| December/January 1991

Little Paradox engine drawing


C. Hoover


26/10/20 Magneto Condensers

Glen L. Schuekr, HCR 2, Box 88, Friona, TX 79035 sent us a very detailed letter on the above subject, and we have elected to use the majority of it herewith, since it explains many of the factors involved with magnetos.

The capacitance of the condenser needs to be matched to each coil. You need to find a capacitor as close to the original capacitance as possible. Any condenser would work, but to prevent excess point arcing it needs to be matched. When you achieve a clean break at the points more current can be induced through the coil, for more output at the secondary, for more spark. The condenser stores the induced surge of energy and discharges back to the primary when the circuit is broken. If the condenser is not matched, it can cause premature failure. That causes leakage, which will then cause a reduction in coil output. Moisture, temperature, voltage variations, and age all combine to affect condenser leakage. There is always a small amount of leakage present in a condenser, though it is not visible unless you are doing testing in a reduced light. Eventually, factors affecting leakage can come together, causing a failure. This may happen sooner rather than later if the correct capacitance is not used. I sometimes get in some new old stock condensers that will all test bad and leak because of their age. I also am not sure about what voltage rating of capacitor to use, but believe you should measure this by the type of magneto. Most early mags did not produce as high a voltage as the later ones, or the industrial styles. So, it would make sense to use a higher voltage rating on the later magneto condensers. I have been using capacitors of the 250v to 400 volt rating with no problems. Usually when you go to a higher rating the physical size of the condenser increases, and this can lead to problems. Most magnetos are rated at 10 to 30 kilovolts (kv) maximum output. A special voltmeter must be used to measure this voltage, but its cost limits to test labs, and similar situations. Some magneto companies recommended the use of a special ammeter to test for rated output. Some also recommend an oscilloscope for trouble shooting. I find the simple test stand and coil-condenser tester to work the best for me, along with the experience acquired over time. You can run a mag on a tester and look at the points while it is running. If you have a lot of blue arcing, and adjusting, filing and cleaning of the points doesn't help, you have a condenser that is leaking. Sometimes though, a condenser will test good on the stand, and while running there will be no blue arcing, but it can still be bad and cause problems. I had an irrigation mag condenser that tested good in every way on the bench. However, when the mag was installed on the engine it performed well until it warmed up, and then it would start to miss. This sounds like a coil problem, but it was not. The condenser was replaced, and the problem was solved.

26/10/11 Empire Engine Colors I would guess that PPG 13594 Blue might be about right for the engines from Empire Cream Separator Co. Mike Persenaire, 875 Etnyre Terrace Road, Oregon, IL 61061.

Among the several letters received on the above, we got one from Paul Detloff D.V.M., Rt. 3, Arcadia, WI 54612. Along with his interest in gas engines, Dr. Detloff also publishes the Cream Separator News, a little journal dedicated to enthusiasts of this equipment. Doc Detloff also sent us a copy of his little book, A Million Miles on Back-roads , a book of 88 poetic thoughts that have passed through the mind of a practicing dairy veterinarian from the hills of rural western Wisconsin. In reading through it, many of Doc's tales bring back pleasant and unpleasant memories of those good of cow milking days!