Mallory Dist cap

Alaska Jim

Alaska Jim

Well-known member
well, as many of you know I had been looking to replace the 2 piece cap on my old Mallory dist in the y-block in my '30 coupe with a new 1 piece cap # MA 5 that is listed in the napa on line web site. I talked to my local napa dealer back at the end of July and although they were still listed, there were none available nation wide. I was told that I could order it and they would request the manufacturer ( who ever that is ) to build some and that it would take about a month. well today the news is that it is on perm. backorder, and they do not know when if ever they are going to build any. so I got my money back . I had ordered 2 caps and 2 rotors ( they were able to locate rotors # MA-7 on the east coast ). so for anyone who may be using this set up, new caps seem to be out of the question, and there are a FEW rotors in the system, and will soon be depleted. the Mallory dual point dist I have has been converted to a pertronix system. I am probably going to replace the dist., but I do not know with what at this time as there is VERY LIMITED space between the firewall and the dist. . I will have to find something with a cap that is no bigger in diameter than the Mallory dist. and cap. this is just for you guys information. I cannot justify spending 2-300$ on n.o.s. caps on flea-bay.---Jim
 
Last edited:
I wanted to replace the 2 piece cap and replace it with a I piece cap, trying to eliminate one poss. problem at a time, and thought that it would be an easy ck/test/fix.
 
flatheadmurre, I am not sure, the latches on the Mallory are pretty wide, and I don't know if the rotors are compatible. It may be possible to change the latches on the distributor. I guess that is something to ck into. thanks for the suggestion . I also want to have a black cap, red or blue would look out of place on my car.
 
I may be way off on this, but see if an early 55 or 56 Chevy, V8 Cap will work. The early SBC Cap is different than the later ones with the screw mounting.
 
Rumor has it, repeat, rumor that MSD has bought out the Mallory name and intends to stop all Mallory production including replacement parts. This, if it is true, is of course a severe wrongdoing, but as we all know big business doesn't care about it's customers, only profit margins
 
replace the Mallory with a stock dist and get rid of all the problems, points dist worked fine for 50 years or so
 
Alaska Jim said:
I wanted to replace the 2 piece cap and replace it with a I piece cap, trying to eliminate one poss. problem at a time, and thought that it would be an easy ck/test/fix.
Click to expand...

Jim, what is the ignition issue you are having?

As far as the 209 cap fitting that is a probably a no go. The YC 2 piece gets aligned with a tab on the distributor body that is 1/16 X 1/2 x 1/16 and the 209 fits over a small pin (on the YL's) pressed into the dist. outer diameter. The locator is there to align the rotor to the cap contacts for proper phasing, and anyway, the register diameters may be different. Same situation with very early SBC cap, different locator and as you previously mentioned both those others use different clips too. If changing to a stock dist. how does that size compare to the Mallory, will it fit with your close clearance?
 
WestCoast said:
replace the Mallory with a stock dist and get rid of all the problems, points dist worked fine for 50 years or so
Click to expand...

Alaska Jim, IIRC your Mallory dist. has some sort of points replacement conversion kit in it.
I'm not a fan of those, had one quit on me (twice in the same week) both times in the middle of a turn, in front of oncoming traffic. Then start right up like nothing had happened... after pushing it out of the road. I'll vote with WestCoast.
 
Fordors, dmsfrr. my Mallory dist. has a pertronix conversion done by previous owner and original builder of the car ,and I do not have the parts to change it back. or I would. my problem is an intermittent miss. sometimes bad sometimes not at all. I suspect the coil wire is one possible problem as it is at least1-2 feet long, as the coil is mounted inside the car and runs down under the firewall and then up into the car to the coil. ( not my work ) I have not checked, but suspect that it has to much resistance. the other problem is that the cap on these Mallory's are for 7mm wires, but somehow the previous owner managed to get 8mm wires in it. I was going to change the coil wire, and mount the coil on the eng., but the coil wire did not want to come out of the cap even after I loosened the 2 screws. with out any other dist. readily available, I just left it. I did change the coil and also pulled the dist. out and retimed the eng. so I could get the dist. to be able to move enough to get 14* on the crank and a total advance of 34*. this made the car run much better, but still occasionally get an intermittent miss. It could be the electronics in the dist. I was trying to get away from the 2 piece cap to eliminate the possibility of the cap. I have been putting off tearing the car apart because of our short driving season. well that is just about over. snow usually comes the 2nd week in Oct. around here. it may not stay on the ground long, but then again it might. you never can tell. I will tear things apart this winter and get it all straightened out. I am also going to start gathering up parts and build the 312 block and crank I have and eventually replace the 272 that is in the car. I have changed the fuel pump ( it failed ) and several sets of plugs ( was running lean ) and changed the jets in the center carb from 51's to 56's (end carbs are temporarily blocked off ) so I can sort out one problem at a time. funny thing is that it never misses at idle only when there is a load some times only a light load other times when I am putting the pedal to it. I have checked the float level, and it is good. I will figure this out over the winter. I started tis post only to let people know that although NAPA still lists the one piece replacement cap on line and in the catalog, it is on permanent back order. took them 5 weeks to tell me that, but at least they refunded my money, as special orders have to be paid for up front here. hope that this little bit of information keeps other people from waiting for something that is not available, but then again if enough people tried to order one maybe they would make a run of these caps.-------Jim
 
Alaska Jim,
What spark plug gap are you running? I have a Ford tractor that the previous owner converted to Pertronix ignition and I had a high speed miss. I took the Pertronix off and threw it in the trash can and replaced it with old Ford used points, condenser and coil and it has been running fine ever sense! This has been over a year! Hard to beat the old stuff.;) Oh, try .025 plug gap and see if this stops your miss.
 
gap is at .035 thought about trying larger or smaller gaps but have not driven the car since the 29 Aug. crappy rainy weather, or the good chance of rain. no fenders and no hood make for a lot of clean up if caught in the rain.
 
The long coil wire and mismatched size wires & cap may or may not be ok, but they probably aren't helping, and if you can't get replacements what's the point.....
A previous owner forcing the plug wires to fit the cap may have internally damaged those wires.
Finding a good '57 or newer oem y-block dist to use would eliminate a bunch of questionable parts, and be easier to get replacements for.
 
dmsfrr , that is looking like it may be the plan of attack. I like the low maintenance of electronic Ign. but do not like the reliability, or lack of reliability in these conversions. if I had the extra money I would consider a vertex or hunt magneto.
 
I left the after-market points conversion kit in that Merc. Comet only long enough to drive to the parts store and get a 'dual point' distributor, never had another problem with ignition.
The dist for my Y-block got rebuilt and now has dual points also.
Electronic ignition is great if it's all oem, for reliability.
 
Jim, I have a Petronix I (the original) in my Fordor and looking at the instruction sheet it has to be powered by a full 12 volts. Was yours hooked up to a full 12V source by the PO? If powered from a resistance wire or ballast resistor it can give the conditions you describe.
Also, I have a Mallory with a 2 piece cap for early Olds. I had trouble getting the old wires out also so I unscrewed the top of the cap, cut off the wires and used a punch to knock out the wires. Mine were very old 7MM and really stuck to the cap, no way could they be pulled out.
 
Fordors, yes I checked, it is getting a full 12 volts, no resistor. the first thing I found wrong trying to fix this was the original coil on the car was the coil that was recommended by pertronixs, but upon inspection of the coil wire tower, I found that the end of the coil wire and the metal part in the tower was badly corroded. replaced the coil with another ( same flame thrower coil recommended ). this cleared up some of the problem, but not all. this car was passed around by at least 3 owners before it was 95% completed when I bought it. there is no telling what bugs I might find, it will just take awhile. you can see the difference in workmanship in different areas of the car. as I said looks to be 2-3 different people. the plug wires appear to be new and as I said before I wanted to try and drive the car as much as possible this year, so I did not rip them out. only have a few possible weekends left before winter here. I hope to have discovered all the problems by then and address them over the winter. thanks to everyone who has posted and made suggestions, it is appreciated.------Jim
 
You must log in or register to reply here.
Back
Top