I was rambling around and found this site , and I was wandering has anybody ever did this , or is it just a waste of time.

http://www.gmtips.com/3rd-degree/dox...tion/spark.htm

 

Common mod (relatively). Is it worth the effort? Depends on your effort. On some of my cars I so it as well as index the plugs, in others I care less. Theoretically it would expose more of the spark. The question is if anyone has ever quantified any effects to TQ or HP.

 

Thanks for the reply.
I just didn't want to ruin a set of plugs if it did not work

 

My theory is, they have so many performance plugs out there that I think they would already be making this if it worked. Come on, they have split fires, u grooves, 4 prong and everything else. Just my opinion, but I am not going to take the time to do it to mine. I still run ac delco r45ts.

 

Actually if you look at Champion and Autolite racing plugs their ground electrodes does not go over the center electrode. What the splitfires and others do is exspose more spark to the mixture...the same as this does. I've never done it before but I have an extra set of AC Delco's that I'm putting on with my new ignition soon. I'll see if there is any differance. I would guess, like most other "free" mods, the results are "I guess it's faster."

Matt

 

That mod is shown in "small block chevy performance" by dave emanuel. It says it's worth 5 horsepower. The plugs won't last as long but do give a definite power increase on the dyno.
I've done it to a couple sets of plugs. I used a dremel to do the job. Its worth it in my opinion because it's free.
When it comes to spark plugs keep in mind that all it takes is one good spark that is exposed as much as possible. Which is what this mod does. 4 electrodes or split prongs actually shield the spark. In other words don't waste your money on some of the stuff that is out there.

 

I'm probably wrong, but wouldn't that make the plug hotter?

 

No. At least not from the stand point that its the insulator that has to do with hotter or colder. If the path for the heat flow is long and difficult, more heat will remain at the tip of the insulator and the plug will run hotter. The main difference between hot-running and cold-running plugs is the length of the insulator nose.

colder on left hotter on right.

 

oops double post.

 

Autolite racing plugs are designed with the ground straps cut back just like that. They are also much thicker to transfer heat away from the tip faster.

 

Give credit for that picture to me

Like ZZ405 said, I saw it in Dave Emmanuel's book. Worth it? Sure. Do I have documented proof? No, but others have. Filing takes forever. I opened up the gap and cut the electrode with side cutters, filed the metal smooth, and gapped it. Takes no longer than just gapping them anyway. And since I use AC R45TS plugs, if I mess one up I'm only out $1. No idle problems, misfiring or anything else - unlike the exotic plugs listed above. They last one year in my car because I change them once a year - regardless of wear. And Autolites... LOL. Maybe in a Ford. I wouldn't put anything but ACs in my car. Ask me how I know

 

Hey... says something about a high powered coil... does the stock HEI ignition count?

 

Yeah, it should work just fine. The gap of the plug does not change. I used it before I installed my high output coil with no problems. Opening the gap will require a higher output coil though.

 

I wouldnt waste my time rounding the edges as long as it's a clean flat true edge. It will create alot more resisence jumping from a rounded point compared to a flat surface. This is seen when you notice a power increase after changing out your worn rounded plugs to new straight/flat ones ones. The rounded edge will negate most all the net gain from filing the electrode back.