MP Distrubutor Schooling Needed!
#1655011
08/04/14 04:10 PM
08/04/14 04:10 PM
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Joined: Jul 2005
Posts: 1,723
North Austin
KnuckleDuster
OP
top fuel
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OP
top fuel
Joined: Jul 2005
Posts: 1,723
North Austin
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 Please tell me how to set this up correctly for my car. Bought new,but with no box or instructions... Please tell me what you need to know to tailor it to my application. Thanks!
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Re: MP Distrubutor Schooling Needed!
[Re: ragtop]
#1655013
08/04/14 05:31 PM
08/04/14 05:31 PM
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Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
RobX4406
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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Old style with slot plate: If you know what the car needs for initial, which should be first up, and total, then it's easy math and a little work. http://www.moparmusclemagazine.com/techa...em/viewall.htmlModifying advance slots degrees / slot size MUTLIPLY by 2 to get crankshaft degrees 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 Newer mallory style. Same take apart procedure, use drill bit shanks to hit the mechanical advance instead of the mallory keys. The sizing is posted somewhere on the site. https://board.moparts.org/ubbthreads/show...amp;Search=trueMRG 925 springs seem to work well for a quicker advance curve.
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Re: MP Distrubutor Schooling Needed!
[Re: KnuckleDuster]
#1655015
08/04/14 08:19 PM
08/04/14 08:19 PM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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(1) set initial with "vacuum gauge method" (2) that's a SB dist so weld/file slots to get 35 total (initial above plus slot length (mechanical) advance (31 if mag heads) (3) toss the heavy spring with elongated loop on one end & sub in a mr gasket or MP light spring (keep the other OE light spring in there) & mix/match springs till you are just under the pinging point at WOT up thru the gears on your hottest/driest (most likely to ping) day and you want the curve to start no less than 200 RPM above your hot in gear idle speed.(4) Then plug in/adj the vac can staying just under the pinging point in everyday driving under varying load (in hg) conditions on your hottest/driest (most likely to ping) day and CCW with a 3/32" allen wrench slows the curve (not the total). On #2 File the welded slots slightly less than the chart as it reportedly is a bit off & you will be in and out of the dist several times (at least) till you get it spot on but it is worth it & you dont want to have to make a return trip to your welder.
live every 24 hour block of time like it's your last day on earth
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Re: MP Distrubutor Schooling Needed!
[Re: KnuckleDuster]
#1655016
08/05/14 12:00 AM
08/05/14 12:00 AM
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Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
Rick_Ehrenberg
top fuel
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top fuel
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
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The pix shows a Mallory / MP unit (note brass). These are an exercise in futility...this info comes right from the engineer who was tasked with "downsizing" Mallory's GM HEI setup to fit a Mopar (small diameter) housing. The flyweights are so light that the springs must also be featherweights. Result: At any point "on the curve" (from just above idle to "all in"), the timing is extremely unstable. There's no fix for this.
Early versions of this dist. were also erroneously shipped with a very fast, long curve, usually resulting in extreme detonation if your combo required more that 5 deg. initial timing. I finally convinced them to fix the "out of the box" curve around 2008, but, as I said, there's no known fix for the spark scatter.
Rick
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Re: MP Distrubutor Schooling Needed!
[Re: Rick_Ehrenberg]
#1655017
08/05/14 01:14 AM
08/05/14 01:14 AM
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Joined: Nov 2008
Posts: 1,565
tennessee
pushbutton
pro stock
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pro stock
Joined: Nov 2008
Posts: 1,565
tennessee
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Quote:
The pix shows a Mallory / MP unit (note brass). These are an exercise in futility...this info comes right from the engineer who was tasked with "downsizing" Mallory's GM HEI setup to fit a Mopar (small diameter) housing. The flyweights are so light that the springs must also be featherweights. Result: At any point "on the curve" (from just above idle to "all in"), the timing is extremely unstable. There's no fix for this.
Early versions of this dist. were also erroneously shipped with a very fast, long curve, usually resulting in extreme detonation if your combo required more that 5 deg. initial timing. I finally convinced them to fix the "out of the box" curve around 2008, but, as I said, there's no known fix for the spark scatter.
Rick
Were earlier units (mid 90's) screwed up as well?
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Re: MP Distrubutor Schooling Needed!
[Re: pushbutton]
#1655018
08/05/14 10:04 AM
08/05/14 10:04 AM
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Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
Rick_Ehrenberg
top fuel
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top fuel
Joined: Sep 2003
Posts: 1,688
Marlboro, NY, USA
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If you see the brass shaft, and quick-adjust weight stops, it is the Mallory design, and you are pi**ing into the wind. I can't remember when they went to that, but it was just about the time when Chrysler's Indianapolis Electrical closed up and they could no longer source the OEM design. Late '90s, maybe?
At the time, I thought "great, how much easier....", then the dirty truth was revealed, backed up by a decade of dyno tests and trying to tune street cars.
What do I do now? If you don't want to go aftermarket (Fire Core, etc.), then use a reman stock '72 distributor for your app (A, B, RB) and tune the old PITA, but rock-solid way.
Rick
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Re: MP Distrubutor Schooling Needed!
[Re: Rick_Ehrenberg]
#1655019
08/05/14 11:11 AM
08/05/14 11:11 AM
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Joined: Nov 2008
Posts: 1,565
tennessee
pushbutton
pro stock
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pro stock
Joined: Nov 2008
Posts: 1,565
tennessee
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Quote:
If you see the brass shaft, and quick-adjust weight stops, it is the Mallory design, and you are pi**ing into the wind. I can't remember when they went to that, but it was just about the time when Chrysler's Indianapolis Electrical closed up and they could no longer source the OEM design. Late '90s, maybe?
At the time, I thought "great, how much easier....", then the dirty truth was revealed, backed up by a decade of dyno tests and trying to tune street cars.
What do I do now? If you don't want to go aftermarket (Fire Core, etc.), then use a reman stock '72 distributor for your app (A, B, RB) and tune the old PITA, but rock-solid way.
Rick
Thanks, Not having a problem. Mine are mid 90's units. 
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Re: MP Distrubutor Schooling Needed!
[Re: can.al]
#1655027
09/07/14 01:17 PM
09/07/14 01:17 PM
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Joined: Jul 2005
Posts: 1,723
North Austin
KnuckleDuster
OP
top fuel
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OP
top fuel
Joined: Jul 2005
Posts: 1,723
North Austin
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Quote:
i had the problem Rick describes with the Mopar/Mallory unit.It came with very light springs and mech advance was all in at 1800 rpm.I replaced them with heavier springs (i think grey and purple) and now mechanical advance is all in at about 2800 rpm and it works fine now.
..just sayin'
From which kit? Gonna try this until I get another distrubutor.
Thanks!
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Re: MP Distrubutor Schooling Needed!
[Re: KnuckleDuster]
#1655028
09/07/14 01:31 PM
09/07/14 01:31 PM
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Joined: Dec 2003
Posts: 22,696
Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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This is a helpful thread interesting thread.
Maybe a candidate soon for archives?
My question, I have a SB Distributor with two pick ups, one 2 wire and one 3, why is that?
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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school us... 
). 
