What coil..?

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Moparbaker

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One of my cars have a -89 318 with only (& so far) heades, intake & carb done, & it's just a daily driver but later on a wilder cam & stuff is gonna be done to it. The other day it just died & stated after a while & next day too so I figured the -77 coil is showing its age.
Then planning ahead...
So I've looked into MSD Blaster 2 & also ACCEL Super Stock but I wonder if there's any use for any of them, what d'ya all think?

& what about resistor..?
The reason for that question is that I have a new standard coil laying but it's "for no reststor" & ofcourse my car has a resistor... So what would happen if I would use that one?
 
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One of my cars have a -89 318 with only (& so far) heades, intake & carb done, & it's just a daily driver but later on a wilder cam & stuff is gonna be done to it. The other day it just died & stated after a while & next day too so I figured the -77 coil is showing its age.
Then planning ahead...
So I've looked into MSD Blaster 2 & also ACCEL Super Stock but I wonder if there's any use for any of them, what d'ya all think?

& what about resistor..?
The reason for that question is that I have a new standard one laying but it's "for no reststor" & ofcourse my ca has a resistor... So what would happen if I would use that one?
Keep the resistor you need it for your stock ignition box.
I run a Pertronix coil on my 340
The first coil was a MSD blaster 2 it lasted about 2 months before it pucked and left me on the side of the road.
 
Are Andover Coils still around? They were American made, and I thought there was a vendor here on FABO ????????????? :realcrazy:
 
the big square-top Accell Super coil is a killer piece that usually lasts decades. It requires a matching resistor. Mine was new in 2004.
Kim, right here on FABO, had a 30 year old one for sale not long ago. check the Forsale section.
You can use that Chevy coil but it will want more input voltage than what comes out your dual-ballast, so you will have to jumper the supply. IDK if or how this will affect the ECU during cranking. I think it will be fine.
 
I would not be in the least afraid to continue using an old coil, nor would I particularly expect it to fail.....unless it is showing signs of damage or leakage
 
I reckon I'll go for the ACCEL Super Stock coil. (don't want the big ugly square one)
But what about my question about what would happen if I use the coil that is for non-resistor?
 
Stay away from the round type super coils, i had one tossed it in the trash after it died and left me stranded in an intersection.
 
I'm not throwing away the resistor, but I wonder what would happen if I use one that's supposed to be used without one..?
& by now I also wonder if many has had problems with the round high performance ones but not with the square ones?
 
I also wonder if a round oil-filled coil that has quit may have been mounted laying down on the engine..?
 
My did the same as yours. Would run till it got hot then die. it would start back up when it cooled down and it turned out it was the ECU.
You have to use the correct coil with the right ohm resistance coil and resistor to make you system reliable
 
I'm not throwing away the resistor, but I wonder what would happen if I use one that's supposed to be used without one..?
& by now I also wonder if many has had problems with the round high performance ones but not with the square ones?
The reason the resistor is there is to reduce voltage to the factory ECU. The coil is matched for the systems reduced voltage on factory ignition system. If you remove the resistor your factory ECU will have a short life.
Now if choose to use an aftermarket ECU and coil you may be able to run without a resistor it depends on the manufacture. You must match the coil with the ECU. The ohm rating of the coil is just as important for peak performance.
 
The reason the resistor is there is to reduce voltage to the factory ECU. The coil is matched for the systems reduced voltage on factory ignition system. If you remove the resistor your factory ECU will have a short life.
Now if choose to use an aftermarket ECU and coil you may be able to run without a resistor it depends on the manufacture. You must match the coil with the ECU. The ohm rating of the coil is just as important for peak performance.
I'm curious on all this as well as electrical is not my strong suit. Two questions:
  • IF you run points and a coil with a resistor in it (MSD II or Pertronix per say), do you need a ballast resistor?
  • IF you have a 4 pin ECU and a coil with a resistor in it, do you need a ballast resistor?
 
Total coil circuit resistance with the stock ECU is designed to be 3-4 ohms, when hot. This can be in the coil plus the ballast, or it can be in a higher resistance coil alone.

For stock coil + ballast, coil resistance is around 1.5 ohms and ballast is 0.6 ohms cold and around 2 ohms hot. (It takes about 30-60 seconds for the ballast to heat up to near final hot resistance.)

A 3 ohm 'no ballast' coil comes pretty close so seems to work OK. The hotter spark produced when starting cold (due to the low cold ballast resistance) is not present with a fixed 3 ohm coil. Using the ballast in series with a 3 ohm coil would reduce the coil current and thus spark energy, cold and hot, so you'll just end up with a weak spark if you try that.

I also wonder if a round oil-filled coil that has quit may have been mounted laying down on the engine..?
Flat mounted on the intake manifold was standard production on a number of Detroit V-8's; so your dead coil is probably just that.
 
I'm curious on all this as well as electrical is not my strong suit. Two questions:
  • IF you run points and a coil with a resistor in it (MSD II or Pertronix per say), do you need a ballast resistor?
  • IF you have a 4 pin ECU and a coil with a resistor in it, do you need a ballast resistor?
- Of course there are always exceptions to the rule.
I believe any time you run points you will need a resistor somewhere in the voltage supply to the system regardless if it is internal to the coil or mounted externally, like mounted on the firewall.
- No if a coil has an internal resistor you would not add another resistor in the system, as long as you are supplying the correct voltage for the ECU's voltage rating.
Perhaps there is another forum member who is better versed in this could chime in.
 
Are you sure that it is not your ECU on its way out? I have had Chrysler ECUs fail in exactly this manner.

If you have some spare parts available you are best to do some troubleshooting before throwing new parts at it.
 
- Of course there are always exceptions to the rule.
I believe any time you run points you will need a resistor somewhere in the voltage supply to the system regardless if it is internal to the coil or mounted externally, like mounted on the firewall.
- No if a coil has an internal resistor you would not add another resistor in the system, as long as you are supplying the correct voltage for the ECU's voltage rating.
Thanks! So a factory coil supplies about 7 volts WITH the firewall mounted resistor? And most coils with built-in resistors supplies about 9 volts? Is this right? And if so, will the extra 2 volts doom the ECU ? Thanks again
 
Thanks! So a factory coil supplies about 7 volts WITH the firewall mounted resistor? And most coils with built-in resistors supplies about 9 volts? Is this right? And if so, will the extra 2 volts doom the ECU ? Thanks again
The higher voltage may make the ECU run hotter, that cant be good in the long run.
 
The higher voltage is going to make the ECU run hotter, that cant be good in the long run.
then I guess the question is, what coil (part number, brand, link etc etc) could be used with the factory electronic ignition that would allow bypassing the ballast resistor. I think Andover Coils bragged about this, but I cannot find a dealer.
 
- Of course there are always exceptions to the rule.
I believe any time you run points you will need a resistor somewhere in the voltage supply to the system regardless if it is internal to the coil or mounted externally, like mounted on the firewall.
It is not so much a matter of points or not, but just having total circuit resistance for regulating the current: to a high enough value that will store adequate coil energy for each spark, and yet low enough so as to not burn things up (like the coil itself or the ECU). Flathead Fords had a problem of no ballast and they would burn up the coil if you left the ignition on but the engine was not running. The addition of an open air ballast resistor, with it's cold versus hot behavior, was a big step forward! (And ballast vacuum tubes had been invented prior to that for current regulation in electronics.)
 
then I guess the question is, what coil (part number, brand, link etc etc) could be used with the factory electronic ignition that would allow bypassing the ballast resistor. I think Andover Coils bragged about this, but I cannot find a dealer.
Boy you got me there.
You my want to call Don at FBO ignitions, I run his ignition system, he is very knowledgeable and has been around for a long time.
Good luck
 
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