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Speedy11(at)aol.com
Guest

Posted: Wed Feb 21, 2007 10:29 pm Post subject: P Mags

The initial info I have is that one P Mag advanced the timing too far resulting in power loss since the fuel/air mixture was ignited as in entered the cylinder.  During a power loss, the pilot should cycle the ignition source to left/right/both to check for any improvement.  The P Mags don't revert to the internal generator until electrical power is lost.  Since electrical power was available, a P Mag would not revert to the backup mode, so that means when the faulty ignition is turned off, the engine would run normally again.   Initial indications are the pilot did not cycle the ignitions through left/right.

 I will be interesting to see what Brad discovers.

 Stan Sutterfield

  

  

  	  Quote: 	
		  Nope Dual P mags. They did NOT fail. I believe ONE of them went to very

advanced timing. It has the effect of fouling up the timing completely

because once the charge has been lit the second spark doesn't do

anything. 	


 



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nuckollsr(at)cox.net
Guest

Posted: Thu Feb 22, 2007 5:22 am Post subject: P Mags

At 01:27 AM 2/22/2007 -0500, you wrote:



 	  Quote: 	
		  The initial info I have is that one P Mag advanced the timing too far 

resulting in power loss since the fuel/air mixture was ignited as in 

entered the cylinder.  During a power loss, the pilot should cycle the 

ignition source to left/right/both to check for any improvement.


	


    Makes sense . . .



 	  Quote: 	
		  The P Mags don't revert to the internal generator until electrical power 

is lost.  Since electrical power was available, a P Mag would not revert 

to the backup mode, so that means when the faulty ignition is turned off, 

the engine would run normally again.


	


    Hmmmm . . . whether or not ship's power is present,

    placing the P-Mag switch in the OFF position should

    shut it down.



 	  Quote: 	
		  Initial indications are the pilot did not cycle the ignitions through 

left/right.

I will be interesting to see what Brad discovers.


	


     As will we all. Thanks!



     A client and I have discussed making a trip to

     Dallas/Ft.Worth area to visit both Plane Power

     and Emagair. I'm hoping to forge some good lines

     of communication with both of these companies

     with a goal of providing accurate, filtered-for-

     sensibility data should either of these folks

     encounter a pot-hole in the road.



     Bob . . .

Fred.Stucklen(at)UTCPower
Guest

Posted: Thu Feb 22, 2007 5:25 am Post subject: P Mags

Interesting problem...  EMAG does have a service bulletin out on  their latest software change. 

 See http://emagair.com/Service%20Notes.htm This is for software updates that occurred

 between 12/06 and  2/07, and it involves how the engine timing is set while in the setup  mode.

 I'm not sure if it would effect timing during  normal engine operation, unless the power to the

 PMAGS was cycled in flight. Then it's perceivable  that the timing could have been changed.

 Of course, this is all conjecture until all the  facts are learned......

  

 Fred Stucklen

 RV-6A N925RV  720 Hrs

 Two PMAGS

 



             Subject:              Re: P Mags        From:               ([email]Speedy11(at)aol.com?subject=Re:%20P%20Mags&replyto=d44.25c73b2.330e91cb(at)aol.com[/email])Speedy11(at)aol.com ([email]Speedy11(at)aol.com?subject=Re:%20P%20Mags&replyto=d44.25c73b2.330e91cb(at)aol.com[/email])        Date:              [b]Wed Feb 21 - 10:29        PM[/b]

 [quote] 	  Quote: 	
		  The initial info I have is that one P Mag advanced the timing too far 

resulting in power loss since the fuel/air mixture was ignited as in entered the



cylinder.  During a power loss, the pilot should cycle the ignition source to 

left/right/both to check for any improvement.  The P Mags don't revert to the 

internal generator until electrical power is lost.  Since electrical power was



available, a P Mag would not revert to the backup mode, so that means when the



faulty ignition is turned off, the engine would run normally again.   Initial 

indications are the pilot did not cycle the ignitions through left/right.

I will be interesting to see what Brad discovers.

Stan Sutterfield 	
[b]

frank.hinde(at)hp.com
Guest

Posted: Thu Feb 22, 2007 6:45 am Post subject: P Mags

Well he didn't discover  anything wrong with mine...Darn those intermittent faults...

  

 Not quite sure I  understand what your saying Stan.... When we say cycle the E/Pmags we mean to  ground the P lead...I.e the mag that is turned off will stop firing. You mention  removing the power to the Pmag but that will do nothing to stop the Pmag firing  because as you say the backup alt will continue to make sparks.

  

 In order to fault find  which P/emag has gone whacko you have to stop each one form working to see if  the situation gets better...i.e ground the P lead.

  

 Frank



   From:  owner-aeroelectric-list-server(at)matronics.com  [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of  Speedy11(at)aol.com

Sent: Wednesday, February 21, 2007 10:27  PM

To: aeroelectric-list(at)matronics.com

Subject:  Re: P Mags

 

  The initial info I have is that one P Mag advanced the timing too  far resulting in power loss since the fuel/air mixture was ignited as in entered  the cylinder.  During a power loss, the pilot should cycle the  ignition source to left/right/both to check for any improvement.  The P  Mags don't revert to the internal generator until electrical power is  lost.  Since electrical power was available, a P Mag would not revert to  the backup mode, so that means when the faulty ignition is turned off, the  engine would run normally again.   Initial indications are the pilot  did not cycle the ignitions through left/right.

 I will be interesting to see what Brad discovers.

 Stan Sutterfield

  

  

  	  Quote: 	
		  Nope Dual P mags. They did NOT fail. I believe ONE of them went to    very

advanced timing. It has the effect of fouling up the timing    completely

because once the charge has been lit the second spark doesn't    do

anything. 	


 



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[b]

frank.hinde(at)hp.com
Guest

Posted: Thu Feb 22, 2007 7:04 am Post subject: P Mags

Yes, OFF being the Plead is grounded.



I certainly would not advocate trying to put the E/pmag in test mode in

flight, too complex and to lengthy to think through.



All you need to do is shut one unit down hard..I.e ground the P

lead...If it gets better great, if not simply repeat in the other

e/pmag.



I have a small bone of contention with the most recent incident. The

story goes the timing was so advanced the charge simply puffed thru the

open exhaust valve, implying this is a relatively harmless event. In my

reading of the effects of excessively advanced timing it seems this can

be very destructive pre-ignition. Remember that I and our friend saw

very high oil temps and CHT's. According to my reading of some of the

maintenance articles published by engine shops, preignition is caused by

the charge being ignited while the piston is still travelling UP the

bore. The piston then has to compress the rapidly expanding (and hot)

charge.



Apparently the very high cylinder pressures can then force this hot

charge past the rings and heat the oil directly. It also adds

considerable stress to the bottom end bearings.



As you can see from the above description this stuation can be very

destructive. I didn't want folks to think this was a relatively harmless

situation as it could (from what has been explained to me) destroy the

engine in short order.



I have yet to do an oil anaylisis which I hope will show no abnormal

levels.



Frank



--

mlas(at)cox.net
Guest

Posted: Thu Feb 22, 2007 7:46 am Post subject: P Mags

Frank is right again!  The point he makes is as a very important.  What

is the effect of an ignition system going off time?  In this case and

the one I was involved with the P-mag appeared to go more advanced.

Pre-ignition in an aircraft engine is a very bad thing!  So it seems

that the change in potential timing advance could be a bigger problem

then a strait forward failure.  Going back to Kelly's position about

mags vs. CDI and the like, I believe this would be one for the mag pro

side of the page.  Mind you, I run dual LSE Plasma III on one of my

airplanes and love it.



Mike Larkin



--

N6030X(at)DaveMorris.com
Guest

Posted: Thu Feb 22, 2007 7:47 am Post subject: P Mags

Yes, I believe the latest word we have from the engine experts is 

that the destructive effects we have always blamed on "detonation" 

are actually caused by "preignition", the latter being the one that 

punches holes in pistons and generally destroys the engine in short 

order.  Whereas "detonation" actually occurs in a broad range from 

"mild" to "severe" with the milder end having no ill effects on the engine.



For reference: http://www.avweb.com/news/pelican/194452-1.html



Dave Morris



At 08:59 AM 2/22/2007, you wrote:

 	  Quote: 	
		  

(Corvallis)" <frank.hinde(at)hp.com>

I have a small bone of contention with the most recent incident. The

story goes the timing was so advanced the charge simply puffed thru the

open exhaust valve, implying this is a relatively harmless event. In my

reading of the effects of excessively advanced timing it seems this can

be very destructive pre-ignition. Remember that I and our friend saw

very high oil temps and CHT's. According to my reading of some of the

maintenance articles published by engine shops, preignition is caused by

the charge being ignited while the piston is still travelling UP the

bore. The piston then has to compress the rapidly expanding (and hot)

charge.



Apparently the very high cylinder pressures can then force this hot

charge past the rings and heat the oil directly. It also adds

considerable stress to the bottom end bearings.



As you can see from the above description this stuation can be very

destructive. I didn't want folks to think this was a relatively harmless

situation as it could (from what has been explained to me) destroy the

engine in short order.



I have yet to do an oil anaylisis which I hope will show no abnormal

levels.



Frank

nuckollsr(at)cox.net
Guest

Posted: Thu Feb 22, 2007 9:52 am Post subject: P Mags

At 08:22 AM 2/22/2007 -0500, you wrote:



 	  Quote: 	
		  Interesting problem...  EMAG does have a service bulletin out on their 

latest software change.

See 

<http://emagair.com/Service%20Notes.htm>http://emagair.com/Service%20Notes.htm 

This is for software updates that occurred

between 12/06 and 2/07, and it involves how the engine timing is set while 

in the setup mode.

I'm not sure if it would effect timing during normal engine operation, 

unless the power to the

PMAGS was cycled in flight. Then it's perceivable that the timing could 

have been changed.

Of course, this is all conjecture until all the facts are learned......


	


   Drop them a note and ask. When in doubt, talk to the

   "horse" . . .



   Bob . . .



        ----------------------------------------

        ( IF one aspires to be "world class",  )

        ( what ever you do must be exercised   )

        ( EVERY day . . .                      )

        (                  R. L. Nuckolls III  )

        ----------------------------------------

nuckollsr(at)cox.net
Guest

Posted: Thu Feb 22, 2007 10:03 am Post subject: P Mags

At 02:59 PM 2/22/2007 +0000, you wrote:



 	  Quote: 	
		  

<frank.hinde(at)hp.com>



Yes, OFF being the Plead is grounded.



I certainly would not advocate trying to put the E/pmag in test mode in

flight, too complex and to lengthy to think through.


	


   How does one do this? Perhaps I'm behind the

   curve on this but I thought that powering up

   a Emagair product with the p-lead grounded offered

   the mechanic a built in "buzzer" used to

   set the mechanical timing. Are there "test"

   functions beyond this capability?



 	  Quote: 	
		  All you need to do is shut one unit down hard..I.e ground the P

lead...If it gets better great, if not simply repeat in the other

e/pmag.



I have a small bone of contention with the most recent incident. The

story goes the timing was so advanced the charge simply puffed thru the

open exhaust valve, implying this is a relatively harmless event. In my

reading of the effects of excessively advanced timing it seems this can

be very destructive pre-ignition. Remember that I and our friend saw

very high oil temps and CHT's. According to my reading of some of the

maintenance articles published by engine shops, preignition is caused by

the charge being ignited while the piston is still travelling UP the

bore. The piston then has to compress the rapidly expanding (and hot)

charge.


	


    If someone observes high temps . . . then this implies

    that the condition existed for some period of time.

    From onset of a problem to the time that any temperature

    becomes "high" has to be on the order of minutes.



    The image painted by these words suggests a sort of

    mental paralysis . . . the fact that the pilot chose

    an off-field landing further suggests that he didn't

    have a good understanding of how his equipment worked

    nor did he have a "plan" for dealing with things that

    have proven to be in-flight diagnosed and dealt with

    toward the goal of a happy ending.

 	  Quote: 	
		  Apparently the very high cylinder pressures can then force this hot

charge past the rings and heat the oil directly. It also adds

considerable stress to the bottom end bearings.


	


    Higher than those pressures/stresses that occur when timing

    is optimized for maximum realization of available

    energy from the fuel?

 	  Quote: 	
		  As you can see from the above description this stuation can be very

destructive. I didn't want folks to think this was a relatively harmless

situation as it could (from what has been explained to me) destroy the

engine in short order.


	


    I'm not sure that the combustion physics teamed

    with knowledge of the strengths of engine components

    and stresses encountered in NORMAL operations

    support the notion that the engine is mechanically

    at risk for the hypothesized failure.



    George Braley - are you watching this thread? Can you help

    with a dissertation on the underlying simple-ideas?



    Bob . . .

frank.hinde(at)hp.com
Guest

Posted: Thu Feb 22, 2007 11:13 am Post subject: P Mags

How does one do this? Perhaps I'm behind the

   curve on this but I thought that powering up

   a Emagair product with the p-lead grounded offered

   the mechanic a built in "buzzer" used to

   set the mechanical timing. Are there "test"

   functions beyond this capability?



Nope I think you got it right there Bob...In theory you could do this in

flight which is what I thought a previous lister was prosing.



 	  Quote: 	
		  All you need to do is shut one unit down hard..I.e ground the P 

lead...If it gets better great, if not simply repeat in the other 

e/pmag.



I have a small bone of contention with the most recent incident. The 

story goes the timing was so advanced the charge simply puffed thru the


	


 	  Quote: 	
		  open exhaust valve, implying this is a relatively harmless event. In my


	


 	  Quote: 	
		  reading of the effects of excessively advanced timing it seems this can


	


 	  Quote: 	
		  be very destructive pre-ignition. Remember that I and our friend saw 

very high oil temps and CHT's. According to my reading of some of the 

maintenance articles published by engine shops, preignition is caused 

by the charge being ignited while the piston is still travelling UP the


	


 	  Quote: 	
		  bore. The piston then has to compress the rapidly expanding (and hot) 

charge.


	


    If someone observes high temps . . . then this implies

    that the condition existed for some period of time.

    From onset of a problem to the time that any temperature

    becomes "high" has to be on the order of minutes.



Depends when you Notice the problem...Yes it is minutes, but you also

have to connect high CHT's to a timing problem...I didn't



    The image painted by these words suggests a sort of

    mental paralysis . . . the fact that the pilot chose

    an off-field landing further suggests that he didn't

    have a good understanding of how his equipment worked

    nor did he have a "plan" for dealing with things that

    have proven to be in-flight diagnosed and dealt with

    toward the goal of a happy ending.



Mental paralysis?.....I'm a MECHANICAL engineer...we don't have

those.... As I said you had to connect high temps to wobbly timing. In

my case the engine was running perfectly, just showing whacko temps...As

all the temps were measured by the Dynon EMS I was a first almost

convinced it was a Dynon grounding issue, I.e not a problem at all.

 	  Quote: 	
		  Apparently the very high cylinder pressures can then force this hot 

charge past the rings and heat the oil directly. It also adds 

considerable stress to the bottom end bearings.


	


    Higher than those pressures/stresses that occur when timing

    is optimized for maximum realization of available

    energy from the fuel?



No but the piston is already on the way down...i.e the peak pressure may

be the same but it is reducing rapidly...We know that blowby always

happens, but in a pre-igniton situation it happens for much longer,

therefore more blowby and direct heating of the oil.



At least this is how it was explained to me...I am not an expert on

preignition by any streatch.

 	  Quote: 	
		  As you can see from the above description this stuation can be very 

destructive. I didn't want folks to think this was a relatively 

harmless situation as it could (from what has been explained to me) 

destroy the engine in short order.


	


    I'm not sure that the combustion physics teamed

    with knowledge of the strengths of engine components

    and stresses encountered in NORMAL operations

    support the notion that the engine is mechanically

    at risk for the hypothesized failure.



    George Braley - are you watching this thread? Can you help

    with a dissertation on the underlying simple-ideas?



Yes inquiring mind most definatly want to know...



    Bob . . .

_Frank

rv9jim(at)juno.com
Guest

Posted: Thu Feb 22, 2007 12:40 pm Post subject: P Mags

Stan,

        Brad has put out a service bulletin on the "E-Mags" to check for

the possibility of a "vacuum" caused timing change.  These units were put

out in the last 90 days or so.  His bulletin says to check the units by

trying to change the timing by sucking on the vac hoses rather than the

"pressure" method.  I had my 'mags in for the latest software change so

they could have had the "wrong" software installed.  I checked them out 

last Sunday and they will not change the timing function no matter how

hoard I suck on the vac hose.  I'm not sure this may have caused the

problem but worth the check out and having the latest software installed.



Jim

BobsV35B(at)aol.com
Guest

Posted: Thu Feb 22, 2007 12:41 pm Post subject: P Mags

Good Afternoon Frank,   

 Actually, if the timing is advanced, the pressures and temperature can, and  probably will, be much higher than the pressures and temperatures developed when  the fire is lit at the proper point. Any time the peak pressure point gets  closer to TDC than ten or eleven degrees, the crank shaft has a LOT more  resistance and the pressure can be as high as twelve hundred to fifteen hundred  pounds whereas if the ignition event is properly timed the same engine may never  see a pressure above eight hundred pounds.

  

 It can make a VERY big difference.

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

Stearman  N3977A

Brookeridge Air Park LL22

Downers Grove, IL 60516

630  985-8503



  

 In a message dated 2/22/2007 1:15:55 P.M. Central Standard Time,  frank.hinde(at)hp.com writes:

  	  Quote: 	
		  Higher    than those pressures/stresses that occur when timing

    is    optimized for maximum realization of available

    energy from    the fuel?



	


 





AOL now offers free email to everyone.  Find out more about what's free from AOL at AOL.com.  [quote][b]

harley(at)AgelessWings.co
Guest

Posted: Thu Feb 22, 2007 1:24 pm Post subject: P Mags

Jim...

 

 >>they will not change the timing function no matter how hoard I suck on the vac hose.<<

 

 Did you try TWO quick short "sucks", so to speak?<G> 0.5 psi or greater?  On reading the email I received from them, I interpreted it as it takes two short pulses to change the setting. 

 

 Mine aren't installed yet, or I'd try it. 

 

 Harley 

 

 James H Nelson wrote: [quote]    	  Quote: 	
		  --> AeroElectric-List message posted by: James H Nelson <rv9jim(at)juno.com> (rv9jim(at)juno.com)



Stan,

        Brad has put out a service bulletin on the "E-Mags" to check for

the possibility of a "vacuum" caused timing change.  These units were put

out in the last 90 days or so.  His bulletin says to check the units by

trying to change the timing by sucking on the vac hoses rather than the

"pressure" method.  I had my 'mags in for the latest software change so

they could have had the "wrong" software installed.  I checked them out 

last Sunday and they will not change the timing function no matter how

hoard I suck on the vac hose.  I'm not sure this may have caused the

problem but worth the check out and having the latest software installed.



Jim



  	
 [b]

frank.hinde(at)hp.com
Guest

Posted: Thu Feb 22, 2007 1:31 pm Post subject: P Mags

Thanks Bob

  

 Yup...that is my fear for  the long term. I will start an oil analysis program as the motor will be about  100 hours old at the next change.

  

 Otherwise the engine  appears normal. The borescope did not reveal any signs of pre ignition on the  pistons.

  

 Thanks

  

 Frank

  

 Do not  archive



   From: owner-aeroelectric-list-server(at)matronics.com  [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of  BobsV35B(at)aol.com

Sent: Thursday, February 22, 2007 12:38  PM

To: aeroelectric-list(at)matronics.com

Subject: Re:  Re: P Mags

 

   Good Afternoon Frank,   

 Actually, if the timing is advanced, the pressures and temperature can, and  probably will, be much higher than the pressures and temperatures developed when  the fire is lit at the proper point. Any time the peak pressure point gets  closer to TDC than ten or eleven degrees, the crank shaft has a LOT more  resistance and the pressure can be as high as twelve hundred to fifteen hundred  pounds whereas if the ignition event is properly timed the same engine may never  see a pressure above eight hundred pounds.

  

 It can make a VERY big difference.

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

Stearman  N3977A

Brookeridge Air Park LL22

Downers Grove, IL 60516

630  985-8503



  

 In a message dated 2/22/2007 1:15:55 P.M. Central Standard Time,  frank.hinde(at)hp.com writes:

  	  Quote: 	
		  Higher than those    pressures/stresses that occur when timing

    is optimized for    maximum realization of available

    energy from the    fuel?



	


 





  AOL now offers free email to everyone. Find out more about what's free from AOL  at <57x4311227241x4298082137/aol?redir=http%3A%2F%2Fwww%2Eaol%2Ecom"  target="_blank">AOL.com. [quote]



href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List

href="http://forums.matronics.com">http://forums.matronics.com



[b]

rv9jim(at)juno.com
Guest

Posted: Thu Feb 22, 2007 7:49 pm Post subject: P Mags

Hi Harley,

        I'll give it a try tomorrow.  I'm adding a 6 position fuse holder

as I ran out of fuses to do things...  Checking out the panel for things

to work so I can close it up soon.

Jim Nelson

RV9-A

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