HEI spark plug help

i kinda agree with ross f1, but I run mine at 50 thou, I use ngk plugs, wider gap makes for a longer flame face in the cylinder to help ignite more fuel
 
The compression of an engine determines the amount of voltage it needs. However, the spark plug gap will increase the voltage necessary to jump the gap. Now this may seem confusing. Lets take an example: .035" In a 6:1 engine might on;y take 6K to jump the gap. 9:1 might twice that. OK now lets open the plug gap to .050". Now the low CR might need 12K and the hi CR might need 20k for the same bang. So lets say you have a 40k system, not a problem?? Unfortunately, The distributors are not designed for this hi a voltage and will begin to break down. That's why The hi voltage distributors have such a large cap. There's a reason for everything and I waz only guessing at the numbers.l
 
Ol' Ron said:
Unfortunately, The distributors are not designed for this hi a voltage and will begin to break down. That's why The hi voltage distributors have such a large cap. There's a reason for everything
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And the wiring as well, most of the wiring used on or installed on flathead engines will not properly insolate higher ignition voltage. It will end up cross-firing between wires and from a wire to any ground source. I have seen engines running in the dark that look like an electrical storm!
 
Plug gap goes with the engine , not the ignition system! The compression ratio and combustion chamber design dictate the plug gap. A typical flathead doesnt have much compression and .025 to .035 is usually very good.
 
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