Replacing distributor pickup

[cu440da]

I found an old (really old) aftermarket Accel billet distributor for a 440 at a swap meet last year- missing the pickup and cap and rotor. After a lengthy call to Accel tech support, I finally got info on what it is and what parts are needed to get it back in use. (BTW- huge thanks to the support staff at Accel. I had no part # and little info to give him and he kept on digging and finally got me replacement part #'s.)

Its a 46000 series Billetech magnetic impulse distributor. Separates into a base that stays on engine, and a top section with simple advance adjustments. I have been able to find all the parts needed, except for the pickup. I feel I can adapt other replacement pickups from Accel, and other manufacturers, as well as a factory pickup. My question basically comes down to...

Will there be any marked difference between an aftermarket Accel or MSD magnetic pickup?
And can they only be used with an aftermarket capacative discharge style ignition?

Last question relates to the possibility that I may hide an HEI module under the base. If they are not compatable with HEI, I would have to adapt a factory pickup inside the housing.

 

[moe7404]

radio shack. photo beam. home made.

 

[cu440da]

Two issues with that...

1- Radio Shack is no longer in business.
2- How does that relate to my questions?

How does photo beam work? I have heard of them but know nothing about them. Is it better/ more accurate than a magnetic pickup?

 

[AJ/FormS]

I can only tell you what I know.
In the Chrysler system, the mag trigger sends an electrical impulse to the ECU, which translates it into an on/off signal(just like points do).It then uses that on/off signal to generate a more powerful signal to the coil. Thats all there is to that. The ECU does all the thinking,amplifying,and signaling.In theory,that ECU should run on any similar magnetic signal.
The optical trigger needs a different translator.
Every brand of ecu needs its matched trigger type. Some will accept different trigger types, using different input wires. The MSD is a very good example; It can be operated on at least 3 different types of triggers.
-As to which type of trigger is better;I cant say.I can say which is poorest, and that would be points, and only because of the maintenance factor.And they are somewhat RPM limited.I like the mag trigger.They are simple,maintenance-free, long lasting,and cheap devices.
-As to accuracy; in my opinion, The dizzy itself and its install,is the biggest contributor to inaccuracy.The Mopar dizzy is driven by the oilpump drive gear. The way that gear is driven, and the way it drives the dizzy are the problem.If there is any tendency for that drive gear to climb the spiral drive teeth, it alters the ignition timing;independently of what the dizzy should be calling for.
Can you post a pic of where the rotor fits, but with the rotor not mounted, but still in the pic?

 

[67Dart273]

If that dist is magnetic, it should be able to trigger either Mopar ECU, MSD, or HEI. "Polarity" matters on the pickup as it slightly changes timing / phase.

 

[AJ/FormS]

Oh yeah,polarity matters. Bigtime. And its impossible to mistake when its wrong.

 

[KitCarlson]

"Polarity" matters on the pickup as it slightly changes timing / phase.

That is a bit of an understatement. It will trigger between the teeth on the reluctor, that is off about crank 45 degrees. That puts trigger between cap terminals. The timing may also fluctuate because the trigger point is not well defined as the normal near tooth edge.

 

[AJ/FormS]

And once you get the idle timing back, it wont take but a tiny bit of throttle. If at that point you put a timing lite on it, youre in for a huge surprise. Although the idle timing is pretty stable, not so as the rpm gets off the screw. The timing lite goes crazy. With drop outs ambiguous numbers,and jumping all over the place. At least that was my experience.