Coil gap on predator question

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I was noticing that people set them from 30 to 70,can I expect to c a difference in performance from 30 to 50 to 70, this is on a restrictor plate engine,Thanks just trying to learn these things,:confused:
 
I've been setting mine at 0.020 to 0.025 inches (similar to a Clone), using a stock coil and flywheel. Not saying that a bigger gap is wrong - just that I haven't tried it.

On my engines I've found that the factory installed the coil closer to the flywheel than that (and usually one leg is closer than the other). Until I reset the gaps I had trouble with cutting out during full throttle (on the straight-away, when the engine had time to rev for a while). I think that the too-close settings were causing the armature to saturate, which in turn caused the engine to cut off. Then the engine re-fired because cutoff allowed the saturation to dissipate (until it saturated again...).

Basically, the way the coil works is to amplify the pulses it sees each time the flywheel magnet passes by. But if the pulse is too big the coil can get overloaded (saturate), and it quits responding to pulses. As you move the coil away from the flywheel, the pulses get weaker – making them less likely to saturate the coil. But get too far away and the coil can’t generate enough power to fire the sparkplug correctly. I don’t know what that limit is, and realize that the necessary spark energy is also affected by conditions inside the cylinder, but generally you want the biggest spark possible. So you might notice a little power drop if your coil gaps are too big.

Maybe an engine builder can put some numbers or limits to this?
 
With a stock cast flywheel you will less performance above .040 gap. Those stock magnets are just too weak. When using an ARC flywheel you can use the gap to help tune the engine. Yes .030 is the absolute minimum on gap but I have many red plate engines out there with .080+ gaps on them. You would need a dyno to see what gap works best for you but most use .050-.070.
 
I was noticing that people set them from 30 to 70,can I expect to c a difference in performance from 30 to 50 to 70, this is on a restrictor plate engine,Thanks just trying to learn these things,:confused:
I have recently done some work in this dept 62.5 thousands is the number engine will backfire at 30 and hard to pull absolutely do not go below 30
 
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