Mallory dual point

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You will either have to build it yourself (IE lathe/ machine work, etc) from other parts or you will have to find a kit, such as PerTronix, "if they make one" for your distributor

http://www.speedwaymotors.com/PerTr...-8-Cylinder-Dual-Point-Distributor,35357.html

a quick Google shows "they" do make some. What model is your distributor?

http://www.summitracing.com/search/...t-type/electronic-distributor-conversion-kits

http://www.jalopyjournal.com/forum/...ry-yl-dual-points-dizzy-to-electronic.602518/
 
the PerTronics are great I put a few of these kits on some old tractors for a few guys
the difference is amazing over points I hope they have a kit for you .
 
Thanks for the replies guys ,a pal of mine has a 383 crysler engine in a pop and it seems to run Well to me , low thirteens I don't know why he wants to change it it's been working great for the last ten years . I think he wants to go faster .if it ain't broke don't fix it is my moto I will tell him not to bother messing with it .
 
Why change ???
Simple !!! the fastest mechanical component ever designed
is still 50% slower than the slowest electronic component.
I changed the 'dual point' for Factory electronic ign in '78.

I suppose if I was running a #'s matching $$$ resto I would have left
same alone. lol,
I just got tired of constant maintenance.
& 10k rpm ?? ok .
 
Actually the electronics are slower. It's called slew rate. Since its predictible, it can be compensated for in the curve if you know its there, or in a few over the counter products its suppsedly done in the electronics.

Points are a certainly harder to setup, especially duals points in the back of the engine. And they do wear out over time. As far as providing better ET or MPH, if everything is set up good, power is really not to be had in the ignition. Some fancy stuff can help in compromised situations or in high HP race engines.
 
Dual points are not difficult to set up. Hook up you dwell meter and place a match book between the secondary set of points. Set dwell to 26 degrees. Remove matchbook and place in the primary points. Set dwell on the secondary to 26 degrees. Remove the match book and put your cap and rotor back on. Takes only a couple minutes.

With a. Properly set up dual point there is little to no horsepower difference when compared to electronic. Electronic ignition has its advantage with long term less maintenance.
 
340dartley said:
Dual points are not difficult to set up. Hook up you dwell meter and place a match book between the secondary set of points. Set dwell to 26 degrees. Remove matchbook and place in the primary points. Set dwell on the secondary to 26 degrees. Remove the match book and put your cap and rotor back on. Takes only a couple minutes.

With a. Properly set up dual point there is little to no horsepower difference when compared to electronic. Electronic ignition has its advantage with long term less maintenance.
Click to expand...

That's true if it's a conventional 8 point cam [V8] Those damned Mallory "rev pol" 4 lobe designs are a PITA
 
67Dart273 said:
That's true if it's a conventional 8 point cam [V8] Those damned Mallory "rev pol" 4 lobe designs are a PITA
Click to expand...

Why? I have an old Mallory Double Life I restored and set up for my Hemi. It almost put itself together and set itself up it was so easy.

I'm not bein a smartass. What did I miss that makes them so difficult?
 
It's been a long time since I've messed with them. If you are familiar with how some of the V6 engines have "paired" cylinders (every other pair of plug towers) You can see that on a scope. In a similar manner, you can get the 4 lobe to (wrongly) do that if mis-adjusted. What this essentially does is to change timing on 4 cylinders in relation to the remaining 4.

This MAY be related to the original rev-pol. I don't know how many Mallory models were made that were other than.
 
Mattax said:
Actually the electronics are slower. It's called slew rate. Since its predictible, it can be compensated for in the curve if you know its there, or in a few over the counter products its suppsedly done in the electronics.

Points are a certainly harder to setup, especially duals points in the back of the engine. And they do wear out over time. As far as providing better ET or MPH, if everything is set up good, power is really not to be had in the ignition. Some fancy stuff can help in compromised situations or in high HP race engines.
Click to expand...


???At 10k rpm ???
with 'factory' capacitor(s) --- or in the vernacular 'condenser(s)' slew rate was completely dependent on mechanical integrity, not the 1'ST evolution of 'bean counter' electronics..
With Respects...
 
I am not familiar with the Rev Pol distributor you are referring to. I have 3 Mallory dual point distributors 1 small block and 2 big block. All have been conventional set up. Set one up on a. Distributor machine at the local college. Had it spun up and firing solid at 5000 plus rpm. That is 10000 engine rpm. I am still running it in my big block Satellite.
 
I think you're talking about rise time of the individual spark which can be altered by the condensor - coil combination. The condensor is a capicitor and certainly creates delay in building the charge in the coil, while minimizing the sparking by the points.

What I was referring to is the timing retard with increasing rpm due the fixed slew rate in the amplifier.
In ref to transiterized amps https://en.wikipedia.org/wiki/Slew_rate
It doesn't come up in 'net discussions much, but its hardly unknown. It's in some of the classic hot rod books and factory performance information/products of the 70s.
Here's a few diverse threads that it comes up in for anyone that is willing to dig through them.
http://board.moparts.org/ubbthreads/ubbthreads.php/topics/150709/re-orange-box.html
http://speedtalk.com/forum/viewtopic.php?f=1&t=10500
http://racingfuelsystems.myfunforum.org/Too_much_advance_at_light_throttle__about666.html
 
I do not think slew rate applies. The transistor in the ignition is driven into saturation, it works as a switch. The transistor "on" delay will be the the same, low or high RPM. The delay however is more degrees of lag higher RPM, because the degrees per second is greater.

In the end, the tuning of the advance curve compensates. I would expect sight difference in overall timing of points vs a conversion like Pertronix.

Points vs transistor for speed, I am going with transistor, they do not have contacts that can bounce. A condenser is not used in modern electronic ignitions, however the transistor has a few hundred pF of capacitance in the junction. That amount of capacitance is much less than the normal condenser.
 
I converted mine with a Mallory unilite kit, about $75 IIRC. I use it with n MSD 6AL box and have no problems. 2 or 3 sets of points and you break even, plus I have not touched the timing since the initial setup.
 
Nothing easier in a big block mopar then setting the points. Just remove dist, set points and put it back. I do think OP stated he was using a 383? Post #7
 
KitCarlson said:
In the end, the tuning of the advance curve compensates.
Click to expand...
That's the key, and the point of my post (#10). Fair amount of details in the links, especially the last, which should help anyone interested. I'll add more when I get back on the distributor machine.
 
Please excuse my mistake, I read post #10 wrong.

I am interested in your results including the timing variation among cylinders. The magnets in the Pertronix, years ago lacked uniformity in "H", resulting in timing variation on a cylinder basis.

I get around timing light delay issues by using a pull-up resistor to 5V, then capturing distributor signal, and reference with a logic analyzer. It is then possible to measure RPM, and individual timings with a high frequency time base.
 
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