Ignition coil

Synchro909

Synchro909

Well-known member
How long do you expect an ignition coil to last? I've just had to replace the fifth one in 45,000 miles and then replace that in about one mile. That's right, ONE MILE from a coil (Bosch GT40). It seems to me that they should last longer than that. Is there anything that could be causing such a short life other than crappy quality? I'd expect a Bosch coil to last for years - it's not like they are another Made in China piece of crap. Or are they???
I AM NOT HAPPY.:(
Oh, by the way, I'm running 12 volts and an FS distributor. The coils have been 12 v units so it's not like I have been feeding them too many volts.
 
Mike V. Florida said:
Does your car use 12 volts?
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Mike, from my OP,
Oh, by the way, I'm running 12 volts and an FS distributor. The coils have been 12 v units so it's not like I have been feeding them too many volts.
I'm at a loss. After this many failures, I think it is time to start asking WHY?
It's 8.30 at night here now so I'll leave it till tomorrow to ring Bosch themselves and see what I can find out. I wouldn't be surprised if no-one there knows anything about old coils like the GT40.
 
I don't know what your coil is filled/cooled with, but, these cars need an epoxy filled coil. That is unless you what to mount it with the wire tower pointing upward.
 
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a lot of the "name brand" coils that in their original manufactured country gave no problems are now made in china, brazil etc and now give trouble after short use
 
Patrick L. said:
I don't what your coil is filled/cooled with, but, these cars need an epoxy filled coil. That is unless you what to mount it with the wire tower pointing upward.
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Yes, I went through two "Oil Filled" coils then finally two years ago switched both cars to the "Epoxy filled" and no coil failures to date. :D
 
Before HEI, there were 2 types of 12V coils, those with an internal resistor and those requiring an external resistor. Which type are you running in your car?
 
As the Bosch GT40 is rated for 12 V w/out an external resistor I would suspect the problem is w/the FS distributor.
You could try contacting FS and see what they have to say.
I see on their website that the supply a "high energy heavy duty coil" that's "matched to the proper OHMs"
 
How long do coils last. In the old days they did not fail often. But today it all depends where they came from. By the way my coil on my 28 Sport coupe is a original coil that came on the car. I have put 24,000 miles on it since I started driving it.

But if you are putting 12Volts on a coil with out a internal or external resistor it will not last, not good for the points also.
 
Synchro909 said:
How long do you expect an ignition coil to last? I've just had to replace the fifth one in 45,000 miles and then replace that in about one mile. That's right, ONE MILE from a coil (Bosch GT40). It seems to me that they should last longer than that. Is there anything that could be causing such a short life other than crappy quality? I'd expect a Bosch coil to last for years - it's not like they are another Made in China piece of crap. Or are they???
I AM NOT HAPPY.:(
Oh, by the way, I'm running 12 volts and an FS distributor. The coils have been 12 v units so it's not like I have been feeding them too many volts.
Click to expand...

Are you running them upside down (coil wire pointing down)? Oil filled don't
like that position...
 
Guys, thanks for your replies overnight (here).The coils I have been using were oil filled and mounted with wires down as Henry did it. Maybe that's what I change. They have all been like the GT40, that is, no ballast resistor required. The last one to fail had a primary side resistance of 3.7 ohms.
When I contacted Mel at FS, he suggested an epoxy filled coil or a RUC15 coil (for 12 volts) which he had had reasonable success with.
I don't know that I would ever have guessed that I should simply turn the coil over!
Now to the telephone to ring Bosch direct. They are only a short drive from home - if the coil lasts!:eek:
 
Not to worry, its somewhat common. Oil coils do not like to be tipped upside down. Funny but they are still upside down even in the land down under aren't they. I even know some people that don't like to be tipped upside down.
An epoxy coil will fix your problem.
 
FWIW: Here's an old thread on Pertronix epoxy-filled coils that may interest some folks:

http://www.fordbarn.com/forum/showthread.php?t=145180&highlight=pertronix+40111


My car is a 6 volt positive ground system and I've run the Pertronix 40111 1.5 ohm "Flame Thrower" coil for several years with an old-school distributor and love it (thanks again, Purdy! ;)). As mentioned by Henry Chauvin in one of the posts, the Flame Thrower will "burn the hair off a rat in 10 feet of water" (:D, still cracks me up).

Mike
 
Just bought a Pertronix Flame Thrower which I will install "wires up". I have a longer lead to go from the coil to the distributor cap. For the price of it, this coil should last till we have peace ion the Middle East!!:D
Wish me luck!!
 
Sync:

Be sure to do your own research on this. Not everybody who posted on the thread I noted above was happy with the Pertronix coil, especially the 3.0 ohm version for the 12-volt system like yours.

Also, since the coil is epoxy-filled, it can be mounted neck-down without leaking. After experimenting with a few coils, and a variety of distributors I'm happy with the Flame Thrower coil and original points. My car is a "driver". I have a high compression head, and found that setting my points at 0.022 and sparklers with a gap of 0.035 works well for me.

"Individual results may vary"!
 
29er said:
... Also, since the coil is epoxy-filled, it can be mounted neck-down without leaking. After experimenting with a few coils, and a variety of distributors I'm happy with the Flame Thrower coil...
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Not all Pertronix Flame Thrower coils are epoxy filled, some are oil filled. Make sure you have the correct one before you "turn it upside down". :p:p

For 12v you want #40611 3.0 ohm coil.

Product Description
While it’s the perfect coil to go with the PerTronix Ignitor breakerless ignition, our 40,000 volt Flame-Thrower canister coil can benefit virtually any distributor type inductive system. Its higher voltage allows largerspark plug gaps for added power, smoother response and better fuel economy. These coils are internally resisted so installation and wiring is drastically simplified. Our oil filled coils offer great heat control for street driven vehicles, while our epoxy filled coils provide superior winding support for high vibration environments in off-road vehicles and boats.
 
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Just in case someone wants an excellent "hot" 6V coil, call a trained Petronix coil technician as opposed to just a Petronix sales person & let them know what 6V Model A ignition system arrangement you have.

Vintage vehicle and tractor coils made in the USA years ago lasted until they were too ugly to use ..... I remember vintage mechanics saying these old coils would never fail.

When out of the USA coils hit the market, they appeared to fail as often as our flashlight D-batteries.

After having several out of USA coils failing, as highly recommended on this Forum by a gentleman named Mr. Purdy Swoft, I went to Petronix ..... glad I did.
 
Well, the new coil didn't solve a thing. The car still sounds like WWIII while running on one or two cylinders. Next, I'm going to remove the FS distributor and go back to points and see what happens.
This episode had proved one thing - I have a very good muffler. After all that backfiring, it is still in one piece.:D
Anybody got any ideas now other than what I have said I will do?
 
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