The good news is that I was fortunate enough to have assembled a complete Mallory Magspark set up for my '51 Olds 303. The bad news is that it's for 6 volts. Anyway, I refurbished the distributor and in the process, replaced the points with NOS Mallory sets. At about $30 per set this is kind of expensive. I was about to toss the old points when I decided to take a quick look at them to see if they could be salvaged. It looks to me that they can probably be made to be as good as new. On a very close look, it looks like the round contact on both sides is about .040" thick. The actual contact (tungsten or whatever) seems to be joined to the steel base by some sort of electric fusion process. The pits in the points appear to be quite shallow (.002 -.003") in relation to the actual thickness of the contact. I would think that using the proper tool, grinding the contact down to where the pit disappears and then burnishing the surface would bring them back as good as new. My concerns would be changes in point geometry caused by the thinner contact patch (which I believe would be minimal because of the small amount of material involved), perhaps spring failure from over use, and contamination of the point surface from using the wrong medium to remove the excess point material. It is this last that most concerns me. If there are any metallurgists out there that can advise me on this, I would like any information I can get. I want to do these sets of points and try to bring them back. If this works, it would be a boon to us fans of traditional ignitions. I tried to take some pictures to show what I was seeing, but my camera is not good enough to show the detail clearly.
Folks have been filing and reusing points for a hundred years....it's nothing new. I have yet to buy new points for the Mallory dual point in my Chevy II, and I've put a lot of miles on it.
I have found that filing points won't do it easily or in a precise and timely manner (trust me, I've tried). To do it properly, a grinding process would be necessary, hence my concern about surface contamination.
I ran a turbo car in the early 80's, It would begin to miss in the high RPM range 6500 -7000, file the points and reset. They didnt run as long as new points, but always worked for a few more passes. I still have the points file I purchased from SnapOn, stashed in the timing light box. The old C60 farm truck ran for many years on filed points, my flathead V8 has been running on filed points for about 6 years now. Slow turning motors are not as picky!
File a new clean contact surface with a METAL file, make sure the pivot isn't in danger of accidentally making a ground contact, don't let the rubbing block go completely flat, lube the cam, and you may have a lifetime set. Once I had a Pontiac straight eight that would get hard to start at times. I traced the problem to the rivet that held the flat spring to the contact arm. The rivet had lost it's tight clamping on the two pieces, and didn't always have a perfect electrical connection. A good squeeze of pliers to tighten the rivet, and the problem went away. Keep up with a few small details, and a set of points could almost last forever. They used to throw away the old points only because it was very cheap to do so back then. P.S. in the old school shop classes, they always taught to use a metal points file, and never sandpaper or fingernail file because of the tiny tiny slight abrasives they could leave behind and burn the points quicker. A metal file didn't contaminate the contact surface with tiny particles. P.S. leaving some pits in the contact surface will not matter. All you want is a smooth surface to touch another smooth surface. A few pits may have a tendency to gather contaminants a little quicker, possibly requiring more frequent cleanings, but that's a whole lot better than filing down the tungsten to almost nothing in an effort to look perfect, and tossing out something you cant replace. tip - If you find that the points develop a pit on one side, and a pointed peak on the other, it means the condensor value doesn't match the coil. They should work fine for almost forever. WHY BE ORDINARY ?
The contact geometry should not change, as the contacts are slightly convex. The thing is that new points become used points pretty quickly, and used points will last a long time if they're clean, aligned, and the condenser matches the coil properly.
While both tubmans and squirrels comments are true, (filing and not a good way to do that), tubman is correct. If you look "closely" at the contacts themselves, with a quality set of points, the contacts are actually not "flat". They are formed with a large radius (at least one side, if not both), like a lifter (for a camshaft). The material is also very smooth. Both the smoothness and the radius are for specific reasons. Can they be filed flat and still work...sure, but the rough surface actually encourages the pitting to come back...even faster than from a fresh set of points. Can the material (tungsten ?) be reformed/ground to a radius and be made smooth...sure, but at what (very high) cost ? Cheaper to buy new. Mike
Why did they invent a "points file" if you weren't expected to file them from time to time? No they won't be as good as new but they will get you down the road. Is this for a hard use (racing) engine?
You can continue cleaning and reusing the points as long as there are points left. You used to be able to buy a special grind stone that ground the points flat and smooth on the bench. I have taken point sets apart and smoothed them on a whetstone. The cleaner and smoother the better. The points will not pit if the condenser is exactly the right value. But they vary, and the requirements of your system can vary. If you check your points and they are not burned don't throw that condenser away. If the capacitor has too much capacitance it will burn the point on the ground side, if it is too small it will burn the point on the cap side. It may be possible to find a capacitor of exactly the right size that no burning occurs, if you have several to chose from and a way to test them. They do vary in capacitance as they come from the factory. You can use modern mylar film capacitors or condensers. Get 600 volt ones. If the new one won't fit inside your distributor put it on the coil, at the other end of the distributor wire. It will work just as well.
While I understand what you are saying, my intention IS to try to get them as "good as new". As to "Mike VV"'s comments about cost, remember, I am referring to Mallory points here that have gotten quite expensive lately. Plus, I'm retired and have some time on my hands.
"Rusty" - About condensers; I make my own "Trash Can" style condensers using modern severe duty film capacitors, and have quite a variety to pick from. I am making .22 micro-farad units (single points) and .33 micro-farad units (dual points) at the present time. My biggest problem is getting anyone using them to put enough miles on them to see if there is any pitting happening at all. So far, everything looks perfect.
Do you mean 0,22 & 0,33 µF? mF would be millifarad, a thousand times larger than microfarad, µF. (I know the m was used for micro on capacitors long ago, but they stopped to avoid confusion.)
Filing points has been done since before I was born. I was shown how to do it when I was a kid. It does work. There is no science behind it, just remember it has to work on a lobe. Easier than eating a Twix.
Yeah, I guess that's right, they are rated in micro-farads. I don't know how to make the goofy backwards "u" with a tail on my computer. Funny, everything I look at says micro-farads; I guess I'll have to start spelling the whole words out to avoid confusion. (I have a partner in this who is an EE who usually takes care of this sorta stuff for me; I'm just an old car guy.)
I was probably the one doing the filing. Again, I know all about filing points; I am talking about taking a few extra steps to get the finish and shape correct so they are as good as new.
I never remember how to make it either. My solution when I need a special symbol is to find it anywhere on the internet, copy and paste to where I need it.
like this? μ Anyways...to get them to be like new, you need to make them the same way they were made when new. To get them to be good enough to use for a long time, you can file them. If you file a slight radius on the contacts, that might be better than filing them flat. I can't file stuff like that perfectly flat, anyways...
Filing points used to be common until somewhere along the line it was decided that it was easier to just replace. I owned a motorcycle that the factory service manual gave directions on how to file the points when doing a tune-up (and at what point they had to be replaced). Owned the bike for 7 years, never replaced the points. I'll agree that there's a bit of skill involved in doing it right, and the filed points don't last quite as long before needing servicing again as a new set would, but I never noticed any performance loss with filed points either as long as they were properly adjusted. Part of the issue was that they started 'cheapening' new point sets, and wear on other parts would get excessive, defeating the reason for filing them.
You could use NGK resistor spark plug caps to reduce the ignition 'noise' with solid core wires. Very common on motorcycles. I do know at one time if your solid core wires put out RF interference that affected others you could be ticketed for it. That's why Corvettes usually had those plug wire 'covers'; to get rid of the interference that the fiberglass body didn't shield. Not an issue with metal bodies...
Good thread. I filed them for years, learned how in 1952. Did it on every tune up, until Porsches came into my life...and I got jobber price on Bosch parts. My point file is still in the right hand top drawer of my Snap On top box...(the upper of 3 stacked, in a 10 drawer chest...) Left side extreme, in the back...its own aluminum tray, from an imported cigar from way back when. It's a Blue Point. Just behind the Porsche and BMW box compartmentalized for the special feeler gauges: Accurate valve lash on 6 basic engine designs... Gawd, I love that top box...especially the ...oh, never mind!
I thought the corvettes only used the distributor and plug wire covers on the ones that came with a radio.
I love points over any pentex crap,I've filed many a set,biggist prob is those that fail to clean after they file or sand etc. Did many with a matchbook cover,file with the striker part,an clean with cover/but not were there is any print on it. Its a bit harder nowday,not many matchbooks around
If I file points or even if I don't on my old 39 Indian I polish them by dragging thru some 2000 wet/dry.
I use a fine diamond file to remove the oxidation and resurface the points. I have been using one set of points on an engine, that gets a lot of use, for thirty years and they are still working like new. There is one difference in my case, in that I am using CD ignition systems that cut the current that the points are switching by a significant factor. This means that there is very little arcing on the points. The fibre tab that contacts the cam lobes needs to be lubricated with a high quality grease, ( use synthetic racing grease). This is important for getting long service out of the points. To check my ignition systems, I put my vehicles on an ignition scope from time to time to check the pattern. The scope can pick up erratic timing, faulty plugs, faulty capacitor, wires, and poor connections. I also agree that if you look at the points carefully after you remove them, you will see that the deposit will be on one contact or the other. This is the indication of the value of the capacitor ( condenser) being too high or too low. I used to know which way to compensate for a deposit on one side or the other, but with the CD system this is not a problem and I have forgotten simply because I haven't needed to correct for this problem. I don't even know if new versions of the CD systems are available any more, because new cars all have electronic HEI systems of one sort or another, so there is no market for these old electronic devices. BTW: using the CD system, allows increasing the plug gap and the increased voltage required to fire the plugs with the larger gap, helps increase mileage, but more importantly reduces plug fouling and the reduced current increases plug life. I have a 396 in my Chevy Cameo, and have not changed the plugs since 1970, when I installed the engine in the truck. The ignition is still functioning flawlessly. I am installing the 454 with a point type distributor, and will be using the CD system and platinum or iridium plugs, and obviously high quality wires. Bob
I run an MSD-6 on my coupe and just as j-jock says the points last forever since the amperage through the points is very low. They do need to be lubed as he said and they might need adjustment once in a while but otherwise no issues. If the MSD box should die on the road you just remove the connections at the coil and put jumper wires on and away you go. The Delco looks traditional with the MSD unit hidden and the hot spark and low maintenance are definite pluses.
$30 is cheap for good points. I have 1920's cars that new points are $150 when I can find them. I also have a machine shop so I resurface old ones on a surface grinder. I hold them in a vice and indicate the surface flat and clean them up on the surface grinder. They last for years as the surface is as smooth as new ones.
Points will last until the rubbing block wears out if you have electronic ignition. Put on a dab of points grease the size of a match head each time you service them and they will last a long long time. Try your Mark X with a carbon core wire for the core wire, this is an old trick for radio suppression on solid core wire jobs. You can use an old Chrysler box with points, also a Ford thick film ignition module and of course MSD. I used to have a schematic for a 6v electronic ignition but don't know what I did with it. Maybe it is still on the net, where I found it a long time ago.
This is the kind of information I was looking for. It's nice to see that someone fully understood what I was asking in my initial post. $30 a set for a dual point distributor is a lot of money to a retired guy with time on his hands. At $150, I wouldn't even be asking the question.
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