add me to the list of "box" users. i ran a mallory in the '70s and used what was probably the first capacitive discharge--a delta 10-B. i put at least 20,000 miles on the points and they still look fine!
There is a program called "Character Map" or "charmap" on most every version of Windows. On older versions click on "start" or "run" and type "charmap". On Windows 10 type "charmap" in the search window on the toolbar at the bottom of the screen. Select the character you want, select copy, and paste it where you want. The Character Map on Windows 10 has almost 3400 different choices. ° °© ʧ Ϫ Ѭ ۞ ֍ ♀♂♦♠♥♣ ♫ Ω
Point files were good back in the day but as they started using tungsten carbide alloys in the 60s, the points are harder than the file. They made carborundum files that look like sandpaper on a stick. Some points only have a thin electroplated coating. Once that is arced through there is softer material under it.
Hmmmm, can you explain that? How would excessive capacitance cause pitting on the ground side? I'm not envisioning how that would occur. btw, the points are between the coil primary side and ground. It is parallel with the points.
Production tolerance of condensers varied more back then than they do today. If you read the old manuals like a MoToRs Repair they discuss this, deposits building up over time on one side or another of the points was remedied by lengthening or shortening the condenser lead itself, this changes the overall capacitance slightly, and is enough to make a difference. The consensus at the time with experienced mechanics was that if the current points installed were otherwise working well and wearing evenly, was to not replace the condenser as part of a tuneup even if new points were due. This especially holds true today not because of slight differences in capacitance, but because they will likely be defective right out of the box. 0.22 MFD or µF or microfarad ; all mean the exactly the same thing. (Periodically, engineers and others seem to change nomenclature just to confuse people.) A minimum 400 or 600 volt DC metalized polypropylene film capacitor should work fine.
I've had the same experience as Engine Man. The point files wouldn't file the points. I stopped buying points many years ago when I discovered that they would clean up nicely with folded emery paper dragged through them. I clean them afterwards with business card type paper wetted with carb cleaner or other clean solvent. There used to be some "wisdom" about using one type of abrasive paper but never the other type. I don't remember which is which though, and if you clean the points after sanding, I don't see the problem. I've cleaned up decades old, corroded points and they work just fine afterwards. Sometimes you have to put a bit of oil on the pivot, and as was mentioned, don't forget to put a bit of proper grease on the rubbing block.
Something about the tuned RLC circuit being not quite right. https://sites.fas.harvard.edu/~scphys/courses/E1b/E1b_3b.pdf
I have three Mark 10 boxes, a couple of Tiger boxes, which are just Mark 10 copies, a MSD 5, and a couple of no name boxes. In all the years of using these boxes, the only maintenance required, was to upgrade to a higher voltage SCR and put a larger heat sink on the SCR for better reliability. Bob
What many seem to miss, is that heat is the mortal enemy of electronics. Put them in a place where they get some cool air flowing over them and they'll most likely last a long time, put them 3" from a red hot header where the air doesn't move at all and they'll fry in no time.
Although my primary reason for making these "trash can" condensers was for appearances' sake (nothing looks "wimpier" than a "flattop" Mallory or an old Dual Coil setup with stock condensers hanging off of it), I was very aware of the reliability problems with current electronic components. My intention from the start was to produce a rock solid reliable component, capable of surviving under the most adverse of conditions. The capacitors we use are resistant to voltage spikes up to 1000 volts and 300 degrees Fahrenheit, which is more that all other units for which we can find specs. They are designed to survive when used with generators and solid core spark plug wires, which routinely destroy modern electronic components (the "Pertronix Problem"). I have been running one of my condensers on my Mercury-powered 1951 Ford with these components for two years without experiencing any problems.
Nah, bet I use fewer keystrokes/clicks than you to copy and paste a special character. If you set Character Map to the Advanced option there is a search feature within it. Built-in Google for characters.
I've had to spend almost half a minute copying and pasting various special characters over the past many years. It would take longer than that for me to set up special characters on my computer (and re set them up when I change stuff on the computer, etc) Points are great, no software required!
Most point have a pretty thick coating of a different material at the contact if when you file the color changes don't expect the life to be as good.
Everybody please remember I am specifically taking about old Mallory points here. They appear to have about .040" of tungsten (or whatever it is) as contacts. I am not talking about trying to resurrect a worn out set of, say, stock 8BA points or anything like it. Just trying to get some advanced information on trying to bring back some no longer available, quality, specialized point sets.
I have been wondering about the possibility to cannibalize the contact points from a new, cheap set of breakers, and silver solder them to an old breaker with worn out points.
I used to have a bag of loose contact points. They were for just that purpose in repairing industrial relays. Don't know if you could buy such today. They were given to me a long, long time ago by an industrial electrician.
Are the point sets hard to get apart? That would make it easy to dress the points. Once you had them dressed run them with some voltage and see how the contact patch looks then adjust as needed.
High quality relays used to use contact points made of solid silver, because silver is the best electrical conductor. Today, to reduce cost, I think many have gone to a thinner silver layer or other materials completely. Ignition system breakers have to open and close WAY more times than any relay, 333 times per second for a single breaker in a V8 at 5000rpm for example, I doubt something as soft as silver would survive very long under those conditions.
The capacitor performs another function too. It provides a trampoline style kickback to the coil which makes the magnetic field collapse quicker and stronger to provide a high voltage spark. Without that super fast current reversal, and fast coil magnetic field collapse, the spark voltage and spark plug power would be very low. Sooo, the current first crosses the points and energizes the coil, hits the capacitor trampoline, bounces back super fast, which provides a super fast coil collapse, and power transfer across the windings to the plug wires. big spark because of that kick. A deposit buildup on ONE side of the points means the battery current was stronger than the capacitor trampoline kickback. If the buildup of deposits is on the OTHER side of the points, it means the capacitor kickback was stronger than the initial battery current. Long points life is the perfect match of capacitor, and coil. One side of the points would deposit a certain amount of arc debris during the tiny tiny welding arc, then reverse and deposit a tiny amount of arc welding debris in the opposite direction. If one side shows more arc weld buildup than the other, it gives you an idea of which direction had the biggest power surge.... the battery or the trampoline. WHY BE ORDINARY ?
That's true as far as this explanation goes, but it isn't telling the whole story. Capacitors change the relationship between the current and voltage, making them 'out of phase' with each other. Explained further, what this means is in a straight resistance circuit without the capacitor, the voltage and current rise and fall together ('in phase'). But you don't have a straight resistance circuit with an ignition coil; you also have inductance due to the coil windings, which also changes the phase relationship. Applying the proper amount of capacitance will help bring voltage/current 'back into phase' as these two effects are opposite. Where the problem lies is both inductive reactance and capacitive reactance will change according to frequency, which in this case is the number of times the points open/close per second. This will obviously change with RPM, so at best you can only 'tune' for a RPM 'range'. How wide that range may be will depend a number of factors, none of which a mechanic will be able to measure unless you have a 'scope. And even then, shortening/lengthening the capacitor lead will simply move the range slightly up or down. The wider the RPM range that motor operates in, the less likely you'll be to achieve a perfect 'tune'. So a 'tune' that works well for Grandma's car where she never sees over 3K RPM may not be as good for a car that sees 6K RPM on a regular basis.
Back when I was a teenager and money was tight I learn the art of filing points from my grandad,as Jim said people have been doing it for a hundred years. HRP
Here is what I have been doing with my mallory points for years now. Like it has been said here the tungsten on these is hard and thick. I was told by a good friend of mine years ago who runs a distributor repair shop to bead blast the tungstens. yes you read that right. I block the points open, wrap duct tape around em so only the tungstens are visible and blast with very fine glass beads in my blast cabinet. they look like new and I have done this to dozens of sets of Mallory points with great results
There was practically a whole lore & ritual incantation thing going on with a tune up back then. Point faces also needed to be checked for alignment, as well as arm tension. A small spring scale was used for this. Higher tension was better at avoiding "point bounce" at high RPM but the rubbing block would wear quickly. It's easy to see that a solid state ignition would have been embraced overnight.
Back in the day and old trick we used to get a car going stalled on the road because of points , was to drag a penny through them , cleaning them enough to get the car going again. Bones
Huh, never heard that. A crisp dollar ($20 for you Alaskans & Californians) has just enough abrasive material to work pretty good in a pinch. (US currency is made with linen, not paper.) Soak note first in lighter fluid or carb cleaner and drag through closed points. A car that has sat for several years will get a layer of skunge on them usually, this will help.
All this points out the shortcomings in a points ignition (pun intended... LOL). Ballast resistors are usually required on 12V ignitions to prevent coil overheating during 'normal' driving. This is due to the coil being 'on' too long at lower speeds. Using a ballast resistor reduces the current into the coil, which reduces the heat build-up but unfortunately also reduces the spark energy output. If you have a strictly race motor that sees very little low-RPM operation, you wouldn't need one. This is addressed in most (but not all) modern electronic ignitions with 'dwell control', which limits the 'on' time at slower speeds. This is why all the coil-on-plug ignition coils are so small; they've been optimized to produce maximum spark at a specific dwell time regardless of RPM, something a points ignition can't do. If you tried using one of these coils with a set of points, you'd quickly burn it up, even with a ballast resistor.
The Jalopy Journal
