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  #11  
Old 10-07-2017, 09:38 AM
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Toobuilder Toobuilder is offline
 
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Indeed the current gen CPI brains are "unsightly", but there is no need to have them in the panel. They can be hidden once programmed.
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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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  #12  
Old 10-07-2017, 10:40 AM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by Toobuilder View Post
...They can be hidden once programmed.
And that is one of the issues with this system, it has to be programmed, and my experience with helping with probably 100+ P-mags installations, I have come to realize that most builders don't understand ignition timing.

With the P-mags, they can be installed, and run. No need for battery backups, multiple components, etc. Once installed, they just work. They can be tuned for specific installations, if needed.

Now back to the OP's question about P-mag reliability...
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Last edited by N941WR : 10-07-2017 at 10:42 AM.
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  #13  
Old 10-07-2017, 10:51 AM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by N941WR View Post
... and my experience with helping with probably 100+ P-mags installations, I have come to realize that most builders don't understand ignition timing...
...and many of us have come to realize that P-mag (the company) doesnt understand ignition timing either.

But unlike the company, builders have the capability to learn. After all, we trust mere pilots with a mixture knob, right?
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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.

Michael Robinson
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  #14  
Old 10-07-2017, 11:00 AM
Bavafa Bavafa is offline
 
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Quote:
Originally Posted by Toobuilder View Post
...and many of us have come to realize that P-mag (the company) doesnt understand ignition timing either.

But unlike the company, builders have the capability to learn. After all, we trust mere pilots with a mixture knob, right?
I read the chart that compares different ignition system and have failed to see the advantages of the CPI over PMAG, perhaps other than programmability. This maybe simply due to my lack of knowledge on the subject matter and it is not based on prejudice

One difference that has been noted, is the ability to custom program the timing on the CPI which to some degree is possible with PMAG. Is this the main advantage of the CPI system as I am looking at choices and advantages of different system for my new plane. Also realistically, how many people program the timing wildly different. I had installed a EICommander in my old plane and end up with the standard curve A which seemed to be the best suited.
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  #15  
Old 10-07-2017, 11:03 AM
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Carl Froehlich Carl Froehlich is offline
 
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Quote:
Originally Posted by Toobuilder View Post
...and many of us have come to realize that P-mag (the company) doesnt understand ignition timing either. SNIP
A bold statement not supported by the hundreds of pMags now flying - nor my personal experience. If you are referring to recent articles on the subject, any timing curve and be optimized for whatever conditions you want. Most of us want overall performance.

If you want timing to just run flat out full power, stay with a mag and fixed timing. If you want efficient cruise with years of demonstrated performace, get pMags. If you must fiddle with timing while flying, then go another path.

Carl
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  #16  
Old 10-07-2017, 11:18 AM
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Quote:
Originally Posted by Carl Froehlich View Post
A bold statement not supported by the hundreds of pMags now flying - nor my personal experience. If you are referring to recent articles on the subject, any timing curve and be optimized for whatever conditions you want...
I was a satisfied P-mag driver for many years, and then I tried CPI. Does your personal experience include flight test, or even ownership experience of the two ignitions? If not, then all I can say is you dont know what you dont know.

P-mags are good... CPI is GREAT!


Quote:
Originally Posted by Carl Froehlich View Post
...If you want timing to just run flat out full power, stay with a mag and fixed timing...
Nope. Not true either, based on actual flight test experience.
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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.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
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1940 Taylorcraft BL-65 -flying
PA-20-inspired "family truckster" -in work

Last edited by Toobuilder : 10-07-2017 at 11:20 AM.
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  #17  
Old 10-07-2017, 02:25 PM
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GalinHdz GalinHdz is offline
 
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Dual P-Mags on a Lycoming O360-A4M since 2013 (over 300hrs) and love them. Taking into account all variables , I would not use any other ignition system. My 2 cents.

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  #18  
Old 10-07-2017, 03:05 PM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by Bavafa View Post
I read the chart that compares different ignition system and have failed to see the advantages of the CPI over PMAG, perhaps other than programmability. This maybe simply due to my lack of knowledge on the subject matter and it is not based on prejudice

One difference that has been noted, is the ability to custom program the timing on the CPI which to some degree is possible with PMAG. Is this the main advantage of the CPI system as I am looking at choices and advantages of different system for my new plane. Also realistically, how many people program the timing wildly different. I had installed a EICommander in my old plane and end up with the standard curve A which seemed to be the best suited.
Hard to find an advantage from that chart. Its just data. About the only thing that really stands out as data is the price advantage to CPI.

The ability to custom program the CPI flies right over the heads of many potential customers because they "trust" that all of these manufacturers have done their homework and come up with an optimal curve. As we have seen time and time again, this is not the case. Are the existing curves melting down engines? Nope, but are they right? Nope. P-mags have been in the spotlight lately and since you and I are both users of P-mags, I can tell you that their curve is generally too aggressive at high power and may not be enough at the high LOP area. Sure you can shift the curve up or down with the EIC or Bill's product, but you can't fix the basic flaw in the slope of the curve. What this means to the customer is that if you want the right timing at high power for detonation margin, and the right timing for LOP cruise you have to get CPI. P-mag simply does not have the breadth to be optimized for your whole profile. It may be "good enough" for some, but so are 172's.

And do people radically alter ther timing from application to application? Not my experience. The high compression guys shift the whole curve down a few notches, but the basic programming is a no brainer. The curve that I developed last year has been passed around to a bunch of people and it works great as a baseline.

Another thing not apparent on the chart: P-mags require regular inspection including removal from the engine. Is it hard? No, but certainly more than the ZERO maintenance CPI requires. Once CPI is installed you dont ever have to touch it again.
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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.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
PA-20-inspired "family truckster" -in work
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  #19  
Old 10-07-2017, 04:04 PM
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schristo@mac.com schristo@mac.com is offline
 
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Default 1200+ hours with two Pmags

I like them. I started with traditional mags, switched to one Pmag after 300 hours, then swapped the second out after another 100. Now, with over 1600 hours, I have quite a bit of time evaluating them.

The early issues that were uncovered as the number in the field increased have been addressed with minor modifications and a few program updates. Rather than adding timing features they have chosen to keep the product stable with reliability focused updates. I use the windows EICAD program with a laptop to adjust the parameters but it would be nice to have more options for managing the advance.

One of my old units had started to give an occasional 'magnet out of range error' that prompted my need to get a replacement in hand in a bit of a scramble right before Reno...

Comparing the new one to the old ones... most notably, both of the old units have developed quite a bit of shaft play. I look forward to seeing what the serviced unit looks like when it makes its way back shortly.

I have had an an occasional (perhaps four times) boot up failure that is reportedly addressed with v40+ firmware. Each time it was resolved by shutting down and re-timing.

One coil pack developed a dead post... I received a replacement.

Much later, one coil pack, on two posts, started arcing a bit with the plug wires... this eventually led to an intermittent spark. I suspect that the root issue was a combination of a lack of dielectric paste and a loose attachment. After replacing the plugs, wires, and cleaning the posts it all worked fine. I use dielectric grease now and ensure that the plug end is firmly attaching to the post.

I have spent quite a bit of time with the advance in search of any top end speed... my advance is set at -4.2
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  #20  
Old 10-07-2017, 04:23 PM
Nova RV Nova RV is offline
 
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I don't understand why someone asks for data from actual users of a product has his thread filled with sales pitches and testimonials for a different product which is "better"? Can't we limit that to A vs. B threads? I am thinking of going with 2 P-Mags and would love to see more actual responses about P-Mags.
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