in the 83 D-150, I have a vacuum advance distributor intended for a 76 Charger, if the folks at Old Parts Northwest were up to snuff,
it is part number 3874714, has a 8.5 vacuum can on it.

from the ignition curve testing done, I can say that it has 28 degrees of total advance in at 1500 rpm and max's out at 38 degrees at 2500 rpm.
This is with 6 degrees initial.

In driving the truck / engine combo,, at about 2500 RPMs is when the motor really comes on, I am running a pretty small oregon ground cam, 212 and 206 at .050 and a Holley 2280,,and the engine was set up for low rpm torque, per dyno sim, the breathing capability flatlines not much above 3000 RPM.

With the low RPM cealing , working on getting more advance in earlier, I have a pull a part distributor, number 3874876 from a 77 Volarie. The can is stamped 11.OR

I also have set of springs from bigslantsixfan and a Crane adjustable vacuume advance kit 99604-1 mentioned in this thread

http://www.slantsix.org/forum/viewtopic ... ane+996041

so cutting to the question(s):

1) is there a cheap and ez garage method to check spring tension,
so I can measure the spring tension capability,

2) in bigslantsixfans instructions he mentions to braze the out board side of advance slot to 0..380 for a slant six, The slots on this 77 Volarie distributor measure right at .3825,, so I am good there, correct?

3) I also see slot length to degree info such as
6 degree 12 degree 0.340
7 degree 14 degree 0.357
8 degree 16 degree 0.375
9 degree 18 degree 0.390

what is that saying?

4) The Crane instructions mention never changing the stock light spring,
but they include a light spring ( what they call they plain spring) to replace the heavy stock spring that starts advance at 800 and is all in by 2400, I think I will start with that one, even though is states for light to medium weight applications.. any thougts on that.

5) does it make a difference what weight gets the heavy and what weight gets the light spring?

6) I see the term primary spring, is the lighter spring the primary?

7) sorry, not done yet,, when puting the distributor back trogether,
recommended lube for the:
* advance plate
* weights
* shaft

8.) the instructions mention using a non magnetic feeler gauge (.007) to set the reluctor gap,, use a sheet of paper? how critical is that, does closer, without contact optimize?

9) One last question, do you really think the c clip inside the distributor shaft is necessary?
Thinking about drilling the counter weight studs to accept a set screw and washer, may allow changing of the weight springs without pulling the distributor,, releasing the shaft circlip was the most time consuming part of the disassembly.

thanks

so cutting to the question(s):

1) is there a cheap and ez garage method to check spring tension,
so I can measure the spring tension capability,

Yes, You can buy a small pull type digital gauge to check rates but it is all relative in the distributor. You have tune the spring set to work with the weights. I spin the shaft in my hands to observe which springs work the best and which way the spring posts need to be rotated.

2) in bigslantsixfans instructions he mentions to braze the out board side of advance slot to 0..380 for a slant six, The slots on this 77 Volarie distributor measure right at .3825,, so I am good there, correct?

Yes, and I would not braze the slots unless you are racing. Just use the big long looped secondary spring to stop the advance at 2500 rpm. I am running a torque build and want it all in soon. Send me your email and I will send you my current recurve sheet that I am running.

3) I also see slot length to degree info such as
6 degree 12 degree 0.340
7 degree 14 degree 0.357
8 degree 16 degree 0.375
9 degree 18 degree 0.390

what is that saying?

You can limit the weight throw with a shorter slot or a stiffer secondary spring. Either way works.

4) The Crane instructions mention never changing the stock light spring,
but they include a light spring ( what they call they plain spring) to replace the heavy stock spring that starts advance at 800 and is all in by 2400, I think I will start with that one, even though is states for light to medium weight applications.. any thougts on that.

You have that backwards. I have the same kit, and Doc has those (4) instructional recurve .jpgs posted on this site, see sheet 4. The small light spring is where you do your tuning..... The lighter the spring the earlier the advance kicks in. In my case it was silly to run the light drag race spring because of the wheel spin. Advance kicks in hard right away! My wife made me run medium springs so the advance was much smoother. Comments where "quite acting like a kid....." So the Crane kits light and medium springs are nice as are Big Slant Six fans spring selection. I am running the long slot 15R governor so the big heavy duty secondary spring is very important to limiting the advance!

5) does it make a difference what weight gets the heavy and what weight gets the light spring?

No, not until you start adjusting the spring posts.

6) I see the term primary spring, is the lighter spring the primary?

Yes..

7) sorry, not done yet,, when puting the distributor back trogether,
recommended lube for the:
* advance plate
* weights
* shaft

10-50w synthetic oil, no heavy grease!

8.) the instructions mention using a non magnetic feeler gauge (.007) to set the reluctor gap,, use a sheet of paper? how critical is that, does closer, without contact optimize?

Very, as the pickup produces voltage. I use a brass .008 feeler gauge. You could use a thin sheet of plastic too...

9) One last question, do you really think the c clip inside the distributor shaft is necessary?

Yes, less wear and tear internally.

Thinking about drilling the counter weight studs to accept a set screw and washer, may allow changing of the weight springs without pulling the distributor,, releasing the shaft circlip was the most time consuming part of the disassembly.

It makes life easier if you make sure everything is nicely polished and lubed. A small blade screw driver and a good fine nose needle nose pliers are your friend. Push one of the ends out with the screw driver and pull up on the exposed end....plink......it's out!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks to both of you for posting this, it answered all my questions.

Dave

_________________
86 Miser 170,000+
2 1/4" exhaust
Holley 1920 #55
HEI MSD BLaster 2
17.8 mpg

Some good instructions:
http://www.slantsix.org/forum/viewtopic.php?t=38471

Some additional info:

John,

Since we are after similar things….. more torque at low rpm, I hope this will be helpful. I have spent a few years fine tuning this type of setup.
Once you get the primary spring figured out and spring post dialed in, then you can start fine tuning the can.
The reason I say that is your truck weighs more than my 3600 lb. Dart Swinger.
The heavier your vehicle the slower (heavier) the primary spring. You don’t want it to ping in the midrange under load. The vacuum can is not engaged at that point,
So it is just the primary spring that governs advance plus your initial….I like to shoot for at least 10 degrees initial, more is better for start ups and shut offs.
Twenty degrees mechanical….. so you have your nominal base of 30 degrees like a race car.
As you can see I run the VC 208 for max throw for max mileage and better combustion.
I hate driving behind stinky cars/trucks to where you smell raw fuel from the tail pipe, especially at highway speeds.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

That's a common 1976 distributor (is for A/B, etc bodies), a somewhat good core to start with.
The original manual calls for an old pull type fish scale (like you hang from a tree), the digital version will be better to work with...Technically speaking I don't use one since I have experimented with lots of cares and have a 'cook book' to work with on common spring combinations.
The 77 volare slot is good for 9 degrees of distributor advance (what I will see on the machine...or x2 at the crank so 18 degrees when using a timing gun on the damper and tab in your vehicle...if you want less advance weld the slot shorter starting at the outside...my friend uses a piece of copper bar stock we have shaped to the size of about a 7R slot and he sticks it in the hole and welds the governor...I then use a die grinder, or file to finish the slot length to 8, 9 or 10 as desired...
I think if I had a Sun Machine moment, I would be tempted to use your nice 714 body, and install a cleaned up governor from the 4876 distributor...install the 4876 light spring, and your choice of the crane springs that puts the advance about 2-300 rpm above your "limit" (I try to reserve about 1-2 degrees sometimes at 2700 if the 'limit' is 2500...for a little extra room.) Use the 714 vacc. advance to start with, unless you have a better power to weight ratio, or have lots of build, start with the 714 vacc. adv. can...I typically leave my truck cans in the 8.5x (17 degree range), using the new VC-239 for best adjustment...If your vehicle is easy to run (i.e you have a 4.11/4.56 rear with the A-833OD), that offsets the heavier vehicle, you may try the VC-208 for more advance, but typically the extra 5 degrees may cause ping in the mid range in moderate geared vehicles (i.e. manual tranny truck with 3.21/3.55), due to load.
That's a good plan, most of the 'linear' recurves just use the stock light spring and another from a V-8 EI distributor to get a nice 'line' of even advance up to about 23-2500 rpm..

If you use two lighter springs (vs. the heavy limiting spring and a light one), it's better to limit the governor slot so you don't get a runaway...If the pegs hit the end of the slots at 2500 and limits it to 18 degrees, it's good....it gets bad if you use a 15L and light springs and the hipo slant has to pass a truck at 4000-5000 rpm...what was 18 with the shorter springs in the long slot can become 26 at the upper range (causing other issues...), this helps if you are limited by gearing and the red line on your tach to not "over do"...most of my end users I won't trust to stay contained with newfound performance (would you, if the go pedal suddenly was much more fun and the engine got another cylinder?) so I mechanically limit the upper end so they don't get that far into the clock if a long slot has to be used (typically it involves using a shorter slotted heavy spring and dialling the post so it limits a little quicker than stock, while letting the light spring govern how the low end advances).
It really does not , but per the manual and installation, the slot for the rotor has to face the heavy spring/weight for the advance to be correct if using differentiated springs (long slot stock and a lighter spring, or a heavy coiled spring and a light one).
Been answered. So I will not comment.
I would use a very heavy oil or synthetic grease...I have used lithium grease in mine since it was easy to get and won't melt off if the engine is to be run for a long period of time or have a hard heat sink (multiple runs at the dragstrip the sitting without running for an hour, being in the hot sun, a 4-5 hour drive to Seattle). Ttimes have changed and it's now easier to get synthetics, but if it does flow downhill it will make it's way around the clearances of the shaft and the body bushings (or if it doesn't have the OEM plastic ring under the mainshaft guarding the vent holes, it will leak out the vents in the body to the crank case...I mic my shafts and bushings and try for about .001-.002 clearance without it being tight (500 grit emery and a cordless 1/2' dewalt can fix a .001 tight shaft)...anything looser than .004 you can feel the 'wobble' when you put the shaft in the body after cleaning it up and pulling on the shaft or rocking the weight plate.
It really depends on your reluctor....008 was standard in the 1970's manuals with a brass feeler gauge. I have had several reluctors stock and Reman, that had one point hat was a little longer than the others so I test every point and set the longest tooth to the pickup at .010 for safety sake (if you do it on a short tooth, the long tooth will make a tick sound at higher rpm and eventually destroy the pickup). Typically .010 on the long tooth can put a short tooth at about a .011-.012 gap, which is still somewhat acceptable per the Truck manuals and late ESC style specs.
Yes...it needs to be there, with out the clip the governor can walk upward on the shaft and stop the advance and allow the weights to contact the body during spool up. The spring/contact on the rotor isn't strong enough and clearance between the rotor and cap will allow it to move up to the under side of the plate.
It's easier if it's clean inside, and you use a slightly bent set of long needle nose small tip pliers, grab on prong and twist the wrist while pulling. Getting it back in is more fun (I use two dental picks, one to hold one side and anchor and smooth the rest into place on the other side...like putting the lid/ rim gasket on a 55 gallon drum.

Helpful hint: use a trashed distributor body that has lost it's cap clips upside down to hold the shaft and assembled distributor while you work as a handy bench holder.

Good Luck,

-D.Idiot

this is the set up that I installed in the 83 D150

3874876 pull a part distributor with the 9R govenor
the Crane 11R vacuum can
one light OE 4876 spring and
the light spring from the Crane recurve kit

https://www.flickr.com/photos/13718356@ ... 176372757/

the advance curve that I had with the 3874714 NOS distributor was
RPM Initial Mech Total
0800 6 0 6
1000 6 4 10
1500 6 14 20
2000 6 14 20
2500 6 14 20
3000 6 14 20

the advance curve with the 3874876 that was built with the two light springs is
RPM Initial Mech Total
0800 10 0 10
1000 10 0 10
1500 10 15 25
2000 10 20 30
2500 10 20 30
3000 10 20 30

I have the Crane vacuum can adjuster all the way into the right then out 1/2 turn.. I drove around yesterday with a vacuum gauge attached to the carb ported port.. at steady highway speeds I see about 6 to 7 inches of ported vacuum.
so far driveability is fine,, a bit more pep..
Working from the spring pull tests posted
http://www.slantsix.org/forum/viewtopic.php?t=55276

the advance weight spring resistance force installed is 93,,
(Crane plain avg is 18, the stock light avg is 77)

If this set up continues to run well without knocking I will substitute in BSSF's yellow spring ( avg of 45) in place of the stock light spring.
that would set the spring resistance force at 63,

Good work!

That's how we do it on MTV!

Nice and simple!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I envy your ability to make sense of all of this. Maybe one day I will as well.

Dadstruck, why the switch, I noticed that from your first post you ended up using a different dist?

Were you unhappy with the one you purchased from Old Car Parts ?

I want known good distributor as a spare,,