secondary resistance

[oldnortonrider]

? Does anybody know how much additional resistance is added for each additional .001" in sparkplug gap? from around .030 - .032" upwards? Seems like a few years back, I ran onto a chart that I Googled up, that had that information. didn't save it. Some expert airplane mechanic guru had it.............

[Ivan]

? Does anybody know how much additional resistance is added for each additional .001" in sparkplug gap? from around .030 - .032" upwards? Seems like a few years back, I ran onto a chart that I Googled up, that had that information. didn't save it. Some expert airplane mechanic guru had it.............

That would be difficult to say. In operation the plug fires through a compressed fuel air mix, which will change depending on a plethora of factors, like compression ratio, jetting, temperature etc.

In the case of the unknown, like on hotrods with amped up ignition, I always used a scope and watched the peak KV on the firing cycle and noted the spark duration, trying to get a good combo of each. To some extent a lower gap will give a lomger spark, a bigger gap a shorter one. The kV is the most affected, bigger gap raises the kV required to jump the gap and viceversa. I know not everyone has a ignition scope, but lots of reasomably prices multimeters have an induction clamp and will give peak kV read outs.

Now that I am thinking about it, I can't remember what peak kV should be....great time for the memory to fail.

Probably find some articles by using google.

[oldnortonrider]

Hey; Ivan; thanks for input on this,..................still doing a bit of research on this..............curious...............