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Engine Running Rough
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Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Mon Feb 19, 2007 9:01 am Post subject: Engine Running Rough

The more I read the more I think there is a case for the single mag and a

single CDI.  Two different technologies, two different weaknesses but when

combined they could offer more protection from an engine out.



One thing is for certain in the very near future there will be a big push on

to clean up GA engines.  Whether you start installing at least one CDI with

variable timing or junk the whole lot and switch to Diesel only the future

will tell.  Be prepared for big changes!



Noel



[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

Terry Watson

Joined: 09 Jan 2006
Posts: 290
Location: Seattle, WA USA

Posted: Mon Feb 19, 2007 9:11 am Post subject: Engine Running Rough

I am surprised no one has yet mentioned E-mags in this thread.

http://www.emagair.com/Intro.htm

I have no experience with them but the reports of their product and service

have been excellent. In essence it is an electronic ignition that is a

bolt-on replacement for a mag. One model requires outside power, but the

other has its own built-in electrical source.



Terry

--

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Mon Feb 19, 2007 9:29 am Post subject: Engine Running Rough

They also have more than one generator.  More than one engine.  %They can

sustain flight on one engine.  If they have a massive electrical failure in

flight the engines won't just stop and become huge anchors.  If the lights

in the cockpit wouldn't tell the crew they wouldn't even know about the

power loss.



Noel



[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

ceengland(at)bellsouth.ne
Guest

Posted: Mon Feb 19, 2007 10:56 am Post subject: Engine Running Rough

Kelly McMullen wrote:

 	  Quote: 	
		   

 

 Yeah, right. I was using CD ignition on a car 35 years ago(and it

 failed within 2 years). Show me an electronic ignition that is self

 powered and stone reliable and I'll come over to your side. So far,

 the automotive technology that has proven superior for aircraft, sum

 total, will fit in a C-150. Porsche tried and failed. Dozens have

 tried the aluminum Chevy, and failed. VW, Corvair, Subaru...all niche

 curiosities that haven't made it to mainstream. Face it. There isn't

 an electronic ignition that passes the dead battery test. Until that

 is possible, you are just bandaiding around the problem with dual

 buses and other backups.


	


For those who don't know yet and are trying to learn:



Mags fail.



Mags fail with some frequency.



There's typically only one carb or injection controller, but there are 

almost always 2 mags. It ain't just about better combustion.



If standalone ignition floats your boat, google 'p-mag' & 'e-mag' to 

come close to the 'ideal'.



Charlie

apilot2(at)gmail.com
Guest

Posted: Mon Feb 19, 2007 1:48 pm Post subject: Engine Running Rough

No, no confusion. Also had later factory electronic ignition leave me

stranded at -40. They have several points of failure. Can't tell you

how many engine management CPUs get changed out regularly. Alternators

are no more reliable than they ever were. All fine for cars. Not so

fine for aviation. A mag failure shortly after overhaul indicates a

shop that is incompetent. I have yet to have a mag actually fail in 35

years of flying. Had P-lead short a mag to ground, but no mag failure.

You are welcome to go complex electronics. Your choice. That is what

experimental is all about.



On 2/19/07, Wayne Sweet <w_sweet(at)comcast.net> wrote:

[quote] 



 You are confusing CDI's of today with 35 years ago. First, cars 35 years ago

 were junk compared to cars of today. All cars today have electronic ignition

 systems; i.e. CDI's.

 Also the only failures I have had with alternators in my MustangII were from

 wire terminal failures, partly my fault for not supporting the B-wire or the

 field wire close the terminal. In 6000  hours of flying "store bought"

 airplanes only had one failure (at night in a Cardinal) that cause a

 complete electrical failure. If that were to happen in my plane, I would

 still be flying 2 hours after the failure because of the backup battery.

 BTW, I had a mag go south because of points coming apart after only 24 hours

 in service; the maintenance facility that overhauled the mag said, "That

 happens sometimes". WHAT!!! REALLY!!!!

 Lessons learned 35 years ago no longer apply today.

 Wayne



 ---

n801bh(at)netzero.com
Guest

Posted: Mon Feb 19, 2007 2:17 pm Post subject: Engine Running Rough

I run the exact set up as NASCAR runs in their cars. Dual 6AL MSD boxes, custom Mallory dual pick up distributor, dual coils,  Ign # 1 is wired to the main buss. Ign # 2 gets its power straight from the positive post of the Optima Red top gel cell battery. When the DAR inspected my plane he wanted to know the redundancy of the ignition system. Once I explained the concept and told him my battery had the capacity of running the ign for 6+ hours he said and I quote " Well, I guess after you land and refuel twice and still keep flying with a bad alternator you should qualify for the Darwin award". The thing is bulletproof and in all the years of NASCAR there has never been a complete failure of both systems at one time. And those boys can really give it the torture test. <G>  There are some pics on my website of my ignition system installed in the beast. Look for the red boxes and coils on the top right engine side of the firewall. Of course this rant is directed at the experimental guys, you certified guys are stuck with 70 year old technology.......................

archie97(at)earthlink.net
Guest

Posted: Mon Feb 19, 2007 3:20 pm Post subject: Engine Running Rough

There is an interior switch that will run one  or the other. (just in case)

  

 [quote]   ---

Speedy11(at)aol.com
Guest

Posted: Mon Feb 19, 2007 7:53 pm Post subject: Engine Running Rough

Kelly,

 No wholly true.

 P Mags (emagair.com) is an electronic ignition that has its own internal generator such that should the electrics fail, it can continue running at speeds above idle (about 700 rpm) therefore performing essentially like a mag.  When power is available, it enjoys the advantages of electronic ignition.

 Stan Sutterfield

  

  	  Quote: 	
		  There isn't an electronic

ignition made that will fire without a power source. Lose your

electrics and the engine WILL quit. OK in a car, not okay in a plane.

A magneto provides plenty of voltage to fire the proper gaps for

aircraft plugs at all engine speeds above idle. 	


 

  [quote][b]

apilot2(at)gmail.com
Guest

Posted: Mon Feb 19, 2007 8:44 pm Post subject: Engine Running Rough

Yes, I was aware of PMag and it probably is as good an alternative as

you can get for a 4 cyl engine. However, it isn't available for a 6

cylinder yet, and:

"Even the P-MAG model needs some source of outside power at start-up.

If you are prop starting because the battery is "low", there is plenty

of power for the ignition. If you're battery is "almost" dead (you

only get a faint glow from the cabin light) you probably have enough

power for the ignition.  However if you're battery is removed or is

absolutely/totally dead, you cannot prop start with the electronic

ignition and "no" outside power. "



On 2/19/07, Speedy11(at)aol.com <Speedy11(at)aol.com> wrote:

 	  Quote: 	
		  

 Kelly,

 No wholly true.

 P Mags (emagair.com) is an electronic ignition that has its own internal

 generator such that should the electrics fail, it can continue running at

 speeds above idle (about 700 rpm) therefore performing essentially like a

 mag.  When power is available, it enjoys the advantages of electronic

 ignition.

 Stan Sutterfield



 There isn't an electronic

 ignition made that will fire without a power source. Lose your

 electrics and the engine WILL quit. OK in a car, not okay in a plane.

 A magneto provides plenty of voltage to fire the proper gaps for

 aircraft plugs at all engine speeds above idle.

douglas.dodson(at)pobox.c
Guest

Posted: Tue Feb 20, 2007 5:45 am Post subject: Engine Running Rough

There are many more benefits to a dual electrical system than just the

ignition system.  If a required vacuum system is replaced by a second

battery and/or alternator, then failure of a primary (electric) gyro is

reduced dramatically.  The additional cost, weight and complexity is

negligible (and for some designs, even negative).



Magnetos are far more failure prone than CDI ignition systems.  One mag, one

EI means you will be spending time and money on the mag for to keep the

redundancy.  Parts commonality is a benefit of two identical systems.



Douglas L. Dodson, Jr.

Glasair II-S FT

Flight Test Engineer, CFI-A,G



--

apilot2(at)gmail.com
Guest

Posted: Tue Feb 20, 2007 6:47 am Post subject: Engine Running Rough

An interesting opinion, not based in fact. A dual electrical system

requires two alternators(heavier than a vacuum pump and one

alternator), two batteries(Significant extra wt), two totally separate

buses. If you interconnect them, you leave the possibility of one

failure taking out both systems. If you don't interconnect you have to

be able to live with what is on either bus by itself, which means you

will need some additional duplication. That is not simpler, nor less

complex. I have yet to see a failure-proof electrical system. Better

to have enough to keep flying when(not if) the electrics fail.

I have yet to see a CDI system that is more reliable than properly

maintained magnetos, in 35 years of flying and maintaining aircraft

and autos. The P-Mag/Emag(and others) may change that, eventually.

They have been talking certification for several years. Prism from

GAMI holds a lot of promise when it gets certified.

The main mag failures you see are when folks try to skimp and run

magnetos 1000+ hours without service. They should be opened and

inspected every 500 hours. Sometimes folks have to relearn hard

lessons all over again. You are free to do that with experimental

aircraft.

KM

A&P/IA

CP ASMEL-I



On 2/20/07, Doug Dodson <douglas.dodson(at)pobox.com> wrote:

 	  Quote: 	
		   



 There are many more benefits to a dual electrical system than just the

 ignition system.  If a required vacuum system is replaced by a second

 battery and/or alternator, then failure of a primary (electric) gyro is

 reduced dramatically.  The additional cost, weight and complexity is

 negligible (and for some designs, even negative).



 Magnetos are far more failure prone than CDI ignition systems.  One mag, one

 EI means you will be spending time and money on the mag for to keep the

 redundancy.  Parts commonality is a benefit of two identical systems.



 Douglas L. Dodson, Jr.

 Glasair II-S FT

 Flight Test Engineer, CFI-A,G

mlas(at)cox.net
Guest

Posted: Tue Feb 20, 2007 6:51 am Post subject: Engine Running Rough

I agree.



Mike Larkin



--

w_sweet(at)comcast.net
Guest

Posted: Tue Feb 20, 2007 6:59 am Post subject: Engine Running Rough

I agree. My plane also does not have the stupid vacuum systems either. Dynon 

D10A EFIS WITH internal battery backup. Is it not time to move past "the 

Past" and come into the 21st Century. I had the chance to fly in a Columbia 

350 with the older Avidyne glass panel; very nice. BUT IT STILL HAS A VACUUM 

SYSTEM! GEZZZZZ!

Wayne



---

jrccea(at)bellsouth.net
Guest

Posted: Tue Feb 20, 2007 8:15 am Post subject: Engine Running Rough

Guys,  I fly a non-electric J-3.  My goal is to keep it as light as 

possible.  In what way would a dual electrical system benefit me?

  

---

mlas(at)cox.net
Guest

Posted: Tue Feb 20, 2007 9:52 am Post subject: Engine Running Rough

Kelly,



If you use have a dual electrical system it requires two alternators

yes.  A small 20 amp B&C alternator is very close to the weight of a

vacuum pump, drive, regulator, and required plumbing.  And the B&C

alternator in my very small 13,000+ hours of flying and my 30 year of

aircraft maintenance shows the it should be much more reliable.  If you

need a 30 amp hour or more battery like a G-35 for starting then two

smaller Odyssey batteries will give you the same start power for less

weight.  And if you are as paranoid as you sound then an old fashion

gang switch for the system inter connect with a safety strap for you

will keep the system disconnected in flight.  As for your following

statements about reliability, almost everything works without failure if

properly maintained.  The electrical system is in my experience the most

under maintained system in an airplane.  How many Cessna's have you

looked at where ALL of the switches are 30 plus years old.  The simple

fact is that most people don't do anything to an electrical system until

something fails.  As far as fail proof, I fly airplanes of all types;

little, middle, and big over 800 hours a year and so far I have not

experienced a total electrical failure to a dark plane.  As for the

P-mag, I recovered an RV-7 from a highway two weekends ago when Both

P-mags failed.  Guess what, the electrical system worked perfectly......



Mike Larkin



ATP MEL, Com SEL, Many Types Rat., A&P, & IE



Lancair Legacy Build and Flown by Me

TS-11 Iskra Restored and Flown by Me

Kitfox IV re-engined and Flown by Me

A320/319 Flown by Me....



Ps- I only get this way with very very closed minded people.....



--

frank.hinde(at)hp.com
Guest

Posted: Tue Feb 20, 2007 10:29 am Post subject: Engine Running Rough

Hello Mike,



If this is the same incident I don't think the Pmags actually both

failed, although the effect was similar. What I think probably happened

was the timing on one of the P mags went way advanced. In this scenario

the second Pmag is just along for the ride, i.e it sparks but the charge

has already been lit at that point and hence doesn't do anything.



This is still the subject of investigation as we speak...I certainly

hope they find it 'cus I run Pmags myself.



I think kelly's point was that the traditional magnetoes are more

reliable than Pmags.



Frank



--

apilot2(at)gmail.com
Guest

Posted: Tue Feb 20, 2007 10:43 am Post subject: Engine Running Rough

Mike,

Unlike you, I'm not trying to persuade anyone that one system is

better than the other. I've stated anyone can select what they want in

experimental and make their own judgements.

 However, I flew for over 20 years in the Alaskan bush. That colors my

opinion. I don't have any reason to fly a GA plane routinely in hard

IFR(I choose not to fly for hire)...that also colors my opinion of

electric systems. Gee...2 Pmags fail in flight...who da thunkit!

Again, Pmag isn't available for 6 cylinders. Fact.......last I checked

Barrett Precsion Engines would not supply an engine with electronic

ignition, and their dyno tests showed less horsepower and hotter CHT

with electronic ignition(IIRC). (they've built and tested more engines

in a year than anyone here will in a lifetime). I'm open to the idea,

but not impressed with the current products on the market. I just was

refuting the claim by someone else that CD or other EI was better than

dual mags. Yes, you can minimize the weight of two electrical systems,

but it still is more complex than a single system with a vacuum pump

powering one gyro, and if it makes you feel better you can add a

second electric AI.  I have experienced total electric failure in two

different aircraft in flight and others on the ground, on well

maintained aircraft. Zero vacuum pump failures. Everyone has different

exeriences

There also is some very careful testing of electronic ignition against

dual mags on the Cafe400 website..well instrumented, etc. For the

narrow spectrum of high altitude, less than 70% power, dual EI showed

some added speed and fuel economy, at the expense of higher CHT. For

all higher power power and altitudes below 10,000 ft, the dual mags

were superior in all instances.

http://cafefoundation.org/v2/research_reports.php



On 2/20/07, Mike <mlas(at)cox.net> wrote:

[quote] 



 Kelly,



 If you use have a dual electrical system it requires two alternators

 yes.  A small 20 amp B&C alternator is very close to the weight of a

 vacuum pump, drive, regulator, and required plumbing.  And the B&C

 alternator in my very small 13,000+ hours of flying and my 30 year of

 aircraft maintenance shows the it should be much more reliable.  If you

 need a 30 amp hour or more battery like a G-35 for starting then two

 smaller Odyssey batteries will give you the same start power for less

 weight.  And if you are as paranoid as you sound then an old fashion

 gang switch for the system inter connect with a safety strap for you

 will keep the system disconnected in flight.  As for your following

 statements about reliability, almost everything works without failure if

 properly maintained.  The electrical system is in my experience the most

 under maintained system in an airplane.  How many Cessna's have you

 looked at where ALL of the switches are 30 plus years old.  The simple

 fact is that most people don't do anything to an electrical system until

 something fails.  As far as fail proof, I fly airplanes of all types;

 little, middle, and big over 800 hours a year and so far I have not

 experienced a total electrical failure to a dark plane.  As for the

 P-mag, I recovered an RV-7 from a highway two weekends ago when Both

 P-mags failed.  Guess what, the electrical system worked perfectly......



 Mike Larkin



 ATP MEL, Com SEL, Many Types Rat., A&P, & IE



 Lancair Legacy Build and Flown by Me

 TS-11 Iskra Restored and Flown by Me

 Kitfox IV re-engined and Flown by Me

 A320/319 Flown by Me....



 Ps- I only get this way with very very closed minded people.....



 --

mlas(at)cox.net
Guest

Posted: Tue Feb 20, 2007 1:01 pm Post subject: Engine Running Rough

Frank,



To the best of my knowledge you are correct.  One of the P-mags came off

time for some unknown reason (we think induced by temperature) and the

other was along for the ride.



Mike



--

s_korney(at)hotmail.com
Guest

Posted: Tue Feb 20, 2007 4:34 pm Post subject: Engine Running Rough

To the best of my knowledge you are correct.  One of the P-mags came off

time for some unknown reason.....



That's not good to hear.....If they knew the reason, they could fix it....If 

they don't know the reason ....  Well, then what?



Best... Steve



----Original Message Follows----

From: "Mike" <mlas(at)cox.net>

Reply-To: engines-list(at)matronics.com

To: <engines-list(at)matronics.com>

Subject: RE: Engine Running Rough

Date: Tue, 20 Feb 2007 14:00:21 -0700






Frank,



To the best of my knowledge you are correct.  One of the P-mags came off

time for some unknown reason (we think induced by temperature) and the

other was along for the ride.



Mike



--

frank.hinde(at)hp.com
Guest

Posted: Tue Feb 20, 2007 5:21 pm Post subject: Engine Running Rough

They may not know for absolute sure but there is a failure mode they

found that allows the unit with certain software versions to lose its

timing. There is a sevice bulletin on the Emag website about it.



It certainly makes sense and fits the description of the issues on the

downed airplane. I also had the same issues but my engine did not

actually quit.



Frank 



--

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