MSD vs Mallory Distributor

[pusherfans]

Okay, so in an attempt to replace the distributor bushing on my MSD 8594, the stud snapped off. Since I am chasing a weird running problem that I suspect is either carb or ignition related, let's try a new distributor.

Attached are pictures of my 1200 MSD unit. Corrosion! How? This car never sees wet weather or winters. I was also unable to set the timing at idle, had to set it at 3000 RPM at full advance and it takes a few seconds to settle down at idle. Also the timing jumped around (38-40 degrees) is that normal?

So here is my question. Does the Mallory suffer from these corrosion issues too? How about the funny timing thing at idle and full advance?

Any draw backs to either one or are they pretty much equivalent?

BTW: the Mallory guys say it will plug right into my MSD box, so that should not be an issue.

[Rick Parker]

The Mallory unit uses an optical light trigger mechanism that has its own set of "Bugs".
The design technology (magnetic flux triggered impulse) used in the MSD is mirrored from Fords Duraspark application. In fact the module is a duplicate other than the base plate. For the most part it's troublefree. To my knowlege all the OEM's use this same basic type technology in lieu of optical for their ignition sytems, if the optical were more reliable I'm sure they would be using that, so would Nascar.

[pusherfans]

this one does not seem to have the optical.

http://www.summitracing.com/parts/MAA-3255311/

[eracoast]

Had same problem with my MSD these caps have their own atmosphere inside because of ionization that builds moisture. What i did was drill two small holes @ 1/8 " on the upper back side of distributor about 1" apart to vent it. Years ago distributors were vented, some of the newer ones are not. Worked for me!

[DAVID GAGNARD]

This car never sees wet weather or winters. I was also unable to set the timing at idle, had to set it at 3000 RPM at full advance and it takes a few seconds to settle down at idle. Also the timing jumped around (38-40 degrees) is that normal?

While outside weather does have some effect on your ignition system, the inside corrosion is caused by a sealed cap.... Everything is outside temp, you start the car a drive around, things heat up, pretty hot under the hood, you come home and shut it off, things cool off, condensation occurs, and that's where the corrosion is coming from, drilling holes in the cap will help........

My timing doesn't really jump around, but does take a few seconds to come back to the idle timing setting once idle rpm is reached, my guess is corrosion will do this also as the weights have to move over rusted metal........

Why MSD doesn't spray the bare metal parts with some type of shelack/sealer before assembly is beyound me........I've seen other factory distributors such as the Duraspark unit that have all bare metal parts coated!!!!!!!!!!!!!!

David

[ERA Chas]

Same Unilite in since '97. Replaced one module, three caps and rotors-ZERO corrosion. 6-AL behind it.

[Zoom This]

Originally Posted by ERA Chas

Same Unilite in since '97. Replaced one module, three caps and rotors-ZERO corrosion. 6-AL behind it.

Are you saying that the Mallory Unilite distributor can just plug in to the MSD 6AL box and away you go??

Bill

[ERA Chas]

With a ballast resister-yes.

[DougD]

If I was to do it again, I'd get a $70 rebuilt Duraspark for a 1976 Ford Pickup with a 360 or 390 at AutoZone or someplace similar. Plug it into a 6AL MSD box and go!

[Ron61]

I use
ed a Mallory magnetic type distributor in my car for years and never had a single problem with it. I have a MSD distributor in the 69 and have to watch the terminals for corrosion and also a weakening of the spring contact with the top terminal.

Ron

[Snakebit]

I use the Mallory 32 series distributor that incorporates a magnetic pick up. 3255311

[bobcowan]

I use a Mallory Unilite. I'v been using them on various cars for many years. Generally speaking, the module is pretty durable, and lasts a long time. But, this car is differant. I guess it's because I race it pretty regularly. But I'v had the module fail more than once. I routinly replace the module every year. And I carry a spare in the trunk.

I have not been able find much of a differance between the optical and magnetic trigger. There doesn't seem to be an advantage to either one. Mallory sells both.

I have had one cap go bad; the center carbon post went to another dimension. That's the same problem with MSD.

I have never seen any corrosion inside the distributer. Although it's generally pretty dry in CO, I have driven in driving rain and light snow. This is not a trailer queen.

The big differance to the Mallory is that the advance mechanisms are below the trigger plate. Makes it a hassle to change the timing curve. But it makes it real easyt to change the module. I like that, because I set the curve once and then leave it alone. But I change the module at least once a year. SOme people prefer the MSD for exactly the same reason.

[DAVID GAGNARD]

Originally Posted by DougD

If I was to do it again, I'd get a $70 rebuilt Duraspark for a 1976 Ford Pickup with a 360 or 390 at AutoZone or someplace similar. Plug it into a 6AL MSD box and go!

ME TOO!!!!!!!!!!!!!
In fact, I'm thinking about doing exactly that now, and keeping the MSD as a spare............

David