I know even on big horse power motors, it only nets little gains. But what the hay, i'm not going to use washers to raise the plugs but would not sure if it would help to have the gap face the intake side or exhaust side. Think i'm going to mark them and try to position them right the gap right in the middle.
Anybody else on a j try this to see what works best?
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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.
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Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
been there done that, i set mine to face slightly to the intake side, so far results have been inconclusive (seems to idle smoother but could be my imagination) but i do it on all performance engines (just a nit-pick thing i do from back from the Turbo Buick days where it did make a difference..)
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** Flat Broke Racing Inc.**
This is actually the first time i've seen anyone ask this on the site. But yes, i an a firm believer in indexing. Whether it works or not, i dont care, it helps me sleep better at night. You are on the right track. Mark the plugs on the side of the gap, and have said mark point towards the stem of the valve. You may have to try all the plugs in all the different spots, but you should be able to find one setup that works.
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Manitoba Motorsports wrote:been there done that, i set mine to face slightly to the intake side, so far results have been inconclusive (seems to idle smoother but could be my imagination) but i do it on all performance engines (just a nit-pick thing i do from back from the Turbo Buick days where it did make a difference..)
Whats slightly? like 15* towards intake side?
Rich Grayo Jr. wrote:This is actually the first time i've seen anyone ask this on the site. But yes, i an a firm believer in indexing. Whether it works or not, i dont care, it helps me sleep better at night. You are on the right track. Mark the plugs on the side of the gap, and have said mark point towards the stem of the valve. You may have to try all the plugs in all the different spots, but you should be able to find one setup that works.
I know, i didnt about till i learnt about it in my apprenticeship. stuff like that helps me sleep better too. lol.. i'm anal about the gap on the spark plugs and now this. However, have you noticed anything ? In theory, wouldn't you want it towards the intake side? So as the air is rushing in and getting compressed it the plug is facing the flow of air. makes sense in my mind anyways.
going to do it as im changing plugs tomorrow, but would like some experienced input to start with.
Thanks!
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
Precisely. Mine was much easier to do, as i did mine mid re-build with the head off. But yes, you do want the gap facing the intake valve.
JBO Stickers! Get yours today!
how much tho? 15 or 30 * ?
Thanks Rich
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
I have mine pointing directly at the intake valve stems. Figure in fluid dynamics. Sure, it's getting compressed, but it's still flowing directionally toward the plug. If you get the mixture directly in between the electrodes, it will ignite faster, and will continue flowing in the same direction. By the time the exhause valve opens, it would (in theory) still be swirling in that direction, and flow out better, pulling in the fresh mixture faster. That's the thick and thin of indexing, at least in my experience.
JBO Stickers! Get yours today!
so right at the intake ports then on a twin cam. Since both intake valves are on the intake manifold side, just have them facing that way
so the same direction as the driver of the car looking out the window. sweet. .002 hp extra and a good night sleep now
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
The problem with indexing plugs is that if you look at each plug, where the the threads are as opposed to the tip, they are almost always not congruent with each other. Instead of rummaging through boxes of spark plugs to find the elusive combination of perfect plug threads that match the cylinder head threads, use indexing washers. These soft copper washers are available from the aftermarket and will fit both flat- and tapered- seat spark plugs. They're available in three thicknesses: 0.060-inch, 0.080-inch and 0.100-inch. Copper's inherent softness along with the various washer thicknesses make it simple to thread the spark plug into the cylinder head and tighten it to the point that the index mark is situated in the correct position relative to the combustion chamber. (Never double up washers; they aren't intended to be used in tandem.)
Generally speaking, the idea of indexing is to position the spark plug so that its gap is facing the center of the cylinder, angled slightly toward the exhaust valve—the most common arrangement. (Some engines work better with other gap locations.) This is important because, as the piston approaches TDC, the air/fuel charge is being compressed. The charge or "mixture" is being forced toward the area of the spark plug—and normally, the exhaust valve. The true speed of this force inside the combustion chamber is extremely fast. Some experts speculate that it surpasses supersonic speeds.
Because of this, the spark generated from the plug should be in a "position" to create the best possible flame front. Looking at a typical side-gap spark plug, you'll note that the electrode can actually block the flame process. On the other hand, if the electrode gap faces the on-rushing air/fuel charge, it stands a much better chance of igniting a flame front.
So NO 2 PRONG, 3 PRONG, 4 PRONG, etc.
I only turned mine towards the intake valve about 25* or so. I wouldnt reccomend it for boosted apps as the added pressure can blow the spark out (back from the T-Buick days we indexed them to about 50* exhaust, but that was with 28lbs of boost) I did the intake side because in the engine i have this done in its still fairly stock (01 Z24 Auto) as to where my 00 Z24 5spd is getting rebuilt.
You'll basically have to play with it to see what works with you. In my old buick we did the indexing at the track and got an average of about .1second off the 1/4 time and a much smoother engine. when the plugs are indexed technically speaking every cylender should have an even flame and burn thus making the engine produce more power and run smoother.
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** Flat Broke Racing Inc.**
This has been talked about on here, but has been many years. I have this done on my car. It is not hard to do. I made sam marks on the top of the plug(where the spark plug boot sits), so I could get it where I wanted. Did it make a difference, not sure, but it did nopt hurt my 14.8 either.
FU Tuning
John Higgins wrote:This has been talked about on here, but has been many years. I have this done on my car. It is not hard to do. I made sam marks on the top of the plug(where the spark plug boot sits), so I could get it where I wanted. Did it make a difference, not sure, but it did nopt hurt my 14.8 either.
So did you put the gap facing the exhaust side or intake side? I was reading some more tech articles and its common to have it towards the exhaust valve. HOWEVER in our case with the 4vl/cl i'm guessing i should have it facing (its between the 2) the 2 exhaust valves. So basically facing dead straight at the exhaust manifold.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
C24s/c wrote:John Higgins wrote:This has been talked about on here, but has been many years. I have this done on my car. It is not hard to do. I made sam marks on the top of the plug(where the spark plug boot sits), so I could get it where I wanted. Did it make a difference, not sure, but it did nopt hurt my 14.8 either.
So did you put the gap facing the exhaust side or intake side? I was reading some more tech articles and its common to have it towards the exhaust valve. HOWEVER in our case with the 4vl/cl i'm guessing i should have it facing (its between the 2) the 2 exhaust valves. So basically facing dead straight at the exhaust manifold.
Nate
Well from what little bit I know about indexing it can be different for different motors (not meaning the same motorex: 2.4 in different cars), but different motors as in a 2.4, or a 2.2, or a 350.
I have my plugs indexed to the rear (exhaust side). I did this based off info I was giving off of this site.
FU Tuning
