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Recurving M.P. Electronic Ignition.

Posted By: yellow sixpack

Recurving M.P. Electronic Ignition. - 04/25/10 02:27 PM

I know this has been touched on before. What is involved in recurving a Mopar Performance stock electronic distributor with a chrome box? Is there a kit? Is it just replacing the spring in the distributor? Is it worth it? Who sells the kit if there is one? I know the sell the springs. What else?
Thanks
Rob
Posted By: Dougsmopars

Re: Recurving M.P. Electronic Ignition. - 04/25/10 02:45 PM

Go to Summit or Jegs. Mallory has a re curve kit. Mallory builds the MP electronic dizzy. Comes with a selection of springs and gauges to set the slots. Nice little kit. Makes re curving very simple. Yes it's worth it if you have some modifcations done to your motor. Increasing initial timing can make a huge difference in performence. Total timing should remain around 36 to 38 degrees. To do this you must recurve the dizzy.
Posted By: CR8CRSHR

Re: Recurving M.P. Electronic Ignition. - 04/25/10 04:13 PM

I opted to go with the 4 seconds flat/FBO set up. After talking with Don, I am now thoroughly convinced that his set up is the only way to go....
Posted By: stickman

Re: Recurving M.P. Electronic Ignition. - 04/25/10 04:16 PM

Could you guys post the contact info & part #
of the kits.
Posted By: CHRYCOFAN

Re: Recurving M.P. Electronic Ignition. - 04/25/10 04:36 PM

http://www.summitracing.com/parts/MAA-29014/

Butch
Posted By: Dougsmopars

Re: Recurving M.P. Electronic Ignition. - 04/25/10 04:43 PM

http://www.summitracing.com/parts/SUM-850535/
Posted By: yellow sixpack

Re: Recurving M.P. Electronic Ignition. - 04/25/10 06:37 PM

Thanks fellas. I guess you can use this kit all types of distributors as long as you know what you have. It not application specific like it states in description.
Posted By: HemiStan

Re: Recurving M.P. Electronic Ignition. - 04/25/10 06:45 PM

It's not that difficult to do yourself. I do all of my own. It is a bit of trial and error without a distributor machine but that's OK. Check out this article by Steve Dulcich. Very good article.

Recurving Distributor

Stan
Posted By: RobbMc

Re: Recurving M.P. Electronic Ignition. - 04/25/10 06:47 PM

The MP distributors built by Mallory use a YH mechanical advance.
Posted By: Dougsmopars

Re: Recurving M.P. Electronic Ignition. - 04/26/10 12:48 AM

Yes they do in deed. Summit number 850535 is the kit for YH dizzy and is complete kit with spring asortment.
Posted By: Sinitro

Re: Recurving M.P. Electronic Ignition. - 04/26/10 01:38 AM

Actually Mopar sells the kit..
Includes springs and 2 degree key set.
#P5153446

Just my $0.01..
Posted By: dave571

Re: Recurving M.P. Electronic Ignition. - 04/26/10 01:40 AM

Quote:

I opted to go with the 4 seconds flat/FBO set up. After talking with Don, I am now thoroughly convinced that his set up is the only way to go....






it's great to know that you can curve it with a kit, BUT you still need to know what you are curving it to. Don is quite knowledgable in this area, as are others
Posted By: Dougsmopars

Re: Recurving M.P. Electronic Ignition. - 04/26/10 01:48 AM

I'm sure Don does wonderful work. For an all out race car i would consider sending my dizzy out. For a street car its not rocket sicience. Find what car wants for initial. Total no more then 38. No big deal. 30 bucks for a kit and a little elbow grease. Don ain't recurving them for 30 bucks.
Posted By: yellow sixpack

Re: Recurving M.P. Electronic Ignition. - 04/27/10 01:00 PM

http://www.summitracing.com/parts/DCC-2932675/
Going with these according to Mopar Tech line these replace the stock springs that come in the distributor in the Mopar performance electronic dist. kit.
Posted By: RapidRobert

Re: Recurving M.P. Electronic Ignition. - 04/27/10 01:54 PM

Quote:

Going with these according to Mopar Tech line these replace the stock springs that come in the distributor in the Mopar performance electronic dist. kit.


What Dougsmopars said: grab most any electronic dist as they dont wear the bushings like the points ones do because there's no side loading from opening the points. Take it apart/clean w solvent/dry/lube/toss the heavy spring w the long loop/keep the oe light spring then drive out the roll pin and add washers to reduce the end play to almost zero and add (1) of the light springs from the aforementioned MP Summitt cellophane kit for a start. Find your ideal initial (vac gauge method has been touted) then shorten the slots for 36-38 total then play w the springs keeping it just under the pinging point @ WOT no matter where (RPM) that makes the slots max out at then plug in the vac adv (if used) & play w it. The spring experimentation is what Don will do and I have spoken w him and I was impressed also and w his knowledge he'll get you close but you can get it even closer/near perfect for your eng plus the temp/humidity he cannot forsee but the only caveat being is that it takes multiple dissassembly of the dist to get the spring combo dead on. You will get good at taking that little clip out and there's the Mallory/MP externally adjustable units (havent seen/used one yet) here's a spring chart that may help/motivate you though the 3 springs in the Crane kit are no longer available (there must be others somewhere) and only the col on the left is important as depending on your idle rpm you want it lower than the advance start point. Just remember to do each one in order and that the vac adv stays capped off until the last.

Attached picture 5949671-dirstspringcurves.jpg
Posted By: 5thAve

Re: Recurving M.P. Electronic Ignition. - 05/01/10 11:12 AM

Ive had electronic distributors with worn bushings.
I bought the Mallory kit a couple years ago for mine. Summitt always wants too much for shipping things here. Got it from a local speed shop instead
Posted By: RapidRobert

Re: Recurving M.P. Electronic Ignition. - 05/01/10 02:01 PM

Quote:

I bought the Mallory kit a couple years ago for mine.


5th ave, do the springs in that kit fit an old style electronic dist? the crane kit in the chart I posted above is not available anymore.
Posted By: CR8CRSHR

Re: Recurving M.P. Electronic Ignition. - 05/01/10 02:03 PM

Quote:

I'm sure Don does wonderful work. For an all out race car i would consider sending my dizzy out. For a street car its not rocket sicience. Find what car wants for initial. Total no more then 38. No big deal. 30 bucks for a kit and a little elbow grease. Don ain't recurving them for 30 bucks.




OK I'll give you that. But I would rather have it done right the first time and not have to re-do it because I was not as thorough as Don is. At this point in my life it is far easier to spend the $$$s. Besides his expertise is unsurpassed...
Posted By: 69CHARGERMD

Re: Recurving M.P. Electronic Ignition. - 05/01/10 02:14 PM

It's not hard to do at all.


I did mine in the garage,,,took about 1/2 hour,,,,

Just need to figure out what your initial and total timing is going to be.


Weld or file the slots in the plate,,,,,

Trial and error on the springs,,,etc,,,,

cost = about nothing,,,perhaps some springs,,,plus i learned ALOT about my car,,,how to tear into the distributor and repair it,,,

Don does great work,,,but for $149 to "curve" it,,,i would try it on your own first,,,,
Posted By: RapidRobert

Re: Recurving M.P. Electronic Ignition. - 05/01/10 02:39 PM

Quote:

It's not hard to do at all.

I did mine in the garage,,,took about 1/2 hour,,,,
Just need to figure out what your initial and total timing is going to be.

Weld or file the slots in the plate,,,,,
Trial and error on the springs,,,etc,,,,
cost = about nothing,,,perhaps some springs,,,plus i learned ALOT about my car,,,how to tear into the distributor and repair it,,,
Don does great work,,,but for $149 to "curve" it,,,i would try it on your own first,,,,


X2. Especially once you figure out how to get the clip out easily. Just do em in order: initial/total/springs/vac adv
Posted By: mr_340

Re: Recurving M.P. Electronic Ignition. - 05/01/10 05:44 PM

Quote:

5th ave, do the springs in that kit fit an old style electronic dist? the crane kit in the chart I posted above is not available anymore.




I guess there are at least two of us with the old Mopar distributors. I bought one of the new timing kits from MP, but they are designed for the new designs (Mallory). I'm going to get one of the new distributors for the Pure Stock 340 I'm building. I like the advance curves they have in the kit. Anyone found a good setup for a strip SB?
Posted By: RapidRobert

Re: Recurving M.P. Electronic Ignition. - 05/01/10 07:07 PM

Quote:

I guess there are at least two of us with the old Mopar distributors. I bought one of the new timing kits from MP, but they are designed for the new designs (Mallory).


Mr_340 are those springs not even close to the dimentions of the oe light spring? (As we know the thick one w the long loop gets tossed)
Posted By: mr_340

Re: Recurving M.P. Electronic Ignition. - 05/02/10 05:41 AM

Quote:

Mr_340 are those springs not even close to the dimentions of the oe light spring? (As we know the thick one w the long loop gets tossed)




I didn't have much luck replacing the heavy spring in the old distributors. I tried that once in my Dart, replacing the heavy spring (with the long loop) with a light DC spring. I found it slowed down the advance since you have two springs (one OEM light spring (blue) and the light DC spring) acting against the couterweights. It was real doggy when I tried it. It seemed like the long loop allowed the advance weights to work on one spring early and then catch at higher RPM for a slow curve up top. This was in a mild 340 and 2.93 gears. My 340 Cuda had two light DC springs in the old Prestolite distributor and worked fine until I put the TQ on it in place of the AVS. Then it would mess with the idle as the advance was coming in and keeping the idle RPM up. My Cuda has 3.91 gears. I put a 340 electronic distributor in it with an MSD-6A and ran it like that for many years. For Pure Stock, I want to go with more initial advance and less mechanical advance. I have some DC race distributors and an MSD distributor (if legal for PS) to try on it. I stopped messing with the distributors 20 years ago. It looks like it's time to start again. I haven't even taken either car to the track in 10 years. They became garage queens. I still got a shed full of 340 engines that I bought for a Stocker that I sold many years ago. Time to drag them out and beat on them.
Posted By: 5thAve

Re: Recurving M.P. Electronic Ignition. - 05/03/10 08:19 AM

Quote:

Quote:

I bought the Mallory kit a couple years ago for mine.


5th ave, do the springs in that kit fit an old style electronic dist? the crane kit in the chart I posted above is not available anymore.




I don't know. I opened up the package when I got it to see everything in it and that's as far as I went. If you want I can take a picture of what's in it. I'll see if I have have an older distributor apart to compare them with.
Posted By: RapidRobert

Re: Recurving M.P. Electronic Ignition. - 05/03/10 08:26 AM

Quote:

If you want I can take a picture of what's in it. I'll see if I have have an older distributor apart to compare them with.


If you could wo alot of inconvenience or if the overall length and the size of the loops are pretty much identical to the OE light spring that would be enough and I'm assuming thicker wire for different rates.
Posted By: Mattax

Re: Recurving M.P. Electronic Ignition. - 05/03/10 12:22 PM

Chrysler built distributors use different springs than the mallory built distributors.
Older p-part light springs are going to be for the chrysler built distributors. The only spring kits I am aware of DC/MP selling for those distributors were very very light springs.

Tach drive distributors were sold with a very light primary spring and a very heavy long loop spring.
Mallory YH kit works with Mallory built p-part distributors.
However the Mopar Performance kit comes with more springs and a more complete chart of spring rates.

At the moment I can't find the digital pics I took of the Crane and Chrysler springs.
Below is a pic of the springs for the YH style distributors. And this is a link
to some more pics of the two styles of MP-DC vacuum advance distributors.

Rates for the Chrysler style internals based on my measurements and calcs;
Primary Springs
Crane Blue: 24 lbs/in, .6 " loop to loop
Crane Silver: 13 lbs/in, .6 "
Crane Yellow: 11 lbs/in, .58"
A-1 brand Rebuild: 8 lbs/in, .72"
MP Vac Dist: 7.2 lbs/in, .72"
Tach Drive: 1.26 lbs/in, .72"
P 2932675: 0.68 lbs/in, .7"

So if you use two springs, double the rate. If you shorten the slots, the same spring will supply less force unless you change the over length by bending the loops. This is why a lower rate spring does not always quicken the advance in the rpm range you're looking for.

Secondary Springs
A-1 brand Rebuild: 45.8 lbs/in, .92"
MP Vac Dist: 113 lbs/in, 1.0"
Tach Drive: 174 lbs/in, 1.09"

As best I can tell, the concept behind the tach drive arrangment was for easy starting and stable advance starting from 800 or 1200 rpm up depending on which primary spring was used.

Just for comparison, the YH type primary springs range from .55 to .68" and have rates from 1.7 to 7.6 lbs/in (or 13 #/in depending on whose numbers you go by). So it looks like they might work on the chrysler made distributors with maybe a little tweaking of the loops. But the loops of the YH secondary springs are probably too narrow to work on the chrysler made distributors.

Attached picture 5961141-Springs-for-MP-YH.jpg
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