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A Fine Example For Others
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Discussion Starter #1
How do you index your plugs, straight up between the intake and exhaust valve, or pointing towards the exhaust valve?
Also do you cut off the existing sparkplug washer or, just place the indexing washer on top of the existing sparkplug washers?

Thank you,
 

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How do you index your plugs, straight up between the intake and exhaust valve, or pointing towards the exhaust valve?
Also do you cut off the existing sparkplug washer or, just place the indexing washer on top of the existing sparkplug washers?

Thank you,
I put the open end between 11 and 1 so piston does not hit the "strap" I usually buy 2 set of plugs at a time and get as many indexed with out indexing washers, for the rest I use washers. I dont index my plugs for performance, I index for piston clearance
 

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I have to or piston smashes the "strap" closed
I thought he was talking about making more HP .

From NGK :

In any case, engines with indexed spark plugs will typically make only a few more horsepower, typically less than 1% of total engine output. For a 500 hp engine, you’d be lucky to get 5 hp. While there are exceptions, the bottom line is that without a dyno, gauging success will be difficult
 

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Open end of ground strap pointing straight down is optimum. By 3 sets of plugs, mark the strap on all and start swapping plugs around until you get it.
 

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I thought he was talking about making more HP .

From NGK :

In any case, engines with indexed spark plugs will typically make only a few more horsepower, typically less than 1% of total engine output. For a 500 hp engine, you’d be lucky to get 5 hp. While there are exceptions, the bottom line is that without a dyno, gauging success will be difficult
Next time you get the chance, hang out at a Competition Eliminator dyno session. You would be amazed at what one will do for 5 HP.
 

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I thought he was talking about making more HP .

From NGK :

In any case, engines with indexed spark plugs will typically make only a few more horsepower, typically less than 1% of total engine output. For a 500 hp engine, you’d be lucky to get 5 hp. While there are exceptions, the bottom line is that without a dyno, gauging success will be difficult
I guess you are correct, he was asking for HP reasons . Oh well , I answered his question "how do you index your plugs " and told him I do it the way I do for clearance not HP.
 

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What about Hemi's? Strap toward the intake, or the exhaust?
 

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Open end of ground strap pointing straight down is optimum. By 3 sets of plugs, mark the strap on all and start swapping plugs around until you get it.

Seems like that would take forever when tuning . Doing that after every pass would just kill me .
 

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bracket racers delema's in this modern age of big HP bracket cars that can cover the set 10.90 dial in by using a throttle stop so their 9second car can run the number without even breaking a sweat. Oh well what ever works.
 

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Seems like that would take forever when tuning . Doing that after every pass would just kill me .
I guess once you go boost , you will never look at 5hp the same ever again . :)
I can appreciate what you guys can do with Turbos. I'd rather work my ass off for 5 hp. At the end of the day, we're both happy and that's one of the cool things about dragracing.
 

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Waste of time, just put enough spark to it.
 

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A Fine Example For Others
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Discussion Starter #17 (Edited)
Open end of ground strap pointing straight down is optimum. By 3 sets of plugs, mark the strap on all and start swapping plugs around until you get it.
I'm not arguing with your reply ^^^ but I have a question regarding it. If the open end of the sparkplug is face down, won't the explosion happen against the closet part of the cylinder wall, compared to facing up so the explosion occurs directly in the center of the cylinder wall?

I'm trying to avoid having one side of the cylinder wall being hotter than the rest of the cylinder wall. I hope I explained this to make sense.
 

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Discussion Starter #18
My plugs are long reach plugs so they extend past the cylinder head into the bore. I don't have any clearance issue, and a few more hp isn't a bad thing. I'm more concerned with having an even heat explosion into the cylinder walls.
 

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I put the open end between 11 and 1 so piston does not hit the "strap" I usually buy 2 set of plugs at a time and get as many indexed with out indexing washers, for the rest I use washers. I dont index my plugs for performance, I index for piston clearance
That would be the only reason!
 
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