Intermotor or Lucas Sport Coil ?

My BJ8 has the ‘standard’ basic coil and I wonder if anyone has used either the Intermotor or Lucas Sport coil. If so, do they give any noticeable improvement of any kind?

SteveHall64Healey said:

My BJ8 has the ‘standard’ basic coil and I wonder if anyone has used either the Intermotor or Lucas Sport coil. If so, do they give any noticeable improvement of any kind?

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If you have the standard coil that came with your car, it is likely more reliable than the modern replacements, which have had quality problems.

The coil that came with my car looks to be about 10 years old - definitely not original...

steveg said:

If you have the standard coil that came with your car, it is likely more reliable than the modern replacements, which have had quality problems.

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I'll second that. My BJ8, with about 210K miles, is still running its original coil (with a dent in it, even). AFAIK, an 'uprated' coil capable of producing a hotter spark--with a larger plug gap--would only be beneficial in a highly-modded engine with compression over the nominal 9.1:1, and you'd need to upgrade the entire ignition system to prevent cross-firing.

Bob_Spidell said:

I'll second that. My BJ8, with about 210K miles, is still running its original coil (with a dent in it, even). AFAIK, an 'uprated' coil capable of producing a hotter spark--with a larger plug gap--would only be beneficial in a highly-modded engine with compression over the nominal 9.1:1, and you'd need to upgrade the entire ignition system to prevent cross-firing.

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Thanks Bob. The existing coil is working just fine and this may be a case of leaving well enough alone. My compression is approximately 9.4:1 according to the firm that rebuilt it and I am running a Pertronix Ignitor 1 ignition. When you say upgrade the entire system, what beyond the wires would that entail?

Thanks
Steve

FWIW - Advanced Distributors sells top entry caps for the BJ8 which will accept modern push-in wires.

Just to close the loop on this. I did purchase a Petronix Flamethrower coil and installed it with the existing Lucas distributor cap and solid core wire set.

Although there was nothing really wrong with the standard coil that it replaces, the change has been worthwhile.

I checked for arcing between wires and found no visible arcing when running the engine in pitch darkness. (I am using the stock black HT leads fro Ahead 4 Healeys). I’ve dealt with bad HT leads before and observed a visible blue plasma between the leads before changing out the wires. I saw nothing resembling this.

I have found that the car starts a more quickly, runs at a slightly higher RPM for the same level of choke on warm-up and when I push the car (eg 4000-4500 RPM) it feels a bit stronger at higher RPM and all the way through the rev range. Nothing dramatic, but positive subtle improvements over a week’s driving.

If I remember correctly, the Pertronix ignition does not like solid wires if You are using that as well.

I used solid (metal stranded) wires for many years with no problems on my previous Pertronix I setup. On their site, IIRC, they now recommend against that. Pertronix II requires modern wires.

Sorry, I neglected to mention that my ignition system is the Petronix Ignitor 1, which uses solid core wires. I’ve been running solid core wires with this system for about 8 years now.
steve

SteveHall64Healey said:

Sorry, I neglected to mention that my ignition system is the Petronix Ignitor 1, which uses solid core wires. I’ve been running solid core wires with this system for about 8 years now.
steve

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I've had a 'I' on my BJ8 for, oh, 15-20 years with stranded wires. The 'II' is not available for positive ground, unfortunately (it has some advantages over the I).

Bob, I have a positive ground car so Petronix II is not an option unless I change to negative ground. What are the benefits of the II ?

Interesting :

That solid wire was used by some.

However , the principal reasons for changing to stranded wire was:

1 It lowered tre electrical résistance allowing more energy to the plugs , but contributed to generating electrmagnetic interference , not so mucch a problem back in the day
:
2 it significantly reduced the potentil for wire breakage , by making the wire more flexible.

SteveHall64Healey said:

Bob, I have a positive ground car so Petronix II is not an option unless I change to negative ground. What are the benefits of the II ?

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Pertronix lists the differences pretty succinctly here: https://pertronix.com/categories

... and here: https://pertronix.com/electronic-ignition-conversions/ignitor-ii.html

Perhaps the most useful is the II supposedly won't fry if you accidentally leave the key in the 'run' position for more than a couple minutes.