Prestolite with Mopar part 2

Discussion in 'Injection Tech' started by Meat Man, Oct 12, 2019.

  1. Meat Man

    Meat Man Farmall Cub

    Aug 15, 2003
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    Wamego, KS
    I wanted to replace Pertronix and didn't have a Holly dizzy. This is also for a carb, so I retained the vacuum advance.

    I used a pickup from 1980 Dodge truck (BWD ME2AP), and a module for 1980 Chevy truck (BWD CBE4P).

    Instructions in Bill's thread were spot on for disassembly and the general theory. The only departure was orientation of the pickup coil and moving the vacuum advance.

    I looked at the original pickup and it was directly inline with the pivot pin and the attachment pin for the vacuum arm. The Mopar pickup mounting will not allow it to be attached without modification. Trim off the "inside" ear of the pickup so it will clear the shaft. The baseplate needs an extension welded on to allow two screws to hold the coil. I used part of the Mopar baseplate and two heavy tacks.

    Drill and tap two holes to attach the pickup coil. I used 10 x 24 because it was the same pitch as the vac advance screws and I needed the same tap. I used the original slotted hole in the pickup and drilled a new one to act as the pivot to set the air gap.

    Set the air gap at 0.008".

    20190827_193750.jpg Extend baseplate.jpg
    Mopar plate reuse.jpg

    The vacuum advance had to be lowered. It has to lowered the same amount the baseplate is lowered. Lower everything 0.350". Bill's instructions reference 0.50", but I think that is too low.
    Use calipers to scribe the line and a cutoff wheel to remove the material. I lowered the factory holes the same amount and drill/tap new ones.
    Side note: I didn't go far enough the first time, the reluctor is not perfectly aligned (up and down) with the pickup, but it still runs.

    Now that the vacuum advance is lower, the cap does not have anything to index off of. I was going to weld on an extension, but I thought it would be better to just rivet it on. It is also attached using the screw that holds on the vacuum advance. The mounting slot for the clip also has to be bent upwards to get the clip close enough to the cap so it will latch.
    20190908_200055.jpg 20190908_201628.jpg

    Assemble and set the phasing as per Bill's original instructions. I used some foil tape and silicone to fill up the empty hole under the wire grommet for the pickup.

    Module mounting is standard fare in the other threads. Seems good so far! Only thing I have noticed is that it takes a couple revolutions to get the coil to fire, but after that is seems OK.

    Last edited: Nov 10, 2019

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