Spark Plug Indexing...
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Burning Brakes
Joined: Aug 2011
Posts: 878
Likes: 2
Waste of time and money on a stock or mild performance engine. In fact using those washers to index your plugs you will affect the depth your plug is supposed to sit at. This indexing craze came out of high end high compression racing engines where .0000001 more in power makes a difference.
Race Director
Joined: Sep 1999
Posts: 11,360
Likes: 382
From: Plano TX
I think this came from some race engines that had such extreme piston domes that they required the plug electrode to face a certain way to clear the dome. Or maybe I'm remembering it wrong. In any case, I can't imagine it making a difference in power.
Thread Starter
Melting Slicks
Joined: Feb 1999
Posts: 2,473
Likes: 10
From: New Paltz, New York USA
My mind is fading fast. Since I turned 68 I cannot remember a thing! I remember asking about this, but I could not remember what the answer was anymore. Thanks.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Maybe I shouldn't drink beer when I am wrench'n
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
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Melting Slicks
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
although it may be a neat thing to do, you will never notice it on a street driven engine....put your $34 into good filters for the fuel and oil and such, it will be $$$ better spent......
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
It's NOT a "neat thing to do". For a street engine it is a complete waste of time and a PITA to do on a C3 engine. If you wanted to increase HP, indexing your plugs would be last on the list. You could get more improvement out of resetting your timing...just right--even if you did the same thing yesterday. 
Melting Slicks
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
It's NOT a "neat thing to do". For a street engine it is a complete waste of time and a PITA to do on a C3 engine. If you wanted to increase HP, indexing your plugs would be last on the list. You could get more improvement out of resetting your timing...just right--even if you did the same thing yesterday.
and what's not so neat about it???? I think it's rather fun, it's a good lesson in perseverance....
Burning Brakes
Joined: Apr 2010
Posts: 1,018
Likes: 9
From: Winston Ga.
its an exercise for those of us with OCD. Knowing no one but myself knows that my plugs are indexed perfectly vertical where they cant be seen.
Now if could only figure out how to make those plug wires stay nice and straight and bend in 90* angles!
That alone is worth 50HP based on the seat of my pants!
Now if could only figure out how to make those plug wires stay nice and straight and bend in 90* angles!
That alone is worth 50HP based on the seat of my pants!
Melting Slicks
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
you guys are all alike......
where is the challenge characteristic in you?????
I had OCD bad when I was younger....
but hardly any now....and I did index the plugs on one of my Vettes way back when. do you know I gained like 7 1/2 extra HP and I couldn't even measure the additional amount of torque it had from that simple mod.....I think I am going to index the plugs on the 82 and for sure on my BB 74 real soon......I know I'll be getting more power.....
I hear you, I hear you............
