Spark Plug Indexing

[Jerry Dobson]

I have asked a lot of people “What direction the open gap should be facing” and so far I have gotten, Up, Down, Left, and Right. Too many shade tree mechanics!

Makes sense to me that the gap should face the intake valve. Does anyone truly know the direction?

INFO: I am sure someone is going to post “what is indexing?” It originally started with high compression engines with dome pistons. You had to keep the plug from hitting the piston. So you would index the electrode away from the piston. You did this by trying different plugs or by installing small washers with the plugs. Now some of us want to try indexing the plugs so that the open gap is facing towards the incoming fuel for some potential HP gain (not sure if it actually works yet).

UP, DOWN, FRONT OR BACK?????

 

[JimDavis MT 97GTS 650R]

Try the "Search function" at the top of the page. Search "Indexing". This topic has been discussed before. Hope this helps.

 

[TOOOFST]

Unless your car is class racing(even then) ,the value of this is right there with snipping off the **** on your pilots.Prove it to yourself and fill two small open lid cans with gas,now drop a match to the side in one and the other centered.

 

[MichaelP]

Oh Yea REAL classy toofist I read about how you help out all these Viper owners and now you post this bullSH!T.

I tried it they both burned the crap out of my eyebrows.

 

[Jerry Dobson]

We'll the prior posts that I have read are not consistent on the direction of the electrode. Some are actually opposite. TOOFST may have a point that the increase in HP will be next to nothing. But the match in a can test is not the same a fuel under pressure.

“Rumor” has it that up to 5hp can be gained on a 450hp V10 motor by indexing. Now, is the HP gained simply by the new plugs or has anyone ever used the SAME plugs on a Dyno and re-run the test?

 

[TOOOFST]

easy now Mike,a little dry humor with an honest opinion based on personal dyno tests of my NHRA 513stoker motor,winning 5 national events,is not BS.Tried Indexing on the dyno,results no soup for me.
"TOOFIST":ambidextrous;a tuner skill,thanks Mike.

 

[MichaelP]

HA tooofst I hope you saw the little smiley face in my post and ahh no I didn't burn my eyebrows, merely singed them.

You see I was kidding that I tried your two different way of dropping a match into gasoline.