At one time, I had the data on secondary coil voltage for both Slick and Bendix mags. My cursory look this morning at the John Schwarner's site revealed that a Slick coil can produce up to 20,000V at 250F in the secondary. IIRC, the secondary voltage voltage in a Bendix coil was considerable higher. That being the case, the Bendix would provide a much faster and powerful spark.
There are many more qualified individuals on this site, but having worked on and operated the Bendix -200 and -1200 series, and the Slick 4300 series mags has made me true to the Bendix mags.
I think they both spark very well when in good condition.
Bendix mags seem to have much better build quaility to me.
Bendix mags can't spark any faster than Slicks...electricity will travel the same speed coming from either brand in my opinion. Just under the speed of light I'm told.
As to the voltage, that's determined by the spark plug gap or rotor gap whichever is greater. When the coil colapses voltage builds until the spark jumps. Wider gap = more voltage. Turn a mag slow with a wide spark plug gap and it may not jump across the gap. (not enough voltage).
Once it jumps the gap the voltage does not continue to increase.
At least that's the way I understand it. Somebody tell me If I'm all wet.
Mark
You're right about the voltage depending on the gap. There are some high voltage limiting devices that work on that principle. You're mostly right on the voltage not creating a "faster" spark. ONE of the parameters that affects voltage rise rate ("slew" rate) in a mageto coil (or any inductive circuit), is the maximim voltage the mag is capable of producing if it doesn't find a gap to jump. A mag with a higher open-circuit voltage will reach the level required to jump the spark gap slightly (micro- or nano-seconds?) before one with a lower maximum voltage. I doubt however that that small difference in timing would make much difference in engine performance.
What a higher voltage mag will do is be more likely to jump a given gap. A fuel-air mixture is an insulator, and the higher the pressure, the more voltage is required to jump the gap. I really don't have a feel for how much voltage is requred vs. compression, but I'd bet a dedicated googler could find out...
Yep...Thanks, Miles.What a higher voltage mag will do is be more likely to jump a given gap. A fuel-air mixture is an insulator, and the higher the pressure, the more voltage is required to jump the gap. I really don't have a feel for how much voltage is requred vs. compression, but I'd bet a dedicated googler could find out...
I think they both spark very well when in good condition.
Bendix mags seem to have much better build quaility to me.
Bendix mags can't spark any faster than Slicks...electricity will travel the same speed coming from either brand in my opinion. Just under the speed of light I'm told.
As to the voltage, that's determined by the spark plug gap or rotor gap whichever is greater. When the coil colapses voltage builds until the spark jumps. Wider gap = more voltage. Turn a mag slow with a wide spark plug gap and it may not jump across the gap. (not enough voltage).
Once it jumps the gap the voltage does not continue to increase.
At least that's the way I understand it. Somebody tell me If I'm all wet.
Mark
Yep...Thanks, Miles.
I do believe that voltage is a function of the number of windings in the secondary circuit. The spark plug gap has nothing to do with secondary voltage output of the mag.
Wanted to know if anybody has some field experience using both Slick 4300 or 6300 series magnetos vs. the Bendix 1200 series.
Looking at running LOP at high altitudes with an IO-540 Lycoming engine on an RV-10.