I am an aficionado of old Mallory "flattop" distributors. Of course, one of the problems with them is parts availability. I haunted eBay etc, and have built up a pretty good supply of spare parts, but ponts, especially, are getting expensive. I get caps and rotors etc., out of used units, and have acquired quite a few sets of used points as well. Surprisingly, most of the point sets are aren't that bad, with one small area of buildup and pitting on the opposing sides. There is a surprisingly large amount of the original contact area that looks clear and smooth as new My old man gave me a point file and some rudimentary instruction years ago, but I'm wondering if there are some tricks out there I don't know about. I have one set of points that I was able to completely disassemble, and I think I got them where I want them. The rest can't be taken apart and present a problem. In particular, I am wondering if a rotary tool (Dremel) might be useful in working on these. Trying to keep the points open and getting a decent stroke with the file is difficult. Several years ago, I purchased some small diamond-coated grinding discs and they look to be likely candidates for cleaning these up. I am kind of concerned about contaminating the contact surface with the grinding medium. Also, I have heard the term "burnishing" to surface the contacts. from what I read about it, it is a method of actually reforming the metal to get a better surface. This is all well and good, but I have to think that tungsten (or whatever it is) would be too hard for it to work. I am going to continue experimenting with this, but just thought I'd check and see if there was any knowledge floating around out there.
If the points are in the distributor, and the distributor is in the engine, then you have it mounted solidly enough to file aggressively. I've gotten to where I take a look at the points, if they're not too bad, I file them with a points file, and add a tiny bit of lube to the rubbing block, and then check the dwell or gap and set it if needed. Then I ignore them for a long time, and don't have any issues with them. I think if you're tempted to use a grinder on them, they might be pretty far gone. I'd rather spend a couple more minutes with the file. Having them mounted, so you can apply some force to them helps. Condensers...you know they're another story...
I have that problem solved to my satisfaction.Making a set of points from scratch is another matter completely, although I have been able to replicate certain types of Mallory points from some readily available Echlin units.
Wouldn’t take much to make a fixture to both keep points open and firmly secured that could be held stationary in a bench vise. That’s just me. The over thinker.
Nope, great idea (IMHO). I'm thinking tha since Tubman has an abundance of old points, making a plate that he can screw the points to and clamp in a vise should provide good access. The plate would be made so that the points protrude off the edge. A file could be used to quickly knock the bad stuff off. Then some fine emery paper glued back to back and slowly drawn between the points to get a better finish. The points would be sticking up at the twelve oclock position and slightly above the metal plate.
> > I am wondering if a rotary tool (Dremel) might be useful in working on these. > > Nah. These work great. All the girls love them!
I would like to point out that the construction of some of these point sets leaves little in the way of space to manipulate the file because of the location of the rubbing block etc. The one set that I was able to disassemble was easy-peasy. Thus the question about the rotary tool. I am finding that there is quite a bit of variety in the diamond grinding discs available for them. Also none of the point sets I have are nearly as problematic as the examples @MOONRNR posted. I realize those are exaggerations, but on just about all I have looked at closely, probably 90% of the original point surface is like new. If I could figure out how to file the points to move the contact patch, I'll bet a set could go 100K miles.
I don't always file my points but when I do I follow up with fine grit, like 500 or finer paper then clean plain paper. the file can leave a rough surface, the sandpaper helps smooth the minute ridges and the plain paper cleans up what the abrasive leaves behind.
I use an MSD 6A with my Mallory YC distributor and the points show very little wear. I don't use a condenser as the points are breaking very small current triggering the MSD. I figure the rubbing on the dist. cam will wear out first.
I pry the arm open enough to stick the POINT FILE (no other kind of file) in between, let the pressure of the point arm hold the two surfaces tight to the file, then gently pull it straight out. If required to get a nice surface, do the same again. I can’t see how you can get parallel surfaces when you are spinning a high speed grinder, held by hand. I’ve never sanded the surface again with any sandpaper. My POINT FILE (no other kind of file) does a good job.
Sandpaper and emery cloth leaves deposits in the tungsten contacts. It's only ok in a pinch to get ya home. Good ol point file (also tungsten) is the only way. Like alky above just said, 1 or 2 strokes ought do it. Wait, shit, I didn't mean to call you an alky @alchemy ...
That’s how I have always done it, I think a dermal tool will be hard to control the amount of material removed and the angle.
My local parts store has them on the wall behind the counter. Last one I bought cost $7, which seemed like a lot for a little file. But they are precision instruments.
I've had good luck using a narrow strip of sandpaper, usually one-sided but sometimes folded 2-sided if I want to cut a minute down to 30 seconds. I can't recall what grit I preferred but fairly fine I think. With the points in the distributor, put the sandpaper between the points, a little gentle pressure on the outer point against the inner point with my left index finger, pull the strip out, and repeat a few times. Save the strip for next year. The point (pun intended) is to keep the point blocks flat and parallel to each other. Old-timers will tell you stories about using the striking strip from a matchbook to temporarily clean up welded-together points so a stranded motorist could limp home or to a service station.
I once read that using emery tape or fine sand paper can leave residue on the faces causing hot spots, only a points file or the like should be used. If cleaned out probably you’d think it would be okay though. I’ve used both and as long as the points were aligned correctly no problems.
when I cheat and use emery tape or sandpaper to clean electric contacts, I do like was suggested above, and run a piece of paper between them a few times to clean them up. This is mainly for situations where a file won't fit, like relays and voltage regulators
I have a contact burnishing tool (2) for the contact surfaces of electrical relays we used in the power plant industry. See below For ignition points I would cut a few inches of 600 wet or dry 1/2” wide, fold it in half, a pull it thru a set of points.
The Jalopy Journal
