Well now. I have seen several folks talking
about increasing plug gap after improving the ignition system. I have a basically stock 350, with an MSD 6A and blaster 2 coil, I am currently running stock gap (.035) How much can I increase this, and what are the benifits??

Thanks.

 

Well, I opened those plugs up to .045" that was what MSD prefers with those mods, but I noticed nothing difference after re-gapped those plugs..

You should definately buy MSD cap&rotor and new set of wires, to carry new increased spark, I mean that your stock cap&rotor contact surfaces may corrode very easily with heavy spark your MSD proudces..
[EDIT] typos... hah..

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'89 Formula 305 TPI T-5
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[This message has been edited by '89Formula305TPI (edited November 07, 2000).]

 

A larger gap exposes more of the "flame kernel" of the spark to the fuel and promote more complete combustion. However, the larger the gap, the greater the resistance and the greater the possibility of a mis-fire and fouling of plugs.

Also, if your wires are a little old, the electricity may short through the wire since the electricity will find the easiest path to complete the circuit. This is when you can see sparks through the wires or notice arcing in the cap if you have a high voltage system. If your system does not have high enough voltage, it may just not fire.

I like .045" for most systems with at least 50,000 volts.

 

Glenn is right. Don't overkill the ignition system. It isn't hard to get a stock system to jump a gap that is one inch long, BUT when you factor in the fact that cylinder pressures, variations in rich/lean, etc... greatly increase resistance, therefore limiting the gap size. If you have an ignition box and coil, it would probably be safe to run .045", but I wouldn't go any more.



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