spark plugs
Thread Starter
Instructor
Joined: Jun 2003
Posts: 200
Likes: 0
From: Tempe AZ
spark plugs
I've heard that people cut back the electrodes in their spark plugs, what exactly does that mean and how do you do it? More importantly, what does it do FOR you? Any drawbacks?
Oh, is there a particular brand of sparkplugs (or type) that I should get? going shopping this weekend :D
Oh, is there a particular brand of sparkplugs (or type) that I should get? going shopping this weekend :D
Race Director
Joined: Aug 2002
Posts: 17,367
Likes: 1
From: Kentucky
Re: spark plugs (Corvettaholic)
65Z01 has a good detailed write up about this on his site. Here is a link to the cut-back plugs. I use NGKs in my L98. http://www.geocities.com/jgkov/CutPlugs.html
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: spark plugs (Corvettaholic)
I've started 3 1/2yrs ago using cut-back Split Fire plugs as they were available at the time; now I am using cut-back AC Delco plugs.
Since I drag race all season I check the plug gap & condition several times during the season. To date I haven't seen any reduction in service life of the cut-back plugs vs stock plugs.
Since I drag race all season I check the plug gap & condition several times during the season. To date I haven't seen any reduction in service life of the cut-back plugs vs stock plugs.
Instructor
Joined: Aug 2003
Posts: 163
Likes: 0
From: Glendale Az
Re: spark plugs (Corvettaholic)
Spark will jump better from a sharp end to another sharp end. By "cutting back" the electrodes, the electrode is placed directly over the center of the tip increasing the area for a spark to jump. That is why the U-groove type of plug became so popular. Also, this practice was used during the old fueler days as plugs would carbon up quicker and the old mags had a hard time keeping the motor lit up. Also used in hi compression engines with big domes so the piston does not hit the plug and close the gap for you. :chevy
Team Owner
Joined: May 2001
Posts: 25,057
Likes: 1,265
From: Virginia
St. Jude Donor '11
Re: spark plugs (69vetteracer)
Spark will jump better from a sharp end to another sharp end. By "cutting back" the electrodes, the electrode is placed directly over the center of the tip increasing the area for a spark to jump. That is why the U-groove type of plug became so popular. Also, this practice was used during the old fueler days as plugs would carbon up quicker and the old mags had a hard time keeping the motor lit up. Also used in hi compression engines with big domes so the piston does not hit the plug and close the gap for you. :chevy
I did not know that :D :cheers:
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: spark plugs (Corvettaholic)
Don't bother with it unless you are running a very high cylinder pressure engine (mega super/turbo charged or very high static compression). You'll see no gains on a less than 500hp engine and you'll end up overtaxing your ignition system (at least reducing it's life considerably if you don't change plugs on a frequent basis).
Leave spark plug "indexing" and "electrode cutbacks" to guys who race to make bread.
Leave spark plug "indexing" and "electrode cutbacks" to guys who race to make bread.
