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I have purchased a Pertronix Ignitor for my BJ8. I have measured the resistance on my new Moss coil at about .5 ohms. Pertronix requires a minimum of 1.5 ohms. I do not want to add a ballast resistor in the wiring. I am confused on whether to buy a ballasted coil to resolve this. I believe that the balasted coils are ~ 1.5 ohms and the non-balasted are ~ 3.0 ohms. Will both work? Are there any advantages to the ballasted type? Additionally, any ideas on why my new coil only shows .5 ohms? It is a Moss #543-020 which I think is a 3 ohm coil. Thanks for you help.
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Pertronix Installation
- Thread starter Greg
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Hi Greg,
As you say, Pertronix requires a minimum 1.5 ohm coil for the six cylinder. The original coils are about 3 ohm. A 3 ohm coil should work ok. You could get a little more output by going to a 1.5 ohm coil such as the #40011 with the Pertronix. The Pertronix can handle a little more current than the points could.
I think that the Moss #543-020 should be a 3 ohm coil. don't know why it measures .5 ohms. Maybe meter error, maybe the wrong coil. What does your old coil measure?
Some cars used a 1.5 ohm coil with a 1.5 ohm ballast to get more starting voltage. To use a ballast setup you would need extra wiring & switching to bypass the ballast during starting only. If you used a 1.5 ohm coil with points & no ballast switching the point life would be pretty short. None of the big healeys had an external ballast or the switching for it so this is not a issue.
A so called "ballasted" coil just has the equivalent of a ballast resistor inside it. The windings have 3 ohms resistance instead of 1.5 ohms.
A few coil specs that I could find;
Lucas LA12 = 3 ohms
Lucas HA12 = 3 ohms
Lucas DLB105 Sport = 2.6 ohms
Lucas 16C6 = 1.3 ohms
Pertronix H40501 = 2.8 ohms
Pertronix 40011 = 1.2 ohms
The very early Pertronix units had some true reliability issues such as the magnets coming loose or moving & internal failures which were corrected quite a while ago. The most frequent problem now is folks connecting things wrong or using a coil with too low resistance. However some folks have a long memory & still can't get past the original problems. You can install as "super" an ignition as you can afford but it is mostly wasted on an engine which is turning less than 7 thousand rpm. I have a couple of MSD "super" ignitions on the shelf which I would not consider using on a non race car application. They were left over from a Mustang Turbo plus nitrous oxide project which really needed the best ignition. My Healey got a Pertronix with 3 ohm coil. No complaints.
Good luck,
D
As you say, Pertronix requires a minimum 1.5 ohm coil for the six cylinder. The original coils are about 3 ohm. A 3 ohm coil should work ok. You could get a little more output by going to a 1.5 ohm coil such as the #40011 with the Pertronix. The Pertronix can handle a little more current than the points could.
I think that the Moss #543-020 should be a 3 ohm coil. don't know why it measures .5 ohms. Maybe meter error, maybe the wrong coil. What does your old coil measure?
Some cars used a 1.5 ohm coil with a 1.5 ohm ballast to get more starting voltage. To use a ballast setup you would need extra wiring & switching to bypass the ballast during starting only. If you used a 1.5 ohm coil with points & no ballast switching the point life would be pretty short. None of the big healeys had an external ballast or the switching for it so this is not a issue.
A so called "ballasted" coil just has the equivalent of a ballast resistor inside it. The windings have 3 ohms resistance instead of 1.5 ohms.
A few coil specs that I could find;
Lucas LA12 = 3 ohms
Lucas HA12 = 3 ohms
Lucas DLB105 Sport = 2.6 ohms
Lucas 16C6 = 1.3 ohms
Pertronix H40501 = 2.8 ohms
Pertronix 40011 = 1.2 ohms
The very early Pertronix units had some true reliability issues such as the magnets coming loose or moving & internal failures which were corrected quite a while ago. The most frequent problem now is folks connecting things wrong or using a coil with too low resistance. However some folks have a long memory & still can't get past the original problems. You can install as "super" an ignition as you can afford but it is mostly wasted on an engine which is turning less than 7 thousand rpm. I have a couple of MSD "super" ignitions on the shelf which I would not consider using on a non race car application. They were left over from a Mustang Turbo plus nitrous oxide project which really needed the best ignition. My Healey got a Pertronix with 3 ohm coil. No complaints.
Good luck,
D
Greg,
First get rid of the Pentronix ignition kit… On my TR6 I installed two of them before finally wised up and purchased a Crane XR3000. The first Pentronix module failed and the second one the magnets moved. I have been running the Crane for about four years now without an issue. With the Pentronix I always kept the old points in the glove compartment just in case it would die again on the road. I plan installing a Crane XR3000 in by BJ7 when the restoration gets to that point.
Terry
First get rid of the Pentronix ignition kit… On my TR6 I installed two of them before finally wised up and purchased a Crane XR3000. The first Pentronix module failed and the second one the magnets moved. I have been running the Crane for about four years now without an issue. With the Pentronix I always kept the old points in the glove compartment just in case it would die again on the road. I plan installing a Crane XR3000 in by BJ7 when the restoration gets to that point.
Terry
Here's an article I wrote some time ago about installin the Pertronix in an BJ8. It really madethe car run better. it's still in the car, providing a smooth idle and strong spark.
Pertronix in BJ8
Here is a link warning of some of the common Pertronix pitfalls:
Pertxonix warning
Pertronix in BJ8
Here is a link warning of some of the common Pertronix pitfalls:
Pertxonix warning
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Hi Thom,
You wrote a pretty nice article.
The Mini link is good also.
For folks who want to try static timing, I have found that placing a 12 volt meter across the coil terminals gives a good indication of when the Pert. has just fired.
D
You wrote a pretty nice article.
The Mini link is good also.
For folks who want to try static timing, I have found that placing a 12 volt meter across the coil terminals gives a good indication of when the Pert. has just fired.
D
Thanks to Tahoe Healey, I have the necessary info to do an article on converting + Ground Tachs to - Ground and I have a "quickie" about adding a fuse to the lighting circui tthat can be quickly removed for concourse situations.
I just need the time to put the bits together and do a little writing. Sometime in 2004 .............
I just need the time to put the bits together and do a little writing. Sometime in 2004 .............
About the failure on the early Pertronix, I have to agree. My Brother had replaced two units he got in Germany. I got one from Pertronix and send it to Germany, he install and the car runs since 1998 with out any trouble. I have my unit in a 3000 since 1996 and never touched the timing again. The best thing for a low rev AH.
Johnny
Darth Vader
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<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>
Here is a link warning of some of the common Pertronix pitfalls:
Pertxonix warning[/QB]<hr></blockquote>
Are you saying this quote is no longer True?
"Carl says if the key is left on for more than 30-45 seconds, the unit can be damaged from overheating.
Carl also says the correct way to static time is to hook a 12 volt light bulb between the NEGATIVE terminal on the coil and ground. When the light changes brightness, that's your firing point.
In my opinon.....leave the Pertonix out until you've got her running and all dialed in."
Can't see any reason to install an electronic ignition, at least not yet. But then again I'm not driving the car that much, yet.
Here is a link warning of some of the common Pertronix pitfalls:
Pertxonix warning[/QB]<hr></blockquote>
Are you saying this quote is no longer True?
"Carl says if the key is left on for more than 30-45 seconds, the unit can be damaged from overheating.
Carl also says the correct way to static time is to hook a 12 volt light bulb between the NEGATIVE terminal on the coil and ground. When the light changes brightness, that's your firing point.
In my opinon.....leave the Pertonix out until you've got her running and all dialed in."
Can't see any reason to install an electronic ignition, at least not yet. But then again I'm not driving the car that much, yet.
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<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Johnny:
Are you saying this quote is no longer True?
"Carl says if the key is left on for more than 30-45 seconds, the unit can be damaged from overheating.
Carl also says the correct way to static time is to hook a 12 volt light bulb between the NEGATIVE terminal on the coil and ground. When the light changes brightness, that's your firing point.
<hr></blockquote>
J,
The overheating part may be true under certain conditions. It has mostly to do with what resistance coil is used. A 1.5 ohm coil would cause about twice the wattage to be dissapated in the Pertronix compared to the 3 ohm coil. This being said, I left a Pert. with a 3 ohm coil energized for four hours with no serious heating. I have no reason to think that a 1.5 ohm coil would seriously overheat for an hour or two.
Even a standard point ignition will get the coil fairly hot if it is left on long enough. Common sense rules.
The part about static timing is correct.
D
Are you saying this quote is no longer True?
"Carl says if the key is left on for more than 30-45 seconds, the unit can be damaged from overheating.
Carl also says the correct way to static time is to hook a 12 volt light bulb between the NEGATIVE terminal on the coil and ground. When the light changes brightness, that's your firing point.
J,
The overheating part may be true under certain conditions. It has mostly to do with what resistance coil is used. A 1.5 ohm coil would cause about twice the wattage to be dissapated in the Pertronix compared to the 3 ohm coil. This being said, I left a Pert. with a 3 ohm coil energized for four hours with no serious heating. I have no reason to think that a 1.5 ohm coil would seriously overheat for an hour or two.
Even a standard point ignition will get the coil fairly hot if it is left on long enough. Common sense rules.
The part about static timing is correct.
D