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Old 09-10-2021, 08:39 AM   #1
gary678*
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Default Spark Plug Gap

I have a 12 volt system, 6.1 Snyder's head, and a Pertronix Flame Thrower 3.0 OHM Coil (40611). Conventional wisdom says with a high compression head that the gap should be .030-.032. However with the Pertronix head the gap can be moved to as much as .040. Experiences? Suggestions? Thank you for any info. Gary D.
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Old 09-10-2021, 09:19 AM   #2
alexiskai
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Default Re: Spark Plug Gap

My understanding is that the .040 capability is just that - a capability. You could do it if you needed to, but I haven't seen anyone actually need to do it on these engines.
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Old 09-10-2021, 10:32 AM   #3
katy
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Default Re: Spark Plug Gap

Try .032" for a while, then try .035" for a while to compare. Every engine/components are different.
You may also try .030".
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Last edited by katy; 09-10-2021 at 11:02 AM. Reason: Addition
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Old 09-10-2021, 11:36 AM   #4
Patrick L.
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Default Re: Spark Plug Gap

Yep, I agree. Start out small and keep increasing the gap, see what happens.

That coil appears to come either oil or epoxy filled. Do you know what you have ?
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Old 09-10-2021, 01:17 PM   #5
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Default Re: Spark Plug Gap

Coil is epoxy. Gary
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Old 09-10-2021, 01:27 PM   #6
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Default Re: Spark Plug Gap

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Increasing point gap advances timing. and decreases dwell time. Timing advance is only a few degrees and not consequencial on a a driver A. To much gap with decreased dwell decreases and weakens spark voltage. Modern electroniuc ignitions automatically compensate.
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Old 09-11-2021, 06:32 AM   #7
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Default Re: Spark Plug Gap

Quote:
Originally Posted by gary678* View Post
I have a 12 volt system, 6.1 Snyder's head, and a Pertronix Flame Thrower 3.0 OHM Coil (40611). Conventional wisdom says with a high compression head that the gap should be .030-.032. However with the Pertronix head the gap can be moved to as much as .040. Experiences? Suggestions? Thank you for any info. Gary D.
No experiences with your coil. Experiment, right down what you did and how it behaved ! Have fun going for test drives ( make the drives on the same roads)
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Old 09-11-2021, 07:39 AM   #8
Patrick L.
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Default Re: Spark Plug Gap

These newer type coils put out 40K volts. So it won't matter much how wide the gap is, it'll get jumped.
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Old 09-11-2021, 08:36 PM   #9
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Default Re: Spark Plug Gap

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Originally Posted by PC/SR View Post
Increasing point gap advances timing. and decreases dwell time. Timing advance is only a few degrees and not consequencial on a a driver A. To much gap with decreased dwell decreases and weakens spark voltage. Modern electroniuc ignitions automatically compensate.
I think he is asking about the plug gap, not the points gap.
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