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E mag P mag reliability

Robb

Well Known Member
My 7 has this set up currently. My other planes have always used magnetos for the obvious reasons. My plane has 300 hrs on a new engine and ignition. I have followed the manual during the annuals and have had zero problems. I was just posting the question to see if any other guys have had any serious issues with them. I do see some guys running dual p mags and I may change one of mine to have more safety and redundancy.



Dues paid
 
pmags @ 125 hr

Robb,
Mydual pmags have been flawless. There are many others with more hrs than me. But I have noted that my carb 0320 can get a couple of cylinders LOP without protest while taking data. Also, my MP / RPM / %power do not agree with LYC charts. I get 2500 with Catto 2 blade at lower MP than the charts. Could be the prop but Catto recommended for cruise because RV3 takes off short anyway.
 
Let's see - right now, I've got:

RV-3 - Dual P-Mags - 650 TT, P-Mags went in for four ware upgrade and checkup at about 500 hours - all fine. Had two corroded plug wires that were causing a misfire - replaced them.

RV-8 - Dual P-Mags - 1850 TT, P-Mags went on about 1400 hours, so 450 on them. Had a "fail-to-start" (failed self-test on power-up. Engine started and ran on one P-Mag fine, but caught the problem in the Mag check)on one unit very early on. It was a known issue that they adjusted for, and back on the airplane in a couple of days. Just had them checked up, no issues found, running great!

Dream Tundra - Dual P-Mags - 130 hours TT- No Issues.

P-Mags CAN fail, just like a Mag, or any other EI. EVen duel failures can occur, just like in other systems. I have found reliability to be statistically better (with a very small sample size) as Slick Mags.

Paul
 
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The early P-mags had some major issues with both hardware and software.

They are now stable product, at least as stable as traditional mags.

However, it is recommended they be removed every year and inspected. You want to check the gear to make sure it is not gauling (There were some non-certified gears sold which have caused issues.)

Make sure your P-mags are on version 40 and you are good to go.

(I have almost 800 hours behind them and would never consider going to traditional mags!)
 
1400 hours on my dual 113-series Pmags installed in 2006. The first 200+ hours were pretty painful, numerous issues, but Brad and company got 'em straightened out and they've been trouble free for the last 1200 hours. Just sent them in last month for the V40 upgrades and general checkup, all is well...
 
500 hrs on dual PMags, no problems. Installed and maintained per factory instructions with no maintenance or reliability issues to date.

I'd do the exact same installation again.
 
Thanks for the info I will send them in at 500 hrs to have checked out. I think I will change the one e mag to a p just for safety
 
260 hrs on 1 mag and 1 Pmag. Sent Pmag in for latest firmware update and flat fee checkup. No problems found. Converted the second mag to another new Pmag recently. About 10hrs so far on the dual Pmag setup with no problems found.

Also added the EI Commander to the system to keep an eye on the dual Pmags.

Something new for me is I have my max advance limited to 25.2? so I am only using them for better starts, smoother idle/running and the benefits of car plugs over massive airplane plugs.
 
One plane, two Pmags. 5, 6 years with PMags, 630 and 530 hours. One had the case bolt failure this last summer. Repaired no charge. A residual intermittent issue remained in the same unit. Board replaced for a discounted fee. Seems to be working well now.

Currently, I'm troubleshooting a problem that's pointing to the second Pmag unit. One more test flight. If the problem still remains, second Pmag is going back in for further evaluation.

Update 9/16 - second Pmag is working as intended.

Slicks I had for years before never failed. But they weren't EI either.
 
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New setup

Glad to hear all the responses.
I just installed a dual Pmag set up in hangarmates RV-6, 0-360.
All according to Emag install manual.
I did get Tom at TSFlightlines to make a really nice MP line with a double tee to serve the Pmags MP lines. Works well.
Also used two pull type breakers and a normal key switch.
No problems. But I did follow all Emags tips/advise and testing, etc.
Worked as advertised.
First test flight last saturday, starts, idles and runs better.
Thanks to everyone that went before me for all the R&D.
 
We bought our RV7 with 125 hours on a fresh IO-360 and 1 Series-113 E-mag and 1 Series 113 P-mag. Per Brad's guidance, we sent them both back during the annual and had them upgraded to both be Series 114 P-Mags. They have worked flawlessly for the last 150 hours. On the last annual (April 17) we switched to automotive spark plugs (also per Brad's advice) and have seen a marked improvement in hot starts.

Now, that being said, I just talked to a hangar neighbor that said he had the electronics fail in one of his, causing the engine to run rough on that mag. It was attributed to too much heat in the circuit board, so he is increasing the cooling to his mags. I think we are going to do the same thing to ours as a preventative measure.

Overall, we are very happy with them.
 
600 +/- hours on P114L's. No issues except CHT's hotter than with mags; when I pull them this week for the inspection and software upgrade while the plane is down for other maintenance, I'll retard them about 2 degrees and see if this doesn't bring me back below 425*F in extended full power climbs, having addressed everything else that's traditionally looked at.

Wouldn't change a thing otherwise. Very happy customer. Hope to put them on an IO-540 in a couple years.
 
100+ hrs on one P-Mag (114, lastest FW) on my -7A and one Slick (non-impulse). CHTs were difficult to manage in climb until I installed the gear fairings. While waiting to fit that in, I retarded the time, which helped with CHTs but hot starts were more difficult and it didn't want to shut down when mixture was pulled to ICO.

Since moving the timing back to standard, all starts are easy and shutdown is much improved. CHTs are easy to manage as long as I don't lean too quickly in the climb. If I maintain 1200-1235 EGT, it's all good.

I'm on the fence as to going dual P-Mag or installing a different EI on the left side. Cold air sump will likely come first for the extra 7 HP.
 
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One small anecdote to add here... Our "project" aircraft has one Slick impulse-coupled mag and one Series 114 P-Mag. On the first engine start I was impressed with how easily the engine started and, after all the oil etc was burned off it purred very nicely indeed.

Then I did a mag check and discovered the Slick wasn't firing at all! So... chalk up one first engine start to the ease of properly setting P-Mag timing. (And I've added a little crow soup to my diet after discovering I had timed the Slick to fire on the exhaust stroke...DOH!).
 
This is a timely thread for me since I am considering installing at least one P-Mag during my CI at the end of next month. I have 400 hrs TTSN on my O-360, and I am not sure which mag to replace: I'm leaning towards the impulse / LH mag since it's slightly more complicated, it seems to be developing a larger RPM drop (although well within spec,) and a coupling failure could be a bit destructive.

Anyway, I'm still trying to justify switching to EI, and if so, one or both mags. It makes perfect sense if the mags are going to require expensive work in the next year or two. I'm unclear about the gear differences, and whether or not I need to buy need ones for each mag, or can reuse one or both. This is a certified Lycoming O-360, btw. Has anyone seen or produced a tutorial / pictorial / video on the process? That would be very helpful - I'm not even sure if I'm asking the right questions, or leaving anything out...
 
I'm unclear about the gear differences, and whether or not I need to buy need ones for each mag, or can reuse one or both. This is a certified Lycoming O-360, btw. Has anyone seen or produced a tutorial / pictorial / video on the process? That would be very helpful - I'm not even sure if I'm asking the right questions, or leaving anything out...

You can reuse the non impulse coupler gear (direct drive) but you cannot use the impulse coupler gear. They are made differently and the later won't fit the shaft of the Pmag.

If you purchase a used one, be aware that there was some non-certified versions of these gears sold a few years ago that most had trouble with in a few hundred hours. Trust the source you get them from!

The Pmag manual gives a few hints on how to remove/install the gear. Pretty straight forward. You have to hold the gear in some manner that does not damage it at all. Remove the cotter key and nut and use a small puller to get the gear off the shaft. Sometimes they will come right off and others they need a little help.

Reverse the process and have fun with that cotter pin!

Note: Do not hammer on the shaft, gear or nut. Do not use bare channel locks on the gear to hold it! When installing on the Pmag do not put any force what so ever on the shaft in the axial direction!
 
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You can reuse the non impulse coupler gear (direct drive) but you cannot use the impulse coupler gear. They are made differently and the later won't fit the shaft of the Pmag.

If you purchase a used one, be aware that there was some non-certified versions of these gears sold a few years ago that most had trouble with in a few hundred hours. Trust the source you get them from!

The Pmag manual gives a few hints on how to remove/install the gear. Pretty straight forward. You have to hold the gear in some manner that does not damage it at all. Remove the cotter key and nut and use a small puller to get the gear off the shaft. Sometimes they will come right off and others they need a little help.

Reverse the process and have fun with that cotter pin!

Note: Do not hammer on the shaft, gear or nut. Do not use bare channel locks on the gear to hold it! When installing on the Pmag do not put any force what so ever on the shaft in the axial direction!

Also worth mentioning that if you replace an impulse mag with a pmag, you need to install shorter studs into the engine case, pmag doesn't use the one inch spacer like an impulse mag. Another thing to note is where your RPM sensor is coming from, if you take off the mag with the RPM sensor you will either need to move that sensor to the other mag, or wire up the pmag RPM sensor wire. (All of this is covered in the install manual)

Last month I installed two PMAGs in place of two impulse coupled slick mags, so I installed shorter studs at both locations and took the RPM sensor wire to my G3X. No issues, overall about an 8 hour job, all is good. I also installed two new circuit breakers, just above my key switch and am using the same (L/R/Both/Start) key switch as with my magnetos. Definitely runs hotter, I used EICAD to retard the advance shift by 2.8 degrees which helped but #4 is still warmer than I'd like at a 75% power cruise so I may knock the shift back a bit more.

And yes, enjoy the cotter pin!
 
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600 +/- hours on P114L's. No issues except CHT's hotter than with mags; when I pull them this week for the inspection and software upgrade while the plane is down for other maintenance, I'll retard them about 2 degrees and see if this doesn't bring me back below 425*F in extended full power climbs, having addressed everything else that's traditionally looked at.

Wouldn't change a thing otherwise. Very happy customer. Hope to put them on an IO-540 in a couple years.

Something to look into; I see two posts here about high CHTs in the climb with with (because of) the PMAGs. As I understand, in a climb, high power low RPM, the PMAGs are firing at (or near) 25 BTDC, so the temperatures would be no different in this phase of flight than with standard magnetos. Isn't it in cruise, when running higher RPM and lower manifold pressure that the spark adavances further BTDC, and gets hotter?

That has been my experience recently, I watched this on my last flight (Friday) I climbed 120 KIAS to 8500' DA , full power, full Rich, with hottest temp say around 375, as I level off, reduce power and lean for cruise, 65% power I can maintain those temps but bump up to 75% power and the hottest temp creeps up in the 390's - 400. (Was 380's with standard mags) Nothing scientific here, and it could be the leaning but definitely seems the temps rise as the firing advances in cruise.
 
Definitely runs hotter, I used EICAD to retard the advance shift by 2.8 degrees which helped but #4 is still warmer than I'd like at a 75% power cruise so I may knock the shift back a bit more.

As I understand, in a climb, high power low RPM, the PMAGs are firing at (or near) 25 BTDC, so the temperatures would be no different in this phase of flight than with standard magnetos. Isn't it in cruise, when running higher RPM and lower manifold pressure that the spark adavances further BTDC, and gets hotter?

Check out Nigel's article in Kitplanes. His data suggest that there is no advantage to any more advance than the typical Lycoming 25° while running ROP. More CHT heat with no performance increase were his findings.

I found that the default B curve bottom at high RPM/MP was around 32.2 and 35-36.4 around 25".

The default B curve shift is +4.2°. If you lowered that by 2.8° or set it at +2.8°, you are likely seeing ~29.4° at high RPM/MP and around 32.2-33.6° at 25".

If you set it to -2.8° (starting at 0) then you are likely seeing 25.2° at high RPM/MP and around 32.2° at 25".

My findings on the default B curve:
2ibhi1c.png


Don Stiver found these numbers for the default A curve:
30ix852.jpg

1. Line two of the data chart notes should read ",,,finally settle at 28..." not 35 as it is written.
 
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Check out Nigel's article in Kitplanes. His data suggest that there is no advantage to any more advance than the typical Lycoming 25° while running ROP. More CHT heat with no performance increase were his findings.

Careful interpreting Nigel's article. He mentioned that he has high compression pistons in his Lycoming.

Since Lycoming recommends 25* BTDC for an 8.5:1 compression engine, with high compression pistons, the best timing should be lower than 25.

The P-mags have two timing "curves" (I prefer to call them "configurations"). The A and B configurations. The A config starts at 26.6* BTDC and the B config starts 4.2 degrees higher.

You do not want to run your Lycoming on the "B" (Jumper out) configuration.

Some testing by myself and a few others indicates that for an 8.5:1 compression engine, it is best to configure the P-mags with a negative 1.4 degree offset and a 1.4 degree reduction in max advance. This will bring the high power, takeoff timing down to 25.2* BTDC.

The P-mags are then timed at TDC, as described in the manual.

This configuration can be accomplished in one of two ways, either by connecting them, one at a time, to the Emag EICAD program or via the EICommander.

My personal experience indicates a slight increase in speed and a ~15* reduction in CHT's.
 
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Check out Nigel's article in Kitplanes. His data suggest that there is no advantage to any more advance than the typical Lycoming 25? while running ROP. More CHT heat with no performance increase were his findings.

I found that the default B curve bottom at high RPM/MP was around 32.2 and 35-36.4 around 25".

The default B curve shift is +4.2?. If you lowered that by 2.8? or set it at +2.8?, you are likely seeing ~29.4? at high RPM/MP and around 32.2-33.6? at 25".

If you set it to -2.8? (starting at 0) then you are likely seeing 25.2? at high RPM/MP and around 32.2? at 25".

My findings on the default B curve:
http://i39.tinypic.com/2ibhi1c.png

Don Stiver found these numbers for the default A curve:
http://i39.tinypic.com/30ix852.jpg
1. Line two of the data chart notes should read ",,,finally settle at 28..." not 35 as it is written.

Yes, good point. I did go -2.8 from "0" (which actually shows up as -12 something when you re-connect to EICAD due to some glitch in the software...) That was a great article from Nigel but I was bummed at the conclusion of essentially no advantage unless running LOP.
 
The A config starts at 26.6* BTDC and the B config starts 4.2 degrees higher.

Don Stiver found using the EI Commander that the bottom of the default A curve was 28° in normal RPM ranges used in flight.

I found using EICAD and my DIY display that the bottom of the default B curve was 32.2° in normal RPM ranges used in flight.

Both curves bring in the advance rather quickly between 24-26".
 
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Yes, good point. I did go -2.8 from "0" (which actually shows up as -12 something when you re-connect to EICAD due to some glitch in the software...) That was a great article from Nigel but I was bummed at the conclusion of essentially no advantage unless running LOP.

Yes that glitch is there for everyone and it will concern you because it actually shows that much positive shift! It is not real however and the number stored in the Pmag is the correct number.

The no-advantage part is why I have my Pmags limited to 25.2° since I rarely run LOP due to my induction system variability. No more ignition advance induced CHT heat for me! Still worth it for the easy starts, smooth idle and running, car plug advantages.
 
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So correct me if I'm wrong; if I set the advance shift of the A configuration to -2.8 (from zero) doesn't that limit the max advance to 32.2 regardless of whether or not I changed the "max advance"? (I think I set max advance to 35 but figured its limiting factor was my change to the "advance shift")
 
So correct me if I'm wrong; if I set the advance shift of the A configuration to -2.8 (from zero) doesn't that limit the max advance to 32.2 regardless of whether or not I changed the "max advance"? (I think I set max advance to 35 but figured its limiting factor was my change to the "advance shift")

I found the top of the default B curve to be 40.6° so if you subtract the 4.2° (the default B curve shift) from that you get 36.4° and then subtract your 2.8° from that you get 33.6°. So I would say yes, your negative shift value is limiting the max advance to around 33.6°. Also be aware that you have to set your max advance limit to whatever you want -1.4°. This is another quirk in the P-mag. Example: If you set it to 25.2°, in reality the limit will be 26.6° so set it to 23.8° to limit it to 25.2°.

The reason for some of the confusion is the quirks in the Pmag and the Pmag documentation.

I would still set the max advance to what you want it to be (knowing it will be 1.4° more than what you enter) just to be sure it never goes above what you want (think MP sensor failure or something like that).
 
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So correct me if I'm wrong; if I set the advance shift of the A configuration to -2.8 (from zero) doesn't that limit the max advance to 32.2 regardless of whether or not I changed the "max advance"? (I think I set max advance to 35 but figured its limiting factor was my change to the "advance shift")


The MAP doesn't do anything until above 1800 RPM, regardless of the configuration, IIRC.

When you go to full power, down low, for takeoff, the A config will set the timing at 26.6*. (The B config doesn't really come in to play as no one with a Lycoming should be running it.)

When MAP drops off, the A config will go out to 32.2.

One of the problems, and I talked to Brad about this the other week, is they are not sure if the P-mag is actually advancing 1.4* past the max advance setting or if it is just reporting that it is advancing 1.4* past the max advance.

The P-mag has basically two settings, Advance Shift, and Max Advance.

The Max Advance is exactly that, the maximum limit to allow the P-mags to advance.

The Advance Shift is the degree shift from zero. If you set the P-mags at TDC, then the Advance Shift is 26.6 degrees.

Say you have an angle valve engine and want to have the P-mags work like a fixed timed mag. You can set the Max Advance to 19.6 and leave the Advance Shift at zero. It is my understanding that the P-mags will only advance to 19.6*. However, when I consult with customers, I recommend they enter a negative number in multiples of 1.4 to move the Advance Shift down to match the Max Advance, just in case there is an issue. There may not be an issue but it doesn't hurt to be cautious.
 
Two notes...

The OP asked about reliability. Let's hope the users are checking internal power generation at every runup. A 114 series normally transitions to internal power by some mid-teens RPM, but there is no inflight indication if it doesn't; it just runs on external power. Not much reason to run P-mags if the generators don't work, and I have found one failed. BTW, runup checks mean panel switches to kill main bus power to each P-mag, not breakers.

Hopefully EI Commander will soon introduce a one-switch feature so users can select an optimum ignition table for ROP climb (meaning zero advance from the usual fixed timing), then transition to a MP-advanced ignition table for LOP cruise. Full rich while advancing the timing with altitude (the current standard) is dumb as dirt compared to fixed timing and progressive leaning to maintain best power.
 
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Breakers

"runup checks mean panel switches to kill main bus power to each P-mag, not breakers."

Dan,
Why are breakers not correct?
Or are Pullable or "switchable" ok but standard non pullable breakers what you are refering to?

From the manual:
?5? connects to your main 12 volt aircraft buss, routed through a dedicated
3 amp switchable circuit breaker (not provided) using 18 gauge wire. If
using a fuse (instead of breaker), use a slow-blow type. The switch
function is needed to test the (P model) internal alternator during ground
run up ? see Operating Notes."

Thanks as always Dan for your input.
 
Hopefully EI Commander will soon introduce a one-switch feature so users can select an optimum ignition table for ROP climb (meaning zero advance), then transition to a MP-advanced ignition table for LOP cruise. Full rich while advancing the timing with altitude (the current standard) is dumb as dirt compared to fixed timing and progressive leaning to maintain best power.

Unfortunately the serial interface on the Pmag is not that smart....

I would love to see EMagAir open source the hardware/firmware inside the Pmag. If they did that there are some geeky people in this hobby that could make it happen!
 
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Back to the OP's question about reliability...

A friend of mine is running dual P-mags on his O-360 powered RV-7A. He had one of them fail shortly after getting the test hours flown off this summer. The Emag guys gave him good support and customer service, but he missed most of Oshkosh this year waiting for a replacement so he could get back in the air?kind of disappointing to miss most of the show with his new airplane.

I love the concept of the Pmag product for the built-in power generation and the ease of installation compared to other electronic ignition systems which have multiple pieces to mount. However, based on watching the forums over the years and firsthand knowledge of multiple friends who have had issues with them, I don?t think the overall reliability is very good. I?d like to think the latest firmware addresses all the issues, but one fundamental challenge to the Pmag design is heat. All avionics companies and engine/airframe OEMs go to great lengths to keep electronics as cool as possible because it?s a proven fact that excessive heat shortens the life of electronic equipment. Many ?black boxes? have integral cooling fans, forced air cooling from the environmental control system, or even liquid cooling in some cases. If you look at the installation manuals for Lightspeed, Electroair, SDS, EFII, etc, they all want you to install the electronics on the cool side of the firewall. See a pattern here? Pmags on the other hand are not only living on the hot side of the firewall, they are actually bolted directly to that big heat generator called an engine. And they are behind the cooling baffles?.you can install blast tubes, but that doesn?t help after engine shutdown when the highest temps are going to occur during heat soak (even if you open the oil door). The electronics in those units are going to have a shorter life because of the heat exposure, plain and simple. The only question is whether their MTBF (mean time between failure) is acceptable for the needs of the customer. For many RV owners, having ignition system failure every 500 hours may be acceptable whereas any commercial or military application is going to want to see more like 10,000 hrs.

For my part, I don?t ever want to have to deal with ignition system problems. This includes having to remove components and send them back for overhaul, inspection, or periodic upgrades. I want my airplane ignition to be like my Toyota vehicles?.the same ignition system should still be running flawlessly a few decades from now when it goes to the junkyard.

To that end I?m leaning toward the SDS CPI system for my -14A. I think the coil packs are probably more robust than those from Lightspeed, plus SDS is a bit less expensive and offers better customer service. The crank triggered timing pickups have no gears, bearings, or moving parts to wear or drift. The electronics will be either in or behind the panel, living a nice cool happy life where they should last indefinitely. It?s more work to install initially than Pmags, but a lot less inconvenient than having problems later on.

The biggest concern with electronic ignition systems (other than Pmags) is that you need to make sure you have a reliable electrical system with some redundancy. Dual batteries (the second one can be small), dual alternators, or both can be installed using one of several architectures that have been well-vetted in many aircraft (see Aeroelectric Connection for some good examples). Based on what I?ve seen for alternator reliability I plan to use a 60A B&C main alternator and the B&C SD-8 backup alternator. Fifteen years ago this might have been overkill when most panels were still steam gauges, but nowadays even most VFR homebuilts are all glass. So having some electrical system redundancy is a good idea even if you?re running magnetos, but it can also enable you to safely run dual electronic ignition that doesn?t generate its own power like the Pmag does.
 
FWIW: I have dual P-Mag (114, v40) on my Lycoming O360- A4M. After more than 400hrs, and counting, they have been flawless.

As Dan recommends, I check the power before every flight to make sure the generators are working properly. I have a CB and push button (NC) switch for each mag so checking them is quick and simple.

:cool:
 
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I am genuinely curious...Have there been any confirmed cases of heat induced failure of a Pmag of the latest design?

My original one has lived happy in my cowl for over 260hrs here in East TN and has never triggered the 200° tattle tail sticker on it. Nothing but the recommended blast tube on the neck of the unit. During this time it has traveled to Osh 6 times and endured some tortuous taxi conditions while there pushing the oil temp over 230° on a couple occasions.
 
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Personally I decided to sell my P-Mag once I saw how rinky-dink the terminal strip connector they use is.

- Matt
 
Personally I decided to sell my P-Mag once I saw how rinky-dink the terminal strip connector they use is.

- Matt

I wish it had a good old D-shell on it as well but so far, my concerns with this connector have never materialized. I do use ferrules on my wires, heatshrink and properly secure them using the adel clamp provided. I have never found one loose when checking them. I think the key is the ferrules... I would not wire a Pmag without them.
 
P-mag dumb question time:

If you have the mags set 1degree after TDC, what would the actual timing be when you take off at full power? 25 or 27 assuming 26 if set at TDC.

:confused:
 
Dan, Why are breakers not correct?
Or are Pullable or "switchable" ok but standard non pullable breakers what you are refering to?
From the manual:
The switch function is needed to test the (P model) internal alternator during ground run up – see Operating Notes.
"

A combined switch-breaker would be fine. FWIW, the wiring diagram in the P-mag manual shows the test switch in addition to the circuit protection device, with the note "can be combined". A pullable breaker could serve, but I don't think they are intended to be used repeatedly as a switch, i.e. the ON-OFF-ON at every runup. Obviously a plain breaker or a fuse needs a separate switch.

Let's consider human factors. If we hide test devices in a row of circuit breakers, we reduce the likelihood that runup checks will be done, in particular with subsequent owners and guest pilots. A pair of switches marked "P-Mag Test" or "P-mag Bus Power" is a lot more obvious. There is no actual inflight reliability unless you know the internal generators work.
 
P-mag dumb question time:

If you have the mags set 1degree after TDC, what would the actual timing be when you take off at full power? 25 or 27 assuming 26 if set at TDC.

:confused:

A curve or B curve? If the B curve, did you modify any settings?
 
Let's consider human factors. If we hide test devices in a row of circuit breakers, we reduce the likelihood that runup checks will be done, in particular with subsequent owners and guest pilots. A pair of switches marked "P-Mag Test" or "P-mag Bus Power" is a lot more obvious. There is no actual inflight reliability unless you know the internal generators work.
Exactly why my mag power test switches are on the opposite side of the circuit breakers, next to the ACS mag/starter switch and labeled. All magneto testing done in the same general panel area. You can see them in this photo.

Completed%20panel%20on%20ground.jpg


:cool:
 
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Since this thread jumped the shark and went into "timing", I'll throw my two cents...

My P-mags have been reliable. Happy with the failure rate, happy with the company.

But - The other job of an ignition system is to provide the correct timing matched to conditions. Magnetos do a poor job of this and as we continue to learn, Pmags have their own issues too. As long as we are forced to play games with mechanically "spoofing" the locked down curve that the Pmags have, I'm not going to consider them as an option for my airplane.

The ignition companies need to learn that one size does not fit all. Fortunately, SDS listens.
 
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My original one has lived happy in my cowl for over 260hrs here in East TN and has never triggered the 200° tattle tail sticker on it. Nothing but the recommended blast tube on the neck of the unit.

In which case you should probably throw the blast tubes in the trash, as they're not doing much to improve reliability. As noted repeatedly in the past, the highest temperatures are after shutdown, when there is no blast tube airflow.
 
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Info of ferrules? link/PN etc...
Brantel, I have no experiance using ferrules in low voltage applications.
Clearly the ferrule would be right at the bend on the control wire. Are there any concerns of a transition point load etc like soldering does?

Also, I did not disect the connection but it appeared from looking like the set screw moved a plate that compressed the control wire not just the set screw pushing against the wire like some high voltage wiring. I thought the connection was fine considering it had the adel clamp there. Other than I don't really like how the wires are exposed to engine oil etc. So I second a D-shell type connection idea.

I have tons of experience with these types of connectors in the industrial automation world. I have seen them loosen over time when you don't use a ferrule on stranded wire. They can even cut the strands due to how the plate edge gets pushed at an angle into them. Using a ferrule goes against Bob Knuckles' advice but I know they work with these connectors so I use them on Pmags.

The ferrules I use have an insulated barrel on the end of them to keep the wire from being able to bend right at the crimp. I also heatshrink those for extra safety. I can't see this having any more risk of breaking the wire than any other means of connecting them. Always leave some slack between the adel clamp and the connector and observe minimum bend radius' and it will be fine.

I use these kind of ferrules:

MOc0787l.jpg


I got mine from McMaster Carr:
https://www.mcmaster.com/#ferrule-terminals/=19cs0qc

I have a bazillion of the various sizes.

I use this tool to crimp them:

https://www.mcmaster.com/#ferrule-crimpers/=19cs170

There are cheaper options out there. My work bought these for me several jobs ago.

They make crimps that look like this:

etX35rjm.jpg


There is no way they will come off if crimped properly and the serrations help prevent the ferrule from pulling out of the connector.
 
In which case you should probably throw the blast tubes in the trash, as they're not doing much to improve reliability. As noted repeatedly in the past, the highest temperatures are after shutdown, when there is no blast tube airflow.

Sometimes you just follow the directions that way you can say you did if you ever have any issues :p
 
P-mag dumb question time:

If you have the mags set 1degree after TDC, what would the actual timing be when you take off at full power? 25 or 27 assuming 26 if set at TDC.

:confused:


"A" curve. :cool:

I posted an image in post 22 here where Don Stiver logged the advance numbers being reported by his EI Commander while running the equivalent of the A curve.

He found the minimum advance at high power to be 28°. So if you mechanically time your Pmag to 1° ATDC the effective timing would be 27° at the same power levels if Don's numbers are accurate and I believe they are based on my own testing.
 
Exactly why my mag power test switches are on the opposite side of the circuit breakers, next to the ACS mag/starter switch and labeled. All magneto testing done in the same general panel area. You can see them in this photo.
:cool:

I went a step further - the P-mags are controlled by three-position switches with an inline fuse for circuit protection. Down = no power, P-lead grounded, Middle=no power, P-lead ungrounded, Up = power, P-lead ungrounded. This also takes up less panel space than a key switch plus two circuit breaker switches.

Bonus is that it makes it impossible to accidently go into timing mode. Doing so requires a jumper behind the panel to be installed, and putting that jumper in place makes starting the engine impossible since the P-leads are grounded.
 
Since this thread jumped the shark and went into "timing", I'll throw my two cents...

...


The ignition companies need to learn that one size does not fit all. Fortunately, SDS listens.

Can we have a P-mag discussion without it turning into an SDS ad? That is why I stopped commenting on comparison threads.

The P-mags are a very good an reliable ignition, simple as that.
 
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