distributor Q

[volaredon]

I have a 3874876 here, electronic ign distributor as was used on Super 6 equipped vehicles from the factory. I actually have 2 of them. One is NOS and is in the original existing engine in my truck. Only has like 100 miles on it. It was suggested to replace the vac advance pod, as (I have not looked) I guess the original has an "11R" on the arm from the vac adv, and it was suggested that one with an "8.5R" would be better for use in a truck.
I have 2 NOS from back in the day "Niehoff" vac advance chambers here. Both "8.5R". I forget the PN, it's "AL....... something" as I remember.
anyway I'm wanting to go thru the more "used" one I have here and restore/rebuild it if nothing else, a spare for my truck. Or I may use this one and keep that NOS one for the spare.
I had bought the NOS one on Ebay a while back for a good price. and it was in its sealed original box from back in the day/ not yet sure if I'm gonna modify that one or not.
Besides the new VA cans, I have a couple sets of those springs that (I believe) I got from Halifaxhops, (whoever was selling them a month or so ago) and a couple of new aftermarket (don't remember if they are Niehoff, Standard or who) pickup plates for a /6.

Anyway I just got a new NOS distributor shaft/governor for the more used/worn out one today in the mail. PN 3755827. I've seen pix both ways as in coming "with" and "without" a new nylon gear. This one came "without".
I also have ONE Napa DG404 distributor gear from back in the day, METAL!!!! I have not been able to find another. I wish I could find the bronze version here, the only way I see those is from Aussie Land and shipping would be the killer there. I plan to use this metal distributor gear on this new shaft/governor when I assemble this distributor.
and I wish I could find at least 1 more metal one.

Anyway, I may wind up with a few questions along the way..... but the 1st one, is that this NOS shaft/governor ***'y is not drilled for the roll pin that holds the dist gear to the shaft. and no instruction sheet as I see some of them pictured on Ebay seem to come with.
How do I figure out where to drill the hole on the lower shaft to hold the distributor gear on? Shaft rotation wise does it matter where this hole is drilled, for the vac advance can to wind up in a good spot and not hit the block or chassis, once installed in the block?

Also, advance curve wise, etc will the needs there change, based on whether I use a factory, 4 pin Mopar ECU vs if I decide to use a 4 pin GM HEI module?
I wish I had access to a distributor machine I could play around on.

 

[halifaxhops]

OK your FSM should have all the distributor specs including the gap for the gear and the position also. 4 pin wise either one works well really depends on what you want to do with it. Those blue dot springs are a performance upgrade not to wild a advance.

 

[volaredon]

"the gap for the gear"? Huh? I thought the only "gap" within the distributor was the reluctor tooth gap?
were there different Governors used in these distributors? How to ID? which one better for what type of application? if I go to weld up the slots on the mechanical advance do I weld up the inside or the outside of the existing square slots?

 

[halifaxhops]

Up down play for the shaft. Usually .025-.035. I dont weld up the slots personally. why? That metal gear should probably have one hole drilled in it already, drill through the shaft with a shim on it should be close. The reason they are not drilled through Mopar never drilled any that I have seen straight across.

 

[volaredon]

How close to optimum would that nos one that I have be, for a d150/ with what I basically take to be essentially an "RV" cam, (Oregon 819) a true measured 8.4:1 CR, (as opposed to really being in the 7s) a super 6 with an nos (318) BBD, 3.21 gears, 727, OS valves ported head?

 

[halifaxhops]

You have to look up the curves on both in the FSM's compare them then figure out what the cam wants.

 

[volaredon]

"what the cam wants" from the distributor wasn't on the cam card.

 

[halifaxhops]

Sorry. I am assuming you know these old cars. You have to see what the mechanical advance curve is in both distributors (in the FSM) and then we can go from there. You also want to know what the curve was the engine started with. Thats by the book. Or you can take the used one and install it and see how it runs then make curve adjustments from there, probably the easiest for you. First early car?

 

[volaredon]

Yeah I know alot about old cars. But Ive never messed with curving or modifying a distributor. Have a problem? Stab a different one into place, set timing for most advance possible with no ping and carry on.
I've replaced vac advance pods and either pick up plates or points and condenser as applies to whatever I was working on, but never messed with advance weights or springs or anything like that.
Both of these distributors I have are the same tag number, the one im looking to modify is one that I never seen work/run in an engine, came among the box of parts that was with the engine that I currently have in the stand. There were 2 in the box/ I don't remember why but I ended y throwing the other one away.

 

[halifaxhops]

Have a minute to talk way easier.

 

[Mattax]

"what the cam wants" from the distributor wasn't on the cam card.

Even though its a 6 not an 8, this will give you some idea.
Distributor starting point for a curve
Remember initial timing is about lead needed to develop maximum pressure when the piston is placing maximum leverage on the crank. Differences between engines relate to the rod and crank ratio, then combustion efficiency (compression, chamber shape, valve timing, heat input). RPM plays into that by creating less time (in miliseconds) as well as by increasing combustion efficiency.
Chrysler summarized nicely in these snips here.

How close to optimum would that nos one that I have be, for a d150/ with what I basically take to be essentially an "RV" cam, (Oregon 819) a true measured 8.4:1 CR, (as opposed to really being in the 7s) a super 6 with an nos (318) BBD, 3.21 gears, 727, OS valves ported head?

Go to the Shop manual and look up the specs. I have nothing that new.
The older books provide everything in the back of the electric section. Advance is given in distributor degrees and distributor rpm.
Double each for crank. Then look up the initial recommened and add that to each point.
Plot them and you get a result like this

You can plot the vacuum advance specs like this

Alternatively you can measure the rpm and timing on the engine and plot that.

 

[volaredon]

From what I understand this distributor was factory spec'd out for the 77-80 /6 with the "super" version/ 2 barrel carb. Which is what I'm running for that part of the setup.
And I have said this before, most of what I ask here, is for everybody's good, not just my own/ I can't be the only one questioning what I do.
Sometimes I kinda have a pretty good idea of what I should do before I ask but as in this case "not always".
I know I do overthink things sometimes.
Which hopefully goes farther in helping others too along the way that might see my post.

 

[volaredon]

Up down play for the shaft. Usually .025-.035. I dont weld up the slots personally. why? That metal gear should probably have one hole drilled in it already, drill through the shaft with a shim on it should be close. The reason they are not drilled through Mopar never drilled any that I have seen straight across.

the way this is worded, don't make sense. You don't weld up the slots. Why? Then you talk about the metal gear that I mentioned that I'm wanting to use rather than the original style nylon gear. I don't believe that drive gear material has anything to do with the welding (or not) of those slots. you never finished talking about why you don't weld the slots.

I have the "well used" distributor apart, ready to drop the metal parts in the ultrasonic. Waiting for the ultrasonic to warm up.....
I have brand new electronic ignition pickups here, a couple of different brands (Niehoff, Sorensen and I think 1 more from "back in the day". I will be replacing that when I reassemble "no matter what". I also have (2) new in box VC239 vacuum advance cans. One will be going onto this unit once I go back up with it.
There is a thread in the FAQ on the /6 forum (other site) and that clip under the rotor? WHAT A PAIN TO GET OUT!!!!! Had to get that out and seperate the 2 halves of the shaft to get the springs off the pin beneath that top half.

I also have this brand new NOS distributor shaft here I just got from Ebay. The (governor??) on the NOS shaft appears to say "151" or maybe "15L".
the same part out of the well used dist that I have apart, appears to say "91" or maybe "9L". what difference would that make if I put the "15" in, vs the 9?
the NOS dist shaft carries PN 3755827 on the box.

 

[volaredon]

another... why does it matter, that the rotor tip is centered between 2 drive gear teeth..... I'd think to "drill it and pin it" as it wants to lay, and just rotate the dist to adjust the timing as usual.... is the position of drive gear teeth related somehow to range of swing, available to adjust timing?

 

[halifaxhops]

the way this is worded, don't make sense. You don't weld up the slots. Why? Then you talk about the metal gear that I mentioned that I'm wanting to use rather than the original style nylon gear. I don't believe that drive gear material has anything to do with the welding (or not) of those slots. you never finished talking about why you don't weld the slots.

I have the "well used" distributor apart, ready to drop the metal parts in the ultrasonic. Waiting for the ultrasonic to warm up.....
I have brand new electronic ignition pickups here, a couple of different brands (Niehoff, Sorensen and I think 1 more from "back in the day". I will be replacing that when I reassemble "no matter what". I also have (2) new in box VC239 vacuum advance cans. One will be going onto this unit once I go back up with it.
There is a thread in the FAQ on the /6 forum (other site) and that clip under the rotor? WHAT A PAIN TO GET OUT!!!!! Had to get that out and seperate the 2 halves of the shaft to get the springs off the pin beneath that top half.

I also have this brand new NOS distributor shaft here I just got from Ebay. The (governor??) on the NOS shaft appears to say "151" or maybe "15L".
the same part out of the well used dist that I have apart, appears to say "91" or maybe "9L". what difference would that make if I put the "15" in, vs the 9?
the NOS dist shaft carries PN 3755827 on the box.

I have all the sizes available from ones I have stripped. I am not a big fan of doing them that way I have seen the advance stick when they have been welded up. Now to limit advance a fbo plate is the way to go. No idea where the metal gear came in. That is a hard desirable piece to have alot of Turbo guys want them and they are super hard to find. Make sure the distributor bushings are good they will wear out faster than the shafts FYI

Those clips are fun. I call them Jesus clips as in Jesus where did it go!

OK on that advance cam the numbers say, 15L means 15 distributor degrees CCW. It is fine though they are the same L or R up to 15 degrees.

Hope it helps. Hard to explain this in type sometimes. I am around most AM's if you want to talk.

 

[volaredon]

Ok I noticed that on the back side of the governor that I'm cleaning up it says 9R where originally on the top side though the number was hard to see due to the numbers extending part way under the part of it where the reluctor slides on.
After cleaning the "9R" was easy to see on the back side.
What is different about them?
What's the best kind of lube? What came off looked like dried out wheel bearing grease.
I have fresh of that, I think I have some white lubriplate, plus sil glyde and a couple tubes of this synthetic stuff I got for "1 job" a couple of years ago and I can't remember what that would have been.
Any different kind of retainer for the metal gear than the roll pin that came out that held the plastic gear on?

You're mentioned being around to talk, can you PM your number?

 

[volaredon]

I've seen where it's said to get rid of the heavy advance spring/ and replace it with something lighter.
I got a couple of sets of those you were selling from you, would both of those be more "right" or one of those, and the lighter one I took out maybe,
Are the advance weights themselves all the same ?
Does it matter which spring goes to which side/with which weight?

 

[halifaxhops]

Just sent my number now would be great time to talk.

 

[Mattax]

Sometimes I kinda have a pretty good idea of what I should do before I ask but as in this case "not always".

And I have said this before, most of what I ask here, is for everybody's good, not just my own/ I can't be the only one questioning what I do.

Totally appreciate that.
Chrysler had many different initials and curves depending on the factors I mentioned, and especially around idle rpms sometimes these were adjusted to change the products of combustion (exhaust). Regarding the emissions, the things they did early on were not always the same as later, because later they had other tricks such as catalytic converters and air and even feedback for carbs.

So what should people do? Well to find out what a distributor with a tag should have in it, the specs are in the shop manual for the years that distributor was used.

Go to the Shop manual and look up the specs..
Advance is given in distributor degrees and distributor rpm.
Double each for crank. Then look up the initial recommened and add that to each point.
Plot them

Once you've done that. Then we know what the distributor has, or should have.

The other option is to run the distributor on the engine or on a distributor machine. In either case we can then plot the advance and know what we have. When its done on the car, we see the initial plus the advance. When done on the machine, we see the advance alone. Just add initial to estimate timing. Same as when plotting factory specs.

When changes are made to springs and governer slots, the result is not always what people expect. Its best to retest and then you know what you actually have.

here's a summary of the factors for the mechanical

How some of this is adjusted on a Chrysler type advance I show here.
As discussed a few posts later in that thread by GTX John & 92B, the secondary spring can be very important in high rpm applications, even drag racing with electronic ignitions. For street use its actually the main control for most of the driving rpm range.
You can follow this thread where Rick, the original poster, made measurements and changes.

Vacuum advance covered here:
How To Limit and Adjust Chrysler Vacuum Advance Cans

 

[volaredon]

Ok I have put my distributor back together.
Largely because I didn't want to lose any parts for it... And I didn't want it to get pushed into a corner, which would get me back to lost parts.
I have never seen parts like those Jesus clips that hold the governor to the main shaft at the parts store haha.

Anyway here's what I did... I put the new Standard VC239 on, as I was advised to do when I initially got the NOS distributor that's in my truck now. (Same number as this distributor) I haven't changed the one in that nos distributor yet, I have one for it.
I also put a new Niehoff AL426 pickup plate in "because I have it" and I had it apart.
I tried a Sorensen one that was just the pickup without the mounting plate on my old mounting plate, and was at the extreme edge of allowable adjustment range when I got my clearance set with the non metallic feeler gauge. Barely. I didn't like being Max'd out and I had these others here so I made a change and saw what that got me. Closer on the Niehoff to the middle of the range. I like that better.
I left the original 9r governor in the distributor like it originally came, put the new shaft with the 15r back on the shelf.
I then opened up Halifax hops' spring kit and used just the heavier of those with the lighter of the 2 original springs.
And I finished it off with a new and damn near impossible to find Echlin metal drive gear. Look for that same gear PN and get a nylon POS now a days.
Biggest thing different between original and now is it's all cleaned up and moves freely.

I also have a few of the old CH403x standard/ Blue streak distributor caps that I found a deal on via eBay last year. And a (I didn't know that AC Delco /Remy made ignition parts for Moparts but that's the rotors I found... cheap and new from back in the day before Chinesium was ever a question. It has a pretty long tongue on it beyond the plastic part of it. PN there is C401.

Again the application is a /6 with 727 and 3.21s in an 85 D150 long bed, engine is a '74, forged crank, head is a "447" casting peanut plug one, a few years newer than the block. Oregon cams #819 cam, 20-over pistons, 0.100 combined off the head and block, Aussie head gasket at 0.051 installed thickness. All that, only just gets me to a measured true 8.4:1 CR.
Ported head, SI oversized valves, cast iron super 6 intake with ported stock exhaust manifold /with the outlet opened up to a true 2-1/4.
Exhaust will be 2-1/4 all the way back.
Carb will be the NOS BBD that I bought just for it.
Tag # 6537s, originally meant for mid 70s 318 truck/van, with "heavy duty" emissions. (Back then that meant "minimal" emissions equipment)
Thoughts on this distributor as I currently have it set up, for this application??
I still have that new NOS distributor in the original engine that's still in the truck, that will be coming out. I can drop that one in as is and see what difference there is between how it wants to run with one vs the other. I should have dismantled that NOS one and cleaned/re lubed it before I stuffed it in, it didn't move as free as this one now does. The grease was definitely dried out from what I'd seen when I took it out of the box.

That one advance spring and the different calibration on the vac advance can I put in, would be the only deviation from how this dist is set up vs factory.

It'll be put in and timing setting will be tweaked til it pings, then backed up 2* like I always do with distributors. No matter what engine or what chassis it's in. That's how I set em. Then tweak the carb settings to suit.
I just need to find orings for the outside of the housing where it slides into the block.

 

[halifaxhops]

Sounds like you nailed it. I have the right O rings if needed.

 

[volaredon]

So then this setup will work and it will be better than it would have been without those 2 changes you think?

On those o rings yeah I'm gonna need a couple, was hoping to be able to get them somewhere around here, while on the subject I'm also gonna need a couple of small block ones too.

If not I'll have to get ahold of you and see how much you're gonna want for them. 2 ea, /6 and Small block

 

[halifaxhops]

Sure and same on the LA ones. Thie slant are the proper square" ones.

 

[volaredon]

So someone has replaced this one before.
I wondered about that. Looks like a square groove in the housing, but that wasn't what I took off.
It had a plain old round beaded o ring on it , as hard as a twig besides.