You need to go to electronic ignition system (GM H.E.I., Pertronix, GM T.I. system, etc., etc.) if you are going to have a "hot" coil in the system.
12V to coil
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Intermediate
Joined: Sep 2009
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From: Wichita KS
12V to coil
1974 big block; Wanting to run 12V to new flamethrower coil in the run position. Any suggestions re: where to pick-up a 12V source that is near the coil that is suitable to feed the coil?
Melting Slicks
Joined: Mar 2005
Posts: 2,838
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From: Austin TX
At the fuse box, you'll see a port that says "IGN" (ignition). Get some 14g braided white wire (white is the same color as the cotton insulated resistor wire that you're using now). Go from the IGN spade, through the firewall and on to the coil.
Without starting a war (see previous posts on the topic), the resistor wire reduces current (not voltage), in an effort to prevent the points from cooking. Still a good idea to bypass it if you're using the FlameThrower coil.
Without starting a war (see previous posts on the topic), the resistor wire reduces current (not voltage), in an effort to prevent the points from cooking. Still a good idea to bypass it if you're using the FlameThrower coil.
Last edited by 73, Dark Blue 454; Mar 24, 2011 at 11:58 AM.
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
73 is right. Current limiting is an important issue to keep in mind in any ignition system. With this new bling coil, what is the mechanism to keep the system from frying? Is there a limiter in the distributor (assuming you're bypassing the resistance wire), or is there a lot of resistance in the coil winding to keep the current to a safe level?
Melting Slicks
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2024 C3 of the Year Finalist - Unmodified
Melting Slicks
Joined: Mar 2005
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From: Austin TX
Agree with the above. Don't change to a hotter coil if you're still running points.
I assumed, that in addition to your new Pertronix Coil, you were also converting to the Pertronix Ignitor kit (which replaces the points).
I assumed, that in addition to your new Pertronix Coil, you were also converting to the Pertronix Ignitor kit (which replaces the points).
Melting Slicks
Joined: May 2009
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2024 C3 of the Year Finalist - Unmodified
Running a performance coil, if it stll has a matching impedance (which I assume is 1.5 ohms) will not trash the points. Jumpering the ballast resistor or resistor wire (which limit current) with a regular wire will burn the points and possibly harm the condensor, due to excessive current in the primary side of the ignition. Ask me how I know this.
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
It's been my experience that it's an argument between EE's and shadetree mechanics. No EE worth his salt is going to argue the ballast resistor/voltage regulation point.
