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-   -   Dual P-MAG Reliability in 2017 (https://vansairforce.net/community/showthread.php?t=154003)

Brantel 10-09-2017 05:43 AM

Quote:

Originally Posted by Captain Avgas (Post 1209650)
I refer again to the concurrent thread 'PMAG Problem' on VansAirforce. The OP of that thread, Loal Wood, required a top end job done on his Lycoming after his sole PMAG lost timing. This is what Loal Wood had to say on his thread following a discussion with Brad at Emag about the incident:

I talked to Brad at Emagair about the evaluation of my Pmag. This is what I learned.

The inspection of my Pmag did not reveal any damage or discrepancies.

My Pmag did not have the V40 update installed.

As stated on the Emag website V40 is not a mandatory update.

He said there is no reason to believe that the V40 update would have prevented my loss of timing issue anymore than the V37 that was installed at the time of the event.

Brad said they do not have enough definitive information at this point to know why this inflight timing event happened.


Now, if I'm reading this right EMAG have stated that they do not know why Loal's PMAG (V37) lost its timing but they doubt that V40 would have prevented the timing loss.

In my opinion, there were/are too many unanswered questions in this case to draw a conclusion as to what really happened there.

WAM120RV 10-09-2017 07:11 AM

Loss of timing
 
If we are talking about the incident where arcing at the alternator apparently caused this failure, my recollection was that V40 was designed to prevent this type of issue.


However that is why we have dual ignition systems, if one malfunctions you go to the other and land ASAP. When my LSE ignition started to play up I knew straight away and wen to the mag. No damage to the engine at all.

Actually I may well fit a a different type of ignition in my next lycoming, with fuel injection, but am a happy PMag customer especially with Bills EIC as you can monitor the mags and see what is going on with them.

Toobuilder 10-09-2017 09:34 AM

Quote:

Originally Posted by Bavafa (Post 1209606)
Is this really the only advantage of CPI over PMAG, 100 hour inspection vs. no inspection? BTW, my understanding has been that PMAG asks to inspect at each annual which is relatively a minor inspection.

With CPI, do we ever need to inspect the crank sensor position/mount or is that not required at all?

You directed this at Ross, but I?ll be happy to add my thoughts as well (What a shock, right?).

P-mag wants you to remove the units and do an inspection. The act of removal and replacement is not horrible, but opening up the back of the engine every hundred hours is not fun and definitely increases the risk of dropping hardware into that gaping hole. But the inspection itself is compelling. You are looking to see that all that stuff is still in place. Shaft endplay, magnet alignment? All that stuff is important and let?s face it, fragile. Plenty of warnings to handle this with kid gloves in the P-mag manual. In contrast, the CPI sensor is bolted to the side of the case with a mount stout enough to lift the engine with. If you have an end play or magnet misalignment problem, the crankshaft is broken.

So yes, to answer your question ? zero maintenance for CPI.

Further, the CPI sensor is potted so it is essentially chemical proof. If you want to wash the engine down with solvent or degreaser, you?re not going to hurt the sensor. Contrast this with P-mag, where the case is open vented. You have to cover the Pmags with plastic or remove them to wash down the engine because the boards will get soaked. And yes, it happens. I had a board replaced because solvent entered the case and ate the board.

But the maintenance free aspect is not the primary advantage of CPI. That belongs to the fact that the P-mag curve ? even the most conservative one ? is too aggressive. We have known for years that P-mag equipped engines run warmer and some even exhibit ?CHT issues?. And thanks to the fairly recent flight test efforts an dissection of their curve by several members here, the cause is now clear: Too much advance at high power. In fact, the issue is so well known that even the maker of the third party programmer recommends his product should be used to adjust the problem away. That, or you can mechanically retard the timing (as I?ve done on my -8). But this doesn?t really solve the fundamental issue, it just masks it. True, people are not melting down engines and the issue is manageable by ?spoofing? the standard program, but why not get an ignition that works right out of the box?

And on the subject of ignition curves, P-mag doesn?t even offer the LOP switch function of CPI. This is a very useful feature and a compelling discriminator for those that do cross country work.

So CPI delivers a safe, cool advance curve for takeoff and climb, as well as a fuel stretching LOP setting and everything in between. The components are robust, proven with decades of use, and maintenance free.

Bavafa 10-09-2017 11:09 AM

Quote:

Originally Posted by Toobuilder (Post 1209707)
You directed this at Ross, but I’ll be happy to add my thoughts as well (What a shock, right?).

P-mag wants you to remove the units and do an inspection. The act of removal and replacement is not horrible, but opening up the back of the engine every hundred hours is not fun and definitely increases the risk of dropping hardware into that gaping hole. But the inspection itself is compelling. You are looking to see that all that stuff is still in place. Shaft endplay, magnet alignment… All that stuff is important and let’s face it, fragile. Plenty of warnings to handle this with kid gloves in the P-mag manual. In contrast, the CPI sensor is bolted to the side of the case with a mount stout enough to lift the engine with. If you have an end play or magnet misalignment problem, the crankshaft is broken.

So yes, to answer your question – zero maintenance for CPI.

Further, the CPI sensor is potted so it is essentially chemical proof. If you want to wash the engine down with solvent or degreaser, you’re not going to hurt the sensor. Contrast this with P-mag, where the case is open vented. You have to cover the Pmags with plastic or remove them to wash down the engine because the boards will get soaked. And yes, it happens. I had a board replaced because solvent entered the case and ate the board.

But the maintenance free aspect is not the primary advantage of CPI. That belongs to the fact that the P-mag curve – even the most conservative one – is too aggressive. We have known for years that P-mag equipped engines run warmer and some even exhibit “CHT issues”. And thanks to the fairly recent flight test efforts an dissection of their curve by several members here, the cause is now clear: Too much advance at high power. In fact, the issue is so well known that even the maker of the third party programmer recommends his product should be used to adjust the problem away. That, or you can mechanically retard the timing (as I’ve done on my -8). But this doesn’t really solve the fundamental issue, it just masks it. True, people are not melting down engines and the issue is manageable by “spoofing” the standard program, but why not get an ignition that works right out of the box?

And on the subject of ignition curves, P-mag doesn’t even offer the LOP switch function of CPI. This is a very useful feature and a compelling discriminator for those that do cross country work.

So CPI delivers a safe, cool advance curve for takeoff and climb, as well as a fuel stretching LOP setting and everything in between. The components are robust, proven with decades of use, and maintenance free.

Thanks Michael for summing up the advantages here, things that had become the needle in the stack in the other thread.

Considering that I am somewhat familiar with the maintenance recommendation of PMAG “ the opening up the back of the engine and all that you listed” I will leave that portion out of the discussion since the complexity and risk of it seems to be a matter of opinion.

What I like to know, what advance curve is provided by CPI and how much of customization is expected for the end users/customer? Not all of us are either interested or knowledgeable in finding the best curve thru hours and hours of flight testing. With CPI, right out of the box, do I get a default timing that is an improvement over other EIS and what is involved in the switch for LOP (both in terms of installation and usage) Is it just a toggle switch?

I appreciate the info.

rv6ejguy 10-09-2017 01:09 PM

Quote:

Originally Posted by Bavafa (Post 1209736)

What I like to know, what advance curve is provided by CPI and how much of customization is expected for the end users/customer? Not all of us are either interested or knowledgeable in finding the best curve thru hours and hours of flight testing. With CPI, right out of the box, do I get a default timing that is an improvement over other EIS and what is involved in the switch for LOP (both in terms of installation and usage) Is it just a toggle switch?

I appreciate the info.

I see many comments on EI threads basically saying that lots of people don't care to know if the ignition curves are optimized for their engines, as long as the thing keeps sparking. This has been the case with all the older EIs without a standard, user friendly pilot interface.

So with CPI, every sale is for an individual engine and client, not a one solution fits all. We ask engine type, CR fuel octane and will enter a custom base map for you if desired, slightly conservative to be safe. No need for you to do any programming if you don't want to.

To think that an A or B curve suits every engine and mission out there is simply nonsense. No way it's optimal for all engines, where we commonly have CRs from 7.5 to 10 and even higher in some cases. Data plate timing for IO-390s is a lot less than most other Lycomings, many people run mostly on mogas, some fly low or high, some fly ROP, some LOP. Interesting how many seem to discount the science of flight testing results by Nigel, Dan and Michael here on VAF.

In short, we can enter a safe curve for YOUR engine and mission, no need for you to do much if you don't want to. Likewise you have the ability to fine tune (in logical 1 degree increments) if you wish, plus change the amount of LOP advance which is selected on/off with a small toggle switch.

So, there is no "standard" advance curve with our products unless you don't give us any details, in which case, we'll generally enter 24 degrees of rpm timing for O-235, 290, 320, 360, 540 engines and 20 degrees on IO-390 engines with zero MAP advance or retard- pretty much standard mag timing. But, this would not be a good idea on a 10 to 1 engine running mogas.

Bavafa 10-09-2017 01:31 PM

Quote:

Originally Posted by rv6ejguy (Post 1209760)
I see many comments on EI threads basically saying that lots of people don't care to know if the ignition curves are optimized for their engines, as long as the thing keeps sparking. This has been the case with all the older EIs without a standard, user friendly pilot interface.

So with CPI, every sale is for an individual engine and client, not a one solution fits all. We ask engine type, CR fuel octane and will enter a custom base map for you if desired, slightly conservative to be safe. No need for you to do any programming if you don't want to.

To think that an A or B curve suits every engine and mission out there is simply nonsense. No way it's optimal for all engines, where we commonly have CRs from 7.5 to 10 and even higher in some cases. Data plate timing for IO-390s is a lot less than most other Lycomings, many people run mostly on mogas, some fly low or high, some fly ROP, some LOP. Interesting how many seem to discount the science of flight testing results by Nigel, Dan and Michael here on VAF.

In short, we can enter a safe curve for YOUR engine and mission, no need for you to do much if you don't want to. Likewise you have the ability to fine tune (in logical 1 degree increments) if you wish, plus change the amount of LOP advance which is selected on/off with a small toggle switch.

So, there is no "standard" advance curve with our products unless you don't give us any details, in which case, we'll generally enter 24 degrees of rpm timing for O-235, 290, 320, 360, 540 engines and 20 degrees on IO-390 engines with zero MAP advance or retard- pretty much standard mag timing.

Thank you Ross for the info, I appreciate having the option and flexibility to fine tune the curve if I can but also I, unlike some, have little knowledge of fine tuning the curve.
Is there some data that compares a fined tuned curve of your system vs. the stock curve, lets say curve A of a PMAG in terms of fuel saving/additional power, etc? I am hoping to see a measureable difference (perhaps fuel burn would be a good measureable indicator).

Toobuilder 10-09-2017 01:48 PM

Quote:

Originally Posted by Bavafa (Post 1209736)
... and what is involved in the switch for LOP (both in terms of installation and usage) Is it just a toggle switch?..

Last question first:

The LOP function is activated by applying system voltage to a discrete pin in the CPI connector. The physical interface for the LOP function is a toggle switch in my case. The LOP function is programmed by scrolling through the CPI windows until you get to a discrete LOP window. You simply toggle up or down to get the additional advance you want (3 degrees in my case). Once set, activation of the LOP switch simply tacks on an additional 3 degrees advance to the existing map. If you’re idling at 20 degrees, then activating the switch will give you 23 (20 + 3). If you’re at the top of climb and the normal RPM and MAP values have you at, say, 32 degrees, then the LOP switch give you 35 (32+3). It’s also noteworthy that this function is deactivated at high MP levels. So if you forget to turn off the switch and do a go around, no problem.

I'm glad Ross answered the “as delivered” program because I never used it. I went straight to building my own. A casual glance in the manual shows it to be very conservative at high power though, and testing confirms that’s exactly what is needed. In fact, my testing shows that even Lycoming’s data plate timing value is more than required for takeoff. My program pulls up to 5 degrees off the data plate value in some circumstances. And for the record, I'm stock (8.5) compression.

rv6ejguy 10-09-2017 02:02 PM

Quote:

Originally Posted by Bavafa (Post 1209766)
Thank you Ross for the info, I appreciate having the option and flexibility to fine tune the curve if I can but also I, unlike some, have little knowledge of fine tuning the curve.
Is there some data that compares a fined tuned curve of your system vs. the stock curve, lets say curve A of a PMAG in terms of fuel saving/additional power, etc? I am hoping to see a measureable difference (perhaps fuel burn would be a good measureable indicator).

I've only had quick glances some time ago at what Pmag runs for timing, it doesn't really concern us. I'd look at what Nigel, Dan and Michael have posted here and at Nigel's Kitplanes article if you want to see what works best on THEIR engines. This will give you some idea of where Pmag maybe has too much or too little advance in their curves.

Too much or too little may cause power loss or CHT issues and too much can reduce detonation margins, especially on mogas with high CHTs and IATs. Too little is generally safer than too much. I think Nigel's data is the most complete and Michael's showed us the extremes of WOT/SL vs. LOP/ low MAP up high.

I think the OP was really asking if the original software, hardware problems experienced by Pmags were now licked and only interested in actual reliability in delivering sparks in the Pmag offerings of today. You'll get different answers from different people depending on their experiences. This thread has taken a new direction discussing other factors outside reliability. I'm not sure that serves the purpose of the OP's question. There have already been other threads comparing the various EIs available today.

Toobuilder 10-09-2017 02:10 PM

Quote:

Originally Posted by Bavafa (Post 1209766)
...Is there some data that compares a fined tuned curve of your system vs. the stock curve, lets say curve A of a PMAG in terms of fuel saving/additional power, etc? I am hoping to see a measureable difference (perhaps fuel burn would be a good measureable indicator).

No side by side comparison but I have enough practical experience with both to throw out an informed opinion.

This issue is the breadth of the curve. P-mags deliver very good LOP efficiency because they advance far enough to do some good up in that rarified air. Unfortunately, they start advancing so early that down low and rich they make plenty of heat and cylinder pressure, but don't do more work. Plenty of credible flight test results on this site to review for confirmation.

In short, a good hot spark can be delivered by any EI, and the engine architecture does the rest when LOP. Rich mixtures are easy to light and there's really no difference what lights it off. But timing is everything.

The compelling issue is if the EI can advance far enough to light the LOP mixture, pull it back enough for the best power mixture, and retard enough to protect the engine at the SL, 100% power mixture. Most any EI can deliver on some of these conditions, but CPI does all of them and that's where the "performance advantage" is found.

And I do agree that the OP's question has been answered long ago. Maybe the mods can split the "comparison" posts out into a more appropriate thread. My apologies for my role in the OT.

Flyfish 10-09-2017 02:19 PM

I thought this was a thread about P-Mags.

Timberwolf 10-09-2017 02:31 PM

Quote:

Originally Posted by Flyfish (Post 1209784)
I thought this was a thread about P-Mags.

You would think so, but the original question of dual p mag reliability seemed to be answered some time ago. This thread has actually thrown out a lot of information for 2 different ignition systems and lays out the benefits and draw backs of both. Almost. The pmags are much easier to install and can be a quick way to get into the EI game. However the CPI is a much more tuneable system from the get go, but it takes quite a bit more work to get installed initially. This thread has actually forced me to do more research on both systems. I do like the tunability with the CPI, but that big clunky controller is probably a deal killer for me. Wish they made a small 2 1/4" that did the same thing, along the lines of the EI commander. Or better yet if garmin would work with one of these companies and build a controller into the g3x system. I'm sure it looks cool in a race car but I feel like it looks too gimmicky for a plane. Either way, this has been an informational thread.

rv6ejguy 10-09-2017 02:41 PM

Quote:

Originally Posted by Timberwolf (Post 1209789)
You would think so, but the original question of dual p mag reliability seemed to be answered some time ago. This thread has actually thrown out a lot of information for 2 different ignition systems and lays out the benefits and draw backs of both. Almost. The pmags are much easier to install and can be a quick way to get into the EI game. However the CPI is a much more tuneable system from the get go, but it takes quite a bit more work to get installed initially. This thread has actually forced me to do more research on both systems. I do like the tunability with the CPI, but that big clunky controller is probably a deal killer for me. Wish they made a small 2 1/4" that did the same thing, along the lines of the EI commander. Or better yet if garmin would work with one of these companies and build a controller into the g3x system. I'm sure it looks cool in a race car but I feel like it looks too gimmicky for a plane. Either way, this has been an informational thread.

Glad it's been informational. The CPI2 under development will have a much smaller footprint than the present setup and the green will be gone. Garmin won't play unless you can show a good case for benefits to them which is totally understandable. They have been approached and there will be provisions to communicate with other devices in the new unit to allow for future upgrades.

drill_and_buck 10-09-2017 02:53 PM

Dual P-Mags, 6 years, 650+ hours
 
A few data points and opinions. I was an early adopter of dual P-mags and have been running them for 6 years and over 600 hours. I had a few teething issues in 2011 during my phase 1 testing that were promptly addressed by P-mag.

At about the 150 hour mark I swapped out my aircraft spark plugs for auto plugs and haven't looked back. The P-mags are dirt simple to time, easy to install and operate as advertised. Company service and support is way above the norm.

I get easy starts, smooth low RPM idle and can easily run my O-360 LOP. I'm not interested in experimenting with timing curves. I'm not saying there isn't a better system out there. It depends upon your mission. If I were to build again, I would make the same selection.

Chkaharyer99 10-09-2017 03:06 PM

Quote:

Originally Posted by RhinoDrvr (Post 1209137)

I like the idea of the P-MAG?s the best, but have been unable to on find any data on reliability of the new, v40 firmware, latest version of the hardware P-MAG?s. I also think the P-MAG would be the most straightforward install given the LASAR setup I would be removing already has a Manifold Pressure Line etc.

What are your thoughts?

The real data regarding reliability of newer Pmags using v40 firmware is probably available and could be provided by the manufacture of the product. But based on past practice I seriously doubt they will share that data. Why? I am left to speculate.

Of all the Pmag related threads I've read here, I can't remember a single post where someone from Pmag has participated in the discussion. Maybe I've missed a few?

The question of reliability remains a mystery save for a small population of users who chose to share their experiences.

I will be replacing my Slicks soon and have gone through a simular information seeking exercise.

Enjoy your RV-8.

Andrew Anunson 10-09-2017 03:51 PM

Quote:

Originally Posted by Captain Avgas (Post 1209650)
Now, if I'm reading this right EMAG have stated that they do not know why Loal's PMAG (V37) lost its timing and they have no reason to believe that V40 would have prevented the timing loss.

That is it... right there in the Captain Avgas quote. P-mags sometime loose timing (still making sparks, just at the wrong time). This greatly reduces engine power (or it quits).

To get back engine power the pilot has to know what to do... turn off the offending P-mag. Now... who among us wants to have to troubleshoot ignitions in flight under an engine out situation? Thats why we have 2 igintions... right? So one can keep us flying until we are ready to land.


With all other ignitions... if one quits or messes up or whatever, the other keeps you going to an airport. The pilot doesn't need to troubleshoot anything till on the ground. That is HUGE! If your ignition isn't automatically redundant like this, you can change it to be.

No other ignition gets off timing like that.

Captain Avgas 10-09-2017 07:04 PM

Quote:

Originally Posted by WAM120RV (Post 1209666)
However that is why we have dual ignition systems, if one malfunctions you go to the other and land ASAP.

I have dual ignition systems so that if one malfunctions the other will automatically keep the engine running without a hiccup and without my intervention. The concept that one ignition failing might cause the engine to quit until the offending ignition is identified and switched off is absurd and extremely dangerous.

If an engine quits in flight an ignition check is way down the list of things to do. If it occurs at take-off or landing it is highly unlikely that the pilot will even have the opportunity to do an ignition check.

KRviator 10-09-2017 09:52 PM

Quote:

Originally Posted by Andrew Anunson (Post 1209816)
To get back engine power the pilot has to know what to do... turn off the offending P-mag. Now... who among us wants to have to troubleshoot ignitions in flight under an engine out situation? Thats why we have 2 igintions... right? So one can keep us flying until we are ready to land.


With all other ignitions... if one quits or messes up or whatever, the other keeps you going to an airport. The pilot doesn't need to troubleshoot anything till on the ground. That is HUGE! If your ignition isn't automatically redundant like this, you can change it to be.

No other ignition gets off timing like that.

Quote:

Originally Posted by @Captain Avgas@
I have dual ignition systems so that if one malfunctions the other will automatically keep the engine running without a hiccup and without my intervention. The concept that one ignition failing might cause the engine to quit until the offending ignition is identified and switched off is absurd and extremely dangerous.

So you've never had, nor heard of, a magneto losing its' timing in flight? A quick Google search shows it is far from rare with traditional magnetos indeed occurring 3 times in a 6-week SDR search, so PMag's are nothing new in this regard, yet everyone seems to be up in arms over it? I don't get it... :confused:

From a CAsA bulletin on the subject:
Quote:

Engine roughness or internal vibration is also frequently linked to incorrect magneto-to-engine timing which can occur during operation, despite the timing being correct at installation.
There has been an increase in SDR reports to CASA describing advances in timing in between periodic inspection periods in 4300 and 6300 series slick magnetos.
Personally, I have dual ignitions (Dual PMag's as it happens) so that if one fails, however it happens, I can get to an airport. Cycling the magneto switch is one of the 'rough-running' or failure checklist actions for most spam-can's I've flown for precisely this reason...

lr172 10-09-2017 10:37 PM

Quote:

Originally Posted by N941WR (Post 1209356)
The P-mags are great ignitions and way ahead of magnetos. Do they extract maximum performance out of an engine, no; however, neither does the ignition in your car or truck.

This is completely incorrect. Auto manufacturers have complete control of their ignition maps and spend 1000's of hours on the dyno optimizing fuel flow (i.e. mixture) and ignition timing. It is also done in harmony with other engine variables, such as temps. Granted, they also factor in reliability and emissions. However, they are highly optimized. They sell cars, in part, based upon HP claims. Trust me, they want as high of a number as they can get.

Timing makes a big impact on performance and even though many here don't want to hear it, it is variable based on many factors, the most profound being mixture. I can't imagine having an EI that cannot be adjusted based upon my mixture setting (ROP vs LOP). It would be like not having a mixture control and just feeding full rich through the flight regime.

I do agree with Bill that if you favor simplicity over performance, the Pmag is a good upgrade option over the mag. However, I would still buy the CPI for cost and reliability.

Just to give one example of the benefits of flexibility, I solved my FI hot idle problem by bumping my idle timing to 35.

Larry

Av8rRob 10-09-2017 11:24 PM

Cockpit switches
 
Ross, with your upcoming CPI2, besides the actual unit you are now designing, what sort of cockpit switches do you recommend for a dual cpi setup? I?m guessing two independent on-off switches for each cpi.

rv6ejguy 10-10-2017 05:45 AM

Quote:

Originally Posted by Av8rRob (Post 1209887)
Ross, with your upcoming CPI2, besides the actual unit you are now designing, what sort of cockpit switches do you recommend for a dual cpi setup? I?m guessing two independent on-off switches for each cpi.

We're trying to eliminate as many external switches on the CPI2 as possible. I can't say at this point until software and testing is closer to completion. That's probably at least a month away.

Captain Avgas 10-10-2017 06:44 AM

Quote:

Originally Posted by KRviator (Post 1209879)
So you've never had, nor heard of, a magneto losing its' timing in flight? A quick Google search shows it is far from rare with traditional magnetos indeed occurring 3 times in a 6-week SDR search

It's not that I'm sceptical, but I think you should state your search criteria and produce the specific case results of your SDR search so that we can ascertain for ourselves if they are valid to the discussion at hand.

maus92 10-10-2017 08:09 AM

Quote:

Originally Posted by rv6ejguy (Post 1209893)
We're trying to eliminate as many external switches on the CPI2 as possible. I can't say at this point until software and testing is closer to completion. That's probably at least a month away.

Is the newer CPI2 a completely new system, or is it basically an upgraded controller / interface box / display? Is everything firewall forward the same?

rv6ejguy 10-10-2017 08:42 AM

Quote:

Originally Posted by maus92 (Post 1209916)
Is the newer CPI2 a completely new system, or is it basically an upgraded controller / interface box / display? Is everything firewall forward the same?

The PCB, case, display will be all new, all FF components the same as before. I can't talk about some of the other new features planned at this time until we're closer to release.

maus92 10-10-2017 08:49 AM

Quote:

Originally Posted by rv6ejguy (Post 1209928)
The PCB, case, display will be all new, all FF components the same as before. I can't talk about some of the other new features planned at this time until we're closer to release.

I guess what I'm getting at is there an upgrade path for those who either have installed the current system, or want to install the current version sooner rather than waiting for CPI2?

N941WR 10-10-2017 10:25 AM

Quote:

Originally Posted by lr172 (Post 1209881)
This is completely incorrect. Auto manufacturers have complete control of their ignition maps and spend 1000's of hours on the dyno optimizing fuel flow (i.e. mixture) and ignition timing. It is also done in harmony with other engine variables, such as temps. Granted, they also factor in reliability and emissions. However, they are highly optimized. They sell cars, in part, based upon HP claims. Trust me, they want as high of a number as they can get.

Timing makes a big impact on performance and even though many here don't want to hear it, it is variable based on many factors, the most profound being mixture. I can't imagine having an EI that cannot be adjusted based upon my mixture setting (ROP vs LOP). It would be like not having a mixture control and just feeding full rich through the flight regime.

I do agree with Bill that if you favor simplicity over performance, the Pmag is a good upgrade option over the mag. However, I would still buy the CPI for cost and reliability.

Just to give one example of the benefits of flexibility, I solved my FI hot idle problem by bumping my idle timing to 35.

Larry

The this is completely incorrect.

While it is true that auto manufacturers spend a lot of time developing timing and fueling maps, they do not tune them to extract maximum performance out of your vehicle. They are looking for emissions, reliability, and performance, not necessarily in that order.

When I was doing the auto racing thing, I replaced the ECU and was able to pickup around 5% more torque and HP by tuning the car on a dyno. Of course it was tuned within a breath of its life, something auto makers are loathe to do for obvious reasons.

Another way to look at it is, why are there so many different aftermarket automotive ignitions available, if the auto manufacturer's ignitions are so good?

My biggest issue with multi component systems is the number of connectors that can fail. That is not to mention the additional complexity required by adding extra batteries and alternators to protect against electrical system issues.

Then you still have the problem one LS user had a few years back. He was on short final when his alternator belt broke, ripping out the wires for the crank angle sensor. Instant glider.

In the end, you as the builder have to weigh the risks, both set up and operational, and pick the system that you feel is best for you.

rv6ejguy 10-10-2017 11:33 AM

Quote:

Originally Posted by N941WR (Post 1209959)
The this is completely incorrect.

While it is true that auto manufacturers spend a lot of time developing timing and fueling maps, they do not tune them to extract maximum performance out of your vehicle. They are looking for emissions, reliability, and performance, not necessarily in that order.

When I was doing the auto racing thing, I replaced the ECU and was able to pickup around 5% more torque and HP by tuning the car on a dyno. Of course it was tuned within a breath of its life, something auto makers are loathe to do for obvious reasons.

Another way to look at it is, why are there so many different aftermarket automotive ignitions available, if the auto manufacturer's ignitions are so good?

My biggest issue with multi component systems is the number of connectors that can fail. That is not to mention the additional complexity required by adding extra batteries and alternators to protect against electrical system issues.

Then you still have the problem one LS user had a few years back. He was on short final when his alternator belt broke, ripping out the wires for the crank angle sensor. Instant glider.

In the end, you as the builder have to weigh the risks, both set up and operational, and pick the system that you feel is best for you.

Almost all auto ECUs today use a knock sensor or CPT to advance timing just short of knock at all times for the given fuel octane plus they're taking into account IAT, CLT, MAP and/or MAF, baro etc. to ensure highest BMT at ALL times, whether cruising at part throttle well lean of Stoich or WOT at redline. Since emissions are not measured at WOT/ high rpm in most tests because most car engines don't spend a high percentage of time there, power is paramount under that condition given a reasonable buffer to the edge of detonation which ANY system should have. To suggest otherwise, especially in aircraft, is reckless.

The auto ignitions are orders of magnitude more sophisticated and precise than a Pmag, CPI, LS or anything else in aviation short of Lycoming's IE2 or perhaps the Rockwell system on the Rotax 912iS, which they easily match or exceed.

Any advance in timing will almost certainly affect knock margins and/or emissions. The aftermarket does not need to meet any emissions spec and most say "for off road use only". I don't see many aftermarket ignitions out there for the cars of today outside of Link, Haltech and Motec which are intended mainly for performance / race use at higher boost levels where factory ECUs are not mapped-that longevity/ warranty card again.

No auto OEMs use integrated ignition controllers these days because they found out long ago that long term reliability is compromised by heat and vibration when attached to the engine. The Pmag integrated design was a marketing decision to make installation easier IMO (which it undeniably is), not something based on best engineering practice.

No auto OEMs today use gear driven timing components because it's less precise and more prone to failure. These are reasons why Pmag mandates 100 hour inspections- to make sure the bearings, gears are ok and the electronics have not been overtemped or got wet. Pmag requires blast tubes for cooling as a result of their design decision and they use non-water proof screw type connectors externally. Really, in 2017? You don't see this stuff on modern auto ignitions.

Poor belt maintenance and questionable installation likely caused the LS incident in Australia. Anyway, we can all learn from that and protect crank sensor cables with armor as we recommend. No way a thrown belt will take out our sensor or cables.

The internal generator in the Pmag has caused issues as outlined in their own documentation. http://www.emagair.com/service-notes/ http://www.emagair.com/downloads/

More reliable than a backup battery? Doubtfully. More spinning, vibrating stuff inside to go wrong and cause damage to other critical parts.

Toobuilder 10-10-2017 11:33 AM

Edit, Ross beat me to it.

Toobuilder 10-10-2017 01:10 PM

Quote:

Originally Posted by N941WR (Post 1209959)
...Another way to look at it is, why are there so many different aftermarket automotive ignitions available, if the auto manufacturer's ignitions are so good?....

Please define an "automotive ignition" so that we have context. Are you discussing something from the 1960's or today? In the 60's you had a true stand alone system: Distributor, amplifier, coil... Today, with the ECU handling many functions, receiving signals from many sensors, its hard to segregate an "ignition system". You can certainly buy aftermarket coils and fat spark plug wires just like in the old days, but a "system"? Please define.


Quote:

Originally Posted by N941WR (Post 1209959)
...My biggest issue with multi component systems is the number of connectors that can fail....

Please cite actual failure rates "caused" by the use of "Multi component systems". Not what "could" happen, but what actual experience shows "does" happen. Compare that to the engineering challenge of cramming all that stuff into one box to satisfy a marketing niche and see where that gets you? Would you like to compare the history of "magnet misalignment " with Ross' product line? How about "lost timing events"?

I'll grant P-mag the benefit of the doubt that their issues are largely resolved (with frequent, repetitive inspections), but we all know that that has been a long, uphill battle - a battle LARGELY the result of the marketing decision to package it all together - But there is no way you can pound the drum that a "distributed" system is inherently less reliable. No way. To do so flies in the face of logic and absolutely overwhelming evidence to the contrary.

It's time to put that bogey man to rest.

KRviator 10-10-2017 03:06 PM

Quote:

Originally Posted by Captain Avgas (Post 1209905)
It's not that I'm sceptical, but I think you should state your search criteria and produce the specific case results of your SDR search so that we can ascertain for ourselves if they are valid to the discussion at hand.

No problems, Google "Magneto losing timing lycoming" and it is the 2nd from the bottom. Of if you prefer, you can login to the CAsA SDR Portal and search using "Magneto" with no date range yourself. But the initial 3 I found were using Google.
From CAsA's Flight Safety magazine, 01August14-22Sep14:
Quote:

Lycoming IO540K1A5 Magneto/distributor?magneto unserviceable. SDR 510019711 RH magneto timing found to be approximately 7 degrees advanced. Magneto had 94 hours TSN. P/No: 6350. TSN: 94 hours
Quote:

Lycoming IO540K1A5 Magneto/distributor?magneto unserviceable. SDR 510019832 RH magneto timing moved to 4 degrees advanced. Magneto had approximately 50 hours TSN. P/No: 6350. TSN: 50 hours.
Quote:

Lycoming O320 Magneto/distributor?magneto unserviceable. SDR 510019703 Magneto losing timing. Timing reset but changed again so magneto replaced. P/No: 4370. TSN: 477 hours.
However, using the SDR Portal, you find the following using no date range and the search term 'magneto':
Quote:

Originally Posted by The CAsA SDR Portal
18 August 2016: On newly overhauled engine after relatively short time in service, magneto timing was advanced by more than 5 degrees. According to Slick SL No. 4300/6300-74-20-001, this amount of timing drift required immediate action. Magneto was therefore removed and returned for warranty claim.

23 December 2015: During a 100 Hourly Inspection, the magneto to engine timing had drifted 4 degrees which was corrected during the 100 Hourly Inspection. On the post 100 Hourly ground run, there was a 200 rpm magneto drop noted on the magneto that had the timing drift (the 200 rpm drop was not there before the timing drift on the pre 100 Hourly ground run). As this magneto drop is beyond limits the magneto was replaced with new, was timed to the engine and a ground run was carried out and found serviceable.

11 November 2015: Left hand engine wouldn't start. The magneto to engine timing was checked (as we have had previous magneto problems) and it was approx. 20 degrees advanced. The magneto was removed and bench checked and was founds approx. 20 degrees advanced with a weak spark below 1,000 rpm.

03 July 2015: LH magneto timing out of adjustment

29 May 2015: LH magneto timing drifting. Investigation found points cam loose. Further investigation found the rotor shaft cam slot had been machined oversize.

05 May 2015: Magneto has a history of the timing setting moving. See attachment for history details.

08 September 2014: RH magneto timing moved to 4 degrees advanced. Magneto had approximately 50 hours TSN.

03 September 2014: LH magneto faulty. Timing was found to be 8 degrees advanced.

02 September 2014: LH magneto faulty. Timing was found to be 10 degrees advanced.

13 August 2014: RH magneto timing found to be approximately 7degrees advanced. Magneto had 94 hours TSN

08 August 2014: Magneto losing timing. Timing reset but changed again so magneto replaced.

20 May 2014: Magneto losing timing settings after a few hours of flight

01 May 2014: Magneto timing advanced 6 degrees from20 degree mark. Found during inspection iaw Slick SB2-08B.

26 April 2014: Magneto losing timing settings after a few hours of flight.

04 April 2014: Magneto losing timing settings after a few hours of flight.

04 April 2014: Magneto unserviceable. Timing advances in use.

25 March 2014: Magneto losing timing settings after a few hours of flight.

13 March 2014: LH magneto timing slowly advances by 5-6 degrees between inspections. Magneto is correctly retimed at each inspection but then slowly advances again.

13 March 2014: RH magneto timing slowly advances by 5-6 degrees between inspections. Magneto is correctly retimed at each inspection but then slowly advances again. See also SDR 510018760 for similar defect on LH magneto.

11 March 2014: Magneto losing timing settings after a few hours of flight.

05 November 2013: On Engine Run-up performance check, right magneto 50 RPM drop. Timing 5 Degrees out.

02 May 2013: RH magneto failed to stay correctly timed. Suspect internal timing slipped due to unknown internal problem. Magneto had been fitted to a newly rebuilt engine.

01 February 2010: Magneto had excessive play in gear shaft bush causing gear to jump teeth and affect timing.

08 August 2008: Magneto internal timing shifted. Timing moved from 20 degrees BTDC to 12 degrees BTDC.

As you can see, PMags are not alone in the lost-timing issue and I dislike the fact that at least two qualified pilots do not understand basic magneto operation enough to understand they too suffer from timing issues - and they can be a relatively common occurrence too - that can affect engine operation, instead trying to point the finger at PMag as being the only possible culprit in this regard. Now, before anyone suspects I am affiliated with Brad or his company - I have no interaction or association with PMag/EMagAir or any of their employees, other than having two PMag L114's installed on my engine at manufacture by ECI.

These SDR's are a relatively new concept from CAsA, and only capture those that are reported, and only then in Australia, which has a relatively small GA fleet compared to the US, so it is certainly within the realm of possibility an American pilot would expect to experience such a phenomenon and be expected to react accordingly. Commentary here suggests this may not be the case, and if this is indeed true, I would encourage a mag-check to be incorporated as part of your IA's following engine roughness or failure and be practiced as such, at the earliest opportunity. As I said earlier, it was part of the spam-can checklists I was trained under and that is going back close to 20 years, and it is there for a reason.

Malndi 10-10-2017 03:38 PM

Quote:

Originally Posted by rv6ejguy (Post 1209982)

Poor belt maintenance and questionable installation likely caused the LS incident in Australia. Anyway, we can all learn from that and protect crank sensor cables with armor as we recommend. No way a thrown belt will take out our sensor or cables.

I'm on the fence and watching the debate, however the risk of the crank sensor and wires being damaged by alternator belt failure is a key concern for me. Particularly given that I wasn't far from that crash and know the occupant who was very badly burnt. Would like to know more about how the crank sensor and cables can be protected, but didn't find the answer on your website. Can you elaborate here.

rv6ejguy 10-10-2017 04:09 PM

Quote:

Originally Posted by Malndi (Post 1210064)
I'm on the fence and watching the debate, however the risk of the crank sensor and wires being damaged by alternator belt failure is a key concern for me. Particularly given that I wasn't far from that crash and know the occupant who was very badly burnt. Would like to know more about how the crank sensor and cables can be protected, but didn't find the answer on your website. Can you elaborate here.

I've posted photos in other threads on this topic. Our crank sensors and mounts are far more robust than the early LS ones- you can lift the engine up from ours. The mounts also incorporate several threaded holes to attach cable armor to. A number of people posted their solutions here: http://www.vansairforce.com/communit...d.php?t=152923

The last post here shows a photo of the mount and armor mounting holes: http://www.vansairforce.com/communit...d.php?t=143608 Go to Page 5, post #44 last page.

I should mention that the early LS crank sensor setup has been superseded by a new design which has the cabling mostly inside the baffle sheet metal.

KRviator 10-10-2017 04:38 PM

And another few examples using "Distributor" as the faulty part:
Quote:

13 March 2014: Magneto distributor block cracked. Suspect due to over torquing of attachment. Investigation also found timing out of limits.

13 November 2013: Maneto distributor block bush worn allowing timng gear teeth to slip and put the timing approximately 180 degrees out. See attachments for photographs.

02 November 2013: LH magneto distributor block failed allowing magneto to retard sufficiently for engine to stop.

23 September 2013: Gear bearing in distributor block was found loose following an uncommanded engine stop on takeoff. Installation of a new distributor block and gear corrected the fault.

08 July 2013: LH magneto distributor block bushing loose causing gears to demesh.

19 June 2013: Magneto distributor block bushing loose resulting in timing problems

17 September 2012: LH magneto distributor block loose allowing distributor gear to jump teeth. Suspect bushing incorrectly installed at manufacture. See attachment for photograph.

02 March 2010: Magneto distributor block bearing dislodged causing misalignment of the distributor gear and affecting engine timing. See attachment for photograph.

23 July 2007: LH and RH magneto points defective. Points out of adjustment and timing moved.
Granted, not all of these instances resulted in engine failures or rough running, however, the SDR's indicate the potential for such problems, should the issue not have been found and corrected.

spatsch 10-10-2017 05:50 PM

Quote:

Originally Posted by KRviator (Post 1210050)
....
American pilot would expect to experience such a phenomenon and be expected to react accordingly. Commentary here suggests this may not be the case, and if this is indeed true, I would encourage a mag-check to be incorporated as part of your IA's following engine roughness or failure and be practiced as such, at the earliest opportunity. As I said earlier, it was part of the spam-can checklists I was trained under and that is going back close to 20 years, and it is there for a reason.

This certainly affects US pilots too. Here just one NTSB report with two fatalities:

https://www.aopa.org/asf//ntsb/narra...20050815X01247

This is also thought as part of the emergency checklist at least by my flight instructor and AOPA points it out too:

https://www.aopa.org/news-and-media/...-magneto-check

So not just a problem on the other side of the world.... .

Oliver

N941WR 10-10-2017 07:56 PM

Quote:

Originally Posted by Toobuilder (Post 1210014)
Please define an "automotive ignition" so that we have context. Are you discussing something from the 1960's or today? In the 60's you had a true stand alone system: Distributor, amplifier, coil... Today, with the ECU handling many functions, receiving signals from many sensors, its hard to segregate an "ignition system". You can certainly buy aftermarket coils and fat spark plug wires just like in the old days, but a "system"? Please define.

Current ODBII ignitions is what I'm talking about Mike.

Quote:

Originally Posted by Toobuilder (Post 1210014)
Please cite actual failure rates "caused" by the use of "Multi component systems". Not what "could" happen, but what actual experience shows "does" happen.

You can use the search function as well as I can.

Quote:

Originally Posted by Toobuilder (Post 1210014)
Compare that to the engineering challenge of cramming all that stuff into one box to satisfy a marketing niche and see where that gets you? Would you like to compare the history of "magnet misalignment " with Ross' product line? How about "lost timing events"?

Show me one failure that has resulted from "Cramming all that stuff into one box" when properly installed.

Quote:

Originally Posted by Toobuilder (Post 1210014)
I'll grant P-mag the benefit of the doubt that their issues are largely resolved (with frequent, repetitive inspections), but we all know that that has been a long, uphill battle - a battle LARGELY the result of the marketing decision to package it all together - But there is no way you can pound the drum that a "distributed" system is inherently less reliable. No way. To do so flies in the face of logic and absolutely overwhelming evidence to the contrary.

More connectors mean more places for vibration to work on.

Yes, the P-mags had some teething problems, most, if not all, of which are behind us. With thousands in use around the world, they are a proven ignition.

Quote:

Originally Posted by Toobuilder (Post 1210014)
It's time to put that bogey man to rest.

I agree!

N941WR 10-10-2017 08:05 PM

Quote:

Originally Posted by KRviator (Post 1210050)
No problems, Google "Magneto losing timing lycoming" and it is the 2nd from the bottom. ...

Last year I spoke with an FAA representative regarding certifying new ignitions.

I asked the gentleman if it would be possible to certify a traditional magneto today. His response was that there is no way to certify a magneto to today's reliability standards.

rv6ejguy 10-10-2017 09:35 PM

Quote:

Originally Posted by N941WR (Post 1210135)

Yes, the P-mags had some teething problems, most, if not all, of which are behind us. With thousands in use around the world, they are a proven ignition.


Yet, are the only ignition systems for aircraft out there with a 100 hour manufacturer recommended inspection interval. Doesn't seem to be a lot of confidence in what they've done. No change in the last 5 years as far as I'm aware. Why haven't they extended the inspection interval if they are so reliable? Not even close to a standard mag.

Captain Avgas 10-10-2017 10:08 PM

Quote:

Originally Posted by KRviator (Post 1210050)
As you can see, PMags are not alone in the lost-timing issue and I dislike the fact that at least two qualified pilots do not understand basic magneto operation enough to understand they too suffer from timing issues - and they can be a relatively common occurrence too - that can affect engine operation, instead trying to point the finger at PMag as being the only possible culprit in this regard.

The specific cases you have raised are typically magneto timing "adjustment problems" of 4-5 degrees. Of course everyone knows that Magneto timing can drift with component wear. That's why we check magneto timing at every annual and recondition them (hopefully) at 500 hours. But the 500-hour major maintenance is frequently neglected, and it's not unusual to see an engine reach TBO without the mags ever having been removed. The fact that mags can continue to function in the face of such neglect is a testament to their inherent reliability.

What we're talking about with PMAGs is something completely different. We're talking about a condition where the timing can advance suddenly and without any warning to such an extreme degree that it causes the engine to quit (or suffer damage).

We need to see this issue in perspective. I'm guessing that there might be at least 400,000 conventional magnetos in service today in GA just in the United States. And yet engine failure caused by a properly maintained magneto suddenly (and without any warning) becoming wildly advanced is virtually unheard of.

Now compare that to the PMAG of which there may be no more than a few thousand in service and yet with a well known history of incidents related directly to extreme timing loss.

Maybe the PMAG is now beyond its loss-of-timing issues. I certainly hope so. I see that many PMAG owners claim that V40 has solved the problem. But I've heard that claim before many times over the last 10 years. It also puzzles me as to why, if V40 is the ultimate solution to the timing problem, it is not a mandatory revision. I'm not sure what that says.

Toobuilder 10-10-2017 10:23 PM

Quote:

Originally Posted by N941WR (Post 1210135)
?..Show me one failure that has resulted from "Cramming all that stuff into one box" when properly installed...

Seriously? Did you just in one fell swoop blame every documented P-mag failure on improper installation? This is the same product thar prides itself on "ease" of installation, right?

You're a smart guy. You have developed and brought to market your own product. Though we understand your product owes its very existence to the shortcomings of the P-mag ignition, I'm not about to believe that you actually think the engineering required to accurately and reliably time a spark event is difficult. Hall effect sensors have been around a very long time. They are proven to be stone axe reliable - and hanging them on the crank and block/case has been used reliably for millions and millions of hours in rain, dirt, chemicals, heat and vibration without fail. So why then did P-mag have such issues with their own application when the rest of the motorsports world does not? It's because they took the "hard way" to force a non optimal engineering solution in exchange for favor in the market as an "easy to install" option. To their credit, many have bought in to this concept (including me) and their outstanding (in my experience) customer service has kept them around long enough to gain market share. Good for them, but that's of little consequence to those who have not realized the dream of trouble free ignition performance.


Quote:

More connectors mean more places for vibration to work on.
Ok, but Ice Cream has no bones

Both are meaningless statements.

The real answer is a connector either meets requirements of the operating environment, or it does not. And it is abundantly clear that the weatherproof, locking, strain relieved connectors common in the current automotive world are more than up to the the task. Billions of hours of use illustrate this in spades. You can not invent a problem that has already been solved. Try again.

...Besides, do you really want to bring up connectors in light of the cheeseball stuff P-mag uses?

Canadian_JOY 10-10-2017 10:45 PM

Quote:

Originally Posted by Toobuilder (Post 1210176)
...Besides, do you really want to bring up connectors in light of the cheeseball stuff P-mag uses?

This one point is what kept me on the fence for a long time, wanting a P-Mag for its advances over a Slick, and not wanting a P-Mag because the designers made a terrible choice in electrical connectors. Eventually the desire to save fuel won out.

Had Ross's CPI not had such an ugly green control box I likely would have gone with CPI as my ignition of choice, but there was no way I was going to have a green monster in my cockpit! :p

When it comes time for our impulse-coupled Slick to be replaced, Ross's CPI-2 might well get the nod. I've got a spot where I can mount the controller on a mechanism which would allow it to be stowed most of the time and swung out into view only those times when its needed. And I've got an essential bus with its own battery so who knows when a CPI might make its way into our airplane.

KRviator 10-10-2017 11:40 PM

Quote:

Originally Posted by Captain Avgas (Post 1210174)
The specific cases you have raised are typically magneto timing "adjustment problems" of 4-5 degrees.

Most true, but certainly not all, and certainly not 'only 4-5*'. 1 in July 2013, 1 in September 2013, two in November 2013, with engine failures. Several close by in 2014 losing timing 'within a few hours of flight' - not just over the course of their annual or 500-hourly inspections...

Quote:

What we're talking about with PMAGs is something completely different. We're talking about a condition where the timing can advance suddenly and without any warning to such an extreme degree that it causes the engine to quit (or suffer damage).
See above. EFATO due timing changes can, and has been repeatedly caused by timing drift of magnetos.

Quote:

We need to see this issue in perspective. I'm guessing that there might be at least 400,000 conventional magnetos in service today in GA just in the United States. And yet engine failure caused by a properly maintained magneto suddenly (and without any warning) becoming wildly advanced is virtually unheard of.
So why are they being reported in Australia, but it is 'virtually unheard of' in the US? Much as CAsA and ASA would like to think so, aviation down here is not that different to anywhere else.

Quote:

Now compare that to the PMAG of which there may be no more than a few thousand in service and yet with a well known history of incidents related directly to extreme timing loss.

Maybe the PMAG is now beyond its loss-of-timing issues. I certainly hope so. I see that many PMAG owners claim that V40 has solved the problem. But I've heard that claim before many times over the last 10 years. It also puzzles me as to why, if V40 is the ultimate solution to the timing problem, it is not a mandatory revision. I'm not sure what that says.
How many instances of timing loss occured after V40? That is the question and the answer is sadly lacking data. Emagair may know for sure, but AIUI, there have not been any engine failures relating to timing divergence since V40 was released. As to why it is not mandatory? Who''s to say?


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