Worth it everytime!
Indexing spark plugs
Thread Starter
Racer
Joined: Jun 2005
Posts: 306
Likes: 1
From: rose city texas
Indexing spark plugs
Does anybody index their spark plugs? I read an article that showedindexing will add about 10% to the performance of an engine. Like to know if anybody on this forum is doing this. Thanks.
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
I notice better faster starting. Smoother over all, not going to get 10 percent. Jacob's electronic's really tested extensively and said it's 1 1/2
hrs per cly. for each thats schrounding it's own spark.Plus it gives a balanced output. I really feel each time i've done it. That it was worth the trouble! About 10 oclock for the ls motors
Safety Car
Joined: Jun 1999
Posts: 3,570
Likes: 3
From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Here is a link to an article to explain it.
http://www.fordmuscle.com/archives/2000/07/indexplugs/
Safety Car
Joined: Jun 2004
Posts: 3,563
Likes: 2
From: Dallas Tx
If it gave you 10 percent more performance every auto manufacturer would be doing it on every engine. I had it work good on a nitrous big block that was misfiring under a big nitrous shot. But that has huge cylinder pressure, and really old style combustion chambers.
I think a lot more thought has gone into combustion chamber design to allow for the electrode variation. With emissions and fuel economy legislation so tight, if there was a hint of incomplete combustion there'd be something done pretty quick.
In a modern OEM engine I doubt it means a hill of beans. Dyno tests can be deceiving. Do test A get X results. Change parts do test B and WOW got Y results. What they don't tell you is the oil is now hotter from the first test, pistons have expanded, rings sealing better ...
That's why all the snake oils add their products for test B.
Then there's the psychological factor. I did all this work, wow does it really feel like a big difference.
I'd say if the chambers have some shrouding issues around the plug, might be worth a try. If it's a half way decent designed chamber, probably not going to mean much of anything. I'll bet an oil change and fresh air filter gives you better results. And for some real results, find a good tuner - that's real hp magic to be had there.
I think a lot more thought has gone into combustion chamber design to allow for the electrode variation. With emissions and fuel economy legislation so tight, if there was a hint of incomplete combustion there'd be something done pretty quick.
In a modern OEM engine I doubt it means a hill of beans. Dyno tests can be deceiving. Do test A get X results. Change parts do test B and WOW got Y results. What they don't tell you is the oil is now hotter from the first test, pistons have expanded, rings sealing better ...
That's why all the snake oils add their products for test B.
Then there's the psychological factor. I did all this work, wow does it really feel like a big difference.
I'd say if the chambers have some shrouding issues around the plug, might be worth a try. If it's a half way decent designed chamber, probably not going to mean much of anything. I'll bet an oil change and fresh air filter gives you better results. And for some real results, find a good tuner - that's real hp magic to be had there.
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Racer
Joined: Jan 2005
Posts: 470
Likes: 9
From: Broken Arrow Oklahoma
Indexing is not about setting the sparkplug gap. It is about orienting the plug so the open side of the electrode is pointed to the intake valve. This way the air/fuel charge does not have to travel around the electrode before ignition. A lot of SCCA autocrossers running in classes that do not allow engine mods take the time to perform this task, as every small improvement counts.
Le Mans Master
Joined: Aug 1999
Posts: 5,411
Likes: 2
From: N Carolina 08 Z51 Coupe
I used to index my plugs in the ole days.. with one coil pack per cyl... I really don't think it matters much anymore.. more than enough spark even if its facing away.. but it can't hurt..
Race Director
Joined: Mar 2007
Posts: 11,331
Likes: 18
From: Missouri City Texas
Indexing is not about setting the sparkplug gap. It is about orienting the plug so the open side of the electrode is pointed to the intake valve. This way the air/fuel charge does not have to travel around the electrode before ignition. A lot of SCCA autocrossers running in classes that do not allow engine mods take the time to perform this task, as every small improvement counts.
Now that you say that I do remember that...guess I just wasn't thinking very well before
