Spark plug gaps

[KidVermicious]

I read a thread on another forum about a guy doing some basic tuning of his Ford motor. A lot of what he was doing is similar to what we do - he increased his air in, bumped his timing, and then he increased the gap on his spark plugs by a couple hundredths.

He figured that with more air and earlier spark, he wanted bigger spark to go with that. I think he's off his rocker and that's not going to do any good unless he opens up his injectors and gets a bigger ignition coil, but as long as I'm under my hood, what do you guys think?

 

[BucknutBob]

I did a little research on this, and opening up the gap will help a little, but it also puts more strain on the other ignition components--the coil needs more voltage, the wires can fry due to increased resistance, and on down the line. There is a sweet spot for the gap, and anything beyond that does nothing to help. I did find one source that said the factory specs are typically too small for optimum burn, and you can increase .010 for better performance. So basically, a small amount can help, but too much not only doesn't help, it can lead to component failure throughout the ignition system.

 

[SV_Dude]

I think the factory does this intentional. They want their engines to run a little rich to help the engine last a little longer and to avoid it running too lean.

If there was a gain from this, it would be very minimal... maybe a couple ponies and the gas mileage difference wouldn't even be noticeable.

I would suggest to leave it stock and reliable. If you want to modify it, do it right and get a MSD and use hotter plugs, not opening the gap on regular plugs.

 

[KidVermicious]

That's kinda what I thought, but I thought I'd check. Stock and reliable it is.

 

[Hyde802]

If your going through all the effort with gaping (hey, every little bit helps) Might want to look indexing the plug too.

FORDMUSCLE.com web-magazine - How To Index Spark Plugs

 

[BucknutBob]

Considering what these engines are being used for, ANY mods concerning spark plugs are a bit over the top--the tiny gains won't even be noticed in anything less than racing conditions. An MSD ignition module would be a better investment, which would give noticeable results for everyday use and trail running.

 

[KidVermicious]

If your going through all the effort with gaping (hey, every little bit helps) Might want to look indexing the plug too.

FORDMUSCLE.com web-magazine - How To Index Spark Plugs

Never heard of that. Makes sense tho.