Technical Mallory Transformer Question

This question is for the ignition guys. Is there a easy way to bench test these transformers to determine rather they are usable or not? Thanks in advance for your reply's.

 

I bought a couple of "MAGSPARK" transformers a few years ago. You can use an ohmmeter to check for conductivity and resistance through the primary and secondary circuits. This way, I was able to determine one was bad (we disassembled it to confirm this). I am still unsure if the other one was good or not. I dropped the idea of using them because they are so hard to find. You can add a jumper between the points and run the "MAGSPARK" distributor as a regular dual point, though.

 

Thanks tubman, I have 4 of these transformers. need to figure them out

 

BTW, there was a thread yesterday that mentioned "MAGSPARK" transformers in passing. One of the posters mentioned that "MAGSPARK" units are polarity and voltage sensitive (unlike conventional coils) and must be used properly. That's about all I know, but I thought I should mention it.

 

Every ignition coil has a polarity, sort of. While they will work connected either way, the spark intensity is reduced by about 30% when connected the "wrong" way.

Something to do with the way a spark jumps easier from a hot ground strap to a cooler center electrode at the plugs or somesuch. Might not be noticeable except when pulling heavy loads or long uphill grades.

"Why then do we worry about coil polarity? Because the spark plugs do care which way the electrons are flowing in the high tension circuit. The spark plug has a thermally insulated center electrode (surrounded by ceramic). With engine running the center electrode runs substantially hotter than the exposed end electrode. Design of the ceramic insulator determines how hot the center electrode will run, leading to the designation of hotter or colder spark plugs. As electrons go, they love to jump away from a hot surface and fly toward a colder surface, so it is easier to drive them from hot to cold rather than from cold to hot. End result is a difference of 15 to 30 percent in voltage required to make spark "initially" jump the gap on the plug depending on which way it is going. So the spark plug prefers to see a voltage potential that is negative on the center electrode and positive on the end electrode for the very first hop of the spark. Oddly enough, this has nothing to do with polarity of the vehicle electrical system, but it is influenced by the common connection inside the ignition coil."

https://mgaguru.com/mgtech/ignition/ig104.htm