would likely be little warning of any failure of this attachment. 2: Having such weight at the tip will increase the chance of a spin and increase the time required to regain control. Not a good combination on final. 3: If during turbulence the wing begins oscillating the extra fuel at the tip will increase the chances of structural failure. The wings on the rv's is very strong and its doubtful this would ever happen but you don't want to find out the hard way.

By having the fuel further inboard you decrease the chances of these problems due simply to the attachment method to the wing and the weight is distributed along the wing spar and not at its end.

Mick
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  #8  
Old 08-09-2008, 09:56 AM
rvnor rvnor is offline
 
Join Date: Aug 2008
Location: 70'N ENNA Norway
Posts: 14
Smile Extra fuel and the performance

Hi Mick.
What do you mean with the extra 38,5 gallons? An inboard tank or extra leading edge tanks next to the ordinary tanks?
Any descriptions or/and pics?

Anyone else with descriptions/pics for xtra leadingedge tanks who works well?

The decision is made a long time ago and i'm planning to build the RV7 but i would like to have larger fuel capacity for longer flights.
What does Van's say to this?

Was my calculations correct for cruise speed, IAS at ground level???
App 170 kts at 75% with IO390 210 hp
Thanks
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  #9  
Old 08-09-2008, 05:59 PM
Steve Brown Steve Brown is offline
 
Join Date: Oct 2007
Location: Alviso, CA
Posts: 405
Default Where do I find: "Non return valave"

Quote:
Originally Posted by Nouj View Post
....non return valve simple ....
Steve
I went looking for one of these and couldn't find it.
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  #10  
Old 08-09-2008, 08:33 PM
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dhall_polo dhall_polo is offline
 
Join Date: Nov 2006
Location: Cumming, GA
Posts: 610
Default tip tanks

Wow, It's amazing see the locations of the responders on this thread. I guess we've got EMEA covered.

Here's an add-on tank kit sold through safeair. I can vouch that I'm happy with other stuff I've purchased from them...
http://www.safeair1.com/HWA/er_RV6.htm

I'm not installing tip tanks, at least from the start. I think I'd need a personal long range bio tank to take advantage of an extra fuel tank. If you went with fuel injection and electronic ignition, the possibilities for more efficient fuel burn might also be a good way to add range.

good luck.

Don
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