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Information on P-mags

ALMARTON

Well Known Member
Folks,

Anyone could give me some information and data that help me to decide to use either

-Standard magnetos; or...
-Light Speed electronic ignition systems; or...
-PMag ignition systems;

What should be better (less fuel consumption or more horse power )

Are them all reliable and dependable ?

Any experiences or readings to help me decide? (I need more horse power wiht same or less fuel consumption but I want safe systems)
 
I run a Lightspeed on one side and P mag on the other. I like the safety of the built in alternator on at least one.
The down side is that my cyls. have been running hotter than with the Slick on one side. Advanced timing is to blame I suspect.
Plane sure starts well and runs strong ... with the hot sparks.
 
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Here is my experience over 425 hrs, I've had all 3 systems that you mentioned...

I started out with an LSE (direct crank sensor) and a slick mag at first flight, 3 years ago this week.

The slick mag was not new, but had been tested, inspected, and yellow tagged by a reputable shop. It failed after 14 hours and was replaced by a P-Mag. I also liked the self-powered aspect of the P-Mag and I require at least one ignition not reliant on ships power.

The LSE has NEVER had an issue of any kind, its been totally rock solid.

The P-Mag has failed 3 times requiring parts or replacement, each failure has unfortunately occurred hundreds of miles from home. Right now I plan to stick with the P-Mag. I have had no issues with temperatures and no timing anomalies.

Having at least one EI will significantly improve fuel economy, having two EIs provides little added benefit from a fuel economy or power perspective. I don't think it matters much whose EI you have, any of them will provide the benefit of easier starting, smooth low idle, better fuel economy, and slightly more power as compared to fixed-timing magnetos.
 
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In my opinion, any of the current EI's would be an improvement over traditional mags. Personally I like the formfactor of the P-mags. No additional coils or brain boxes to install. Pmags are more of a component replacement situation.

The earlier E-mags had some issues but I have not seen any problems posted here for a long time now. The newer Pmag 114 are the most recent version.

Slightly higher CHT and lower EGT can be expected with any EI system over mags.

Better fuel economy (in cruise configuration), easier starting, smoother idle, less ignition maintenance with EI.

Pmag factory support is top notch.

Bevan
 
What should be better (less fuel consumption or more horse power )

Are them all reliable and dependable ?

Any experiences or readings to help me decide? (I need more horse power wiht same or less fuel consumption but I want safe systems)

You are asking a series of questions that are difficult to answer without telling us how you want to use the machine. In my opinion all three options you list are well proven, safe and reliable as long as properly installed and maintained.

  • Only mags stand any chance of surviving a lightning strike. They are also easily repaired in remote locations (when you don't live in the US this can be a consideration).
  • The Lightspeed is redundant when installed on both sides, but relies on ship's power. Klaus has certified a version of it on the Cabri G2 helicopter (EASA) - supplemented by a mag on the other side. They need to be installed properly, locating coils in the wrong place and exposing the box to excessive vibration/heat has caused issues for some builders.
  • P-mags will run on their own, without ship's power and are fully redundant. They are self contained and easy to install.
  • EFII is a little cheaper than the others, but not redundant without the duel ECU option. Adding two ECUs and their electrical box significantly increases the complexity (and cost).

Performance and economy wise the electronic ignitions are the better option. They start more easily, produce more power and use less fuel. There is no free lunch - your engine may well get hotter due to the advance and need more cooling.

I don't think there has been a conclusive bake off of all of them, so no one can really tell you which system produces the most power. I really doubt there is a lot of difference between the electronic options.

On a four cylinder I'd buy duel P-Mags (and that is what I have been running for the last 500 hours). I like the ease of installation and redundancy. They have been bullet proof and the company support is outstanding if you need them.

If you really want performance, make sure you install a constant speed prop. That will make a lot more difference than a few extra HP from electronic ignition.
 
You are asking a series of questions that are difficult to answer without telling us how you want to use the machine. In my opinion all three options you list are well proven, safe and reliable as long as properly installed and maintained.

  • Only mags stand any chance of surviving a lightning strike. They are also easily repaired in remote locations (when you don't live in the US this can be a consideration).
  • The Lightspeed is redundant when installed on both sides, but relies on ship's power. Klaus has certified a version of it on the Cabri G2 helicopter (EASA) - supplemented by a mag on the other side. They need to be installed properly, locating coils in the wrong place and exposing the box to excessive vibration/heat has caused issues for some builders.
  • P-mags will run on their own, without ship's power and are fully redundant. They are self contained and easy to install.
  • EFII is a little cheaper than the others, but not redundant without the duel ECU option. Adding two ECUs and their electrical box significantly increases the complexity (and cost).

Performance and economy wise the electronic ignitions are the better option. They start more easily, produce more power and use less fuel. There is no free lunch - your engine may well get hotter due to the advance and need more cooling.

I don't think there has been a conclusive bake off of all of them, so no one can really tell you which system produces the most power. I really doubt there is a lot of difference between the electronic options.

On a four cylinder I'd buy duel P-Mags (and that is what I have been running for the last 500 hours). I like the ease of installation and redundancy. They have been bullet proof and the company support is outstanding if you need them.

If you really want performance, make sure you install a constant speed prop. That will make a lot more difference than a few extra HP from electronic ignition.

Very informative, thanks a LOT !
 
On my injected 180hp 10:1 360; I started with 2 Bendix mags, ran fine but not the best for starting when hot. Then I added an ElectroAir to the right and left the Bendix on the left. Huge difference in performance, smoother running and started hot or cold easy. Used this setup for many years, never a hiccup. Then I went to 2 P-mags (114) with an EI Commander. The engine ran even smoother with the L/R timing the same, started just as easy hot or cold, lost some performance, CHT's a bit higher... But I had nothing but problems with both P-mags over and over again. After months of screwing around with them, swapping parts myself, I finally got them stable. They've both been working fine since but you can bet I keep my eye on the EI Commander.
 
I run a Lightspeed on one side and P mag on the other. I like the safety of the built in alternator on at least one.
The down side is that my cyls. have been running hotter than with the Slick on one side. Advanced timing is to blame I suspect.
Plane sure starts well and runs strong ... with the hot sparks.

What is the standard timing for your engine and do you have the jumper installed in your P-mag?
 
Don't forget the Electroair. It is based on an inductive-discharge automotive system that is manufactured in the thousands per year. They also have a certified version. I prefer inductive-discharge systems for arcane technical reasons.

Having experienced an electronic ignition failure in flight (installation error), I would highly recommend a conventional mag as a back-up. Having two electronic systems does not provide the right redundancy... Certainly not two identical systems.

I also prefer electronic ignition systems where all of the electronics is on the cold side of the firewall. High temperature, temperature cycling and vibration reduce the reliability of electronic components.

One factor often ignored, but should not be, is the effect of ionizing radiation caused by cosmic rays or gamma ray bursts.... Which increase with altitude. I don't think any of the extant electronic ignitions are sensitive to these due to the fundamental design, but as we become more dependent on deep submicron devices and intolerant programming, it will become a factor.

In the computing industry, we normally detect errors and hault (e.g.blue screen). In the telecom and datacom industry, we just flag the error and keep on operating. This requires self-initializing devices with no hidden lock-up states.

Aerospace is a lot like telecom... High reliability, fault tolerant and field serviceable.

At least one EFIS vendor I know has a telecom pedigree.... Don't know about the ignition vendors.

... And that's why your backup should be a Magneto.
 
I have had a Tailwind, a Thorp and currently have 2 different Pitts all with dual LSE ignitions (both the Plasma II and III). Probably over 700 hours of flying between them, and never had any problem or issue, except that I could not get a tach signal from them, so went in each case to a separate hall effect type sensor. All types of flying, depending on the airplane of course. Ditto with prior comments on fuel economy, ease of starting, etc. My RV-4 will have dual EI. No mags, and I prefer no moving parts and prefer back up battery systems--so no Pmags. FWIW...
 
So why???

On my injected 180hp 10:1 360; I started with 2 Bendix mags, ran fine but not the best for starting when hot. Then I added an ElectroAir to the right and left the Bendix on the left. Huge difference in performance, smoother running and started hot or cold easy. Used this setup for many years, never a hiccup.........

Randy.......so why didn't you stick with Electroair? Anybody else have Electroair experiences to share? The only people i have spoke to about them(only a handful) had great reports on them!
 
Randy.......so why didn't you stick with Electroair? Anybody else have Electroair experiences to share? The only people i have spoke to about them(only a handful) had great reports on them!

Used one on my -8 about 12-13 years ago for a period of time and it worked as advertised. Bulky and lots of pieces then. No idea of the system config today.

Currently using dual P-mags. Have been happy with these for 2-3 years. IMO, the key to long life is keeping cooling air supplied.
 
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I have an 0-360 with CS prop and Electroair and one mag. Very happy with the ignition system. The engine starts better, runs smoother (all qualitative factors). I never measured performance change so can't really say, but I want to think I get some improved power/economy.

They have a mag adapter for timing that is very easy to install, much easier than a crank sensor. Everything except the timing sensor and the high tension coil is mounted inside the cockpit.

They recommend aircraft plugs, which I did, but if I ever have to change the plugs, I will go to automotive plugs. No cleaning and cheaper.

My only complaint is the wire harness (not ignition harness) that they provide. It uses commercial 100 degree C wire, which for heat and flammability concerns I replaced with aircraft wire. I have never heard of problems, but some of the wiring does go forward of the firewall to the coils and the timing adapter. This was my only complaint.

This system is a slightly modified version of a system from the auto racing community. Electroair has certified a version, and the only major change I know of is EMI hardening of the coil pack, and the use of aircraft wire in the harnesses.

On a previous airplane I had a Plasma II system. Dealing with Klaus was a pain and never really got resolution to several issues.
 
Randy.......so why didn't you stick with Electroair? Anybody else have Electroair experiences to share? The only people i have spoke to about them(only a handful) had great reports on them!

Ya know what Bob.... If I could go backwards I would have kept the ElectroAir. My engine ran cooler and had more performance then the two P-Mags. The only difference is it's a bit smoother now with the timing being equal L&R. Probably the best setup would have been dual ElectroAir's but I don't like the idea of a total loss. This was my first experience with P-Mags on my plane, I have friends that had problems with P-Mags, too. They have a very small Ford econo car coil that does not put out the power the ElectroAir coils put out. The ElectroAir NEVER gave me one problem, couldn't say that about the P-Mags. Took me more months the I care to remember to get them working. I like Brad and I think the company is honest, and they are trying their best but I wouldn't use P-Mags again. Unless you can compare different systems you don't know how one performs over another.

As for the Plasma's, I've never used one but I've worked on them. Again, I don't like the tiny coils, they fail and are very expensive from Klaus only. I've seen a few failed controllers.
 
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...the Electroair uses standard GM coils which can swapped out easily in the event of a failure.
 
Currently using dual P-mags. Have been happy with these for 2-3 years. IMO, the key to long life is keeping cooling air supplied.

Similar story here - dual 114-series P-mags, 360 hours, no issues. Each has a dedicated blast tube pointed directly at the cooling fins.
 
Here's my 2 cents

Background

I actually own a company that makes it's own electronic (and traditional) ignition systems. We have been doing this for 38 years. Our work is mainly automotive, but we also do some industrial and we have made certified systems for aviation engine manufacturers in the past (which we abandoned due to product liability concerns)

I own and operate a Pitts Special S1-S with a 0-360 B4A (Fixed / injected). I had about 300 hours on it with Bendix mags when i decided to go electronic.

After much research I decided to go for Pmags (one a time due to UK approval concerns). The reason was that I liked the "self contained" concept, the non Hall Effect trigger system and the build quality and documentation looked good.

My objective for the change was to improve mid range torque and hopefully cruise economy.

My purchase experience was painless, Everything fitted and worked straight from the box, although you do have to plan a little and be ready to deal with peripheral issues such as tach feeds and "secure" power supplies.

The comments below were on the "B" (spark advance / via manifold pressure) curve

My experience in use was that mid range torque did improve (my test was a standing start nil wind from numbers to numbers drag race on out main runway with GPS terminal speed reading. It consistently went from 122 mph to 138 mph over many tries)

CHT went from around 360 to 375 (I did try a little extra spark advance hoping for more top end power - just got heat)

In a 2250 rpm cruise I saw around a 6% improvement in fuel economy

I could reduce the tickover speed by about 200 rpm easily (I run about 470 now)

125 hours of hard acro into the mission they have always worked perfectly.

The down sides were (don't forget this is a bare bones lightweight Acro install)

I could not use the tach i had for 1 pmag and 1 bendix when I made the first change (signal issues)

CHT's went up a little (but still acceptable)

The P mag is sensitive to voltage drop when cranking. If the voltage it sees goes below about 9v it re boots and does not spark. In my case this was down to using a lithium battery a long way from the starter on the Pitts.

(I get around this by using a small battery for supplying the left pmag on startup only)

Bottom line - I'd never buy a new set of mags over electronic again.

If I had good traditional mags then I'd struggle to justify the pmag cost on performance criteria alone - but if you already need an overhaul I'd certainly go Pmag again.
 
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P-Mags ARE hall effect, it's on the inside not on the outside like crank triggers. That was one of the failures, the magnet came loose. (Since resolved)

I agree, I would never buy mags before buying electronic. Just the cost of the new mags doesn't make sense over a good EI. But if I was to choose the best EI that I've used or worked with I'd have to say it's the ElectroAir by far. Jeff Rose knew what he was doing and he designed a very reliable, powerful, quality EI for aviation.
 
P-Mags ARE hall effect, it's on the inside not on the outside like crank triggers. That was one of the failures, the magnet came loose. (Since resolved)

I agree, I would never buy mags before buying electronic. Just the cost of the new mags doesn't make sense over a good EI. But if I was to choose the best EI that I've used or worked with I'd have to say it's the ElectroAir by far. Jeff Rose knew what he was doing and he designed a very reliable, powerful, quality EI for aviation.

Jeff took an off the shelf Electromotive auto ignition and fabricated a mag timing housing to adapt it to our airplanes. Support for the older generation of Electroairs pretty much ended when Electromotive discontinued the product.

The current Electroair is the newest version of the Electromotive ignition, with no changes other than the stickers on the outside and a different product name in the manual. Even the wiring diagrams are identical in the manuals. Nothing wrong with that, but it isn't like someone is scratch building the thing specifically for our end use.
 
Here's my 2 cents

...
The comments below were on the "B" (spark advance / via manifold pressure) curve

My experience in use was that mid range torque did improve (my test was a standing start nil wind from numbers to numbers drag race on out main runway with GPS terminal speed reading. It consistently went from 122 mph to 138 mph over many tries)

CHT went from around 360 to 375 (I did try a little extra spark advance hoping for more top end power - just got heat)

In a 2250 rpm cruise I saw around a 6% improvement in fuel economy
...
With your engine, you should think twice about running the "B" curve (no jumper). That starts at 30* and most parallel valve engines should start their timing at 25*, which is the "A" curve (Jumper in).

The P mag is sensitive to voltage drop when cranking. If the voltage it sees goes below about 9v it re boots and does not spark. In my case this was down to using a lithium battery a long way from the starter on the Pitts.

(I get around this by using a small battery for supplying the left pmag on startup only)
...


You should see this thread for help with starting your plane when the battery runs down.
 
I was using a pair of these, they worked great. Direct plug in. Higher output.
http://www.summitracing.com/parts/msd-8224
Yes, but do they provide more power than the others?

I have to ask because once the fire is lit, does it really matter how it was lit?

It has been argued that there is no power difference between any of the electronic ignitions and a magneto, if they are all timed the same. Where electronic ignition shines is its ability to advance the timing, based on MAP, or more exactly, a reduction in MAP. This helps provide better efficiency.

The argument regarding which ignition is best is no different than the arguments about tip-up vs. slider, nosewheel vs. tailwheel, etc.
 
I started with one Slick mag and one p-mag. After the 2nd failure of the p-mag, I replaced it with a second Slick. No mag problems since. Before the RV-7, I flew about 5,000 hours behind regular mags with no failures.

I believe that reliability trumps slightly better performance.
 
I've had magneto failures, they are not totally reliable either.
Most mags have a 500 hour service interval, additional problems are found and repaired during this inspection.
Over time, electronic ignition is 'coming of age'. Reported failures are decreasing, and performs better. The service intervals are longer than mags too.
It's just a matter of time before electronic ignition is considered the standard, and mags are considered 'quaint'.
I only have one Electronic ignition, a Pmag. I like it so far...It replaced a failed mag that needed a $700 overhaul.
 
Yes, but do they provide more power than the others?

I have to ask because once the fire is lit, does it really matter how it was lit?

It has been argued that there is no power difference between any of the electronic ignitions and a magneto, if they are all timed the same. Where electronic ignition shines is its ability to advance the timing, based on MAP, or more exactly, a reduction in MAP. This helps provide better efficiency.

The argument regarding which ignition is best is no different than the arguments about tip-up vs. slider, nosewheel vs. tailwheel, etc.

How Does a High Performance Ignition Coil Help Performance?
A high performance ignition coil helps engine performance four important ways. First, the higher voltage allows for a larger spark plug gap, which results in a more robust initial flame kernal at the start of combustion. The result is a real-world engine torque increase. Second, having more voltage on tap means the voltage required to bridge the spark plug gap gets there faster, leaving less time for voltage diversion through the spark plug's inevitable carbon deposits. Third, the higher voltage potential creates a stronger "push" on the electrical stream to the plug, resulting in increased electrical current, i.e. more energy, more snap. Fourth, with more voltage available, there is more in reserve for non-standard situations.

There is no doubt that higher power ignitions produce more HP and torque. You don't see racing engines using stock ignitions. The coil on the P-Mag is wimpy and weak (stock Ford Focus) compared to an MSD street race coil. If you compare my ElectroAir to my P-Mag there would be very little, if any, timing difference. The plugs and wires pretty much exactly the same, so the only real difference is the much higher output of the coils on the ElectroAir (even the stock GM coils the ElectroAir came with). I can say for sure that one ElectroAir produced more performance and cooler CHT's the two P-Mags.
 
Sounds like in extreme lop operations, more spark energy may be useful. However, if higher output coils produce more power or better fuel economy, everyone would be using them.

The problem is that once you get to a critical voltage, the ignition leads will start arcing, leading to rough operation, so there is an upper limit. I see problems with CDI systems that misfire with old wiring or ungroomed ignition wires. More is not always better. Sometimes good enough is good enough.

BTW, this is one of the reasons I prefer inductive discharge systems over capacitive discharge systems. Inductive discharge is more tolerant of ignition wire condition because it uses a lower voltage, long duration spark compared to the CDI systems that use multiple higher voltage impulses. Either system can deliver similar energy to light the fire.

FYI for those of you having funny problems with your LS ignitions, lower your spark plug gaps.... This will reduce firing voltages and may prevent misfires. As for upgraded coils, if you keep the plug gap the same, the firing voltage will be the same so there is no benefit there. Perhaps a longer spark duration will result, hence the LOP benefit.
 
Going to wreck a cylinder

Need some help with my P mag. A member here sold it to me after having trouble. The factory, put a 114 board in and checked it out. I pulled a Slick mag off the O-320 (8.5 pistons) and installed the P mag. Timed it per the instructions and plumbed the vacuum line. First flight I had much higher cylinder temps. Particulary the dreaded number 3. Cut a hole in the cowling to let more air out with a baffle... before doing a full blown electric cowl flap.
Have had dangerously high temps ever since. Cannot run WOT. As the temps soar through 410 degrees, I have to pull power back to 2300 rpm on the fixed pitch Catto.
Today, I tried a few things. Removed the vacuum line from the P mag and flew. It is supposed to fail safe to normal mag timing. Temps rocketed up with full power. On the return flight from Phoenix I tried pinching the tubing on the Lightspeed ignition (other set of plugs). That would have created a situation where neither electronic ignition was advancing with manifold pressure. No change. Then, as a final test, I just turned off the P mag. The temps settled back to 350 approx for all the cylinders. Ran wide open throttle, temps stayed stable. Turned the P mag back on and one cylinder hit 425 F before I pulled the power back and added fuel with the mixture.
I will call them Monday, but in the meantime, has anyone experienced flat out unacceptable temps with P mags? All the threads allude to higher CHT, but not this high... I am hoping. Thanks for any help.
 
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I had the plugs out and brought number one to the top. Then confirmed the TDC mark on the flywheel was correct... and that the 25 degree mark was offset. Is there a conceivable way to get that wrong, following the procedure I used?
 
The first question I have is, did you put the jumper in to force your P-mag to the "A" curve?

Running the "B" curve (no jumper) can cause the problems you described.
 
I had the plugs out and brought number one to the top. Then confirmed the TDC mark on the flywheel was correct... and that the 25 degree mark was offset. Is there a conceivable way to get that wrong, following the procedure I used?

No there shouldn't be, but I would double check that the base timing is correct.

The first question I have is, did you put the jumper in to force your P-mag to the "A" curve?

Running the "B" curve (no jumper) can cause the problems you described.

I have run the P-Mag on both curves and could barely notice the difference although I know some folks have seen large CHT changes, can't explain that.
 
No there shouldn't be, but I would double check that the base timing is correct.



I have run the P-Mag on both curves and could barely notice the difference although I know some folks have seen large CHT changes, can't explain that.

Walt, see this thread on timing.
 
The jumper is in place... but if I read correctly, with vacuum disconnected it does not come into play????
 
The jumper is in place... but if I read correctly, with vacuum disconnected it does not come into play????

The jumper just changes the initial timing; 26 or 29DBTDC. The advance goes above that number. With the vacuum disconnected, the timing still starts at 26 or 29DBTDC, depending on the jumper; however, the P-mag should not advance and should act like a fixed time magneto. One that is timed at either 26 or 29DBTDC.

I have found that even having your ignition mistimed a degree or two can make a huge difference in CHT's.
 
Bill, if I were to err on the side of caution, and start all over tomorrow timing the P mag---- would it be better to be a couple of degrees past TDC when doing the pressure (blow in the tube) set procedure?
 
Just to close the loop... Bill and I talked on the phone.
Monday, I am going to confirm base setting for TDC on the P mag.
A software upgrade might be in order at the factory as well.
Will post results in the future...
Thanks to all who helped today...
 
Walt, see this thread on timing.

Yes I did, can't expain your results.

I have found that even having your ignition mistimed a degree or two can make a huge difference in CHT's.

Definately not true for my engine, but then again I've never had a CHT problem like many folks have.

Bill, if I were to err on the side of caution, and start all over tomorrow timing the P mag---- would it be better to be a couple of degrees past TDC when doing the pressure (blow in the tube) set procedure?

Not Bill but I normally do this just to be safe, I believe emag also recommends this if you run a lightweight prop as well to avoid kickbacks.
 
How Does a High Performance Ignition Coil Help Performance?
A high performance ignition coil helps engine performance four important ways. First, the higher voltage allows for a larger spark plug gap, which results in a more robust initial flame kernal at the start of combustion. The result is a real-world engine torque increase. Second, having more voltage on tap means the voltage required to bridge the spark plug gap gets there faster, leaving less time for voltage diversion through the spark plug's inevitable carbon deposits. Third, the higher voltage potential creates a stronger "push" on the electrical stream to the plug, resulting in increased electrical current, i.e. more energy, more snap. Fourth, with more voltage available, there is more in reserve for non-standard situations.

Sheesh.

http://www.motorcycleproject.com/motorcycle/text/high_perf_ignition_coils.html
 
I'm not Dan, but I believe the point is that one should credit the source when copying text verbatim rather than just presenting it as your own.
 
Need some help with my P mag. A member here sold it to me after having trouble. The factory, put a 114 board in and checked it out. I pulled a Slick mag off the O-320 (8.5 pistons) and installed the P mag. Timed it per the instructions and plumbed the vacuum line. First flight I had much higher cylinder temps. Particulary the dreaded number 3. Cut a hole in the cowling to let more air out with a baffle... before doing a full blown electric cowl flap.
Have had dangerously high temps ever since. Cannot run WOT. As the temps soar through 410 degrees, I have to pull power back to 2300 rpm on the fixed pitch Catto.
Today, I tried a few things. Removed the vacuum line from the P mag and flew. It is supposed to fail safe to normal mag timing. Temps rocketed up with full power. On the return flight from Phoenix I tried pinching the tubing on the Lightspeed ignition (other set of plugs). That would have created a situation where neither electronic ignition was advancing with manifold pressure. No change. Then, as a final test, I just turned off the P mag. The temps settled back to 350 approx for all the cylinders. Ran wide open throttle, temps stayed stable. Turned the P mag back on and one cylinder hit 425 F before I pulled the power back and added fuel with the mixture.
I will call them Monday, but in the meantime, has anyone experienced flat out unacceptable temps with P mags? All the threads allude to higher CHT, but not this high... I am hoping. Thanks for any help.

I had the exact same issue with my O360 running 2 P-Mags on the "A" curve (jumper IN). First I made sure the baffles were good so all the little leaks were completely sealed. This brought the CHT's down a bit but nowhere near where they should have. Then I moved the timing about 2 degrees AFTER TDC and everything worked perfectly. Now CHT #3 (highest) runs around 400 degrees in climb and about 390 degrees in cruise.

So, move the timing about 2 degrees AFTER TDC and see if it fixes the CHT issue. I didn't think it would make that big a difference but in my case it sure did.

:cool:
 
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Dual Pmags for me

I will add my logic for going with Dual Pmags. The initial bugs on the Pmag had been solved by the time I was making the decision so I felt confident in the product.

I looked at most of the systems offered, I like the simplicity of the Pmag and that it was not dependent on ships power. It was very simple to install and time.

Brad at Pmag has supper customer service. Some state that having traditional mags will help if stuck on the road and to some extent that is true. My one and only issue with my Pmag happened away from home. In just over 24 hours my Pmag was to Brad and a fix made and returned to me. My issue was with a circuit board.

I am at nearly 300 hours and 2 years and have had not further issues with my dual Pmag setup. I think most EI will do the same as far as performance so then the desision comes to simplicity in set up and maintenance and of course reliability. Pmag went through some growing pains but from what I have been able to determine, they worked through them with class and great customer service.

Get out and see some aircraft with the different systems and how they are installed, this will give you a better idea on what system you might like in your plane.

Cheers
 
I'm not Dan, but I believe the point is that one should credit the source when copying text verbatim rather than just presenting it as your own.

This was a point of facts asked by a forum user that was interested in some information regarding coils, not a point of plagiarism. It's obvious that some forum users spend far too much time combing posts hoping to find something to criticize rather then to join in on the conversation and perhaps contribute or possibly even learn something. I'll quote you something most of us were all taught by our parents: "If you have nothing nice to say, don't say anything at all".
 
I'm not Dan, but I believe the point is that one should credit the source when copying text verbatim rather than just presenting it as your own.

Yes. For example, if I were to post these classic ignition illustrations, I would attribute them to the Bosch Automotive Electric/Electronic Handbook, Robert Bosch GmbH, 1988:



They illustrate several basic points to remember in any discussion of inductive ignition.

Regarding coils....as the magnetic field is collapsed, secondary voltage rises until flashover/ionization at the plug gap, after which voltage drops to a low level for the duration of the spark. The actual voltage required to ionize the plug gap varies with gas pressure and content, electrode gap, geometry, and material, and a few other factors. A serviceable coil can be defined as any capable of generating a higher voltage than required under any likely condition. How much higher doesn't matter, as long as there is some reserve. For example, a 30kV coil or a 75kV coil would both be perfectly serviceable in an application requiring 15kV with a new plug, or 20kV with a worn plug. Those are the maximum voltages the coil will reach in service, regardless of any "voltage available" claim.
 
Outstanding support from E Mag

Thanks for the weekend replies to my questions about the 9A overheat experience. Brad, at E Mag spent the better part of an hour this morning in discussion on the phone regarding the issue. In the end, I removed the P mag to see if the drive gear was tight as a precaution. I put it back on and re-timed it to 2.4 degrees after TDC. My ring has 149 teeth... which meant I simply moved the prop forward one tooth from the original install setting. Flight testing showed a 30 degree drop minimum in cruise and about 20 degrees in a hard climb to 8500 ft. I suppose I am surprised just how much a one tooth shift can alter the timing curve and cool the CHT's down significantly. (jumper is still in)
One additional data point that both Brad and I found surprising. With the green light on, at TDC... I could back the prop up a full gear tooth before any internal gears moved. While the P mag was off the accessory case, I reached in to confirm that nothing moved while backing the prop up a full tooth.
I also learned from Brad that simply removing the vacuum line to default to simpler behavior does not imply a fixed value of course. As you climb, the ambient pressure drops, resulting in the P mag sensing it..... tube or not.
I live at 5000 ft. and do all testing above that altitude.
I will fly for a week with the jumper in and then for a few flights without, to compare temps. More data to follow. Thanks E mag for outstanding support.
 
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