Technical INDEX SPARK PLUGS ( anyone else do it )

i allways did to my harleys gonna give the chevy a go .cant do any harm!.can it?

 

It gives you something to do, eh?

I have never bothered.

 

I have done it before, but not anymore

 

I've heard of it but never tried it. Not sure what good it is supposed to do. I know on race cars it is supposed to eek out some fraction of a horsepower but I don't know why. If your ignition won't work right because of the position of the ground electrode you have a bigger problem than indexing the plug.

 

I did it too all my race cars,being I also drove them,it may of tuned up the driver more then the engine.
Always go for anything that only cost time,that maybe the others will not do !!
Raced from 1960 to 2001,won around 400 events.

 

I index my valve stems, tire lettering and bolt/screw heads but any more than that is just a bit crazy.

 

I do it on my race car. I wouldn't bother for a street car unless I was worried about a piston hitting the ground electrode. To answer your question, no, it wouldn't do any harm.

 

Rivet counters ; }

 

It's kind of a pain in the azz. I did it once just for the hell of it. I'm not racing anything. There's different ways to go about it. One is to start with a stack of spark plugs, mark the strap line on each with a sharpy, and start fitting them one at a time, a single set of 6 or 8 won't be enough.

Or use washers sold for the purpose. It did make for a noticeably crisp idle. If you're set on the idea, once a set of plugs has been indexed to a particular set of heads can make a tool like this:



and in the future immediately tell which cylinder a given spark plug should be fitted. Source:

http://www.eatonbalancing.com/2009/06/12/spark-plug-indexing/

Side-gapping is another plug modification that seems to improve idle. Seems too, that the plug manufacturers would do this already. Hm.

 

I try to index oil filters on the fleet I maintain that way I can snap a pic of the part # just before heading out to Napa.

 

I have been side gapping my plugs too since the 70s.
Ever since we got another tenth in the drag car when we tried it, I make sure I do it on my daily's too.
An actual exposed side-gap makes me think that indexing wont really change the exposed spark at all, so I don't bother indexing as long as it has the exposed side-gap.
I use dykes wire cutters to snip the ground electrode because it leaves a crushed sharp edge for the spark to fire across. Electric spark energy loves a sharp edge compared to a smooth surface to jump from...

WHY BE ORDINARY ?

 

I find its better to file the ground back to the center of the electrode. With the end there I found no reason to index. I would also file the end at a 45* angle when I raced.

 

Always did it on the race car and still do it on the Daily. It's VERY EASY to do my ratchet extension has a hole on the end that goes on the ratchet (what it's for I have no idea but it came new like that). I just put the plug in the plug socket so the open end of the plug is lined up with that hole then just tighten until the hole is facing the intake valve.

 

Unless your smashing your plugs shut from high dome pistons you are wasting your and ours by asking this question here.
Go ahead and do it you won't notice a difference on your flattop or dished piston small block.
I raced dirt track for years and rules called for no more than 2 eyebrow flat tops. No difference and tried splitfires, side gapped plugs. Anything to get an edge.
When I drag raced I was forced to index the plugs on my big block to clear the domes. Eventually machined a notch for flame travel and spark plug clearance. Side gapped plugs gave me a half of a tenth and short life on plugs when spraying 300 shot of nitrous .

 

I did it on the flathead Hudson engine in the Pacemaker and it went 3/10ths quicker in the 1/8 mile. I aimed the open end of the gap into the center of the cylinder on all 6 cylinders. I had to use different thickness of washers to do this since on each cylinder the spark plug had to be aimed a little different to align it to the center of the cylinder. I was not expecting it to make that much of a difference.

 

the eaton balancing article explains it all.good read

 

ill be indexing the plugs, in search of max power and looking for the best idle i can get. no racing for me. this is my hobby ill make the time for it.

 

I haven't done it since about '80. I'm just lazy I guess.

 

Seems like more trouble than it's worth, can't imagine it making that much difference.

 

I do it on my Eddie Meyer head equipped flatty. I need to have the electrodes at either 6:00 or 12:00 so the valves don't hit them.

 

This was originally started back in the 60's when huge domed pistons would close the plug gap from the piston hitting the ground electrode.
I know it started at least that far back as that was a job that I did on a friends Jr. Gas Dragster (Jr. Fuel only on gas).

Then the "Fire Slot" came about and the indexing went away for a while. The Fire Slot was a big gouge or slot cut in the piston dome to both clear the ground strap and to supposedly let the, as the name applies, let the spark plugs fire not get put out by the domed piston.
Then skip ahead a few years, and the big name tuners started doing this because they thought that the ground electrode should be presented in a specific location.

Funny thing, the "experts" didn't agree. Some thought that the ground strap needed to face the intake valve, some thought it needed to face the exhaust valve..!

Today...don't know what people are doing..! I have a friend that puts the ground strap toward the back of the chamber, no real relation to the valves on his C/ED (small inch, Dodge big block dragster).

Mike

 

When drag racing I won one race by 0.003 second. Every little thing matters then.

 

excellent response

 

Just imagine how faster you'd go if you lost 40 lbs.

 

Lol....... wait a minute, who are you calling fat?

 

I was talking about me....I did that, it helped.

 

If I lost 40 lbs I would be so skinny I wouldn't even cast a shadow.

 

Never have but I understand that every little thing matters with time slips.

 

My last chopper was built from an early 1984 FXWG Wide Glide. Shovelhead, factory 4-star cases (Evo bottom end), belt with dry clutch, 4-speed w/kicker, first big-bore Mikuni carb Ron Simms sold, and Jerry Branch double-plugged heads with 5-angle valve job, forget whose pistons (maybe Arias). Indexing plugs made a difference on that engine. Most race cars don't seem to care one way or the other.

 

I never view working on my Race Car or Hot Rod as "trouble"
Some folks go to the race track to make fun runs, some go to compete. That would be the difference.