Locking out advance with welds

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subcom

subcom

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I have an old freebie 2 wire distro I want to completely lock out to try with my Fitech EFI unit which has timing control. Do I just need to tack weld the weights at the places I have circled in the picture? Should the weights be in the closed position before welding, or spread open like during full mech advance when welding? And I could probably remove the springs, right?

And no, I don't want to buy the FBO plate or a lean burn distro. I want to lock this one out. Thanks!

distributor_weights.jpg
 
Well yeah but... there are other spots where the tack weld is much easier undone in the future if necessary.
 
Lock it out at what?
 
RustyRatRod said:
Lock it out at what?
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That's a good question and maybe I've oversimplified the process in my mind. I want to control timing advance and retard with my EFI setup and just set the initial timing physically at the distributor and with a timing gun and let the EFI timing control do the rest.
 
That is one way to lock out timing. How do you plan to phase the rotor? re-groove the reluctor?
 
If you don't want any advance at all, instead of wasting all your time and energy, just remove the advance weights altogether and weld the top shaft solid to the bottom. Done. Over and out. Roger Wilco.
 
That would do it, but you want to weld it with the weights where they are in the picture so the rotor doesn't end up partially out of phase with the cap terminals.
A light tack where the green is might be better, unless you don't care about ever undoing it, but those distributors are available everywhere.
It would be a lot easier to undo and have the distributor work right again later if the weights themselves are not welded to the slot.
Leaving or removing the springs won't matter one way or the other, but if for some reason you want to remove as much weight as possible take the top section out, knock the slotted plate off, take the springs and weights out and weld the shaft like RRR said.

distributor_weights.jpg
 
Its a matter of phasing. I weld the slots with the weights in their fully extended position. That maintains the relationship between rotor, cap and breaker plate where the factory intended it to be at high rpm.
 
Thanks guys for all the ideas and feedback. I was just reviewing the phasing aspect of it on the Fitech docs, and obviously I was overlooking an important part.
 
Welding is a bad idea. Many reasons, so skipping that. Drill and tap the top hat for 3 6-32 allen screws 120 degrees apart. Take out flyweights and springs. I assume you know about the c-clip below the felt oil disk. The 3 allens carefully adjusted are used to avoid run out. There is a few 0.001" slop in the 5/16" to top hat ID, just one screw results in significant run out.
 
KitCarlson said:
Welding is a bad idea. Many reasons, so skipping that. Drill and tap the top hat for 3 6-32 allen screws 120 degrees apart. Take out flyweights and springs. I assume you know about the c-clip below the felt oil disk. The 3 allens carefully adjusted are used to avoid run out. There is a few 0.001" slop in the 5/16" to top hat ID, just one screw results in significant run out.
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I'd like to know why welding is such a bad idea.
 
subcom said:
Thanks guys for all the ideas and feedback. I was just reviewing the phasing aspect of it on the Fitech docs, and obviously I was overlooking an important part.
Click to expand...
I beat that exact issue into the GROUND on the fitech and sniper threads...

Buy this, Lock it, Done. I sell them to you guys for like $150
TSP-JM7613R Mopar SB Pro Series Pro-Billet Electronic Distributor. Red Cap
Adjustable Race Rotor MSD Ignition 84211 - Pace Performance Parts

The fitech units simply do not like OE, OE aftermarket, Lean burn, Rock auto, Or any other non-billet type distributor for the timing control. If the OE stuff had more than a 1:500 success rate I wouldn't be pushing product on you guys, but thats all there is to it.


Now on my race car, with a carb. I welded the weights open just like Tony is talking about, and i tapped a screw through the advance plate to hold it stationary. Been that way locked at 42 for years.
 
whitepunkonnitro said:
Its a matter of phasing. I weld the slots with the weights in their fully extended position. That maintains the relationship between rotor, cap and breaker plate where the factory intended it to be at high rpm.
Click to expand...

I was kind of wondering about that, but it seemed if it was locked out it wouldn't matter.
Myself I would verify the rotor position to the cap contacts and lock er up right where they line up together.
 
whitepunkonnitro said:
I'd like to know why welding is such a bad idea.
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The first weld cools and shrinks the second does not compensate. Unless you a dial indicator, or listen to the engine tone or use a scope, you will escape the run out that results in timing variation between cylinders. That is ok if do don't mind it pinging on a cylinder or two first. Just back it off some, then the lagging cylinder will lag more. It does not matter if using points or VR sensing.
The other is once boogered with weld, no further adjustment. If welded at top hat slots, still slop in inner shaft to top hat.
 
TrailBeast said:
I was kind of wondering about that, but it seemed if it was locked out it wouldn't matter.
Myself I would verify the rotor position to the cap contacts and lock er up right where they line up together.
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The position of the weights dictates where the rotor sits in relation to the driven part of the distributor.
 
KitCarlson said:
The first weld cools and shrinks the second does not compensate. Unless you a dial indicator, or listen to the engine tone or use a scope, you will escape the run out that results in timing variation between cylinders. That is ok if do don't mind it pinging on a cylinder or two first. Just back it off some, then the lagging cylinder will lag more. It does not matter if using points or VR sensing.
The other is once boogered with weld, no further adjustment. If welded at top hat slots, still slop in inner shaft to top hat.
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OK, now you've completely lost me. How does welding the slot the weights ride in effect runout or timing variation between cylinders.
You sure we're talking about the same thing??
 
I have welded up the whole slots and drilled them the same diameter as the pin on the weights with the advance positioned where I wanted it several times for race cars with no noticeable issues. It often took a few tries to get it right where I wanted it though.
 
whitepunkonnitro said:
OK, now you've completely lost me. How does welding the slot the weights ride in effect runout or timing variation between cylinders.
You sure we're talking about the same thing??
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I'm with you... Some of us are talking about welding the weights in a fixed position, so the timing on the engine would remain FIXED...and will NOT advance at all.....and then some are talking about something completely different...lol
 
whitepunkonnitro said:
The position of the weights dictates where the rotor sits in relation to the driven part of the distributor.
Click to expand...

Well duh! :D
I know that Tony, but I thought as long as the rotor was in range (phased) to the cap contacts the amount of advance on the rotor wouldn't matter if locked.
So basically I guess the question I am having is why does it matter where the weights are as long as the rotor tip is in the correct range of the cap terminal when the pickup fires?
Apparently you are saying that the rotor tip IS where it needs to be if the top hat of the shaft is locked at full advance of the weights.

Correct?
 
Johnny Pace said:
I'm with you... Some of us are talking about welding the weights in a fixed position, so the timing on the engine would remain FIXED...and will NOT advance at all.....and then some are talking about something completely different...lol
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The amount of overthinking in this thread is mind boggling.
Pop the springs off...spread the weights out...zzzzap, zzzzap, DONE
Never to be an issue again. Set the distributor where you want it, and never look back
 
TrailBeast said:
Well duh! :D
I know that Tony, but I thought as long as the rotor was in range (phased) to the cap contacts the amount of advance on the rotor wouldn't matter if locked.
So basically I guess the question I am having is why does it matter where the weights are as long as the rotor tip is in the correct range of the cap terminal when the pickup fires?
Apparently you are saying that the rotor tip IS where it needs to be if the top hat of the shaft is locked at full advance of the weights.

Correct?
Click to expand...
The cap and rotor are phased to be in optimum alignment with the advance fully in, as would be seen at highway speed. Less gap to jump between rotor and post
 
Johnny Pace said:
I'm with you... Some of us are talking about welding the weights in a fixed position, so the timing on the engine would remain FIXED...and will NOT advance at all.....and then some are talking about something completely different...lol
Click to expand...

Not really, as Kit is talking about tolerances being affected by one weld pulling things off center and the other weld not being able to recover it.
He is used to things being extremely accurate, and it bugs him when they are not.
Problem was/is nothing on these cars is. :D
I get what he is saying, I just don't think it would be near enough to make any real difference.
 
whitepunkonnitro said:
OK, now you've completely lost me. How does welding the slot the weights ride in effect runout or timing variation between cylinders.
You sure we're talking about the same thing??
Click to expand...
20161207_115725.jpg

The inner shaft with the spirals is a bit loose to the top hat due to clearances. Welding will very likely, pull the top hat to a side, or make a wobble. And pulling to side, changes when spark triggers, advancing on near side, retard on far side. The set screws as suggested and use of dial indicator can null out run out. On VR distributors, welding may result in magnetization, and that can mess with sensor signal. VR sensing is inaccurate enough in standard form. I use tab wheels with significantly increased diameter, and digital outputs for accurate timing reference. I found that blueprinting distributors helped, improving the sensing technology with optical tab sensing is far superior, and cost effective, with features not possible with VR.

You can say nonsense and that is OK. My wife points out your white Dart, on occasions when it is stalled at a busy intersections in M'boro. She looked at me and said you have given me cars to drive for over 40 years, they are not new, but I have never been stalled.
 
whitepunkonnitro said:
The cap and rotor are phased to be in optimum alignment with the advance fully in, as would be seen at highway speed. Less gap to jump between rotor and post
Click to expand...

Ah, ok then.
I never personally verified if they aligned closest at idle or full throttle.
I guess I just assumed it was at idle and it got farther away as RPM's rose, or was before the terminal at idle and after at WOT and full advance.
So they align closest at WOT then.
Thanks for answering that.
 
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