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Plug Indexing

Posted: Thu Nov 15, 2007 7:23 pm
by crwdog
anyone every play around with Plug Indexing on the 540 motor?

Posted: Sat Nov 17, 2007 12:16 am
by Vmax540
Not that I'm aware of...... isn't this for if you use different thickness of base gaskets ?

Posted: Sat Nov 17, 2007 12:46 pm
by crwdog
plug indexing is when you line up the spark plug electrode to face either the intake or exhaust ports. Maybe alittle black majic, but there is claimed to be some effeciencies to be gained

Posted: Mon Nov 19, 2007 8:34 am
by Vmax540
Interesting..... I use the O.E.M. spec. BR9EV plugs and have gotten as high as 16m.p.g. on a hard pack trail ride so, I'm not sure if there is any thing to be gained unless you're not getting a good burn ?

Posted: Mon Nov 19, 2007 11:12 am
by crwdog
Chuck
this is what I are talking about:

Indexing:

This is for racers only!!

Indexing refers to a process whereby auxiliary washers of varying thickness are placed under the spark plug's shoulder so that when the spark plug is tightened, the gap will point in the desired direction.

However, without running an engine on a dyno, it is impossible to gauge which type of indexing works best in your engine. While most engines like the spark plug's gap open to the intake side of the cylinder, there are still other combinations that make more power with the gap pointed toward the exhaust side.

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 200hp engine, you'd be lucky to get 2hp. While there are exceptions, the bottom line is that without a dyno, gauging success will be difficult

Monty