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04-30-2015, 12:21 AM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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Quote:
Originally Posted by czechsix
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...
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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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04-30-2015, 06:05 AM
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Join Date: Apr 2012
Location: Tampa (BKV)
Posts: 926
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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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04-30-2015, 06:57 AM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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Quote:
Originally Posted by ColoRv
Lycon does know their stuff and build great engines, but their dyno is notoriously optimistic, borderline comical.
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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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04-30-2015, 07:10 AM
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Join Date: Sep 2007
Location: Central IL
Posts: 5,516
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Quote:
Originally Posted by czechsix
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...
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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!
__________________
Bill
RV-7
Lord Kelvin:
“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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04-30-2015, 08:32 AM
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Join Date: Dec 2006
Location: New Orleans, LA
Posts: 474
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GPH
Quote:
Originally Posted by BillL
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 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!
__________________
Stoney
First RV-14 Flight 04/17/2016
Serial #140087, N214SW - Sold
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04-30-2015, 09:38 AM
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Join Date: Oct 2005
Location: 08A
Posts: 9,500
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Quote:
Originally Posted by BillL
BSFC = .562 - that is likely what they trade off.
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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.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Last edited by DanH : 04-30-2015 at 11:59 AM.
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04-30-2015, 09:54 AM
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Join Date: Nov 2005
Location: KRTS
Posts: 1,798
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Quote:
Originally Posted by BillL
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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My lycon built IO-360 cruises at 170kts TAS on 8 gph with a three blade MT for comparison.

__________________
Next?, TBD
IAR-823, SOLD
RV-8, SOLD
RV-7, SOLD
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04-30-2015, 10:15 AM
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VAF Moderator / Line Boy
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Join Date: Jan 2005
Location: Dayton, NV
Posts: 12,256
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Quote:
Originally Posted by Sig600
My lycon built IO-360 cruises at 170kts TAS on 8 gph with a three blade MT for comparison.
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And it apparently does that inverted!!! 
__________________
Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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04-30-2015, 10:17 AM
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Join Date: Dec 2006
Location: New Orleans, LA
Posts: 474
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Fuel Burn
Quote:
Originally Posted by BillL
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.
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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... 
__________________
Stoney
First RV-14 Flight 04/17/2016
Serial #140087, N214SW - Sold
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04-30-2015, 10:19 AM
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Join Date: Nov 2005
Location: KRTS
Posts: 1,798
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Quote:
Originally Posted by Ironflight
And it apparently does that inverted!!! 
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Thought I fixed that... Shows right side up on my iPad. Must be operator error. 
__________________
Next?, TBD
IAR-823, SOLD
RV-8, SOLD
RV-7, SOLD
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