Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 08-10-2018, 09:40 AM   #1
IndyA
Junior Member
 
Join Date: Dec 2016
Posts: 27
Default Coil Voltage ???

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
IndyA is offline   Reply With Quote
Old 08-10-2018, 09:43 AM   #2
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 1,479
Default Re: Coil Voltage ???

Check the resistance of the primary windings, it they are around 1.5 ohms you can use it with a 6 volt system.
__________________
Talk slow, think fast.
katy is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 08-10-2018, 10:05 AM   #3
IndyA
Junior Member
 
Join Date: Dec 2016
Posts: 27
Default Re: Coil Voltage ???

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
IndyA is offline   Reply With Quote
Old 08-10-2018, 01:23 PM   #4
California Travieso
Senior Member
 
Join Date: Mar 2014
Location: Moreno Valley, CA
Posts: 481
Send a message via Yahoo to California Travieso
Default Re: Coil Voltage ???

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
California Travieso is online now   Reply With Quote
Old 08-10-2018, 07:34 PM   #5
40 Deluxe
Senior Member
 
Join Date: May 2010
Location: now Kuna, Idaho
Posts: 2,555
Default Re: Coil Voltage ???

Quote:
Originally Posted by IndyA View Post
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.
40 Deluxe is online now   Reply With Quote
Old 08-11-2018, 08:20 AM   #6
eagle
Senior Member
 
eagle's Avatar
 
Join Date: Aug 2011
Location: Eagle Bend, MN
Posts: 1,333
Default Re: Coil Voltage ???

If it throws a good spark it is just fine to use.
__________________
"There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."
eagle is offline   Reply With Quote
Old 08-11-2018, 08:53 AM   #7
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 1,479
Default Re: Coil Voltage ???

Quote:
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.
__________________
Talk slow, think fast.
katy is offline   Reply With Quote
Old 08-12-2018, 12:00 PM   #8
gustafson
BANNED
 
Join Date: Oct 2017
Posts: 128
Default Re: Coil Voltage ???

Some say you should only use a performance coil. I am not one of them
gustafson is offline   Reply With Quote
Old 08-12-2018, 02:20 PM   #9
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,652
Default Re: Coil Voltage ???

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 is offline   Reply With Quote
Old 08-12-2018, 05:31 PM   #10
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,652
Default Re: Coil Voltage ???

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 !!!

Last edited by Purdy Swoft; 08-12-2018 at 05:36 PM.
Purdy Swoft is offline   Reply With Quote
Old 08-12-2018, 07:43 PM   #11
gustafson
BANNED
 
Join Date: Oct 2017
Posts: 128
Default Re: Coil Voltage ???

HaHa If everyone would pay close attention we would all learn something!!!
gustafson is offline   Reply With Quote
Old 08-12-2018, 08:19 PM   #12
Cape Codder
Senior Member
 
Cape Codder's Avatar
 
Join Date: May 2010
Posts: 920
Default Re: Coil Voltage ???

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?
Cape Codder is offline   Reply With Quote
Old 08-12-2018, 08:47 PM   #13
gustafson
BANNED
 
Join Date: Oct 2017
Posts: 128
Default Re: Coil Voltage ???

We have removed such coils here because of this issue, and cross firing between cyls due to excess voltage leak
gustafson is offline   Reply With Quote
Old 08-12-2018, 08:58 PM   #14
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,652
Default Re: Coil Voltage ???

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 .
Purdy Swoft is offline   Reply With Quote
Old 08-12-2018, 09:30 PM   #15
29er
Senior Member
 
29er's Avatar
 
Join Date: Apr 2013
Location: Oregon
Posts: 460
Default Re: Coil Voltage ???

Quote:
Originally Posted by Purdy Swoft View Post
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"!
29er is offline   Reply With Quote
Old 08-12-2018, 10:04 PM   #16
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 27,122
Default Re: Coil Voltage ???

Quote:
Originally Posted by 29er View Post
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.
Tom Wesenberg is offline   Reply With Quote
Old 08-12-2018, 10:32 PM   #17
Mike V. Florida
Senior Member
 
Mike V. Florida's Avatar
 
Join Date: May 2010
Location: South Florida
Posts: 13,750
Send a message via AIM to Mike V. Florida
Default Re: Coil Voltage ???

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.
__________________
What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

Last edited by Mike V. Florida; 08-12-2018 at 10:41 PM.
Mike V. Florida is offline   Reply With Quote
Old 08-13-2018, 12:38 PM   #18
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,652
Default Re: Coil Voltage ???

Quote:
Originally Posted by 29er View Post
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 .

Last edited by Purdy Swoft; 08-13-2018 at 06:49 PM.
Purdy Swoft is offline   Reply With Quote
Old 08-13-2018, 01:00 PM   #19
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,652
Default Re: Coil Voltage ???

Quote:
Originally Posted by 2831As View Post
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.
Purdy Swoft is offline   Reply With Quote
Old 08-13-2018, 01:27 PM   #20
gustafson
BANNED
 
Join Date: Oct 2017
Posts: 128
Default Re: Coil Voltage ???

"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
gustafson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 06:59 PM.