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manually setting the total advance limit
#913509
01/25/11 11:12 AM
01/25/11 11:12 AM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Hey gang..
Anyone have a method they use to manually limit the amount of total advance the counter-weights will produce in their OEM Chrysler distributors? I'm looking to do some experimentation. Seasoned Mopar builder once told me our big block mopars like more initial curb idle advance (somewhere like 14 degrees). With that though, you have a tendency to produce higher than desired total degrees after final inertial movement by the weights. If I had a way to limit the movement of the weights within their slots, I could possible achieve this... I'm looking to modify a traditional points distributor, with and without a Pertronix kit. May try this experiment on one of my dual-point Prestolites as well...
Thanks in advance...
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913510
01/25/11 11:57 AM
01/25/11 11:57 AM
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Joined: Jan 2006
Posts: 587
IL . usa
cjs69mope
mopar
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mopar
Joined: Jan 2006
Posts: 587
IL . usa
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Not really easy as far as i know it can be done but it will take a lot of time and effort.
What has to happen is spin on a machine or in the engine with a dial back timming light and record the base setting .
Then remove the distributor and gas braze the slots smaller and spin on machine to see how much change is made then file the slots where welded until you get them where u like the advance limit total .
This used to be done at shops that specialized in distributor re-curving for a nominal price .
If it were me i would just buy a new Mopar distributor because the slots in the MP one are adjustable and the keys from a Mallory distributor will work to set the amount advance limit .
FYI i run 20 deg initial @950 rpm and total of 38deg starting at 1000 rpm all in by 2100 rpm this is what works best on my engine .
it has taken me 4 years of tinkering with it at home to fully understand this ....and get it right .
Last edited by cjs69mope; 01/25/11 12:02 PM.
1969 Dodge Charger
1969 Dodge Superbee
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Re: manually setting the total advance limit
[Re: express]
#913512
01/25/11 12:28 PM
01/25/11 12:28 PM
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Joined: Sep 2005
Posts: 12,481
Chino Valley
RodStRace
I Live Here
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I Live Here
Joined: Sep 2005
Posts: 12,481
Chino Valley
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A friend did this on my small block. He used braze rod, it's strong enough for the application, and easy to file.  I ran 18 initial and 36 total.
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913513
01/25/11 12:51 PM
01/25/11 12:51 PM
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Joined: Mar 2007
Posts: 3,285
West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,285
West Coast, USA
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....or you could send your unit to FBO and get their ignition kit. Easy, proven and relatively inexpensive.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: manually setting the total advance limit
[Re: jbc426]
#913515
01/25/11 12:58 PM
01/25/11 12:58 PM
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Joined: Jan 2003
Posts: 75,058
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,058
U.S.S.A.
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Quote:
....or you could send your unit to FBO and get their ignition kit. Easy, proven and relatively inexpensive.
I think FBO has a plate that drops in over the slots to limit advance , since Troy will be using a pertronix it makes no sense to send the dist to FBO and/or get their ignition kit.
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Re: manually setting the total advance limit
[Re: JohnRR]
#913516
01/25/11 01:31 PM
01/25/11 01:31 PM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Quote:
Quote:
....or you could send your unit to FBO and get their ignition kit. Easy, proven and relatively inexpensive.
I think FBO has a plate that drops in over the slots to limit advance , since Troy will be using a pertronix it makes no sense to send the dist to FBO and/or get their ignition kit.
I was just reading that John, looks interesting to experiment for sure. I could add it to my existing set-ups I will eventually have and get the best of all worlds...
Is this what you're talking about?
Last edited by hemi68charger; 01/25/11 01:33 PM.
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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Re: manually setting the total advance limit
[Re: JohnRR]
#913517
01/25/11 01:32 PM
01/25/11 01:32 PM
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Joined: Oct 2007
Posts: 3,897
Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,897
Oregon
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Here ya go  Pull the distributor apart, then weld the slots shut to get the total length corresponding to the advance you want. Before doing that, I would find your ideal initial by advancing the timing to get max vacuum, then backing it off 1"hg. Someone else recommended to weld up the inside of the slots, so the light springs have a little preload on them, rather than welding the outside of the slots. dist. degrees X 2 + initial= total dist. degrees / slot size 6.............. .340 7............... .355 8............... .375 9............... .390 10.............. .405 11.5 ........... .420 12.............. .435 13.............. .445 14.............. .460 15.............. .475 16.............. .490 17.............. .505 18.............. .520
If you ever find yourself in a fair fight, your tactics suck.
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913518
01/25/11 04:34 PM
01/25/11 04:34 PM
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Joined: Jan 2003
Posts: 75,058
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,058
U.S.S.A.
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Quote:
Quote:
Quote:
....or you could send your unit to FBO and get their ignition kit. Easy, proven and relatively inexpensive.
I think FBO has a plate that drops in over the slots to limit advance , since Troy will be using a pertronix it makes no sense to send the dist to FBO and/or get their ignition kit.
I was just reading that John, looks interesting to experiment for sure. I could add it to my existing set-ups I will eventually have and get the best of all worlds...
Is this what you're talking about?
Yes that's it , I may get one to put in my Dual point to limit mechanical without having to weld on my original A body 383 dual point.
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Re: manually setting the total advance limit
[Re: six-barrel]
#913520
01/25/11 08:35 PM
01/25/11 08:35 PM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Quote:
Whats your cam spec @50, this generally dictates what your initial timing should be.
The motor is a bone stock OEM '69 Chrysler New Yorker 440... Now in a '69 Charger 500 with a 440 six pack on it.... Who would have figured? 
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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Re: manually setting the total advance limit
[Re: hooziewhatsit]
#913521
01/25/11 08:54 PM
01/25/11 08:54 PM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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Quote:
Pull the distributor apart, then weld the slots shut to get the total length corresponding to the advance you want. Before doing that, I would find your ideal initial by advancing the timing to get max vacuum, then backing it off 1"hg. dist. degrees X 2 + initial= total
dist. degrees / slot size
6.............. .340
7............... .355
8............... .375
9............... .390
10.............. .405
11.5 ........... .420
12.............. .435
13.............. .445
14.............. .460
15.............. .475
16.............. .490
17.............. .505
18.............. .520
What Hoozie said, (1) find the ideal initial for YOUR individual combo (w eng warmed up) then w that figure in hand braze then file the slots to get (2) 36-38 total (BB).(3) Play w the springs staying just under the pinging point at WOT up thru the gears then (4) then vac adv (if used) staying just under the pinging point at PART throttle (light throttle/high vacuum) at or above the RPM where the springs (total) are maxed out & can adj (A) WHEN the slope starts (& therefore ends) and (B) can solder feeler gauge strips on either side of the notch in the arm to limit the AMOUNT of advance. You have to open it up to add the FBO plate which only has so many selections so you might as well open it up & braze/file it & get it spot on
Last edited by RapidRobert; 01/25/11 11:12 PM.
live every 24 hour block of time like it's your last day on earth
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913522
01/26/11 12:08 PM
01/26/11 12:08 PM
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Joined: Jan 2003
Posts: 75,058
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,058
U.S.S.A.
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Quote:
Quote:
Whats your cam spec @50, this generally dictates what your initial timing should be.
The motor is a bone stock OEM '69 Chrysler New Yorker 440... Now in a '69 Charger 500 with a 440 six pack on it.... Who would have figured?
Must not be very impressive with that 383 2bbl cam in it ?
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Re: manually setting the total advance limit
[Re: JohnRR]
#913523
01/26/11 12:37 PM
01/26/11 12:37 PM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Quote:
Quote:
Quote:
Whats your cam spec @50, this generally dictates what your initial timing should be.
The motor is a bone stock OEM '69 Chrysler New Yorker 440... Now in a '69 Charger 500 with a 440 six pack on it.... Who would have figured?
Must not be very impressive with that 383 2bbl cam in it ?
No clue.. It's still on jack-stands and will be there for a bit. It's a major accomplishment to just get it started. Now it's on to the tranny to make sure it works properly and then begin on the brakes. One step at a time. I'll be happy that it's running, whether or not it's a putt-putt motor or an Elephant. With the 4.10 Dana in it, I believe she'll get out of her way. Eventually, I can make internal changes... I'll be happy just to go to the grocery store or Lowes in my'69 Charger 500. Plus, I'm hoping my wife will like it and drive it. Can't get her to drive the Daytona...........
Last edited by hemi68charger; 01/26/11 12:40 PM.
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913524
01/26/11 02:02 PM
01/26/11 02:02 PM
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Joined: Nov 2003
Posts: 1,029
Southeast Virginia
68jim
super stock
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super stock
Joined: Nov 2003
Posts: 1,029
Southeast Virginia
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Troy, There was a good thread on this some time ago. old thread I welded up and filed my dual point distributor slots to the dimensions on that chart for the Hemi and it worked out sweet. Jim
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Re: manually setting the total advance limit
[Re: 68jim]
#913525
01/26/11 03:46 PM
01/26/11 03:46 PM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Quote:
Troy,
There was a good thread on this some time ago.
old thread
I welded up and filed my dual point distributor slots to the dimensions on that chart for the Hemi and it worked out sweet.
Jim
Thanks Jim,,,
I appreciate it.. From the above chart, if I'm interpreting it correctly, does this make sense:
10(.405) x 2 + 14 = 34
If I wish to run my car with an initial curb idle timing of 14 degrees but only go to 34 total mechanical (with vacuum hooked up), the slot needs to be no bigger than .405 inches.
This make sense?
The vacuum advance pod hooked up will give me the increased timing based on increased throttle movement. If I wish for the timing to "kick" in earlier, then I'd need to swap one of the weight springs to a lighter one...
Last edited by hemi68charger; 01/26/11 03:47 PM.
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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Re: manually setting the total advance limit
[Re: hemi68charger]
#913526
01/26/11 03:59 PM
01/26/11 03:59 PM
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Joined: Oct 2007
Posts: 3,897
Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,897
Oregon
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Quote:
Thanks Jim,,,
I appreciate it.. From the above chart, if I'm interpreting it correctly, does this make sense:
10(.405) x 2 + 14 = 34
If I wish to run my car with an initial curb idle timing of 14 degrees but only go to 34 total mechanical (with vacuum hooked up), the slot needs to be no bigger than .405 inches.
This make sense?
The vacuum advance pod hooked up will give me the increased timing based on increased throttle movement. If I wish for the timing to "kick" in earlier, then I'd need to swap one of the weight springs to a lighter one...
Yes, that is how the timing will work; initial + mechanical = total (34* in your example).
Vac advance will only come into play at high vacuum, low throttle times (ie, cruise down the highway), and will add another 10-20* on top of the total, so you'll be in the ballpark of 55*.
With the engine running, you can see the timing curve easily if you have a timing tape on the balancer. As you rev it up, you'll be able to see the timing advance until it gets to the total, then it will stop advancing. You also want strong enough springs that it doesn't start advancing the timing until you're a couple hundred RPMs higher than your idle speed.
If you ever find yourself in a fair fight, your tactics suck.
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Re: manually setting the total advance limit
[Re: RapidRobert]
#913528
01/26/11 05:06 PM
01/26/11 05:06 PM
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Joined: Aug 2003
Posts: 8,828
Houston, Tx
hemi68charger
OP
master
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OP
master
Joined: Aug 2003
Posts: 8,828
Houston, Tx
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Quote:
Quote:
10(.405) x 2 + 14 = 34
If I wish to run my car with an initial curb idle timing of 14 degrees but only go to 34 total mechanical (with vacuum hooked up), the slot needs to be no bigger than .405 inches....
You would want to get your 34 amount w the vac can line unhooked/plugged then plug it in & 34 is a bit low.
Cool..
Thanks... I was just using the 34 as a mathmatical example. I would probably go 36-38 total......... Just making sure I have the theory down.
TroyHouston Mopar Connection Club'69 Charger Daytona 440 - auto - 4.10 Dana (now with 426 hemi) '69 Charger 500 440 - 4speed - 3.54 Dana '70 Road Runner 383 - 4speed - a/c (now with 440)
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