MSD 44 Coil life?

How long is the life expectancy[number of passes] of MSD 44 amp coils before changing? What are the most common causes of failure? What number of passes would be the expected service-run- life on average in a AFD-TAD? Is there any simple way to track test them without sending them off. What Ohm readings-high to low-are correct. Thanks! JR

 

I had a brand new one go bad in 6 passes. It cut out and then came back and put a pretty good shock on the drive train. Put one from 2010 back on and it ran fine. Didn't ever find out a cause, but MSD did warranty it.

 

from the msd tech forum:
How often should coils be replaced?
This is a tough question to answer, there are only two reasons to replace coils when one is "Open" or has a shorted winding. In either case most can be found with a simple L.C.R. (Inductor, Capacitance and Resistance) meter. Notice that there are several numbers inscribed on the back of all coils.

One set is the date code (which had been changed to an easier method to read) and the second and third sets are the inductance values of the coils. In this case the numerical value does not represent any form of performance like 709 vs. 899 these numbers are simply inductance values of the windings. These numbers are used to monitor a change within the coil. Keep in mind that these numbers are relative to the meters being used, several variables can account for the values: coil temperature, lead length, and meter model and meter frequency output. So if you purchase an LCR meter these numbers will differ slightly from actual numbers on your coils. Once you acquire a meter it would be wise to log these values and periodically check them to see if they have changed. Theoretically, once a coil is built and has run successfully down the track it should never fail unless due to exterior damages.

In the beginning (1994) our coils were capable of extremely high voltages. The coils were capable of 55,000 volts to 60,000 volts as time passed we found that these voltage capabilities were unnecessary and were resulting in a high yield of coil failures prior to shipping. We redesigned the coils limiting the output voltages to 45,000 volts, this resulted in cooler running coils that were not capable of destroying themselves yielding higher percentages of higher quality coils.

Prior to purchasing a set of coils they have already met several of our quality benchmarks. One of the outstanding test is the coil must run for 5 minutes running at 1800 RPM without a coil wire attached, this test is performed 3 times before arriving the packaging department. This is to test the quality of the potting material, assuring that porosities or air bubbles are not present. In most cases if either are present the coil will fail prematurely. Eventually coil usage will degrade coil life or performance, unfortunately translating this into a number of passes, races or years is difficult to determine.

 

1 year of racing! Buy a new one then keep it for a spare. Then the following year sell the first one and buy a new again. Always start with a new coil. Sounds expensive but I looked like an idiot adrl a race this year. Car kept starting , Revving up, doing burnouts. But under a load , or lunch. It would fart and pop and fall below the 2 step chip!!! Looked like a jackass! Changed every electronic part except the coil when I had a new spare, I figured it started so it was doing it’s job. A coil is load dependent, ie under a major load is when it’s shows failure. Dont do as I did , change it every year and never doubt it again

 

Several A/fuel teams I know have lcr meters and I just purchased one for the same reasons. Not a huge expense..

 

https://www.amazon.com/lcr-meters/b?node=5011684011

 

More robust construction, oil filled, higher output, and rebuildable, so you won't be increasing your doorstop or paperweight collection

https://fuelinjectionent.myshopify.com/products/44-plus-coil-for-mag-44-8142-replacment

 

Spuds oil filled transformer is the ONLY 1 WORTH RUNNING,
U cannot put expoxy "potting " around a thousand stranded wires & not expect them to touch, sooner or later,

Expecting a thicker than molasses viscosity epoxy style "glue" to fully saturate around every "hair folical sized" copper strand, AS IT MUST do, TO DO ITS JOB Correctly,

ITS just not possible in high percentage production,
Yes, they test good, but are not.
Those who know, "KNOW" Those who dont, think u can run them for a race, a season, or forever, then send them out for testing, then keep running, (msd brand)

Bottom line is your mph is best prognostic indicator of a coil at 100% saturation & dump,

For that reason, there is NO LIFE EXPECTANCY OF A MSD COIL, ONLY "Good, till it is bad" Then it still tests good most of the time!

THERE IS 1 test;
Once your mph drops off, its time to junk it, & replace it w/ Spuds deal,
even thou the eng runs. Engs run w rods hangin out of pans too,

a typical hemi 200 mph car, U know its time,
when u loose
3-5 mph ,
using an MSD COIL for ur needs,

& since the coil wire ITS SELF gets used 8 times more than the rest,

if your not buying wire buy the spool,
& putting a new coil wire on every race weekend, & especially every final rnd, just like u do a $250 dollar blower belt,
Then it dont make much sense to put the new blower belt on for every rnd, race, or final round either then, does it?

Get a FIE coil & be done,
All this above, is assuming ur running the "Parts eating 44 amp mag,
If not, its a diff deal all together,

But most run a 44 , so its applicable
The jackazz