which aftermarket distributor

[f85gtron]

Which aftermarket distributor is the "ONE".  I like the updated look of the cardone with its more robust magnet star wheel....not chincy looking like oe.  Mine is corroded and i keep getting bouncing timing light readings, plus i still have a party throttle dropping feeling that i now believe may be associated to the distributor.
My dist shaft doesn't have any slop or play, but the magnet appears cracked and what better time to upgrade?
So, here's the part in the question that i turn to you gurus for answers!  What say you?
Ron

[Fierofool]

I'm not going to make any recommendations, but just relate my experience.  My original distributor lasted for more than 20 years with the original pickup coil.  Covered in rust.  The rust is a natural result of the spark generated at the end of the rotor button.  It creates Ozone as the spark passes through air.  Ozone is corrosive.  So, with time, any metal inside the distributor will rust.

I picked up an almost new distributor (no rust inside) of the star wheel type.  Found it in a Fiero in the pull-a-part yard.  When I did the 3.4 upgrade, I had it installed into the engine.  I would guess it's been about 6 years, now. 

Last year, I had to replace it and go back with my original OEM distributor.  The aftermarket star-wheel distributor was chewing up the plug wire terminals inside the distributor because the bearing or bushing in the top of the distributor was worn out.  So badly that the star wheel tips were able to touch the stationary points. 

This may not be common, but that's just what happened with mine.  I put a new pickup coil into my OEM distributor and put it back into the 3.4. 

One thing I do like about the star wheel is that if you wish to reposition the distributor to make easier access to the module harness, with a manual trans car, you can put it into third or fourth gear and lightly push the car to line up the tips of the stator and reluctor, rotate the distributor to line up the next set, then move your wires correspondingly and you're still in time.  With the flat oem style, it's not as precise. 

[f85gtron]

Much appreciated. 
Just a side note, i bent the "fingers" out, closer to the pickup feelers, and my idle went smoother and it runs stronger. I read on a forum that you want about a paper's width between those items. I know your not supposed to believe everything you see on the infronet, but it worked for me! 
I can only image that the star shaped distributor would be better, with a stronger magnet.
Ron

[TopNotch]

Just a side note, i bent the "fingers" out, closer to the pickup feelers, and my idle went smoother and it runs stronger.

Theoretically, that makes sense, but it would have more effect at idle and low engine speeds. As the engine runs faster, the faster changes in magnetic field produce more current in the pickup coil, so the distance is less critical.
If you have any wobble in the bearings at all, bending the fingers could be a problem.

[f85gtron]

OMG!  What a difference!  The whole time I've had this car, I've been second guessing the experience i had test driving one in college...NOW I HAVE IT!  I can't believe that adjusting those stupid little finger things would make that much of a difference, but it does. I've driven to work and back today in a new car! 
I can only imagine that by adjusting the fingers, the pickup has a much stronger signal, a clearer hall-effect type signal, to send to the icm.
All i can say is wow! 
I'm curious how the signal would look on an oscilloscope between the oe and star version.

[Fierofool]

Great information and R&D.  Can you take a feeler gauge and give us an average gap that's working for you?  Avoiding the tendency to let the extra ponies run, keep track of your mpg to see how it is affected, too. 

Have you also increased the spark gap on your plugs?

[f85gtron]

Oh man, thanks a lot   spark gap, something else to worry about!  I can't remember what i gasped them at. I think i used the modern recommendation from the forums and not the one on the sticker.
10/4 on the feeler guage. I'll get a reading and submit it here.
I went ahead and bought the cardone a1 dist. So, I'll have a new one to compare it with. I know a guy that runs a cb shop with an oscilloscope.  Maybe he'll get a reading on these two for me?
Ron

[f85gtron]

Avoiding the tendency to let the extra ponies run.....

Sir,
I am Offended by your usage of the term "ponies" on this forum. These are HORSES in my car.  FULL GROWN, ADULT STEEDS.....but not quite Clydesdales.....none the less, HORSES!
next, instead of calling that thing on the badge a Pegasus, you lot will be calling them Pretty Ponies! 
Geesh!

[f85gtron]

Looks like they threw an extra magnet on top the one that was there already.....hmmm. i guess it would work?

[f85gtron]

My feeler guage only goes down to .008" and the clearance is a hair tighter than that....i put a thin sheet of paper in the gap, then used a screw driver to pry the gap closed until the paper dragged. It was so close that some of the rust got knocked off.
I would be careful if you have any play, as not to mangle your dizzy. 
Ron

[Fierofool]

Since there is a possible 36 combinations of fingers and pickups, I'm wondering what was your process.  Did you keep the shaft at the same position relative to the feelers and make 6 settings, or did you rotate the shaft and get the same clearance between each finger and each of the 6 pickup's? 

I have a good stock distributor, a good star type distributor and a star type with the bad shaft bushing.  Something I noticed on the star type is that two of the feelers are shaped a little differently and have a finer tip on them than the other 4.  I also see what appears to be a different gap even though there's no play in the shaft of the good one.  This makes me think that the original stock distributor might be better for 'tuning' such as you've done. 

I was thinking that because the star type can't be tuned, that there would be a gap that could be used as a guide for setting the older style, but now I'm not sure.  In the next couple of days I'll get out the feeler gauge and the vernier calipers and see what kind of measurements I get between the different star wheel points. 

[TopNotch]

Because the star is more massive than the fingers in the OEM distributor, the gap wouldn't have to be as small to produce a given strength of current pulse. However, the star design probably produces a wider pulse than the OEM type. I'm not sure how the ECM deals with that.
In any case, all the pickup coil in the distributor has to do is produce a current pulse every 60 degrees of rotation, and how it does it is actually irrelevant. If you had a notched wheel on your crankshaft, you could use a crank position sensor to produce the pulse, and then you'd have a strange hybrid ignition system -- a distributor to distribute the spark, and a crank sensor to provide the pulse. And you wouldn't have to time it, as far as the pulse is concerned. But you'd still have to "time" the spark distribution correctly.

[Fierofool]

Something I see when comparing the old style and new style distributors is that the surface area of the fingers and pickup on the old style are wider.  More surface area.  In my mind, this would allow for a less precise point of signal discharge than would that of the star type.  The star type having a much smaller surface area to trigger the signal discharge.  Does this by chance allow for a more precise timing of the spark being as the two surfaces are in any degree of alignment for only maybe 2 degrees of rotation, while the old style might have 6 or 8 degrees where any parts of the finger and pickups are in alignment? 

With the old style, does the signal build as the 2 parts come into partial alignment and reach a peak when the full surfaces are perfectly aligned, or could the ignition pulse be discharged at any point.  The surfaces of the finger and pickup are each about 1/8 inch wide.  This gives a total width of 3/8 inch where the surfaces have some point of alignment.  The star wheel has a total of about 3/16 to 1/8 inch where the tips are in some degree of alignment. 

[f85gtron]

Since there is a possible 36 combinations of fingers and pickups, I'm wondering what was your process.  Did you keep the shaft at the same position relative to the feelers and make 6 settings, or did you rotate the shaft and get the same clearance between each finger and each of the 6 pickup's? 

I didn't rotate the shaft until after i made the adjustment. But now that you mention it, i guess i got lucky. I rotated by pushing the car in 4th with my knees and watching before i actually cranked it over.


Ron