FAQ: Which Spark Plugs & Ignition Wires should I use?

I like the AL104, cheap, and best for performance. Why look elseware?
If they dont fix the problem your not out much money anyway...
Also i tried some of those bosh +4 thingies, ran like shit in my 3.8 lesabre, later read some things about bosh plugs being garbage on the GM 3.8 engines.

just buy some AL104 when hes not looking and pop them in the car.

like a ninja mechanic...

I would recommend AL 605s to you. I don't think you need to go as cold as 104s. I do run 104s now, but ran 605s for a year before that, and AP 605s the three years before that.

Don't get those funky 2- or 4- electrode plugs.

Yes, I asked my dad before he started being like that and he said the spark only comes from whichever tip it thinks is closest so only one really does the work. Will 605s still give me less knock than any old regular plug? If I had to order them (I think I would have to for 605s as well), I'd just assume use the 104s.

The only problem like I said, I don't know how to gap spark plugs - nor do I know much of anything about putting spark plugs in other than they twist in. I've watched so many things being done before due to my dad's insistence and I can't remember if you're suppose to put oil around the edges of it or anything like that when putting it in. I do know something about anti-seize but not anything else about how much to use and all that.

It might also be a problem that all of the tools are his and if he wanted to he could tell me I can't use them...

Kevin, this is not that complicated a matter. Relax. You are 18, and last I checked, that's old enough to start making your own decisions.

Your Dad doesn't have the knowledge we do about these engines. It doesn't mean he's an ass, and it doesn't mean you need to go behind his back and sneak some alternate plugs in there. I just means you need to make a decision and do what you think is right.

Here are the worst things that can happen in this situation:

1. In the case of 4 prong electrodes, platinum/iridiums, experimental designs, etc., you spend way too much money on a type of plug that doesn't do you any good. Consequence: You spent $40 instead of $9 with no guarantee the plugs will last longer or perform better.

2. In the case of AL104 copper plugs, you foul the plugs because they are too cold for your application. This can happen if you don't run the engine WOT enough - hard to do if you ask me. Jack the R ran AL104s for a few thousand miles on a stock motor with no fouling. Consequence: You replace the AL104s with AL605s, losing $9.

3. In the case of platinum or iridium plugs, you pay a lot to gain electrode life, but these are not intended for racing engines, or boosted applications like ours. If you decide to push the car to the limit, there's a chance you will see more knock than with a copper plug. Consequence: You pay more to increase the chance of decreasing power and chipping pistons.

4. You use your Dad's old plugs and your car may not run. Consequence: You feel very stupid.

There is not an exact right plug for your situation. All plugs make sparks, which means most all will work. But what's better in the long run - that depends on you. If you use your car only for long drives through the country, platinum/iridium plugs are fine. If you drive in the city, or like to hit the gas a lot for fun, the copper plug with a cooler heat range is better.

Read this thread from the beginning, and I think you'll know what to do.

REALLY helpful comments, Aaron.

By the way, Shintsu - to gap plugs you'll want to get a gapping tool. They are inexpensive and the 'promotoional' ones work fine if you only put plugs in once in a while. Also, at bigger/busier auto parts stores they often have a special "spark plug gapper" tool and will gap plugs for you if you ask. When I buy plugs at my local NAPA (they come in boxes not blisterpaks) they gap plugs for me. Their tool looks like this:

http://store.summitracing.com/partdetail.asp?part=sum-900313

and it takes a second or 2 per plug to set the gap. A 'promotional' gap setter and feeler gauge is problematic. The feelers won't measure the gap properly on some plugs, and the little hole for setting is likely to damage the center electrode or ceramic insulator around that electrode on iridium and other small-electrode plugs. Here is an example of such a setter:

http://www.essentialgears.com/tho/tr/product/UNIVERSAL-SPARK-PLUG-GAP-TOOL-1038934.html

and here is a better one - still has the feeler problem:

link

Your dad probably already has a satisfactory tool for this. By the way - when you set the gap, you might want to use a set of needlenose pliers, they will let you grip the electrode on the plug and make the gap wider or narrower pretty easily, without risking damaging the plug.

You may find this Canadian web site instructive:

http://www.techguys.ca/howto/spark_plugs.html

All the best,

Albertj

I know it's not the best way, but I've always used a flat head screw driver and a feeler gauge to gap my plugs. If done with patience and care, there is no damage to the electrodes.

Yep, with standard plugs that's fine and with the Iridium pluge there usually won't be damage, but the risk of screwing up is somewhat higher.

Maybe it's just a thing with the local NAPA - but they've always been pretty cheerful about gapping plugs for me and whoever else buys from them. Really, it takes 'em a couple seconds per plug with that contraption they have.

Aside to Shintsu: the amount of antiseize to put on plug threads for installation is about the size of a good booger. For those of you not into boogers, a 1/4" or 0.5 cm dot will do it. You can smear it around or leave it and it will smear itself into the hole when you install the plug. Goes on the threads, near the bottom of the plug... be sure to keep it off the end of the plug and not to get any in the combustion chamber. Idea is to get a thin coat over the threads so the plug does not weld itself in place.

Albertj

Maybe it's a good idea, but I've never used anti-seize, albertj. My plugs always come out easily when I ask them. I guess changing plugs once per year helps keep them from getting stuck.

Actually what might keep 'em unstuck w/o antizeize is the compositon of the head. One of my Buick dealer's mechanics (not Doug) told me that sticking is not all that likely in our alloy heads. Some aluminum alloy heads (audis and some others I am told) can have issues with seizing. Actually, I've only had one plug seize in a head - a 1975 Dodge Colt my dad owned that I'd work on. Ended up installing a helicoil. Got the car used - never did figure out if it was my fault the hole got buggered up. But I fixed it.

Lately, I've noticed that some plugs come with a not-very-noteceable schmeer of antizeize on them already.

Albertj

which kinds would you reccomend for the na series II?

Heh heh... as the other list members have already said - but not in a summary fashion - depends on what you're trying to accomplish.

If you want to run a long time betwen plug changes, use the OE iridiums.

If you want (somewhat) better performance, use the reocmmended Autolites.

Based on the comments from people who've tried them, it's not clear that other plugs (platinums, multi-cathode plugs like the Bosch Platinum +2 or +4) buy any performance improvement in our NA or SC applications. My personal experience - my Audi ran best on Bosch Platinum +2s or Denso multi-electrode plugs; my Subaru on Autolite Platinums or NGK standard plugs; my Chryslers on Champions or Autolite Platinums; the Volvo seemed to run best with standard ACs.

It would be nice to run different plugs on an engine conencted to an analyzer and running on a dyno to see what if any difference was measurable. A "butt dyno" really is not enough.

Albertj

Who's paying for the plugs and wires and who's the titled owner of the car?

Has anyone used those Pulsestar PULSE PLUGS?
They are supposed to promote more efficient combustion and give you more power. But at $25.00 per plug, I wanted to know if anyone has used these in their RIV.

Haven't heard of them, but I don't trust anything besides a standard plug in these engines. Don't pay it. The stock ignition system is very very good.

You clowns are trying to tell me some CHEAP ass almost a $1 a plug POS is HIGH PERFORMANCE. And every one lists it in their specs like OMFGZ0RZ I HAZ AL104s - Iz gotz 500 hp n0wz wit my cheepz plugz! Spark plugs do not make that big of a difference so they're not worthy of mention. I mention mine only to show I'm not an idiot and bought nicer plugs. To implicate some $1 or $2 a plug plugs are better than these is ridiculous. Like the mechanic who told us OMG, you're using NGKs in a GM! You HAVE to use AC Delcos (this was on the Aurora). Yeah, because NGKs know it's not a damn Japanese car and make it go slower because it isn't...

I'll check the plugs when I put those wires on but hell no I'm not buying new plugs. I put these in like 2,000 miles ago. They're not bad, but I can believe the wires went bad (or are not working fully).

Shintsu wrote:

You clowns are trying to tell me some CHEAP ass almost a $1 a plug POS is HIGH PERFORMANCE. And every one lists it in their specs like OMFGZ0RZ I HAZ AL104s - Iz gotz 500 hp n0wz wit my cheepz plugz! Spark plugs do not make that big of a difference so they're not worthy of mention. I mention mine only to show I'm not an idiot and bought nicer plugs. To implicate some $1 or $2 a plug plugs are better than these is ridiculous. Like the mechanic who told us OMG, you're using NGKs in a GM! You HAVE to use AC Delcos (this was on the Aurora). Yeah, because NGKs know it's not a damn Japanese car and make it go slower because it isn't...

I'll check the plugs when I put those wires on but hell no I'm not buying new plugs. I put these in like 2,000 miles ago. They're not bad, but I can believe the wires went bad (or are not working fully).

Spark plugs from different manufacturers have different heat ranges. Different materials in spark plugs react differently with heat. Your stock plugs are unique because they are made of a special metal that lasts a long long time in the combustion chamber. Iridium I believe is the core. The problem with Iridium plugs is that they don't transfer heat away as well as a copper plug will. Copper is well known for it's ability to transfer energy, be it heat or electricity. That's why they used it in spark plugs for so many years (100+?). The 'modder' will switch to a copper core plug because it pulls away it's heat better, theoretically resulting in less KR. Having a plug with a copper core means you need to check the gap frequently. Having a plug with an iridium core means not having to check the gap for 100,000 miles. Good for the average, lazy car owner not interested in performance. Platinum plugs are in between - they last longer than copper, but do not transfer the heat away as well as copper. The AL 104 is also several heat ranges 'cooler' than the stock plugs, resulting in again theoretically less KR under full load. I have not seen specific testing to prove or disprove the gains in this engine, but many years of automotive experience confirms these theories for me.

Mocking in scorn at people's "mod list" without knowing what the stuff stands for makes you even more foolish sounding. Find out why they list these things as "mods" (I hate that term) before you mock and scorn.

None of the above information will aid a faulty or broken spark plug into working.

Shintsu wrote:

Spark plugs do not make that big of a difference so they're not worthy of mention. I mention mine only to show I'm not an idiot and bought nicer plugs.

If spark plugs don't make that big of a difference, why buy the more expensive ones? Why not just save the money for something else?

No one said cheapest is best and it has been well explained more than once why everyone doesn't or shouldn't buy certain ones. No one is trying to make a general statement that cheap plugs are the best. It just happens that copper is significantly cheaper than more precious metals.

What Aaron was suggesting is AL104's or copper plugs in general are not the end-all, be-all answer for everyone. I would say for you, you're probably right in your choice. You have a stock motor and you don't want any more maintanance hassles than necessary. Keep with the factory NGK iridiums. If you want to mod or start beating on it more, it might be a good idea to switch to coppers.

Codith has a good point.

Been interesting watching the discusson on spark plugs, with the requisite syllogisms from Shintsu. Syllogism? A syllogism has a major premise, a minor premise and a conclusion. People use syllogisms a lot in political and spiritual rhetoric. They work when those in the audience can be bluffed or persuaded to accept the premises.

In this case, the syllogism is - major premise "being expensive is better (to a point)" and minor premise being that "all people make decisions primarily based on what they can afford." Neither premise is bad, on their face, but there are a couple big distortions here.

One distortion is that 'afford' is based on price alone, not on value. Price is a factor in value, but technology may give dramatically different value to two otherwise comparable things.

In brief, the thing about copper-core spark plugs is they are almost a commodity, the materials are inexpensive too. So they can be a really good value if in the eyes of the customer their virtues (good heat dissipation) outweigh their drawbacks (gap erosion). To avoid the gap erosion one needs to use materials that don't vaproize into plasma just because one puts an electrical pulse through them - which brings us to the platinum and iridium plugs. This is why typicaly the cathode (ground electrode) on spark plugs is a nickel alloy of some sort. Can't be copper, it would vaporize (turn to plasma) fairly quickly in a combustion chamber.

There is a really nice (and blissfully short) web page describing platinum plugs at http://www.ngk.com/sparkplug411.asp?kw=Platinum&mfid=1 - have a look. Point is that platinum plugs are copper-core plugs with platinum wafers bonded on the anode (center electrode) and cathode (side electrode). For those who want to run a longer time between plug changes these plugs may be a better value, in part due to the trade-off between the price of the plugs and paying someone the labor to change the plugs every so often. So the point of all this is that the price/value tradeoff has something to do with the price of the plug and also something to do with the labor involved in replacing the plugs. If the labor is expensive enough, then the pricier plugs add value for the consumer by extending the plug change interval a lot.

As for the fine-wire platinum and iridium pugs - NGK has another page, http://www.ngk.com/sparkplug411.asp?kw=Fine+wire&mfid=1, with another short description. Point being that smaller-anode plugs require less voltage to jump the spark gap, which means less misfiring and better gas mileage. Problem is, a copper fine-wire would be blasted away into plasma - so metals that conduct well enough but won't blast away as fast are used on the anodes.

As for cooler heat range plugs - there are kind of two ways to go. One is racing plugs - if available - which use the more durable iridium and platinum tip materials and also dissipate that heat fairly quickly. The other, which is a good enough value for many, is to use a copper-core plug of a cooler heat range, which for our engines puts you into Autolite 104s, Champion 401s, Denso 5032s, NGK 3623s, or Bosch 7971s. The plugs are not identical - plugs that have the same nose length (the threaded part that screws into the block) will have somewaht different mettalurgy - and the different metals will make them dissipate heat differently among other things. And they are all inexpensive copper-alloy plugs. (by the way - The Bosch and NGK plugs in the list have shorter noses than the others and may run a tad cooler.) Another point concerning the Autolite 104s is that a number of people have found they work well in our engines if the engine is modified (or driven) in ways that will cause spark knock with the OE-specified plugs. For your driving you might or might not get better results with one of the other plugs in the list above. Also, if you're curious, the Denso iridium 5326 is a cooler iridium plug - point being one could get longer durability and less spark knock in a modified SC 3800 engine -- although I can't say for sure because I have not tried it..

As for the coper plugs being cheaper - well, look at the list. There are lots of them. Think of it this way - if there are 10,000,000 cars on the roads and they need a set of (copper) plugs each hear, that is 60,000,000 plugs per year. If the technology is pretty much the same across plugs, manufacturers need then to compete on price or customer service. Whoever raises the price of their copper plugs isn't going to sell that many. So the copper plugs, although engineered to be more than satisfactory for the application, are made of relatively inexpensive materials in large numbers, and so are not priced all that high. Part of the price of the more expensive plugs is driven by material costs, and part is driven by the manufacturer recapturing a portion of the value they create for the consumers.

Hope you find this helpful, or at least interesting.

Albertj

A nice shower of logic. Thanks also, Albertj

I did find it interesting, and helpful. Thanks Albertj.

Whether a "good" plug can last 10 years or 100k miles is not really of interest to me. I still contend that, like motor oil, spark plugs are not something you want to leave in your engine for extended periods of time. There is value in the plugs being cheap because it encourages the habit of changing and examining of spark plugs each year or every 20k miles.

I don't use synthetic motor oil for the same reason - I change it so frequently that it would be a waste of $$$. Why change it? Because it's so easy to do, conventional oil is cheap, and it can give knowledge = insurance. So what if someone can brag about using the same oil for 15k miles, or the same plugs for 100k miles? Those are two things that, if changed frequently, can tell you in advance of problems and conditions with your engine that would normally go undetected. Why be ignorant and give up the opportunity to learn something? You go to the doctor for a check up now and then, right?

Too many people nowadays don't have any desire to know what's happening beneath the hood, nor do they care to prevent problems before they happen. They don't want to be bothered with what we used to call "engine maintenance". Instead, according to some, an engine is just supposed to run forever (thank you Toyota) until: A) it fails, possibly causing catastrophic failure, or B) if you're lucky, a detection system throws a DTC or SES light. I'm not one of those people. I don't expect an engine to run forever - I still find it unbelievable that engines run for as long as they do. I want to know exactly what's happening inside my engine, so I can detect minor issue and take minor steps to prevent big problems that will likely cost big money. And there is a satisfaction in doing that that I hope most of you reading can understand.

engines run as long as they do in part because machining accuracy and precision, as well as manufacturing tolerances, shrunk dramatically in the 1980s and 90s.

Albertj

This might be a good deal if you damage a front wire:

http://www.zzperformance.com/grand_prix/products1.php?id=974&catid=109

AA wrote:

This might be a good deal if you damage a front wire:

http://www.zzperformance.com/grand_prix/products1.php?id=974&catid=109
...

wow, that's cheap! Good deal!

How long do the stock plugs usually go for? Are the stock plugs iridium or something else? I'm planning on putting a smaller supercharger pulley on when I get the other pulleys replaced. I could return the iridium and get something else. It's gotta be in stock around here though. What do you recommend? I want to reduce pulley size to the smallest before getting into any PCM mods. I want the best plug for combined longevity and mod friendly performance. No extremes.

Any advice on getting to the rear plugs? They look like a big pain in the ass.