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Pertronix distributor on an early BJ7

pschauss

Freshman Member
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I have an early BJ7 with the DM6A distributor and I am debating whether to replace my distributor with a Pertronix or have my existing one rebuilt. I installed a Pertronix on my MGB three years ago and it has performed very well for me. Looking at the information on Moss Motors site, however, I see that there would be some extra steps involved in fitting one of these to my car. They describe how you need to remove the drive dog from the Pertronix and drill an extra hole in the shaft in order to fit the existing drive dog. From looking at my shop manual, it looks like the part they want me to fit to the new distributor is the spindle which sits in the tachometer drive housing.

I would be interested in hearing from anyone who as actually tried this. Is it really as simple as the instructions from Moss describe it?

Thanks,
Peter Schauss
1963 BJ7
1980 MGB
 
Peter:
Installed a Pertronix on his MGB three years ago and it has performed very well .

Do the same thing on the BJ7--------YEP it is just like falling off a log it is so simple to install--:encouragement:
 
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Using the drive dog as a guide, and a sharp drill bit, it's an easy DIY job. A vise and a drill press would simplify things, but not mandatory.

I't not even all that critical where__circumferentially speaking__as wherever the number one firing spot lands is the new number one spot (for the sake of appearance, it doesn't hurt to try to be close, but x-number of degrees either way means nothing). The elevation of the new hole on the shaft is only slightly more critical, as you can't have the rotor bobbing up and down, and there must be room for thermal expansion to allow oil to pass.

I didn't have to jump through any hoops when fitting the drive dog to this Mallory distributor.

IMG_2892.jpg
 
If You go Pertronix, don't use stock solid copper plug wires.

I've run stock stranded copper wires with a Pertronix for over 70K miles with no problems. Newer, wrapped carbon fiber wires won't work--for long--with a stock distributor cap which pierces the wire and core.
 
I've run stock stranded copper wires with a Pertronix for over 70K miles with no problems. Newer, wrapped carbon fiber wires won't work--for long--with a stock distributor cap which pierces the wire and core.
True, You need a top load cap for spiral wires. Pertronix tech people e-mailed Me when I had a random miss-fire issue explaining that eventually the solid wires will cause the unit to burn out. Carbon wires cured the random miss.
 
True, You need a top load cap for spiral wires. Pertronix tech people e-mailed Me when I had a random miss-fire issue explaining that eventually the solid wires will cause the unit to burn out. Carbon wires cured the random miss.

I've been generally impressed with Pertronix support--spoken to them a few times--but I'm having trouble understanding that logic. The Pertronix is electrically isolated from the output voltage by the coil, but there may be some other issue but, since I'm not an EE, I don't know what it could be. I run resistor plugs--I think the nominal resistance is 15 (or 150?) KOhms, and that would limit the spark current somewhat. The only time I've had misses with a Pertronix was when I tried to run new-fangled, carbon core wires with the side-output cap.
 
I've been generally impressed with Pertronix support--spoken to them a few times--but I'm having trouble understanding that logic. .

Well BOB:
Don't loose no sleep over it they was dreaming----:highly_amused:
 
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