Rebuilding an Iron Duke distributor... (Page 1/1)
82-T/A [At Work] JUN 08, 05:10 PM
Sigh, ok... my daughter is rebuilding her distributor, and wouldn't you know it... the little magnetic piece that goes between the pickup coil and rotor surround broke. It's like a simple little ferrous piece of metal that sandwiches between the two brackets (for the better-style distributor). I can't find anywhere that they sell these pieces separately. I just had to order a whole new cheaper rebuilt distributor just so that I could get that one part from it so she could finish rebuilding the distributor. Totally ridiculous...
Vintage-Nut JUN 09, 09:59 AM

quote
82-T/A:
I can't find anywhere that they sell these pieces separately.



BTW
I found and got the separate parts needed when rebuilding my V6 distributor by using the "1984-1988 Pontiac P Part and Illustration Catalog"

Group 2.000 / Page 10
I believe you're talking about the main shaft which is a complete assembly.....

------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

82-T/A [At Work] JUN 09, 10:12 AM
I probably could have included pictures, so that's what I'm doing now. This is the part in question:



Some things I noticed:

- The part is magnetic
- When the piece split in two, the magnetism reversed, and it's opposed to itself when I attempt to piece it back together.


It sits underneath this piece, and mounts to the bracket that the ignition "pickup coil" sits on.




Ultimately, I mentioned that I bought a rebuild distributor that came with these pieces *new*. I'm still going to rebuild and use the old distributor, but my daughter simply transfer-over the pieces she needs from the new to the old distributor (which she's completely cleaned and is now immaculate). The reason I want to re-use the old distributor is that it was stamped / marked on the casing to the block, so it'll be easy to line-up how it came from the factory (from what I can tell, it's the original). There's no play in the shaft, and after I scuffed it up with a scotch-brite, it looks like new.


Couple of things I noticed... when I removed the item (from image 2), I could see a little line / discoloration in the metal. It aligned with where one of the split-areas were on the part in image 1. So my questions are... what does this magnetic spacer do, is it integral to the operation of the distributor (other than acting as a spacer) and would this being "cracked" cause timing issues? From what I can tell, it was cracked before, and the car still ran pretty well for having (as I now understand it from the original owner) almost 300k miles on it.

Asking because I'm curious and want to explain it to my daughter.


Thanks!
cartercarbaficionado JUN 09, 08:10 PM

quote
Originally posted by 82-T/A [At Work]:

I probably could have included pictures, so that's what I'm doing now. This is the part in question:



Some things I noticed:

- The part is magnetic
- When the piece split in two, the magnetism reversed, and it's opposed to itself when I attempt to piece it back together.


It sits underneath this piece, and mounts to the bracket that the ignition "pickup coil" sits on.




Ultimately, I mentioned that I bought a rebuild distributor that came with these pieces *new*. I'm still going to rebuild and use the old distributor, but my daughter simply transfer-over the pieces she needs from the new to the old distributor (which she's completely cleaned and is now immaculate). The reason I want to re-use the old distributor is that it was stamped / marked on the casing to the block, so it'll be easy to line-up how it came from the factory (from what I can tell, it's the original). There's no play in the shaft, and after I scuffed it up with a scotch-brite, it looks like new.


Couple of things I noticed... when I removed the item (from image 2), I could see a little line / discoloration in the metal. It aligned with where one of the split-areas were on the part in image 1. So my questions are... what does this magnetic spacer do, is it integral to the operation of the distributor (other than acting as a spacer) and would this being "cracked" cause timing issues? From what I can tell, it was cracked before, and the car still ran pretty well for having (as I now understand it from the original owner) almost 300k miles on it.

Asking because I'm curious and want to explain it to my daughter.


Thanks!


it can cause issues but generally does not. my 86 v6 engine distributor (new style) actually didn't even have one that was magnetic. it was a litteral chunk of rubber in my case that changed timing drastically and was impossible to find the correct pickup for so a new dist was my solution as well. as far as I can tell it matters more on the old style which can cause single cylinder misfires when its broken. exactly on the point of a cylinder
82-T/A [At Work] JUN 09, 09:07 PM

quote
Originally posted by cartercarbaficionado:

it can cause issues but generally does not. my 86 v6 engine distributor (new style) actually didn't even have one that was magnetic. it was a litteral chunk of rubber in my case that changed timing drastically and was impossible to find the correct pickup for so a new dist was my solution as well. as far as I can tell it matters more on the old style which can cause single cylinder misfires when its broken. exactly on the point of a cylinder




Thanks, yeah... I'm glad I got a new one, I just worry about her removing the new one and breaking that one too! But it seems this one was already broken.
Vintage-Nut JUN 10, 09:51 AM

quote
82-T/A:
This is the part in question:



STATIONARY POLE PIECE & PLATE
82-T/A image #1 is the PLATE
82-T/A image #2 is the POLE PIECE


quote
what does this magnetic spacer do



See MSD (Multiple Spark Discharge) Distributors

Magnetic distributors operate like a mini-generator producing a voltage. This voltage serves as a trigger signal for precise spark timing.

As the metal reluctor wheel with evenly spaced trigger tabs rotates, each tab passing the magnetic pickup generates a trigger signal, firing the ignition system.

EDIT


quote
The reason I want to re-use the old distributor is that it was stamped / marked on the casing to the block, so it'll be easy to line-up how it came from the factory



To me, if I'm merely servicing the distributor with new parts; I use the base mark at the block and the rotor pointing at some 'mark' at the engine to keep the timing.

However, you're rebuilding the engine...

I hope you know to rotate the engine watching for cylinder #1 compression stroke at the balancer TDC mark with the distributor rotor pointing at #1 spark wire post.
(Do not make the common mistake by putting the distributor at "180-degrees out". Going by the crank, the ignition timing can be 360-degrees out.)

[This message has been edited by Vintage-Nut (edited 06-10-2024).]