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Electronic Ignition Survey

redhawk

Well Known Member
Greetings out there..
I’m thinking of changing half my ignition to electronic on my Lyc 0-320 engine in my -3B.
There’s a few choices out there and just want to get some feedback on preferred systems ?
Thanks…
 
In my opinion it's hard to beat the P-mag, its easy to install and time. It is also self powered. I've been running one for years and am very happy with it.
 
This subject has been beat around pretty thoroughly. I believe I've even seen surveys posted before. Definitely hundreds of posts on the merits of this system versus that.
 
I bought my RV-9A with dual Pmags a few years ago. First airplane I've ever owned (or even flown) with electronic ignition so I have limited comparison but this system has been completely reliable and easy to maintain. I have forgone the idea of an EI Commander as the system works great as-is and I have a desire not to tinker with anything forward of the firewall, but I understand that others have found that device to be very useful. I do like using automotive spark plugs.
 
Sure-Fly

I have the Certified Sure-Fly Electronic mag, two years since installed.
There is no AD's on them and absolutley no maintennance before 2.000 h.
Installation is easy with a green diode that indicate the setting point.
If you instal one Sure-Fly, it will be powered by the ships battery.
You will have redundancy from the standard mag.
It's just set it and forget it.

Good luck

https://www.surefly.aero/
 
Running SDS CPi on current RV. Install it - set it - forget it!

Had similar experiences with Lightspeed Plasma II on prior RVs.

I think most systems out there now are well thought out and run reliably. Choose one & go with it.
 
When i finished my 6a in 1997 I knew i would be in Baja a bunch. Nothing like cleaning points and carrya capacitor for field repair. In that era electronic was not reliable enough for this old school guy. Today seems to be different, but will stick with my mags
 
Two curves

Hello,
SDS (www.sdsefi.com) has the ability to have two ignition curves and includes a built in back up battery capable of running until fuel exhaustion. Consider looking into the SDS CPi-2 system.

Disclosure: I am a current user of the SDS full fuel and ignition system so consider that bias.

Marvin
 
Had SDS CPI on the RV 10, no issues.

Now have complete SDS EFI&I setup on the new plane---again no issues.

Many folks running P-Mag without issues also.

Ditto Lightspeed.

Do your research and go for it.

If you think you may someday go for electronic fuel injection, I think SDS can be run with only ignition and later add the fuel side of the equation with the same control box. Just something to think about.
 
Lightspeed

Both of my RV-7's with IO-360-A1B6 (200HP Angle valve) were equipped with Dual Lightspeed Plasma III's, 1 with original circuit board pickup, and 1 with mini-sensors.

(Knocking wood), no issues to date (1000s of hours)

I did make some changes to the wiring and terminations (No RG-400, Solder-cup D-Subs, etc.)
 
Dual Pmags

I have a 0-320 with C/S prop, on an RV6 with 600 hours on a dual magneto ignition. 2+ years ago I replaced the left mag with a Pmag which was an easy conversion which run very well for about 100 hours. The second mag was replaced by a second Pmag about 55 hours ago. The engine runs the same as it did with one Pmag, but that was expected, and that's what I got. If I was to do it again I would change out both at once. Engine starts better, runs smoother and is a bit faster but it could not be an easier modification and very easy to time. Also the use of auto plugs due to the hotter spark from the Pmag (s) is much cheaper than Aviation plugs with .035 (+ or -) gap which can't be done with aviation plugs.

Dick DeCramer
N500DD Rv6
flying since 2004
RV8 Sold 2017
Webster, MN
 
Electronic Ignition

Thanks Dick…
I think I’m sold on the P-Mags !
And thanks to all others for responding !
 
Greetings out there..
I’m thinking of changing half my ignition to electronic on my Lyc 0-320 engine in my -3B.
There’s a few choices out there and just want to get some feedback on preferred systems ?
Thanks…
This topic can be opinionated and passionate. I have my bias but I'll be transparent.

1) ALL EI's do basically the same thing. Give a "fatter", "hotter", "long duration" higher spark energy over a magneto. One prime advantage over magnetos. Spark energy can only be so much. Anything above what is useful is wasted.

2) ALL EI's have some function to advanced timing at lower power (lower MP and RPM). This is another prime advantage of EI's over magnetos. Aircraft EI's use simple RPM and MAP to advance. Cars also use O2 sensor and KOCK sensors with other inputs. For aircraft engines operation at fixed RPM most of the time not needed or can not use KOCK sensors (too loud air-cooled) or O2 (leaded gas). How a brand of EI schedules timing varies. Most can be adjusted, one can not.

3) Simplicity of EI's is another prime advantage of EI's. No moving parts, points or rotor/distributor cap. They all use some type of magnetic or hall effect sensor to trigger timing of spark. Some use magnet in ring gear holder "flywheel" with pickup mounted to engine. Others mount the mag/hall effect sensor on the accessory case, driven by magneto drive (PMag, Surefly, Lightspeed optional mag drive trigger). With these only wear part is the gear/shaft/bearings, but those are simple and reliable, well proven with magnetos.

4) ALL EI's need battery power except for one, which has self powered ability. So your option is have standby power for emergency or run one EI and one standard MAG. 80%-90% of the benefit in regards to performance of EI is achieved with one (1) EI. If you run a Mag with EI the Mag is going along for the ride once the EI starts advancing, however you get that self powered redundancy. Back up power is more weight (extra battery) and more wires and switches. Not a big deal. One brand of EI has built in backup power switching but you still provide that backup battery.

5) Almost ALL EI use automotive plugs and adapters verses MASS ELECTRODE aircraft plugs. Difference? Auto plugs (usually NGK) allow wider gap to take advantage of the larger spark ENERGY; Aircraft plugs are very expensive. NGK's are very inexpensive. Auto plugs is another prime advantage of EI's over magnetos and, larger spark energy fires across a larger gap.

6) Two brands of EI's have an option for EI + EFI (electronic fuel injection):cool:, SDS (Canada) and EFII (USA). Both offer the EI only option.

7) Some offer both an experimental version and STC version that can be used on standard cert aircraft. (Not a factor for RV builders but worth mention. As with most things where you have non Cert and certified versions of a part, the Cert version cost more. However in one or two cases I think having their experimental units based on certified versions limits them, in my opinion.

8) Top or popular EI brand names that come to mind in my causal order of preference (I have dual P-Mags):

E-Mag (P-Mag) - Feature mounts direct to and driven off engine, self powered over 900 RPM, ease of wiring and installation, well made and supported with service history. Negative of checking bearing every year is a no brainer and over blown, but it is a factor, but not a big deal IMHO. It is installed and you forget it, like a MAG, although recommended runup procedures recommends checking L & R for both operation and L & R for self power. Brad and customer service is top notch. There is a 3rd party company EI Commander that allows cockpit monitoring of P-MAG. Again I don't want to mess with my EI after set up. BTW people claim the advance is too aggressive? It is easily adjustable, but base timing or programing with laptop. This is the easiest to install and performance is as good as any other EI. Although marketing will say otherwise. Again limit to how much energy you can use or need. More is wasted. People get triggered (pun intended) over the manufacture recommendation to check the shaft bearings every condition inspection. It is not big deal and they are reliable. Some do not do the inspection. Some claim the 2nd party in cockpit EI Commander that allows monitoring the PMAGS in flight can indicate bearing wear. Some do NOT check the bearing every condition inspection. Last early teething issues were long sorted out. This is a mature design. I will disclose I bought mine 2nd hand from a builder selling project. So I got a sizable discount. LAST Brad and customer service TOP notch.

SDS - Ross has posted extensively about his development here on VAF. It uses flywheel timing pick ups. This is his 2nd generation and since released made more changes. The look of parts are great. Canada, shipping support may be a small issues. For this to work you need a large pulley ring gear "flywheel" and drill and mount magnets. Not a big deal. However you do have more wires, external brain box, wires to coils. If workmanship and routing of quality aircraft wire with good connections, it should be very reliable. However this is battery powered so you will need back up. I like Ross included backup power input into his system. This sets it apart from other battery dependent systems. However back up power is fairly easy to add to any EI. Backup power regardless requires an extra BATTERY and weight (but not too much). Ross from his post an exchanging comments on other forms is solid and should give great customer service.

Lightspeed - Klaus has been around a long time and it features CDI, Capacitance Discharge Ignition. It has ability to adjust timing advance in flight (which could be good or bad). I have talked to Klaus and liked talking to him. I never owned or operated his product but many have over the decade or two he has been selling his EI. He has the OPTION to put the trigger pickups in the magneto drives off accessory case vs. flywheel pickup. NOTE CDI is unique to Lightspeed, all others use "INDUCTION" ignitions. You can research the pros and cons. CDI has advantages, but not sure it is taken full advantage of in a slow RPM 4 stroke aircraft engine. Klaus has had complaints from, comments I read over many years. I have talked to him as potential buyer and found him helpful and very knowledgeable.

Surefly - New kid on the block. Came out with certified unit out the gate. Not sure if they can run only with magneto in other hole or they have STC approved backup power. They are NOT self powered and do not allow user programable timing advance curve. You can select fixed timing. They do only offer recommend and only offer harness for aircraft plugs. This is unvaried but a source says based on the components they use, spark energy is on the low end for an EI. but more than magneto. This may be why they only recommend Aircraft plugs (which are easier to fire with smaller gap but smaller spark); Or it could be a nod to being certified and they can't be bothered with variations. They do look pretty. However if I am going to mount something off accessory case I want it self powered (PMAG).

Electroair - This is the grandchild or the original Rose electronic Ignition. The current design is nothing like original which was clever but crude by today's standard for experimental EI's. The new design is aircraft quality. Their claim to fame is they have approval to be installed on standard Cert airplanes. I talked to one of the owner not long ago by chance. Nice guy. They know airplanes. They also claim extremely high spark energy. Again limit to how much you need or can use.

EFII- know very little about them, but their website is impressive marketing. I think some VAF Forum member or members have this brand. I also called them and got interesting info I can't verify. They claim the hottest of hot sparks. They also offer EFI (fuel injection). Interesting.
NOTE ON ADV....With fire breathing High Compression Engines detonation is a real concern. That is why Mags are run fixed at 25 BTDC or less typically. That is fine at full power but at altitude at 65% power, that spark is late, not very efficient. ALSO magnetos have to jump three GAPS. One is the rotor to the cap. The other is the spark plug. The last is the points. At low atmo pressure when flying at high altitudes you can get arching of the points. That is why there are pressurized magnetos. Again all that eliminated with no point or distributor.
We have choices!
PS Prices vary but all are expensive, and the difference is fairly small.
 
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Plus 1 for PMAG, I have had them on three RVs with excellent experience. The ease of install, especially in a flying plane and self powered capability is a huge plus for me. I also have the EIC which gives me the ability to change timing curve in the air but I have found there is hardly any gain for changing the curve.
 
I chose the SDS CPI-2 for the following reasons:

1. I don't like the idea of electronics bolted to a hot vibrating thing, so I wanted remote mount.

2. I wanted a zero maintenance part. From what I understand the p-mag requires 100 hour inspections. This is a deal breaker for me.

3. I wanted to program in my own curve (I'm going to start with a flat curve like a mag for break in) but be able to change it later for LOP.

4. All EI boxes need power, so your choices are ship power (CPI, lightspeed, etc), ship power with generator fail over (p-mag), ship power with dedicated battery fail over (CPI2). Out of those choices I felt the little lead acid battery would be more reliable than bearings and a generator.

5. I have an io-540 and the 6 cyl p-mag has a gear reduction unit in it and I felt that would be less reliable than a crank position trigger as gears and bearings have harmonics and wear out. Gear reduction systems are not simple!

If it wasn't for the CPI2 I probably would have stuck with mags.
 
This topic can be opinionated and passionate. I have my bias but I'll be transparent.

1) ALL EI's do basically the same thing. Give a "fatter", "hotter", "long duration" higher spark energy over a magneto. One prime advantage over magnetos. Spark energy can only be so much. Anything above what is useful is wasted.

3) Simplicity of EI's is another prime advantage of EI's. With these only wear part is the gear/shaft/bearings, but those are simple and reliable, well proven with magnetos.

SDS - Ross has posted extensively about his development here on VAF. It uses flywheel timing pick ups. This is his 2nd generation and since released made more changes. The look of parts are great. Canada, shipping support may be a small issues. For this to work you need a large pulley ring gear "flywheel" and drill and mount magnets. Not a big deal. However you do have more wires, external brain box, wires to coils. If workmanship and routing of quality aircraft wire with good connections, it should be very reliable.

Well, even though we've been making EIs for 27 years now, you'll notice we don't say much about spark energy. That's mostly marketing fluff IMO. You'll note that several Sport class winners at Reno have used magnetos on Lyconentals with a BMEP of around 400 psi and you'll note that Top Fuel dragsters have used mags for decades- BMEP 1700. Stock Lyc is around 150 by comparison. Lighting off a naturally aspirated Lyc. at 2700 rpm is an easy task for almost any type of ignition...

When people read other EI makers marketing hype and then ask us what the spark energy of SDS is, I say I don't know, but Andrew Findlay did a 409 mph lap with our ignition... That usually makes the point that it should do the job on a stock Lycoming ok. Ours is nothing special- automotive coils, inductive discharge. It works.

I think customers can attest to our support. Fedex and UPS can still get you parts overnight if you need them that fast plus the coils we use are OTS and you can get them locally or from places like Rock Auto quickly and inexpensively.

Nothing is more reliable than Hall Effect crank sensors- no gears or bearings to fail or check. People ARE seeing issues with the latter as reported right here. We have over 20 million hours collectively on our hardware and nearly 1 million flight hours. I'm not aware of a single Hall sensor failure (electronic) in that time.

We don't like the idea of electronics inside the engine where heat is a concern, external cooling is recommended, telltale heat tape is employed and yearly removal/ internal inspection is recommended. We don't do any of this.

We don't believe in canned or secret ignition curves. Our CPI, CPI-2 and EM-X all have user programmable rpm and MAP timing which can be adjusted on the fly easily, if desired-standard, nothing else to buy. You can optimize for your mission, fuel and compression ratio. We also have LOP advance available on all 3 systems at the touch of a switch- also standard.

No one EI suits all people or missions. The marketplace has plenty of choices. That's a good thing in my view.
 
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Greetings out there..
I’m thinking of changing half my ignition to electronic on my Lyc 0-320 engine in my -3B.
There’s a few choices out there and just want to get some feedback on preferred systems ?
Thanks…

Probably just going to come down to how much effort you want to put into retrofitting ...
 
I chose the SDS CPI-2 for the following reasons:
[SNIP]
If it wasn't for the CPI2 I probably would have stuck with mags.
I don't disagree, your choice is spot on for your wants and needs.

All the terrible sounding harmonics, vibrations and heat is over blown, like it's about to explode. Ha ha. The whole engine from prop, crank, rods, pistons, rings, cam, pushrods, lifters, valves, rockers, accessory case gears is vibrating with harmonics and heat O-plenty. The Mag drive is least of it. I am an engineer. You are right, the PMAG is bolted to the engine that vibrates and gets hot. It is MADE and DESIGNED to do that, including the PMAG. The one factor that is most significant is HEAT. Brad at EMAG Air will tell you that. Hot oil splashes on the drive gear, shaft and back of the PMAG housing. So cooling is recommended. That is easy to do and is more than compensated (for me and my choices) by EASE OF INSTALLATION.

It is RECOMMENDED (not an AD or mandatory) to do 100 hrs inspection of bearing play. Removing it during an "annual" condition check is about an hour more work. The actual check takes a minute, wiggle the drive gear and look for play. No big deal thing to check it, but if that is a deal breaker than pass on the PMAG. There are people that do not check every 100 hrs, either extending it or just don't do it. [I do NOT recommend this, just reporting.] The PMAG will start to misbehave if a bearing is failing (which is rare from my research). I am told the EI Commander cockpit display shows if a bearing is misbehaving early. I don't have a EIC so I assume it is delta timing L to R? This may justify (up to individual) forging 100 hr inspections. Again it is NOT a huge deal to inspect for me. I like looking in the accessory case for a look see. The advantage of PMAG is great engine performance and ease of installation AND Self Powered.

CPI12 has more fun with timing advance MAP I am sure. For people who tinker or have special needs, high compression, NO2, turbo, racing. Is this a big advantage for average RV driver?

PMAG is not for racing and max ultimate super high performance, blah blah. It gets 98% of the EI advantage in a simple easy to install and operate package. PMAG can change it's base timing and advance point or limit max advance. HOWEVER for a normal RV driver you will just want fixed timing from 100% to 75% power then a linear advance to the max allowed by the software. This is a flat constant advance "curve" followed by a straight line ramp up linear "curve" to max allowed than flat again. Nothing fancy is needed for airplanes and normal operations.
NOTE: You fat finger your adv curve and run high adv and high power you can detonate. The destruction can be massive, head, valves, piston... It can happen suddenly with damage happening fast and with little indication.

PMAG is not for everyone. CPI2 is nice and frankly there are things I like about the other ones. We have a wealth of options. PMAG has been out a long time, +15 yrs. I found a used set, with gears, harness, for less than current price, a discount. That was a factor as well, price.

Last comment, NOTHING wrong with traditional MAGS, big fan. If you are an RV driver who never goes above 8500 ft, flies at 70% to 100% PWR, like you stole it speeds, MAG's are pretty awesome, stick with it. However if you are starting from scratch with your ignition, and/or love flying into the TEENS, sucking O2, LOP at low power settings, EI will "pay for it self"? Qualify pay for itself. You will have to fly A LOT to save enough fuel to outright pay for EI, if you already have MAGS. If starting from scratch, EI makes more sense, and will add to the resale of the airplane.
 
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George, "ease of installation"? Seriously? P-leads and an airframe power supply, same as a Surefly, plus blast tubes. Big 'ole chunky thing too, with that Ford coil parked on top, so getting it in and out for a 100 hr isn't easy in a tight engine space.

Betcha I can R&R one of my homemade $50 ignition triggers for inspection, and fly away while you're still blowing a tube like Louie Armstrong ;)
 

+1

I have megasquirt systems on both my planes. One has a custom mag replacement box for the hall effect sensors and the other has magnets in the flywheel (used the 12 pre-drilled holes). Very reliable and quite inexpensive (complete dual ignition on the 540 was $800 with dual control units). Fully customizeable and even have a potentiometer based advance adjustment (+/- 5* on the fly) for optimizing advance to the mixture. Also have table switching for LOP/ROP. Will also do knock retard if I could find a reliable way to mount a knock sensor. Downside is you have to make custom brackets and solder your own control boards. For me, it was fun but may not be for others.

Larry
 
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I have the FlyEFII System 32 in my 14A and absolutely love it. I chose it as my engine shop is a distributor for that system so they installed, tested, mapped the fuel and pre broke in the engine for me. The only thing is that additional firewall ports are needed to retrofitting might mean needing to remove the engine.
 
Full SDS on my RV9A, and I'll do it again on the 10. I won't ever go back to mags.
 
Dual Bendix mags, 370 w/9.6 CR. if I ever do change it would most likely be CPI so I can control timing.
 
Lightspeed on Our Airplane

We have an RV-6, O-320 Lycosaur, carburetor, Lightspeed III with crankshaft sensor replacing the right magneto, Slick on the left to bring us home if the battery, alternator or Lightspeed itself stops doing their thing(s). Lightspeed has been flawless for something over 200 hours and four years. We love the “can’t miss” starting! Gotta admit though, installation of the Lightspeed is a bit of a slog. Plan on all day if you have the right tools. Klaus provided exceptional support.
 
George - The fact that the inspection interval on the Pmag is not regulatory is beside the point. The key takeaway is that the Pmag features a wear item (the bearing), and the SDS solution does not. The SDS is (by regulation or otherwise) maintenance free. That is a practical discriminator to many owners, regardless of how "easy" it is for you to remove your ignitions. SDS owners do not have to do that - EVER. There is much made of the "ease of installation" for the Pmag, but when you have to remove it every year of its life to make sure its not eating itself, the slightly harder, but permanent installation of the SDS product starts to look a whole lot better on the whole, wouldn't you agree?

You also diminish the practicality of the LOP feature of the SDS and seem to paint it as an edge case for "racers". You also ask how practical it is to the average RV driver... Well, how many pilots are still flying around full rich on their monthly pancake runs? Probably a few - and for them, Pmags (or magnetos) are just fine - but the rest of us are using our airplanes to get somewhere and we are jumping on the LOP bandwagon in ever increasing numbers. I have detailed many times on this very forum (using actual flight test data) how valuable the SDS LOP ignition shift function is.

You may not mind removing your Pmags every 12 months, and you might not mind burning a bit more gas on every hour you fly, but some of us have better things to do.
 
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Electronic Ignitions..

OK…now you’ve peaked my interest in the SDS system. I’d never heard of them before.
 
SNIP…

You also diminish the practicality of the LOP feature of the SDS and seem to paint it as an edge case for "racers". You also ask how practical it is to the average RV driver... Well, how many pilots are still flying around full rich on their monthly pancake runs? Probably a few - and for them, Pmags (or magnetos) are just fine - but the rest of us are using our airplanes to get somewhere and we are jumping on the LOP bandwagon in ever increasing numbers. I have detailed many times on this very forum (using actual flight test data) how valuable the SDS LOP ignition shift function is.

You may not mind removing your Pmags every 12 months, and you might not mind burning a bit more gas on every hour you fly, but some of us have better things to do.

A little hyperbola here…..

There is a lot of good data out there on the advantages of EI timing advance to gain engine efficiency when running LOP. All the data I have leads me to conclude that up to ~9 degrees of timing advance is the “peak of the curve” on this. This is what pMag is when running with the recommended timing jumper in. That does not mean the advance is always that much however.

Consider that regardless of your fuel or ignition system you are not going to make these engines into something they are not. In other words I have found no data (or anyone willing to testify) that any electronic ignition system and/or electronic fuel delivery system has a power or engine efficiency gain over a nice AirFlow Performance fuel injection (with balanced injector nozzles) and a dual pMag install. For twenty years I’ve run dual pMags LOP. Implying that this is not practicable is simply not true.

Yep - and annual pMag inspection. I do that and have never found a problem. I have however found installs on ship dependent ignitions on flying RVs so horrible I tell the owner to go out a buy a lottery ticket as they are obviously very lucky.

In other words, while the annual pMag inspection might be too onerous for some, I’m hopeful they take the time to inspect and verify by testing whatever they are using for backup power to keep the fan running. Hint - just adding a standby alternator and calling it good is receipt for disaster. Same goes for standby battery(s) that are under powered, not wired directly to the ignition, and my experience the after install periodic maintenance/replacement is often forgotten.

There is no “one and done” for our airplanes.

Carl
Three builds running pMags. New RV-10 build will be the same.
 
OK…now you’ve peaked my interest in the SDS system. I’d never heard of them before.

http://www.sdsefi.com/

Been around 25+ years, started in automobile world as I recall.

In the early days, EFII the company, was using SDS for their brain box.

Dont be confused by the acronym EFII ( electronic fuel injection/ignition) and the company that uses the acronym for their name.
 
There is a lot of good data out there on the advantages of EI timing advance to gain engine efficiency when running LOP. All the data I have leads me to conclude that up to ~9 degrees of timing advance is the “peak of the curve” on this. This is what pMag is when running with the recommended timing jumper in.

Careful Carl. Better to express best advance as actual timing. Pretty sure you meant base "25 and change" when set at TDC, jumper in, plus 9, total 34, because you were thinking of correct values for a parallel valve engine. The angle valve owners don't want 34 total. They must either clock the initial installation, or alter the programming, so that max is not more than 30. I can't find any value in more than 28.
 
Hello Carl

Carl,

Respectfully, I have done a few years of testing my angle valve 390 and I do not find anything but heat with advance values above 28BTDC, That is at 50LOP. From less than 50LOP all the way to 150ROP I could not find an advantage of anymore than 23BTDC. That is why I prefer a system with two curves that can be set to specific values by the pilot. Sure I can run at more than 23BTDC ROP but the result is increased CHT with no speed gain.

Marvin
 
Careful Carl. Better to express best advance as actual timing. Pretty sure you meant base "25 and change" when set at TDC, jumper in, plus 9, total 34, because you were thinking of correct values for a parallel valve engine. The angle valve owners don't want 34 total. They must either clock the initial installation, or alter the programming, so that max is not more than 30. I can't find any value in more than 28.

Corrects Dan, parallel valve engines. For angle head the 20 degree base works well with the pMag jumper in 9 degree max advance.

Carl
 
Carl,

Respectfully, I have done a few years of testing my angle valve 390 and I do not find anything but heat with advance values above 28BTDC, That is at 50LOP. From less than 50LOP all the way to 150ROP I could not find an advantage of anymore than 23BTDC. That is why I prefer a system with two curves that can be set to specific values by the pilot. Sure I can run at more than 23BTDC ROP but the result is increased CHT with no speed gain.

Marvin
Perhaps. Keep in mind the pMag “max of 9 degrees advance” typically translates to a lot less than 9 degrees. I suggest for an angle head engine a pMag set at 20 degrees BTDC base timing and jumper in is a good match. I also note the timing advance gains show up most when cruising LOP at altitude.

Of note I do not run more than 20-30 degrees LOP. The power drop off going more LOP exceeds the efficiency gain of reduced fuel flow.

Carl
 
Carl-

The LOP function of the SDS products adds a valuable capability the Pmag lacks. That's not hyperbole, that's a "product discriminator".
 
A little hyperbola here…..

There is a lot of good data out there on the advantages of EI timing advance to gain engine efficiency when running LOP. All the data I have leads me to conclude that up to ~9 degrees of timing advance is the “peak of the curve” on this. This is what pMag is when running with the recommended timing jumper in. That does not mean the advance is always that much however.

The issue is not that the pmag doesn't advance when LOP, it is that it is also advanced when ROP. The big problem is that the MAP keeps dropping at WOT during the climb. As the MAP is dropping, the advance keeps increasing due to a one size fits all table. This reduces power and increases CHTs. Until I made modifications to my advance approach, as soon as I got to 8K or so, the CHTs just kept climbing the higher I went. There are simple laws of physics that tie flame speed to mixture ratio, as well as MAP, and optimum ignition advance is very closely tied to flame speed, once you have sorted out the unique characteristics of a combustion chamber shape (key reason that folks see different optimum advances in the AV vs PV cylinders).

Larry
 
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Data point

Done a lot of flying in Les Kearney's RV-10 PV 540 9 to 1 CR. 30-75 LOP, 2400 rpm, 16,000 feet, no speed gains with more than 30-32 deg timing, just higher CHTs.

ROP, appears there's no gain in speed past 26-27 deg at 8000-16000 feet WOT.

I see no reason to run 34 deg ROP on a PV engine and probably no reason to run that much advance LOP unless you are 100F+ LOP which gives less MPG actually than 30-50 LOP.
 
George, "ease of installation"? Seriously? P-leads and an airframe power supply, same as a Surefly, plus blast tubes. Big 'ole chunky thing too, with that Ford coil parked on top, so getting it in and out for a 100 hr isn't easy in a tight engine space.

Betcha I can R&R one of my homemade $50 ignition triggers for inspection, and fly away while you're still blowing a tube like Louie Armstrong ;)
Dan don't mock me with "Seriously?" Yes I am. You are grousing about ONE WIRE POWER, ONE VAC TUBE, ONE KILL WIRE (P-lead),
which can be wired to key ignition OFF-L&R-Start switch like a magneto. I deny your claim. Ha ha.

Yes Sir Mr. Dan, ease of installation (and timing). Compare to say SDS.... Separate triggers, magnets drilled ring gear wheel, separate ECU control box, separate coils ALL CONNECTED WITH LOTS-O-WIRES, and mandatory back up battery with more associated switches and circuit protection and weigh. Not a problem in my eyes but don't say the PMAG is not easier and does not require backup power. Please.

BTW Retrofit scenario. RV'er has been flying for years with magnetos, one goes bad and other suspect. Wants to go EI. So remove old magnetos and put in Pmags. Use existing ignition switch, add two CB's or fuses and tap into manifold pressure. Now, let's say they also have small pulley on ring gear holder/flywheel. That has to be replaced, need big pulley. Prop has to come off to drill for magnets regardless. Then you have to mount coils and ECU and run wires, add a switch or three. No big deal, but don't tell me PMAG is not easier to install.

You state PMAG is "bulky"? It is all in one self contained not bulky (smaller than a magneto, or Surefly or other EI's coil packs). The PMAG is the size of a coil pack. The all in one aspect of the PMAG makes it less complicated to install and wire. Dhaaaa. That is a 3xW BIG dot DEAL, plus the fact it is SELF POWERED. Cool. No other system has this. Now look at SDS. arguably one of the best EI's out there, but total "bulk" volume more than PMAG. SDS has two beefy coil packs (almost as big as the PMAG alone), ECU, control/display unit, triggers and all the wiring, hardware and fittings to mount them. Not to mention the backup battery and associated wiring and weight to make that happen. It is all spread out. As I wrote Ross, his system is very nice. Yet me doth thinkist ye protest too much. PMAG is easier to install? As far as repair? Well depends on what fails. If your ECU fails you have to get one. Climbing under the panel to get that box might be a chore. Take cowl off, standing next to plane remove harness, spark leads and one bolt... slide PMAG out. However you do need a spare, granted, just as much as an ECU for another type of EI.

Then you go to irrelevant non sequitur about SureFly. Surefly EI is a totally different product, not self powered and has lower spark energy and only allows aircraft spark plugs. Surefly is easy to install like the PMAG, but not self powered, a big difference. You discount that as a trivial feature or gloss over it. Backup power source battery and switching/wiring/switches for ignition is also fine. Little more complex. I am not anti-backup battery. It does add to installation complexity, weight the PMAG does not need, so which is easier to install? For you no big deal, me too. But I am lazy. Ha ha.

Then you go off about Ford Coil. Oh boy. You don't think SDS uses off the shelf automotive components, including coils? ALL EI BRANDS use automotive components, and off the shelf electronics and sensors. All the other EI's use BULKY coil packs almost the size of PMAG alone... I just don't get your point. I hope you regret making it. Ha ha.

TO BE CLEAR, I think all EI's on the market have value, with pros and cons. They all have proven to be reliable and provide improved engine efficiency. What is your angst with PMAG's Dan? PMAG for better or worse is unique in the market and two things it has no others have, easier installation/timing and SELF POWERED... It's proven, with all the known limitations. Give credit where it is due Dan

"Betcha I can R&R one of my homemade $50 ignition triggers for inspection, and fly away while you're still blowing a tube like Louie Armstrong " Ha ha I am sure you can. First what makes you think your DIY triggered failed? What about the ECU going TU? Doha!! Oh and to pressurize the PMAG to put it in timing mode I pinch the TUBE and squeeze it or use a syringe. What is your point? You are MacGyver? True and agree. Not everyone is. BTW I am a drummer not a trumpet player, but from New Orleans. So please do not bring Sainted Louie Armstrong into this. Ha ha.

I have to laugh at your comments Dan. Please. You lost me and disagree. The PMAG is a well designed, well made EI that works great, plus great customer service, EASE of install and self power. This takes NOTHING away from any other brand of EI. It is not for everyone.
 
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Done a lot of flying in Les Kearney's RV-10 PV 540 9 to 1 CR. 30-75 LOP, 2400 rpm, 16,000 feet, no speed gains with more than 30-32 deg timing, just higher CHTs.

ROP, appears there's no gain in speed past 26-27 deg at 8000-16000 feet WOT.

I see no reason to run 34 deg ROP on a PV engine and probably no reason to run that much advance LOP unless you are 100F+ LOP which gives less MPG actually than 30-50 LOP.

Correct - and pMag does not run 34 degrees advanced under typical cruise conditions. Shoot fire, I have a hard time on long cross countries keeping CHTs up to my 350 target (reference is Mike Busch’s comments on sticking exhaust valves). My flight Friday I could not keep CHTs above 300 (but it is winter).

While we can dabble in the margins on “what is perfect timing for each flight condition” I suggest that for the majority of RV pilots they will find the pMag to be about right - right out of the box. I also suspect they will find the other options equally valid.

As I previously stated, while I can go 100 degrees LOP I find no value in doing so. I run 20-30 degrees LOP. I’m not interested in minimal fuel burn per hour. My focus on miles per gallon.

So why do I care? I get a lot of questions as to what engine, prop, avionics and such that I recommend. The discussion tends to go along the lines of “Carl, you are wrong” - and this is from first time builders. It gets to the point where I just walk away as I’m the person just wants me to validate whatever choice he has already made. My point is this forum and others tends to polarize build choices into two camps:
1. Do it this way and you will have utopia.
2. Do it any other way and you will die.

As this discussion has demonstrated, we have choices. Translating those choices into how we build our planes should be data centric. The first step is to validate the data. Here Dan Horton’s post should be carefully reviewed. From there open the aperture to look at the choice as a “system” and evaluate the other stuff needed to install and maintain, then look at how that system can be leverage for the rest of the plane’s mission. Here anyone installing ship power dependent stuff should find opportunity to have designed in backup power modes for the ship, not just the engine.
https://www.danhorton.net/Misc/Nigel Speedy - Ignition Advance .pdf

Carl
Now walking away……
 
Carl, you accuse me of hyperbole when I'm providing factual information, and then in the next post you speak for "most" of the RV pilot population when you claim the Pmag curve is "...about right - right out of the box".

Well, for the 100th time (and that's far from hyperbole), its not. No single curve can serve the two requirements of ROP and LOP operation, regardless of the name printed on the outside of the box.

So once again, without hyperbole:

Pmag does not offer the option to optimize curves in flight when you transition from the ROP climb to the LOP cruise phase. SDS does.

Pmag requires removal from the engine at regular intervals to determine it is not coming apart. SDS has no moving parts, no wear items and requires no regular maintenance.

These are facts, not hyperbole. The value proposition is up to the individual consumer to decide - not you.
 
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Done a lot of flying in Les Kearney's RV-10 PV 540 9 to 1 CR. 30-75 LOP, 2400 rpm, 16,000 feet, no speed gains with more than 30-32 deg timing, just higher CHTs.

ROP, appears there's no gain in speed past 26-27 deg at 8000-16000 feet WOT.

I see no reason to run 34 deg ROP on a PV engine and probably no reason to run that much advance LOP unless you are 100F+ LOP which gives less MPG actually than 30-50 LOP.

Ignoring all the other interpersonal mess happening here (grow up, guys)....

In my PV IO360, optimized for my preferred cruise conditions in the mid-teens and running 30-50 WOTLOP, I have my ignition set for 29 degrees total. That seems to be about optimal for my setup, running 93E10. YMMV.
 
Well, even though we've been making EIs for 27 years now, you'll notice we don't say much about spark energy. That's mostly marketing fluff IMO. You'll note that several Sport class winners at Reno have used magnetos on Lyconentals with a BMEP of around 400 psi and you'll note that Top Fuel dragsters have used mags for decades- BMEP 1700. Stock Lyc is around 150 by comparison. Lighting off a naturally aspirated Lyc. at 2700 rpm is an easy task for almost any type of ignition. (I am aware and never bashed Magnetos. They work well and I commented if you have good mags, consider sticking with them.)

When people read other EI makers marketing hype and then ask us what the spark energy of SDS is, I say I don't know, but Andrew Findlay did a 409 mph lap with our ignition... That usually makes the point that it should do the job on a stock Lycoming ok. Ours is nothing special- automotive coils, inductive discharge. It works. (I agree 100% and that was what I was trying to say.)

I think customers can attest to our support. Fedex and UPS can still get you parts overnight if you need them that fast plus the coils we use are OTS and you can get them locally or from places like Rock Auto quickly and inexpensively. (That is a great point and not sure why Dan was bashing Ford Coils. Do coils go out often? As a motor head they tend to be reliable IMHO. But being able to buy direct a coil pack from Auto parts store is great! The FORD EIS coils on Pmag have aftermarket high performance replacement coils in fancy colors... ha ha. I will resist the temptation. I doubt it would make much if any difference except the fancy coil housing color. As far as shipping from Canada, I am sure it's fine, but why is Canada letting Chinese balloons float into USA? Hummm Ha ha.)

Nothing is more reliable than Hall Effect crank sensors- no gears or bearings to fail or check. People ARE seeing issues with the latter as reported right here. We have over 20 million hours collectively on our hardware and nearly 1 million flight hours. I'm not aware of a single Hall sensor failure (electronic) in that time. (I am not disputing that. Having the PMAG on the engine, hot and shacking with GEAR drive is a challenge. However the internal trigger in a PMAG is a hall effect. The controversy is the shaft bearings inside the PMAG wearing. They can, have and do eventually. Therefore you check them. Not required for your design and common with several other EI's.)

We don't like the idea of electronics inside the engine where heat is a concern, external cooling is recommended, telltale heat tape is employed and yearly removal/ internal inspection is recommended. We don't do any of this. (That is the main design issue, but if designed properly electronics can handle vibrations and heat, but it's not a trivial issue. Having the ECU bolted down behind the firewall is a much better environment for the electronics. Hall effect on the engine vibrates, can get hot, but "solid state" and durable.)

We don't believe in canned or secret ignition curves. Our CPI, CPI-2 and EM-X all have user programmable rpm and MAP timing which can be adjusted on the fly easily, if desired-standard, nothing else to buy. You can optimize for your mission, fuel and compression ratio. We also have LOP advance available on all 3 systems at the touch of a switch- also standard. ( I agree. PMAG allows customization and in cockpit monitoring with aftermarket display. Surefly I believe does not allow tuning the timing map and is canned or secret. That is why I passed on that. I think your CPI2 is one of the best for customization and overall a great design, and quality looks fantastic. If you like to send me a free dual CPI2 I'll put it on and try it. :D Ha ha.)

No one EI suits all people or missions. The marketplace has plenty of choices. That's a good thing in my view.
Your last comment is spot on. That is what I said. I think SDS CPI2 is a top notch product and can't go wrong with it. For me the design of the PMAG was better for my mission, but it was a tossup with the CPI2. But I sent an email to you about buying and did not get a reply or I missed it, as I do time to time with emails. Not too late Ross my offer above stands. Ha ha. Cheers.
 
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I was going*to get into this discussion with some of the exaggerated*opinions, borderlining hyperbole but I think I am going*to just get some popcorn and enjoy the reading.
 
Ignoring all the other interpersonal mess happening here (grow up, guys)....

In my PV IO360, optimized for my preferred cruise conditions in the mid-teens and running 30-50 WOTLOP, I have my ignition set for 29 degrees total. That seems to be about optimal for my setup, running 93E10. YMMV.

Concur, we have Les set at 30 deg total for WOT around 30 LOP. Seems the best for speed and low CHTs.
 
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Your last comment is spot on. That is what I said. I think SDS CPI2 is a top notch product and can't go wrong with it. For me the design of the PMAG was better for my mission, but it was a tossup with the CPI2. But I sent an email to you about buying and did not get a reply or I missed it, as I do time to time with emails. Not too late Ross my offer above stands. Ha ha. Cheers.

George, I make a point of responding to every email in less than 24 hours (48 if you sent it on a Friday). I could have missed it or been away at that time or never received it.

The CPI-2 isn't the best for all missions or users as I've said before. I talked a guy into a Pmag on Friday in fact. If you're happy with the Pmag, I'd stick with it. Appreciate the attempt to contact us anyway. :)
 
George, I make a point of responding to every email in less than 24 hours (48 if you sent it on a Friday). I could have missed it or been away at that time or never received it.

The CPI-2 isn't the best for all missions or users as I've said before. I talked a guy into a Pmag on Friday in fact. If you're happy with the Pmag, I'd stick with it. Appreciate the attempt to contact us anyway. :)
No worries the cheap skate in me won over with old new stock PMAG's from builder selling project. As far as Reno, you are too modest. Your SDS ignition was on Reno Sport Class winner....

PS I am almost sure any Reno racer running mags was also running massive electrode aircraft plugs with smaller gaps, not 0.035 auto plugs. Does it matter? No but kind of. Well for economy of course, measured reduced fuel burn of 4% or more and smooth LOP operations with EI on our RV's (only if you fly at reduced power). Racing? HP / Torque is the goal, often they retard timing for NO2, super charger, turbos. You don't need my lectur... you know better than I do. Love your design. Cheers
 
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