Plug Indexing

crwdog · Post by **crwdog** » Thu Nov 15, 2007 7:23 pm

anyone every play around with Plug Indexing on the 540 motor?

Post by **Vmax540** » Sat Nov 17, 2007 12:16 am

Not that I'm aware of...... isn't this for if you use different thickness of base gaskets ?

crwdog · Post by **crwdog** » Sat Nov 17, 2007 12:46 pm

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

Post by **Vmax540** » Mon Nov 19, 2007 8:34 am

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 ?

crwdog · Post by **crwdog** » Mon Nov 19, 2007 11:12 am

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