Pertronix coil

G

Geo.T

Member
I read somewhere that the Pertronix 4011 (1.5 ohms) Flame-Thrower coil was the best coil available for the model A. I ordered one for my 6v positive ground "A" which arrived today.
On the box it states:

"1.5 ohm coils suitable for 8 cylinder engines; use a 3.0 ohm coils for 6 and 4 cylinder engines except for racing applications, where 1.5 ohm coils may be used."

I always understood that the model A should have a 1.5 ohm coil. I see that Less Andrew's book states that the actual measurement should be in the range of 1.6 to 1.8 ohms. Did I go wrong here?
Should I install this coil?
Many thanks,
George
 
Hi George,

I called for a technical person at Petronix for a recommendation for a 1930 Model A (4) cylinder Ford engine, with a 6 volt positive ground battery & standard original Ford distributor, whereby he recommended Petronix Part #40111, Coil F-T, (1.5 ohm).

I got the black epoxy Flame Thrower in lieu of the chrome model which works just great.

Are you sure yours is not #40111 in lieu of #4011?

With 6 volts you should be able to burn the hair off of a rat in 10 feet deep water.
 
I use the 3.0 ohm version on my 12 volt positive ground with original points distributor model A and couldn't be happier. Six volt cars would use the 1.5 ohm version. Neither of these coils need an external resister. Both are 40.000 volt. It doesn't matter how many cylinders, the coil fires the ignition no matter how many cylinders. I can't imagine why they add confusing words about the number of cylinders. The name Flame thrower and 40.000 volts scares the hell out of many. I was after hotter spark and improved performance and the flame thrower delivers for me
 
I and many others have had the Pertronix Flamethrower coil fail in a 12V application on a Corvette. Perhaps it will be better in a 6V application but I for one will never use one of their coils again. In my opinion, their ignition system (for 12V) is great, Their coils, not so much so,
 
I too have had a failed 12v Pertronix Flame Thrower Coil in my Model A. It was failing intermittently when it got hot. However, Pertronix replaced it for free. On rare occasions, I've continued to experience intermittent ignition problems which I've not yet found a smoking gun for, and I wonder if my replacement 12v Pertronix Flame Thrower coil might be the culprit. Therefore, I am looking for an alternate 12v epoxy-filled coil that I can use, mounted upside down like the original coil. I welcome recommendations; thanks.
 
Pat Martone said:
I too have had a failed 12v Pertronix Flame Thrower Coil in my Model A. It was failing intermittently when it got hot. However, Pertronix replaced it for free. On rare occasions, I've continued to experience intermittent ignition problems which I've not yet found a smoking gun for, and I wonder if my replacement 12v Pertronix Flame Thrower coil might be the culprit. Therefore, I am looking for an alternate 12v epoxy-filled coil that I can use, mounted upside down like the original coil. I welcome recommendations; thanks.
Click to expand...

This is what I have on mine. Need ballast resistor if using points though. I have an MSD ignition so I don't need the resistor.http://www.msdignition.com/Products/Coils/Race/8222_-_High_Vibration_Blaster_Coil.aspx
 
Thanks, but I'm looking for a 12v upside down (solid, not liquid core) mounted coil that doesn't require a resistor, for use with my stock points. I recall someone had NAPA part numbers for a coil that I could use?
 
1930 coupe said:
Custom extra high voltage coils have no advantage in a low RPM - low compression model A engine. They might benefit a NASCAR engine but they are not needed in a model A engine. The extra voltage can also cause arcing inside the distributor and cause very difficult to troubleshoot problems.
Click to expand...

i agree, ----- as an apprentice school from day one, (the 50s), and classes since it has been explained to us that a coil only puts out what is required at any set time, the idea that a coil will put 40.000 volts all the time is a misconception, it will under heavy loading such as high RPM and compression, anybody that as used an oscilloscope will know this
 
A few years ago I bought two such coils, one a 12-volt version for a 29 coupe I had, the other a 6-volt version for my Victoria. On a long tour from Southern California to Yellowstone the Vic started acting up in hot weather north of Las Vegas (like 105 ambient). Every time I stopped for gas the car would start, but cough an sputter until I was back up to cruising speed. This went on for a number of days until we reached cold weather at Yellowstone. During the time the car ran bad I changed everything out, Carburetor, distributor, spark plugs, but not the coil because I didn't have a spare.

On the return trip through hot country it acted up again. A week or so after returning home the car wouldn't start at all and I replaced the coil and it fired right up and ran well.

A while later I went on a tour with the 29 coupe out to Palm Springs. The weather was very hot and the coupe started acting up just like the Vic had. I immediately pulled over and replaced the coil with the original I had taken off and all was well.

I later contacted the retailer I had bought the two coils from. I had bought them from a company on the internet. I explained the difficulty I had had with them. My contact was very courteous and asked me to send them back to him.
Upon receipt he advised me he had received them and had sent them back to the manufacturer for testing. About a week later the retailer contacted me and said both coils had tested ok. I asked if they were tested under heat and load. He immediately contacted the manufacturer and passed my question along. A week or so later the answer came back that they had not because their heat and load testing equipment was in storage.

Needless to say I saw no further need to pursue this project. I never did hear again from either the manufacturer or retailer, nor did I ever see or hear of the two coils again. I chalked it up to a lesson learned.

The moral to this story is leave it the way Henry ordered, it works just fine that way.

Tom Endy
 
Individual different opinions & individual different experiences reported should always be respected for many different reasons.

For example, years ago, some may remember hearing from intelligent & knowledgeable senior mechanics born prior to WWI that the last electrical item to fail on any car or tractor was the coil.

The main difference was that "all" coils back then were manufactured in the US under strict quality control standards.

Then coil manufacturers began making cheaper coils outside the US whereby they paid much less for labor & naturally quality took a dive.

My experience is that today, coils are far more likely to fail.

This vintage US quality control does not exist today with foreign made products; hence, we witness all of these unpredictable honest individual experiences & honest opinions drawn from said different experiences.
 
why not get a 6V coil directly from FSI ignitions? they are one of the few sources left of American made 6V coil. It will be 1.5 ohms or close.

Per FSI the 12 V coils (3.0 ohms, and thus having an internal resistor since the windings are actually 6V) are from overseas and thus in my opinion already half-way to the scrap heap.

In a 12 V system what have you accomplished by moving the ballast resistor from outside the coil to inside the coil? Simple: you have added all the heat from the resistor to the coil itself, which runs hot enough by itself. Thus you have shortened its life. Is this really what you want? There is nothing wrong with an external ballast; get the heat away from the coil. If you are 12V then you are already not stock so what does the external ballast resistor matter?

If you think about it, if a coil were actually wound for 12V (meaning no resistor required) then the physical size would be twice what they are now!

I agree with Purdy that a coil does not care how many cyls. the car has. Perhaps the engineer who wrote that had been out in the hot sun too long.
 
tbirdtbird,

Your info makes sense to me; thanks.

I guess my next step will be to use a solid core 6v coil with ballast resistor.

Since I am running 12v, do you have a recommended coil and ballast (resistor) that I can get at a local NAPA, or on-line?

Thanks.
 
1930 coupe said:
Custom extra high voltage coils have no advantage in a low RPM - low compression model A engine. They might benefit a NASCAR engine but they are not needed in a model A engine. The extra voltage can also cause arcing inside the distributor and cause very difficult to troubleshoot problems.
Click to expand...

I agree completely with 1930 coupe. A high voltage coil will do nothing for a Model A engine.

Joe
 
I am stumped, unless they used a finer wire gauge for the primary

My main point was to keep the ballast resistor outside the coil because of heat buildup, and the poor quality of overseas coils
 
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