Spark plug indexing


It is more for 4 strokes with valves. You want to place the open side of the electrode facing the intake valve, or toward the transfer ports on a 2 stroke. I don't know about any hp gains but it will make all things equal, as far as where the plug is firing in the cyl., especially on a multiple cyl. engine. you need indexing washers usually to get it right.
 
actually if the exh. port was at 12 oclock,the transfer/intake would be at 8,10 and also at 2,4 and 6 oclock. indexing plugs on a 2 stroke is pointless.
 
i was going to buy those spark plug indexing washers..... but i'm not sure as if its a problem that you will be changing the height as to where the plug electrode sits above the piston. so, by using the washers i may be losing performance rather than gaining it?

for those that don't know, the purpose of the washers is to align the open part of the spark plug towards the intake port of the cylinder.

spointless on a 2 stroker, as stated above? anyone use 'em?
 
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Dynotech (google) may have tried it. The exact location would be different with different engines, it would have to be tested on a dyno to see where is best. The fuel mixture swirls in a combustion chamber and the point is to get the electrode aligned to get the stream to flow between the gap. Any benefit may only come at a lower RPM and only be enough to be practical for racing.
 
You could make all things equal by indexing, but with multiple transfer ports, the location if the electrode could be just about anywhere. You would be just making them all the same at this point.
 
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