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04-13-2017, 07:16 AM
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Join Date: Jul 2015
Location: Omaha, NE
Posts: 63
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Look on Van's website. They're E-Mags. Looks like a great step in the right direction. Bob
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04-13-2017, 08:49 AM
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Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 2,596
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But - they will only sell you an engine with one pMag. If you want a dual pMag set up (like most people) they will sell you an engine with one pMag and nothing in the other mag slot. You then buy the second pMag from Emag.
I assume there will be a credit for not getting the Slick mag - I drop my order for engine and prop later this week so I'll find out.
Carl
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04-13-2017, 08:57 AM
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Join Date: Dec 2009
Location: St Louis, MO
Posts: 957
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E Mag
Anyone know if Vans will sell just an E Mag by itself?
__________________
RV-8, Flying
Previous airplanes: Corby Starlet, Citabria, Cessna 140, Vari-Viggen, RV-3, RV-4
RV grin every flight
"Sure is nice to have smart friends"
2018 dues paid
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04-13-2017, 09:41 AM
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Join Date: Feb 2005
Location: Chesterfield, Missouri
Posts: 4,514
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Quote:
Originally Posted by Carl Froehlich
But - they will only sell you an engine with one pMag. If you want a dual pMag set up (like most people) they will sell you an engine with one pMag and nothing in the other mag slot. You then buy the second pMag from Emag.
I assume there will be a credit for not getting the Slick mag - I drop my order for engine and prop later this week so I'll find out.
Carl
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The reasoning behind one pMag makes sense.
A single pMag will provide 95% of what 2 will provide, why give up redundancy of mag back up? Plus there is no concern over back up electric system to power 2 IE's.
I have one IE and one mag firing top plugs. RPM drop on mag check is same, old mag technology is not all that bad, it works pretty well at least up to 500 hours.
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04-13-2017, 11:28 AM
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Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 2,596
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Quote:
Originally Posted by David-aviator
The reasoning behind one pMag makes sense.
A single pMag will provide 95% of what 2 will provide, why give up redundancy of mag back up? Plus there is no concern over back up electric system to power 2 IE's.
I have one IE and one mag firing top plugs. RPM drop on mag check is same, old mag technology is not all that bad, it works pretty well at least up to 500 hours.
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I do not agree that one mag and one pMag provide any advantage or redundancy over a dual pMag install - and offer that this set up present some disadvantages. Examples:
- With the pMag and mag combination, the mag does little but you are still stuck with overpriced plugs that get fouled.
- The pMag provides it's own power - no backup electrical power required.
- The mag requires more care and feeding than a pMag (personal experience).
- The thumbrule is one pMag and one mag provides 80% of what two pMags provide. I want the other 20%.
For those who fly low and at full power all the time the pMag has less advantage over the mag. I fly high and LOP - where the pMags provide the most value.
Carl
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04-13-2017, 12:02 PM
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Join Date: Oct 2005
Location: 08A
Posts: 9,500
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One EI of any kind offers improved starting performance, cold or hot, and improved idle. The rest is about spark timing, not how the spark is generated.
As for p-mags, recent data demonstrates what many of us have suspected all along...the advance schedule is wrong as a soup sandwich. Carl's argument about lots of advance to run high and LOP is reasonable, and the p-mag delivers it. However, you must first climb to a suitable altitude, and the advance schedule is not optimal for climb at best power ROP.
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Dan Horton
RV-8 SS
Barrett IO-390
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04-13-2017, 12:41 PM
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Join Date: Feb 2015
Location: Locust Grove, GA
Posts: 621
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Quote:
Originally Posted by DanH
One EI of any kind offers improved starting performance, cold or hot, and improved idle. The rest is about spark timing, not how the spark is generated.
As for p-mags, recent data demonstrates what many of us have suspected all along...the advance schedule is wrong as a soup sandwich. Carl's argument about lots of advance to run high and LOP is reasonable, and the p-mag delivers it. However, you must first climb to a suitable altitude, and the advance schedule is not optimal for climb at best power ROP.
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Dan, can you provide a link and/or data that shows this information? It's a little hard to understand that a mag with fixed timing would somehow be better than EI with MP based variable timing. Thanks.
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Krea Ellis
Locust Grove, GA
DA20-A1 "Princess Amelia" - gone home to Amelia Island
RV-7A Phase 2
RV-10 under construction at Synergy Air South
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04-13-2017, 01:09 PM
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Join Date: Jan 2005
Location: SC
Posts: 12,887
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Quote:
Originally Posted by DanH
... However, you must first climb to a suitable altitude, and the advance schedule is not optimal for climb at best power ROP.
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I'm not sure that is a correct statement.
With my 8.5:1 O-360, which is spec'ed at 25 degrees before TDC, the P-mags do not start advancing until you are going through 4,000 to 6,000' at climb power.
The key to the P-mags is understanding what the proper timing is for your engine and configuring the P-mags to match. Forcing them to the "A Curve" by adding a jumper between pins 2 & 3 is close but it is best to add a negative offset of 1.4 degrees and reduce the maximum advance by the same amount.
If you have an angle valve engine that requires 20 degree timing, then you should enter a negative offset to get it down to 19.6 degrees and reduce the max advance by the same amount.
Once you make a change the P-mags, you do not install the jumper between pins 2 & 3 as that will just force it back to the "A Curve".
These changes can be made with the EICAD program available for free from the Emag website or with our EICommander.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
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04-13-2017, 01:45 PM
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Join Date: Feb 2005
Location: Chesterfield, Missouri
Posts: 4,514
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Quote:
Originally Posted by KatanaPilot
Dan, can you provide a link and/or data that shows this information? It's a little hard to understand that a mag with fixed timing would somehow be better than EI with MP based variable timing. Thanks.
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It is true.
CAFE FOUNDATION established some years ago with extensive flight testing, EI offers little advantage over magnetos until above about 8500.
Go to cafe.foundation and dig it up, the report is still there somewhere.
__________________
RV-12 Build Helper
RV-7A...Sold #70374
The RV-8...Sold #83261
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