Odd Coil Failure

[Tony]

I asked John because - well, like you, I know he has an FE.. all three of us have our coils in the same place, though, so that's good enough for me (It was good enough for Ford as well, I think!)

Does it really matter where the coil is mounted when the engine is still sat on the garage floor Aaron?? 

[aaronjb]

My previous coil (the type with a fancy heat sink) failed at about 800 miles, positioned on the inner wing , but effectively getting radiant heat from the headers, although given most of the time it was used, most of the heat would have been removed via air flow from the side vents. I replaced it with a conventional coil and mounted vertically on the front of one bank of cylinders. No problems since.

I asked John because - well, like you, I know he has an FE.. all three of us have our coils in the same place, though, so that's good enough for me (It was good enough for Ford as well, I think!)

[Chris]

A few years ago I replaced my coil that is and still is mounted on the right hand inner wing with the chimney pointing downwards at about 30 degrees, that being about five inches away from no1 header .
The only reason that I replaced it was that the SD1 rv8 coil (Lucas) was over forty years old and thought it
would be fair to treat it to a new one .
All the correct readings and no oil leaking out.
The new one is supposedly a genuine Lucas, but I cannot be certain as lots of stuff comes out of China these
days. I still carry the original coil in the boot as a back up .
The point that I am making is that over the many years there has not been any issues with regards to melted ht
leads or ignition failures, that being through a few fairly hot summers as well.
The positioning of my coil could be up for debate but it seems to work without breaking down.
Chris.

Left hand inner wing from sitting in the car.
Silly me !

[Chris]

A few years ago I replaced my coil that is and still is mounted on the right hand inner wing with the chimney pointing downwards at about 30 degrees, that being about five inches away from no1 header .
The only reason that I replaced it was that the SD1 rv8 coil (Lucas) was over forty years old and thought it
would be fair to treat it to a new one .
All the correct readings and no oil leaking out.
The new one is supposedly a genuine Lucas, but I cannot be certain as lots of stuff comes out of China these
days. I still carry the original coil in the boot as a back up .
The point that I am making is that over the many years there has not been any issues with regards to melted ht
leads or ignition failures, that being through a few fairly hot summers as well.
The positioning of my coil could be up for debate but it seems to work without breaking down.
Chris.

[KevinW]

My coil is mounted on the inside wing and not on the front of the cylinder head were most are mounted. I was thinking that it has a better air flow and no heat soak transfer from the engine. So it has its advantages but you have to ensure the HT lead from the coil to the distributor is long enough so engine movement could pull the lead loose if not long enough.
The use to say always vertically munt a coil as these where in the early days of oil filled ones.

Any coil windings do not like heat and can break down in time if heat is constantly applied. The same occurs with starter motor windings.

My previous coil (the type with a fancy heat sink) failed at about 800 miles, positioned on the inner wing , but effectively getting radiant heat from the headers, although given most of the time it was used, most of the heat would have been removed via air flow from the side vents. I replaced it with a conventional coil and mounted vertically on the front of one bank of cylinders. No problems since.

[CraigH]

It used to matter the orientation it was mounted in years ago with oil filled coils but im guessing the Pertronix is a dry coil?
Its normally heat that kills them.

[JON1D]

My coil is mounted on the inside wing and not on the front of the cylinder head were most are mounted. I was thinking that it has a better air flow and no heat soak transfer from the engine. So it has its advantages but you have to ensure the HT lead from the coil to the distributor is long enough so engine movement could pull the lead loose if not long enough.
The use to say always vertically munt a coil as these where in the early days of oil filled ones.

Any coil windings do not like heat and can break down in time if heat is constantly applied. The same occurs with starter motor windings.

[Eggbert]

It's mounted on the front of the left cylinder head, a factory original spot. I think I have a bit of rubber wrapped around it to give a little vibration isolation from the clamp. I don't suspect heat other than maybe many years of "some" heat. More likely either just old age or the new wires being of a lower ohmage.

On the GIFs... When I finally got a new computer last year, I could not get my old GIF animator to work as I need a new code from the company, but they're out of business. I did do a lot of fiddling, such as looking into the old registry, but no luck. So I had to buy a new one which seems to be OK, but I know isn't as flexible as the old one.

Also, I use Paint to make the individual frames. That recently changed too, but no big deal. The blank canvas starts centered in the screen vs. the top left hand corner. This may make frame alignments a little more tricky. But there is 1 good thing about the new Paint. It has a single function for eliminating background from a picture. It leaves that area transparent which is really helpful when you to post the subject on a different background. I have other software to do that, but not nearly so easily.

[aaronjb]

Behold! The GIFs are back!

Out of interest, where do you have your coil mounted, John? I mean, that's unlikely to have caused the failure in and of itself seeing as it lasted 13 years, so I'm just curious really!

[Eggbert]

A while back I had some trouble with my car. Once well warmed up (20 to 30 minutes) it would die. It would crank, had fuel, but spark looked weak. Once things cooled down (another 20 to 30 minutes), it would start right up.

First time it happened was when I stopped to refuel. Once done, the engine would crank but not fire. Eventually it started.

Second time it happened, (just minutes after the first time) I was crossing a bridge. Fortunately a young man (early 20s) came over to push and was soon joined by two others. They pushed me off the bridge, made a right turn and then pushed me into a parkade.

Since it was common to all cylinders, I suspected either the coil or the ignition module. After I checked all voltages, etc., I found was that if I cooled the coil down by holding a wet rag against it and then pouring a cup of water over the coil, it would start right up. I confirmed this three times. Just let it idle until it died, then the water treatment on the coil. Started right up each time.

As it sort of confirmed a bad coil, I ordered another one. Now this system is a Pertronix Ignitor with a Pertronix 1.5 ohm coil (P/N 40011). Best upgrade I ever made. You can feel the difference over points... so much smoother.

I've never seen a coil fail when hot unless there's a break in the internal coil windings that spreads apart once it gets hot. This one checked out with no breaks although the high tension side resistance measures a bit lower than spec, and a bit lower than that when hot.

A Google search reveals there does seem to be a number of people reporting a similar coil problem with Pertronix, but they all had problems early on. Mine has worked flawlessly for about 13 years.

It has occurred to me that the last set of wires I put on were rather a low ohmage and that might have caused an increase in spark current and damaged the coil, but I doubt that alone would account for the failure. Spark current ought to be safely dealt with by the coil's internal resistance.

I'll look into this some more if the new coil fails prematurely, but it's been fine for about 2 years now.

So no real questions from me. Just wanted to share as coil issues are seldom the reason for ignition problems. Usually dist cap, rotor button, wires or plugs. But in this case...