spark plug keying.

[sho4life]

Something new I read today. IS it worth the bother on a SHO engine.

 

[itwonder]

You mean sparkplug indexing? Not likely.

 

[sho4life]

If its the same term..something to do with using different crush washers to get the electrode in the proper position for optimal burn.

 

[pjtoledo]

new?????

it's been around since, what, the 50s?

 

[sho4life]

something i read that was new to me

 

[Lorenr]

Indexing your spark plugs

We tried this years ago and it involves screwing in the plugs until the electrode is 180 degrees from the exhaust valve (At least I think it is the exhaust valve and not the intake valve). Anyway, theoretically it is supposed to help power.

Unfortunately it falls under category: Romance BS.

Once spark plugs have the right heat range, multiple electrodes, etc almost never work.

Platinum Plugs (double or single), Iridium plugs, Duel spark plugs and spiral core plug wires do work.

:wave:

 

[AREA 91]

Most engine builders call this spark plug indexing.

It's not worth it on a street engine.
This does help when getting into high compression race engines.
Ignition systems have come a looong way! The racer's of the 60's could only dream of the ammount of energy available in a modern ignition system.

I have this done on a few drag racing engines.

 

[rbruso]

I was under the impression indexing was only really useful on 2 valve heads where the plug was way off center in the combustion chamber.

 

[itwonder]

It is useful in certain direct injection engines.

 

[firebat45]

I was under the impression indexing was only really useful on 2 valve heads where the plug was way off center in the combustion chamber.

This. Our spark is right in the center of the chamber, not way off to the side or in a pocket somewhere. I'd be very surprised if it was worth the hassle to do it on the Yamaha. Who knows though, I could be wrong.


I misread the title as "Spark plug keyring"...