Per a buddy of mine that has a Talon on e85, over on the DSM forums, they are talking about indexing the spark plugs and the benefits. Supposedly, indexing them will create a better burn and in turn, make more power and help reduce acids in the oil from e85 because of the better burn. Also per my buddy, they are claiming 20-30 whp gains when upwards of 500-600 whp, but IMO I just dont know about that.

Has anyone done any real testing on this to see if it really has any benefits?

If this really does work, which way do you point the open end of the ground electrode? Toward the intake or exhaust valves?

 

worked for a few whp (5-10) in some muscle cars that my buddy has built.

You point the open end of the electrode towards the intake... since we have 4 valves per cylinder you point it straight down the middle of the 2 intake valves.

E I
->
E I

if that makes sense

 

I think I see what you mean. Have the closed end of the ground electrode facing between the two exhaust valves.

Doing a little research, it seems to work on non hemispherical heads, like on a v8 engine that has a kidney shaped head bowl and the spark plug is coming in at the side. They say you want the open end of the ground electrode pointing towards the quench area. That area would be the area in the head bowl that isnt part of the kidney shape and is the part that the piston comes closest to at TDC.

Looking at our hemispherical heads, the plug is in the center of the head bowl and we basically have 4 different quench areas from what I can tell. Each quench area would lie between each of 2 valves and near the edge of the bowl. To me, indexing the plugs wouldnt benefit any on our type of heads.

Does this make sense?

 

Thats sorta what I was going to say. The way our heads our designed, I don't think you would see a huge benefit.

I've never bothered with it personally, so I'm talking out my a$$.

Question, I typically just tighten them down snug...how do you keep them tight, but have them all point the same direction?

 

^^They make shims for indexing purposes. I think anywhere from .010"-.060".

I always TQ my plugs down to 20 ftlbs or 240 inlbs with a copper antiseize.

 

Actually, looking at more pics of my head bowls, there are only 2 quench areas from what I can tell. I believe I was wrong on my last post and assessment. I believe the 2 quench areas are between the 2 intake valves and the 2 exhaust valves.

So, maybe indexing the plugs would help?

If so, which way would be best? Just have the ground electrode pointing in a direction between the intake and exhaust valves? This way the closed part of the ground electrode would be pointing towards a non quench area.

Like this.....(This is the one I think would work best)

EX(quench)EX
......<---->
IN(quench)IN

Or should the closed end of the ground electrode be pointing towards the mid point of the 2 exhaust or 2 intake valves?

Like this.....

EX(quench)EX
.........^
.........|
.........v
IN(quench)IN

 

I would go with between the intake valves as an educated guess... so the first diagram.

 

on a 4 valve head with the plug in the middle of the chamber its not going to make any difference.

 

I'm thinking this.



However, I'm also thinking, the higher the plug sits in the cylinder head due to spacers and indexing, I'd imagine that would be more "harmful" to the cylinder liting off, then being pointed the right direction.

I'd want my plug down in the "mix" instead of sitting on top of it...just my opinion however.

 

you want the plug in the richest part of the mixture.. fortunately for most honda motors, thats right where the spark plug is