Ignition help

[98Redline]

67 BJ8 with a Crane XR700 ignition and optical pickup installed. PO had someone install this unit for them. Also the car has been changed to Negative ground.

No spark and after much troubleshooting I am relatively certain the XR700 is dead (It is an older box without the diagnostic LED). I have also found out the system is running a 1.5 ohm coil with no apparent ballast resistor installed.
I did the ballast resistor ID procedure from the Crane manual and the voltage from Coil(+) to ground will drop from 12.67v to 10.08v when I temporarily ground the Coil(-) terminal. The Crane manual says that anything above 8V has no ballast installed.

I am sure that the lack of ballast may have caused the premature demise of the XR700.


So now on to the fix.
I have looked at a number of units for replacing the ignition, and even looked at possibly going back to conventional points (not my first choice).

So what would the collective group suggest as the best replacement ignition?

Another XR700, Pertronix Flame Thrower, 123 Ignition?

I searched the archives but have not been able to find anything terribly conclusive.

 

[Keoke]

So what would you suggest as the best replacement ignition?



A Pertronix and a Lucas sport coil

 

[98Redline]

The sport coil over the Flame Thrower coil.....hmmm
Any particular reason or just good experience with the Lucas?

There seems to be a few threads out there on varoius LBC forums that say the Pertronix ignition needs to be matched to their coil to keep from cooking it in relatively short order.

Being a noob to the whole British car thing I am truly learning every day so I truly appreciate your insight.

-Greg

 

[Keoke]

r just good experience with the Lucas? Greg-----Keoke

 

[John Turney]

I have the XR700 and a Lucas sport coil and it's been working just fine for several years. Is your XR700 in a relatively cool spot?

(Of course, with my luck it will die as soon as I go to start it.)

 

[98Redline]

The XR700 is mounted on one of the supports just outboard of the distributor, however the car has not run in the last 12 months (long story). I tired to go out and start it and it would not fire up. I don't think the heat cooked it.

 

[98Redline]

So after looking into a bunch of ignitions, I decided to go with an MSD 6AL (thanks Randy Forbes!) and their recommended Blaster high vibration coil. I changed out the optical trigger from the old Crane unit with an mechanically identical Crane model that is compatible with the 6AL (715-0020). This meant that my original ignition timing could be used, eliminating one more potential pitfall.

After connecting the ignition up I decided to run a test just to check the spark from this units.

WOW! The 6AL throws a serious spark. When triggering the unit it fired the plug for a full 1/2 to 3/4 of a second! The literature says it is multiple sparks but to me it looked like a continuous blue arc.

When I tried to fire up the car for the first time I was very pleasantly surprised with a quick start on the 2nd try and a nice smooth idle.....with no choke.

Keep in mind that this car had been sitting for a year since it was last started and prior to that had only run about 15 minutes in the past 5 years. The gas was old and I am sure the carbs are pretty gummed up.

A quick road test yielded a smooth running engine that did not backfire or miss at all.

As of right now, I wouldn't have any hesitation of recommending this ignition to anyone looking to replace either their existing stock ignition or upgrade another electronic ignition.

Add to the fact that the 6AL has a built in rev limiter makes this a really nice unit.

 

[Randy Forbes]

Love it.