My COIL EXPLODED

19Fordy

19Fordy

Well-known member
Car wouldn't start. Checked the coil and discovered the top plastic part had actually lifted out of the case. Never had that happen before. The ignition is 12V with Pertronix kit and matching coil. It has worked fine in the past. Coil is the oil filled Pertronix unit shown here:
https://www.amazon.com/PerTronix-40001-Flame-Thrower-Volt-Coil/dp/B00199F2XG/?tag=atomicindus08-20

I suspect that the engine compartment heat caused the coil failure.
Would installing an aluminum coil cover like the ones shown below dissipate enough heat to protect the coil from overheating?
https://www.google.com/search?q=fla...HJD5IBBDIuMTSYAQCgAQHIAQfAAQE&sclient=gws-wiz

Or would it be better to wrap the coil in aluminum foil and foam insulation material. The coil is mounted on an aluminum bracket attached to a water pump bolt so radiator fan blows air on it. Should I relocate the coil?
Opinions welcome.
 

Attachments

  • IMG_5718b.jpg
    IMG_5718b.jpg
    79.3 KB · Views: 487
Last edited:
Or maybe an internal short caused the excessive heat. Why not just replace the coil? Probably will never happen again. Maybe replace with a regular coil cuz your flathead can never make use of that 40,000 volt boy-racer coil.
 
Thanks for the answers. I know Tubman is a points only guy.
The distributor is a Mallory dual point with mechanical advance so I could go back to points.
Who makes good high quality points?
 
I had two of those fail in the last year. Won't buy any more and know others who have had problems also.
 
tubman, Thanks. I appreciate your suggestions and knowledge. Here's some interesting about BOSCH BLUE COILs.
https://vwparts.aircooled.net/12V-Bosch-Blue-Coil-with-Mounting-Bracket-00-012-p/00-012us.htm

When I bought the Pertronix kit (ML-181)it came with the Pertronix coil # 40001 with 1.5 ohm primary resistance. I not using a condenser or a ballast resistor.

My distributor is a Mallory YL 2527501 Series 25 dual point unit converted to a Pertronix using their ML-181 kit. Pertronix told me to use their Flamethrower 1.5 ohm coil, not the 3 ohm coil.

The more I read, the more confused I get about what coil is the correct coil to use with my Pertronix.
Additional thoughts welcomed with open arms.
Thanks, JIM
 
Last edited:
All I know is that I purchased one when they were on special for my engine test stand. (Most of the engines I test run are 12 volts.) It has worked fine for me.
 
Check on Ebay for the Bosch coils. Sometimes you can find a deal on there for them. But like almost everything else, I am sure they have probably gone up!
 
Looks to me like you have it in a place where plenty of air can get to it . . . so, I'd probably just buy 2 replacement coils and keep one in the trunk.

As it is matched to the Pertronix ignition (their recommendation) - would run what they recommend, otherwise you may experience other issues (like a failed ignition component).
 
Also, you really don't know WHERE the heat was coming from, so kind of hard to determine if insulation would hurt or help the problem (heat from inside or outside).
 
Bored&Stroked said:
Looks to me like you have it in a place where plenty of air can get to it . . . so, I'd probably just buy 2 replacement coils and keep one in the trunk.

As it is matched to the Pertronix ignition (their recommendation) - would run what they recommend, otherwise you may experience other issues (like a failed ignition component).
Click to expand...

This sounds like good advice to me.

Your coil is 1.5 ohm, correct for 6 volt. Are you still 6 volt?
 
19Fordy said:
tubman, Thanks. I appreciate your suggestions and knowledge. Here's some interesting about BOSCH BLUE COILs.
https://vwparts.aircooled.net/12V-Bosch-Blue-Coil-with-Mounting-Bracket-00-012-p/00-012us.htm

When I bought the Pertronix kit (ML-181)it came with the Pertronix coil # 40001 with 1.5 ohm primary resistance. I not using a condenser or a ballast resistor.

My distributor is a Mallory YL 2527501 Series 25 dual point unit converted to a Pertronix using their ML-181 kit. Pertronix told me to use their Flamethrower 1.5 ohm coil, not the 3 ohm coil.

The more I read, the more confused I get about what coil is the correct coil to use with my Pertronix.
Additional thoughts welcomed with open arms.
Thanks, JIM
Click to expand...


My understanding is Petronix needs a 1.5 ohm coil. I would suggest calling their help line if you are unsure. I've found then to be very helpful.
 
I think Bosch has been changing colors on some coils.

The key is getting a coil with the recommended primary ohms specification for any system. If the electronic system uses a coil that no one else produces then the customer is stuck with that brand. Most electronic systems use the 3 Ohm type with modern epoxy insulation but I've heard of problems with the Pertonix coils. Few automobile electronic systems are made with a single coil in this day and age so the single coil systems are mostly relegated to the aftermarket industry with overseas manufacture.

I think I'd try an Echlin with the same or recommended ohm value but a person just never knows what your going to get now days.
 
That damage is from too much current to the coil. Did you ever feel how hot the coil was getting? I'd run a coil with around 3.5 ohms resistance.
 
THANK YOU all for your answers.
Tim: I tried calling Pertronix help line but couldn't talk to a real person.
I posed this question as the more I read about selecting the right coil, the more confused I get. I called Pertronix today but couldn't get through and talk to a real person. Here's my question.

Several years ago I converted my Mallory YL 2527501 mechanical advance dual point distributer to electronic using the Pertronix kit ML-181. At that time I was told to use the Pertronix Flamethrower coil 40001 with 1.5 ohms primary resistance. I installed this coil without using a ballast resistor. However, I keep wondering if I should instead be using the Flamethrower coil with the 3 ohm primary resistance OR should I install a 1.5 ohm ballast resistor with the 1.5 ohm coil I am currently using? I am confused. Sorry about the redundancy but I don't want to do something stupid.
THANKS, JIM in FL
 
I talked to a Pertronix tech about coil resistance. You can run more resistance to reduce heat. Don't run less than the unit calls for. He said the only tradeoff using more resistance is less performance at high RPM. I don't think that is a problem with a flathead.
 
You must log in or register to reply here.
Back
Top