spark plug gap

[JohnR]

Hi guys, my 74 satellite with a 318, its old spark plugs I removed had a gap of 0.50 and was idling smooth, the manual tells me the gap should be 0.35 I replaced the old ones with new plugs the same sort (Champions) it seems to idle smoother with a 0.50 gap. My question is has this got anything to do with the electric ignition, thanks.

 

[HALIFAXHOPS]

Cold be the coil is getting weak.

 

[PRND21]

Electronic ignition plug gaps are typically wider than with a points type ignition.

 

[69a100]

I'm running a Pertronix in both a /6 and 383, both plugs are set at .50". If it works good, use it!

 

[PurpleBeeper]

I'm on the other side of the fence.... I say gap them at .035" per service manual. Years ago I read in the old Direct Connection book to that "wide gapping" plugs helped performance, so I tried it. In my '73 318 Charger using a stock coil a 0.040" plug gap would not fire at all.... put it back to .035" and it started right up. If you have a really hot ignition coil you can get away with it, but no reason I can think of to "wide gap" a stock or close to stock engine.

 

[JohnR]

Thanks guys will set the new plugs to 0.50 and test the coil and see how we go. Again thanks.

 

[69a100]

I'm on the other side of the fence.... I say gap them at .035" per service manual. Years ago I read in the old Direct Connection book to that "wide gapping" plugs helped performance, so I tried it. In my '73 318 Charger using a stock coil a 0.040" plug gap would not fire at all.... put it back to .035" and it started right up. If you have a really hot ignition coil you can get away with it, but no reason I can think of to "wide gap" a stock or close to stock engine.

With the newer technology and performance that's out today, it's easier to get away with stepping outside the box like this with no problems.