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  #41  
Old 08-08-2016, 10:55 AM
sblack sblack is offline
 
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Whoa! Wait just a cotton pickn' minute!!!!! Replacement carbon fibre RV6 wing? How did that slide past without anyone commenting??????
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RV 4, with an engine...and other stuff
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  #42  
Old 08-08-2016, 12:51 PM
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Kevin Horton Kevin Horton is offline
 
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Location: Ottawa, Canada
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Quote:
Originally Posted by sblack View Post
Whoa! Wait just a cotton pickn' minute!!!!! Replacement carbon fibre RV6 wing? How did that slide past without anyone commenting??????
Stop dreaming about carbon fibre and get back at bashing metal, or you'll never get that thing flying
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  #43  
Old 08-08-2016, 01:50 PM
BillL BillL is offline
 
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Location: Central IL
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Quote:
Originally Posted by sblack View Post
Whoa! . . . . carbon fibre RV6 wing . . .
Because it is fully covered in another thread, now we BOTH should get back to work and fly.
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  #44  
Old 08-08-2016, 06:57 PM
sblack sblack is offline
 
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Quote:
Originally Posted by Kevin Horton View Post
Stop dreaming about carbon fibre and get back at bashing metal, or you'll never get that thing flying
Bunch of slave drivers!
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RV 4, with an engine...and other stuff
VAF dues 2016
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  #45  
Old 08-08-2016, 07:48 PM
David-aviator David-aviator is offline
 
Join Date: Feb 2005
Location: Chesterfield, Missouri
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Quote:
Originally Posted by DanH View Post
Here's a clean RV-8, dead stock 390 with Slicks and AFP constant flow, similar altitude....hauling camping gear, clothes, and three half-cases of Spotted Cow back from OSH. 178 knots on 7.8:



25~30 LOP was the limits of smoothness with the Slicks, which is why I'm now converting to EI. Go a bit leaner, and the airplane will slow down and burn a little less fuel, closing the gap on that 174/6.8 benchmark. The catch will be mixture distribution with 0.028 restrictors as fuel flow drops closer to 7, and the flow divider starts playing a larger role in cylinder balance. Without question, the SDS EFI will maintain superior balance at very low flows, in particular with the new on-the-fly balancing capability.
I took my stock 180HP RV-8 up to 11,500 today to see how it would do compared to Dan's IO390 RV-8. My airplane has AFP FI with one mag and one EI from Robert Paisley. The EI runs at 30 BTDC, that is max advance.

No big surprise, I was about 10 knots slower.

...the numbers...
MP=19.9
RPM=2590
F/F=8.1 (-50/LOP)
TAS 167



Clearly, Dan's airplane is faster and more efficient. Could be the CS prop is a factor. He was running at 2360, mine is a Catto and runs 200 rpm faster, don't know if that is good or bad.

PS ...still like my 8..suppose I could rouse a speed passion and get it going faster..
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Last edited by David-aviator : 08-08-2016 at 07:52 PM.
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  #46  
Old 08-08-2016, 08:04 PM
Kyle Boatright Kyle Boatright is offline
 
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Location: Atlanta, GA
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Quote:
Originally Posted by DanH View Post
Here's a clean RV-8, dead stock 390 with Slicks and AFP constant flow, similar altitude....hauling camping gear, clothes, and three half-cases of Spotted Cow back from OSH. 178 knots on 7.8:
Did you leave the kid at Oshkosh? What a guy will do to bring home a few beers...

;-)
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2001 RV-6 N46KB

Last edited by Kyle Boatright : 08-08-2016 at 08:27 PM.
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  #47  
Old 08-08-2016, 08:52 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by Kyle Boatright View Post
Did you leave the kid at Oshkosh? What a guy will do to bring home a few beers.
;-)
Naaaa. Delivered him back to Birmingham. That photo was '14 or '15, can't remember. Got one EI on it now.

BTW, thanks for that shanty. It was good.
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  #48  
Old 08-08-2016, 09:45 PM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by David-aviator View Post
...My airplane has AFP FI with one mag and one EI from Robert Paisley. The EI runs at 30 BTDC, that is max advance.

No big surprise, I was about 10 knots slower.

...the numbers...
MP=19.9
RPM=2590
F/F=8.1 (-50/LOP)
TAS 167

Clearly, Dan's airplane is faster and more efficient. Could be the CS prop is a factor. He was running at 2360, mine is a Catto and runs 200 rpm faster, don't know if that is good or bad.

PS ...still like my 8..suppose I could rouse a speed passion and get it going faster..
At that altitude and that lean, I can say with near certainty you need at least 6 degrees more advance (assuming single EI). If you had a "LOP switch" and dialed in that extra 6 degrees you would pick up 3-4 knots at exactly the same fuel flow.
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WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

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  #49  
Old 08-21-2016, 08:54 AM
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rv6ejguy rv6ejguy is offline
 
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Default MPG Testing

Another update from Dave who got tired waiting for cooler weather.

"I flew down to see a friend even though they were forecasting 109 here today. There were no problems with any temps either with the engine or injectors.

Anyway, I saw the post from Dan Horton where he reported:
7.8 GPH 11500’ Palt 19.3” MAP 2360 RPM producing 178 KTAS.

Today, I had an opportunity to pretty much finish my MPG testing and I tested his numbers on my plane. At 11500’ I can get 20.7” MAP, so I used 19.3’’ map at that altitude so I would be using about the same HP as Dan was using.

My plane in that case was:
7.8 GPH 11500’ Palt 19.3” MAP 2360 RPM producing 188 KTAS
if i run the available MAP I can get at 11500':

7.8 GPH 11500’ Palt 20.7” MAP 2360 RPM producing 198.3 KTAS, however I never cruise at that high an RPM so these are the numbers to produce a 178 KTAS cruise: 5.8 GPH 11500’ Palt 19.3” MAP 2190 RPM 178 KTAS-that’s 25.6% lower fuel flow.

The best MPG I can get now with my lower compression engine is around 41.3 MPG.
In my past data records I found in march 1997 I was running the same compression I am now. In those records I had a FF at 14000’ and the records I have now are at 14500’ so it’s similar.

Then, I was able to get 36.2 MPG and today I am getting 41.2 MPG. That seems to be about 14% better. I did do the fast back on my plane to further the drag reduction since then and that added about 4 MPH to the top end, so that would have less effect at these lower speeds and my guess is that I’m getting about 10-12% better MPG today with the EFI than back then. sorry I don’t have better data to compare."
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Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW since 2003- 422 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm



Last edited by rv6ejguy : 08-21-2016 at 09:18 PM.
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  #50  
Old 08-21-2016, 10:18 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by rv6ejguy View Post
Anyway, I saw the post from Dan Horton where he reported:
7.8 GPH 11500’ Palt 19.3” MAP 2360 RPM producing 178 KTAS. (snip)
My plane in that case was:
7.8 GPH 11500’ Palt 19.3” MAP 2360 RPM producing 188 KTAS
if i run the available MAP I can get at 11500':
7.8 GPH 11500’ Palt 20.7” MAP 2360 RPM producing 198.3 KTAS
Very cool....but how much beer was Dave hauling?

Apples to apples, add a week's worth of clothes, camping gear, and my big butt too.

Quote:
my guess is that I’m getting about 10-12% better MPG today with the EFI than back then. sorry I don’t have better data to compare."
All kidding aside, that's not a crazy guess. At very small fuel flows the EFI can produce great cylinder balance with the new on-the-fly trim, and with dual EI's to fire it, get very lean. An optimized constant flow (small restrictors, and tuned for the specific conditions) could probably get close, but certainly would not be as easy to tune.

Remember this?

Returning to Fig.2, that is 35X higher than the mechanical system's pressure at a 6 GPH economy cruise flow. At idle the difference is even greater. The injector open time can be tailored for a small flow quantity, but the pressurized spray remains consistent and well atomized. You can expect the EFi system to be smoother at idle and partial power.

And this?



That's a 540 with a Bendix RSA-10 and Slicks (in beige) and dual EI and EFI (in blue). On the dyno, the EI/EFI combination would pull much leaner without significant torque loss. Here, the difference was 1.5 GPH saved with minimal loss of power. BSFC went from .525 to .483. That's an EI/EFI win, and precisely the sort of thing Dave is now demonstrating live with his RV-4.

It's from Kitplanes. At the time I was handed a lot of grief because the peak HP numbers were not what EFii fans wanted to see. The knowledgeable guy who did not find fault was Ross.

Folks, this is what EI/EFI does really well.
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