Plug gap opinions

[Ghoste]

Where do most of you start to customize plug gaps?  I have a 383 with auto trans and 4:10 rear. Compression is 10.5, Holley single plane, MP 484 cam, MP chrome ecu Blaster II coil with appropriate ballast and MP electronic ignition.  So far, I am just using the mfg recommended plug gap but would any of you customize that?

[Chryco Psycho]

.045 with high output coils

[Ghoste]

Why do you gap them where you do Neil?  Why 45 for a high output coil?   Why closer or wider at any point?

[firefighter3931]

Lower compression responds well to larger gaps and conversely, a higher compression motor requires less gap. I would gap a 10:1 motor at .040

Ron

[Wakko]

You want the gap to be widest possible but still have a powerful spark.  If you gapped it too wide with a standard coil, the spark may not have enough power to completely fire the fuel charge or fire at all.  If you have a power coil and a narrow gap, you're not maximizing the size of the spark and therefore the exposure.  I used .045 with a Jacob's ignition and coil.

[89MOPAR]

 I tried using wide gap, like a .045 with Jacobs Pro-street ignition. Unfortunately the Turbo was blowing the spark out [?] 
I had to close down the gap even though Jacobs said it would be OK to have a .050 gap w/ turbo

Jacobs also sells crushable aluminum or copper [ cant remember which] washers to put between head and plug. To index the spark plugs so the electrodes are all facing the same direction. I bought them but didn't get serious enough to use them...

[cudaken]

 With MSD I run .040.

Worth maybe 1 to 2 HP, index the plug so the gap is facing down. When I was racing I use to do it. Did it make more HP? I don't know but at the time the big boys where doing it.

                                    Cuda Ken

                               

[Brightyellow69rtse]

hell i gaped mine AT .054 msd6al, blaster 2 coil, mopar electrinic distributor, super conductor wires, never had a problem. would it make a difference if i gap iem smaller?............Mike

[Chryco Psycho]

it may help to close the gap some , it depends if it is misfiring at that wide gap

[Ghoste]

Most opinions seem to be 40 or 45 so maybe I'll just split the difference.