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  #11  
Old 04-30-2015, 12:21 AM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
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Originally Posted by czechsix View Post
I find this pretty amazing...I trust LyCon's dyno is properly calibrated and the tests were conducted around standard atmospheric conditions to get a fair apples-apples comparison with Lycoming's rating of 210 hp...? If they were boosting the compression ratio it would make more sense, but getting an extra 43 hp out of the IO390 without changing compression is really surprising. If you look at the list of mods, adding electronic ignition doesn't typically increase hp much...it improves efficiency, but most of the spark advance happens at lower manifold pressures (high altitude cruise). At least that's what Klaus Savier told me when I put Lightspeeds on my O-360, maybe the Pmags have a new trick that provides a measurable max hp increase.

The port flow surely helps, but Lycoming claims the 390 already has a tuned induction system and the angle valves breath better to begin with than the parallel valve engines, so I thought the port flow process didn't make a huge difference for angle valve engines.

Balancing will give you a very small gain by reducing vibration losses, and the only other significant thing on the list is the performance grind on the camshaft. Not sure how much that is worth, but it begs the question what does LyCon know the Lycoming doesn't know? What is the tradeoff? If they are opening valves more abruptly and keeping them open longer, does that put more stress on the valve train? Is this a brand new camshaft for the 390, or does it have a good service history with other engines like the IO-360? Is it getting better max hp at the expense of performance in some other part of the operating envelope?

Sure would be nice to understand the physics of how they are doing this, and why Lycoming doesn't do the same with the stock 390...
Check many of the fastest opposed stuff at Reno is built by LyCon for many years. When it comes to hp and lasting, few engine builders have the track record and wins that they do. The camshaft change would make a world of difference. LyCon knows their stuff.
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Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, Shorai- RV6A C-GVZX flying from CYBW since 2003- 441.0 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi2.htm


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  #12  
Old 04-30-2015, 06:05 AM
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ColoRv ColoRv is offline
 
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Lycon does know their stuff and build great engines, but their dyno is notoriously optimistic, borderline comical.
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  #13  
Old 04-30-2015, 06:57 AM
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rv6ejguy rv6ejguy is offline
 
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Originally Posted by ColoRv View Post
Lycon does know their stuff and build great engines, but their dyno is notoriously optimistic, borderline comical.
Ah, the old X dyno vs. Y dyno. The only way to know if your statement is true would be to do a calibration test. Who's to say that some other engine builder's dynos are correct? Everyone likes to think their dyno is dead on.

Like I said before, LyCon has the race wins to prove they build some of the most powerful opposed engines in the world. No matter what, I suspect this engine in the thread is putting out a lot more hp than the stock Lycoming IO-390.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, Shorai- RV6A C-GVZX flying from CYBW since 2003- 441.0 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi2.htm


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  #14  
Old 04-30-2015, 07:10 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
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Quote:
Originally Posted by czechsix View Post
I find this pretty amazing...I trust LyCon's dyno is properly calibrated and the tests were conducted around standard atmospheric conditions to get a fair apples-apples comparison with Lycoming's rating of 210 hp...? If they were boosting the compression ratio it would make more sense, but getting an extra 43 hp out of the IO390 without changing compression is really surprising. If you look at the list of mods, adding electronic ignition doesn't typically increase hp much...it improves efficiency, but most of the spark advance happens at lower manifold pressures (high altitude cruise). At least that's what Klaus Savier told me when I put Lightspeeds on my O-360, maybe the Pmags have a new trick that provides a measurable max hp increase.

The port flow surely helps, but Lycoming claims the 390 already has a tuned induction system and the angle valves breath better to begin with than the parallel valve engines, so I thought the port flow process didn't make a huge difference for angle valve engines.

Balancing will give you a very small gain by reducing vibration losses, and the only other significant thing on the list is the performance grind on the camshaft. Not sure how much that is worth, but it begs the question what does LyCon know the Lycoming doesn't know? What is the tradeoff? If they are opening valves more abruptly and keeping them open longer, does that put more stress on the valve train? Is this a brand new camshaft for the 390, or does it have a good service history with other engines like the IO-360? Is it getting better max hp at the expense of performance in some other part of the operating envelope?

Sure would be nice to understand the physics of how they are doing this, and why Lycoming doesn't do the same with the stock 390...
You wanna know what the trade off is? Blow up that dyno picture and look at the lower left side of the screen. BSFC = .562 - that is likely what they trade off.

Better breathing, and higher hp, but at the expense of higher specific fuel consumption. Maybe Tom (gZero) can tell us about his new 8, and compare his fuel burn for cruise compared to others. That is the only way to know for sure.

This is going to be one nice performing 14!
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“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”

Last edited by BillL : 04-30-2015 at 07:45 AM.
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  #15  
Old 04-30-2015, 08:32 AM
jswareiv jswareiv is offline
 
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Default GPH

Quote:
Originally Posted by BillL View Post
You wanna know what the trade off is? Blow up that dyno picture and look at the lower left side of the screen. BSFC = .562 - that is likely what they trade off.

Better breathing, and higher hp, but at the expense of higher specific fuel consumption. Maybe Tom (gZero) can tell us about his new 8, and compare his fuel burn for cruise compared to others. That is the only way to know for sure.

This is going to be one nice performing 14!
I promise to report back once I get it flying and can let you know the true GPH burn. At least I won't have to worry about short field takeoffs!
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  #16  
Old 04-30-2015, 09:38 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by BillL View Post
BSFC = .562 - that is likely what they trade off.
That's not out of line for a WOT power run. It will be interesting to see BSFC leaned for cruise with that modified cam, which I suspect moves the torque peak well up the RPM range.
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Last edited by DanH : 04-30-2015 at 11:59 AM.
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  #17  
Old 04-30-2015, 09:54 AM
Sig600 Sig600 is offline
 
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Quote:
Originally Posted by BillL View Post
You wanna know what the trade off is? Blow up that dyno picture and look at the lower left side of the screen. BSFC = .562 - that is likely what they trade off.

Better breathing, and higher hp, but at the expense of higher specific fuel consumption. Maybe Tom (gZero) can tell us about his new 8, and compare his fuel burn for cruise compared to others. That is the only way to know for sure.

This is going to be one nice performing 14!
My lycon built IO-360 cruises at 170kts TAS on 8 gph with a three blade MT for comparison.

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  #18  
Old 04-30-2015, 10:15 AM
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Ironflight Ironflight is offline
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Originally Posted by Sig600 View Post
My lycon built IO-360 cruises at 170kts TAS on 8 gph with a three blade MT for comparison.
And it apparently does that inverted!!!
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  #19  
Old 04-30-2015, 10:17 AM
jswareiv jswareiv is offline
 
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Default Fuel Burn

Quote:
Originally Posted by BillL View Post
You wanna know what the trade off is? Blow up that dyno picture and look at the lower left side of the screen. BSFC = .562 - that is likely what they trade off.
Of course that fuel burn is at full throttle. I should be able to pull it back a bunch so you can keep up with me and the fuel burn should be similar. However, if I want to get there faster than you...
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  #20  
Old 04-30-2015, 10:19 AM
Sig600 Sig600 is offline
 
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Originally Posted by Ironflight View Post
And it apparently does that inverted!!!
Thought I fixed that... Shows right side up on my iPad. Must be operator error.
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