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Mallory Dual Point Distributor

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tontonene

tontonene

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I have installed two Mallory dual point distributors in the past two years. Both have failed electrically. I returned the first to Moss and received another. The second failed after approx three months use. The failure mode is that the car begins to miss and the problem progressively gets worse. I have changed all of the electrical system while troubleshooting the issue. I have since re-installed my original Lucas single point distributor and things are back to normal. The only changes made to the electrical system that are not stock are that I have added a higher voltage coil and cooler plugs. Both these seem to work ok with the original distributor.
Anybody experience issues with these distributors? I am now leary and will look for another alternative. The application is a BN-2.
Thanks,
 
I've had a Mallory on my car for the past eight years. The only failure has been a condenser after about six months. I replaced it with a Lucas item with no problems since.
 
I put a Mallory dual point on the Buick V6 that I had in an MGBGT. The only issue I had with it was an overheated coil (correct voltage/correct ballast resistor). I went back to a Lucas sports coil (prevoiusly used a Mallory) and never had any more trouble__at least with the ignition...

If I was to buy another aftermarket distributor for my Healey (something is on the list), I think I would try the Mallory unilite. What I really want is to go with a distributorless system, like that from DIS https://www.directignition.com/products.html
 
I have run a Mallory dual point in my TR3A for a good 20 yr. In that time I have just recently replaced the coil and cap for the first time. I can only remember changing the points, rotor and condenser three times. I check/reset pt gap annually. I did have the car shut down once on a longer trip; all I needed to do was to readjust the points. I would say I am more than happy with the Mallory; the build quality is far superior to that of the Lucas IMO.
 
Tontonene, Just out of curiosity what polarity ground system exists in your car ?---Keoke
 
I have been running a Unlite for several years--only problem I ever had was when my ground connection came loose.
 
[ QUOTE ]
Positive.

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Are you sure you had the coil connected the right way around: The + terminal goes to the dizzy and the - terminal goes to -12v . Failing to observe this configuration with a positive ground electrical system can cause premature failures in the secondary system---Keoke ?
 
Was your new coil rated the same input impedance, ( 3 ohms ?), as your original lucas coil ? If not, then either the points or the new coil would be subject to too much current and would rapidly deteriorate causing your symptoms......
Edit.. Randy said he had a problem with his coil overheating, perhaps that is your root problem if you were using the same brand of coil as Randy. But your failure symptoms would make me suspect the coil in any case.
 
[ QUOTE ]
The positive of the coil is tied to the distributor.

[/ QUOTE ]

Well try this: order a new set of points and clean them throughly with Petrol, Brake Cleaner-etc.prior to installing them and see if it will not work correctly.---Keoke
 
The existing points are in good condition without pitting and are adjusted properly. The distributor looks to be fine. I can find no evidence of arcing or grounding. I will try another condenser when I re-install the Mallory for testing. I am presently running my original Lucas distributor with the new coil and the cooler plugs. The car runs great with this set-up. I do not have the vaccum advance hooked up, but this does not seem to be a factor.
 
You are on the right track. If the coil and points are good and you already replaced wires, cap, and rotor. That
doesn't leave much else. But it's ALWAYS the LAST thing that you replace !
/ubbthreads/images/graemlins/grin.gif
 
The Mallory Dual Point requires a Ballast Resistor in-line.
This distributor works best with the Chrome Mallory Coil. Good Luck.
/ubbthreads/images/graemlins/cheers.gif
 
"The Mallory Dual Point requires a Ballast Resistor in-line"
--------------------------------------
Look at the Mallory site and I believe you'll find that the resistor is not needed with the points unit but is strongly recommended for the Unilite and I presume also the Mag-Lite. The purpose of the setup is to give full voltage for starting but to reduce current while running and thus protect the module from overvoltage spikes. FWIW I ran the Unilite on my car in ignorance without a ballast resistor for about a year with no damage. The Mallory coil and others are ballasted and require no resistor.
 
[ QUOTE ]
The Mallory Dual Point requires a Ballast Resistor in-line.
This distributor works best with the Chrome Mallory Coil. Good Luck.
/ubbthreads/images/graemlins/cheers.gif

[/ QUOTE ]
That's what I had. I thought Mallory distributor, Mallory coil, but it left me on the side of I-10.

I had the Delco-Remy HEI distributor in the back and that's what got me home (MGBGT w/transplanted Buick 3.8 V6).

Once the Mallory coil cooled down, it worked again, but I didn't trust it. /ubbthreads/images/graemlins/jester.gif
 
Please read very carfully!!! I know exactly what is happening with your distributor. About 6 years ago Terry Larson restored my C-Type Jag using a Mallory dual point distributor. About 3 - 6 months into the use of the car I had the same cutting out problems you discribe. Up until then it ran like a "well oiled clock." We went through carburetors, etc. trying to fix the car. Finally changing the condensor solved the problem. About 3-6 months after that the same probem resurfaced. A change of the condensor again solved the problem. I then decided to install a bracket with 2 condensors on the distributor so that when I was on a tour I could quickly change and keep going. I assumed that there was some sort of grounding problem and that I was just destroying the condensors. Needless to say this was very frustrating!

Terry finally called Mallory and, after much discussion, was then told that they indeed had a probem with their condensor supplier and that they estimated that about 25,000 condensors were delivered defective and that yes, this was the source of our problem. They had no idea where the 25,000 condensors went so they had no way of pulling the faulty parts off the market. We discovered that they were installed on new units as well as the spare/replacement parts you could buy separately from Mallory.

The only solution is to buy a new condensor of a different make appropriate for the car. Just go to the auto parts store and by a 12volt condensor that will fit. You will never have the problem again.

Since that time I started racing my Austin Hekaly 100S (restored with a Mallory dual point condensor) and guess what, a little ways into using the car the same symtoms came up; I was in a race at Coronado and in the middle of qualyfing. Needless to say I was not very happy about being visited by the Mallory "condensor ghost." I got the car back to the pits, changed the condensor, and no problem since. The Mallory dual point in the Healey was purchased in the last 2 years. So the moral of the story is these defective untis are still out there and being sold.

Every defectvive condensor I have seen has an orange wire. My advise is, if you have a Mallory distributor with a condensor that has an orange wire, change it!! Sooner or later it will fail, usually at just the wrong time. If you are buying replacement parts for your Mallory distributor I wouldl not buy their condensors. Just buy an equal part of another make. You will not have any problems.

I hope this helps. We chased the problem for a long time. It would have been better if Mallory owned-up to the problem and advised the motoring public of the issue. However they have elected to let us all find it outt on our own. There is no telling how many people have been stranded by this problem.

GregJ
 
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