Posted By: Rosco
Distributer modifying - 08/23/09 06:50 AM
Which slots get welded when recurving a dist.for a BB? Any pics?
Distributer modifying
Posted By: D_C
Re: Distributer modifying - 08/23/09 07:02 AM
Posted By: RapidRobert
Re: Distributer modifying - 08/23/09 12:48 PM
these
Posted By: JimG
Re: Distributer modifying - 08/23/09 01:11 PM
Rapid Robert and others:
Slightly OT, but this chart has been floating around Moparts for some time:
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
Last week I used the chart for the first time (in the past, I just used the trial-and-error method - kept filing until I had the slot length correct).
I needed 8.5 distributor degrees, and ended up needing a slot that was around .410" to get it.
I checked it with 2 different timing lights (a dialback Snap-On and a non-adjustable Craftsman with a timing tape). I've recently read about timing lights being inaccurate at high RPM, but both timing lights agreed w/each other, FWIW.
My question: has anyone confirmed the accuracy of the chart? And if the chart is accurate, what am I missing? This certainly seems simple enough...
Thanks,
Jim
Slightly OT, but this chart has been floating around Moparts for some time:
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
Last week I used the chart for the first time (in the past, I just used the trial-and-error method - kept filing until I had the slot length correct).
I needed 8.5 distributor degrees, and ended up needing a slot that was around .410" to get it.
I checked it with 2 different timing lights (a dialback Snap-On and a non-adjustable Craftsman with a timing tape). I've recently read about timing lights being inaccurate at high RPM, but both timing lights agreed w/each other, FWIW.
My question: has anyone confirmed the accuracy of the chart? And if the chart is accurate, what am I missing? This certainly seems simple enough...
Thanks,
Jim
Posted By: Bill MeLater
Re: Distributer modifying - 08/23/09 01:41 PM
While you're at it, do yourself a favor and very carefully remove the vacuum canister, smash it flat with a hammer, throw it in the garbage and weld these two plates together. Your motor will thank you for it.. 
Posted By: 62maxwgn
Re: Distributer modifying - 08/23/09 01:45 PM
Only if you don't run it on the street! 
Posted By: Bill MeLater
Re: Distributer modifying - 08/23/09 01:51 PM
Quote:Absolutely correct, this modification is for street use only...And strip.
Only if you don't run it on the street!
Posted By: RapidRobert
Re: Distributer modifying - 08/23/09 02:10 PM
JimG thanks for the heads up as I'm going to be using the chart for the first time here real soon.
Posted By: moparmattkos
Re: Distributer modifying - 08/23/09 02:19 PM
Quote:
While you're at it, do yourself a favor and very carefully remove the vacuum canister, smash it flat with a hammer, throw it in the garbage and weld these two plates together. Your motor will thank you for it..
This method locks the timing advance currect? How many areas does it needed to be welded at? do you have to set anything else or just take the advance off and springs off and weld the plates?
Posted By: JimG
Re: Distributer modifying - 08/23/09 02:22 PM
Quote:
JimG thanks for the heads up as I'm going to be using the chart for the first time here real soon.
Robert:
Shout back with your results.
Thanks,
Jim
Posted By: Anonymous
Re: Distributer modifying - 08/23/09 02:25 PM
Quote:Quote:
While you're at it, do yourself a favor and very carefully remove the vacuum canister, smash it flat with a hammer, throw it in the garbage and weld these two plates together. Your motor will thank you for it..
This method locks the timing advance currect? How many areas does it needed to be welded at? do you have to set anything else or just take the advance off and springs off and weld the plates?
As much as it pains me to bring this up--because I think the problem is vastly overblown-- when/if you weld an advance plate, CHECK the rotor phasing, and make sure with a reluctor that where you end up with the plate that you have enough range to properly adjust the reluctor gap.
IF you look the plate over, you'll find that the two "sit" parallel on two little shoes. You need to make sure this is OK before you tack it together. Doesn't take much to hold it but it DOES need to be correct.
Just me, but if I was going to all this work in this day 'n age, I'd go aftermarket.
Posted By: RapidRobert
Re: Distributer modifying - 08/23/09 02:33 PM
Quote:I will do and I am trying to drill the ends of the slots & add set screws so I can adj it externally but I'm having a hard time finding a #43 drill bit hard enough. Any suggestions
Shout back with your results.
Posted By: Bill MeLater
Re: Distributer modifying - 08/23/09 02:33 PM
Quote:Quote:Quote:
While you're at it, do yourself a favor and very carefully remove the vacuum canister, smash it flat with a hammer, throw it in the garbage and weld these two plates together. Your motor will thank you for it..
This method locks the timing advance currect? How many areas does it needed to be welded at? do you have to set anything else or just take the advance off and springs off and weld the plates?
As much as it pains me to bring this up--because I think the problem is vastly overblown-- when/if you weld an advance plate, CHECK the rotor phasing, and make sure with a reluctor that where you end up with the plate that you have enough range to properly adjust the reluctor gap.
IF you look the plate over, you'll find that the two "sit" parallel on two little shoes. You need to make sure this is OK before you tack it together. Doesn't take much to hold it but it DOES need to be correct.
Just me, but if I was going to all this work in this day 'n age, I'd go aftermarket.
Posted By: JimG
Re: Distributer modifying - 08/23/09 03:38 PM
Quote:
I will do and I am trying to drill the ends of the slots & add set screws so I can adj it externally but I'm having a hard time finding a #43 drill bit hard enough. Any suggestions
No specific experience, but here's a thought. McMaster-Carr has a wide variety of bits. Perhaps Cobalt Steel or Powdered Metal Steel would survive. I see they have both in #43.
Jim
Oops, forgot the link...http://www.mcmaster.com/#drill-rods/=3bfmng
Posted By: hooziewhatsit
Re: Distributer modifying - 08/23/09 04:58 PM
I welded up the thingy in my 318 distributor, and observed results like the chart says.
In fact, originally, the stock heavy spring was heavy enough, it was acting as an advance limiter
(I never go over 3k; work truck).
If you take out the vac advance and weld that plate in place, you'll lose any advance from the vacuum. You'll still have mechanical advance.
The only benefit to doing this would be to keep the plate from jittering around and bouncing the timing. Or, if it's solely a race engine. For the street, I'd tune it so it works
In fact, originally, the stock heavy spring was heavy enough, it was acting as an advance limiter
(I never go over 3k; work truck).If you take out the vac advance and weld that plate in place, you'll lose any advance from the vacuum. You'll still have mechanical advance.
The only benefit to doing this would be to keep the plate from jittering around and bouncing the timing. Or, if it's solely a race engine. For the street, I'd tune it so it works