Coil Voltage ???

[IndyA]

While trying to isolate a motor problem in my '29 coupe, I dug into a box of parts that came with the car to get another coil to install... It was marked "12V"... put it on. Later resolved the problem (not the coil) ... Question.. can I keep this one on the car even though the car has the traditional 6 volts system ??... Thanks

[katy]

Check the resistance of the primary windings, it they are around 1.5 ohms you can use it with a 6 volt system.

[IndyA]

Katy... thanks for the fast response... do I put my multi-meter on the negative coil terminal and ground to test the resistance of the primary coil ???? IndyA

[California Travieso]

Katy . . . How do you test the secondary winding, and what is the value? I got a coil at a Swap Meet and Googled some articles on testing coils but they didn't give the values for either the primary or secondary windings.

David Serrano

[40 Deluxe]

Originally Posted by IndyA

Katy... thanks for the fast response... do I put my multi-meter on the negative coil terminal and ground to test the resistance of the primary coil ???? IndyA

Connect your ohm meter leads to the primary terminals, not ground. Disconnect the wires first.

[eagle]

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If it throws a good spark it is just fine to use.

[katy]

Connect your ohm meter leads to the primary terminals, not ground. Disconnect the wires first.

Ditto

Regarding the resistance of the primary windings,
6 volt coil should be aprox 1.5 ohms.
A 12 volt coil that uses an external "ballast resistor" is usually also around 1.5 to 1.7 ohms and will work fine on 6 volts.
Some 12 volt coils have a built-in resistor and are usually around 3 ohms.

[gustafson]

Some say you should only use a performance coil. I am not one of them

[Purdy Swoft]

I don't remember ever hearing anybody say that a person should only use a performance coil . It is a matter of choice !!! Before trying the Pertronix flame thrower coil , I had never heard of anybody using one on their model A . The Pertronix flame thrower coils are offered in both 1.5 and 3 OHM like most other coils. I prefer the 3 OHM coil on 12 volts simply because it doesn't require the use of a ballast resister . Resisters don't look original on the model A and they get very hot.. I personally could care less what type coil that a person uses . Being my own man , I make my own choices . If the type coil that I use didn't preform flawlessly I wouldn't use it .

[Purdy Swoft]

Who said that anything was wrong with original model A coils . If in good condition original coils are probably better , stronger and of course prettier than most standard over the counter coils . I prefer performance coils on some of my cars . There is not necessarily anything wrong with original . Some are interested in upgrades. Some onlywant original for show purposes. A lot comes down to whether the car will be an ocaisional driver or a mostly
trailored show car . Its freedom of choice , if thats over your head , too bad !!!

PS If you pay close attention , you may learn something !!!

[gustafson]

HaHa If everyone would pay close attention we would all learn something!!!

[Cape Codder]

I have read that the Pertronix flame thrower coil or similar product which produces too much voltage, therefore, wearing the points much quicker than a regular Model A Coil. has anyone experienced this?

[gustafson]

We have removed such coils here because of this issue, and cross firing between cyls due to excess voltage leak

[Purdy Swoft]

The mention of 40.000 volts scares some people . I'm still running the same original style points that I got from Brattons in 06 when I installed the coil .

[29er]

Originally Posted by Purdy Swoft

The mention of 40.000 volts scares some people . I'm still running the same original style points that I got from Brattons in 06 when I installed the coil .

Roger that. I've got > 7,000 miles on my coupe with a Pertronix Flame Thrower 1.5 ohm coil and original points. "Power you can feel in the seat of your pants"!

[Tom Wesenberg]

Originally Posted by 29er

Roger that. I've got > 7,000 miles on my coupe with a Pertronix Flame Thrower 1.5 ohm coil and original points. "Power you can feel in the seat of your pants"!

Yep, that's the exact experience a worker had at the yard where I worked. Someone wired the coil to the driver's seat spring, and the driver felt the power in the seat of his pants. True story.

[Mike V. Florida]

The voltage and current at the points is the same no matter what coil or points you use if the resistance of the coil is about 1.5 ohms for 6 volt and about 3 for 12 volt. The 20 or 40.000 volts do not go through the points.

[Purdy Swoft]

Originally Posted by 29er

Roger that. I've got > 7,000 miles on my coupe with a Pertronix Flame Thrower 1.5 ohm coil and original points. "Power you can feel in the seat of your pants"!

Thanks 29er for telling it like it is .The flame thrower coil gives power that a person can feel and we ain't talking about getting shocked . Some can't seem to understand this and it scares the hell out of them . The spark comes from the coil . Hotter spark in most cases increases power .

[Purdy Swoft]

Originally Posted by 2831A’s

Coils, brakes , FP regulators over and over. Whats wrong with stock

You obviously have a lot to learn, Manners being number one . Reading all of your posts doesn't really share any model A information that could be useful to anyone , whether it be original or aftermarket upgrades . Your ignorance and rudeness is obvious.

[gustafson]

"Hotter spark in most cases increases power"
We'll have to assume this is opinion. Are you able to cite an independent writeup from the automotive engineering trade?
Does an increase in spark to 80,000 make even more power?

Power is determined by the CR and cam specs. Once the charge is lit, no matter the voltage, the flame front is the same.
Readers are being led to believe that the stock system is inadequate.

See #12