Spark plug modification

[turboglenn]

Who here modifies their plugs on their DSM's? Just wondering if anyone else has experimented with "side gapping" or "stress relieving" the edges of their plugs?

Not that it's a big deal or anything, just wondering who else does all the little stuff *shrugs*

[Rob10_99]

I dont see a point in messing with something thats semi fragile at 4,000*
Not my engine!

[DougR]

Stress relieving?? Explain Please..

Depending on the plug type. Iridium. etc.....
I File the ground Strap to as close as I can eyeball it, 90* edges. The sides, bottom and end. Sharper the better.
I use a Old school File for Points based distributors. It is very fine and leaves a nice finish.
There is a noticable Diference in small displacment engines.
Been doing this since, I raced 2 stroke dirtbikes.

Want you plugs to go the distance, while providing maximum spark?
Sharpen that Fooker, 90*.
Dont touch the electrode. just the ground strap...

[Defiant]

Iridium spark plugs are only for longevity. It's pointlessly wasting money to use them in an engine whose plugs are accessible. Sharpening the side electrode will increase the amount and speed with which it erodes.

Fiddling with spark plugs beyond making sure they're properly gapped -and that includes using a wire gapper, not a ramp- is the sort of thing you do to get that extra .001 horsepower out of each cylinder. You'll have more variance between cylinder firing events than you'll gain from exorcising your Obsessive-Compulsive Disorder through plug tweaking.
But if we weren't like that, we'd just drive Chevys.

[turboglenn]

Well, the stress relieving was the only word i could think of at the time, i had read in an old hot rod book about smoothing the edges that were sharp off the round part of the plug (where the threads end) I've never done it, but i have experimented with side gapping and it really didn't make a noticeable difference, but some people swear by doing it, so i thought I'd see if it was common for people to do.

[Defiant]

Oh, you're onto dulling the end of the plug, and the crests of the threads where they might enter the combustion chamber. You'd be taking the anti-seize plating off the end of the threads, but I can't see that mattering any if it's only the last thread or two. I think the plug body at that point would probably be too close to the head casting to be able to hold enough heat to cause a hot spot, but it's not a bad idea. I'd only be surprised if it'd be of any benefit other than on motors that are tuned to within an inch of their lives.

[TunaTalon]

Originally Posted by Defiant

Iridium spark plugs are only for longevity. It's pointlessly wasting money to use them in an engine whose plugs are accessible. Sharpening the side electrode will increase the amount and speed with which it erodes.

Fiddling with spark plugs beyond making sure they're properly gapped -and that includes using a wire gapper, not a ramp- is the sort of thing you do to get that extra .001 horsepower out of each cylinder. You'll have more variance between cylinder firing events than you'll gain from exorcising your Obsessive-Compulsive Disorder through plug tweaking.
But if we weren't like that, we'd just drive Chevys.

A spark jumps from a sharp small electrode at a lower voltage than from a rounded large electrode. That’s why lighting rods are pointy and Van De Graaff generators are round.

And that’s why Iridium plugs with their tiny positive electrode could have a tiny advantage over Cu plugs.

And what’s wrong with being a little bit obsessive compulsive?

[xveganxcowboyx]

Originally Posted by TunaTalon

A spark jumps from a sharp small electrode at a lower voltage than from a rounded large electrode. That’s why lighting rods are pointy and Van De Graaff generators are round.

Fortunately we have a pretty stout ignition system and don't have to worry so much about weak spark.

[Defiant]

Originally Posted by TunaTalon

A spark jumps from a sharp small electrode at a lower voltage than from a rounded large electrode. That’s why lighting rods are pointy and Van De Graaff generators are round.

So, we'd want big, fat, round plug electrodes in order to get a higher-voltage, fatter spark?

And what’s wrong with being a little bit obsessive compulsive?

I'll explain after I wash my hands. Again.