Warp11XX Posted January 18, 2006 Share Posted January 18, 2006 Here is an easy newbie question... :roll: or two... I've never installed any of the iridium plugs in anything yet. I read something somewhere (here?) the other day that said the rare metal plating is so thin and fragile on these type plugs that standard gap guages can ruin them. True or false? If true, how do you gap them? Are any of the plugs pre-gapped from factory per application? My Z71 Sierra calls for iridium plugs too? Same deal for all rare metal plugs on the market? Quote Link to comment Share on other sites More sharing options...
Redbird Posted January 18, 2006 Share Posted January 18, 2006 standard gap guages can ruin them True. They come pre-gapped, leave them alone. Quote Link to comment Share on other sites More sharing options...
pug Posted January 18, 2006 Share Posted January 18, 2006 True, if you want to measure them you have to use wire gap gauge. I think that they are oK straight out of the box. Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted January 18, 2006 Share Posted January 18, 2006 As said. They are pre-gapped. The iridium is a plating. Bending the electrode can crack the plating or create a weak spot. Leave 'em alone. Quote Link to comment Share on other sites More sharing options...
sykotek-xx Posted January 18, 2006 Share Posted January 18, 2006 Why is it that these engines need these special plugs? Quote Link to comment Share on other sites More sharing options...
sykotek-xx Posted January 18, 2006 Share Posted January 18, 2006 And why did I double post? Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted January 18, 2006 Share Posted January 18, 2006 Dunno, maybe you're up too late. Shouldn't be working all night, anyway. You can run plain old Champions in the engine. The point of the iridium tipped plugs is that they resist breakdown longer than standard, or platinum plugs. That DOESN'T mean they resist fouling any more than a standard plug except for their consistant spark. Gas, oil, and ingested Bic pen parts will foul iridium plugs just as well as any others. Its a double edged sword....similar to the oil discussions, eh? Quote Link to comment Share on other sites More sharing options...
sykotek-xx Posted January 18, 2006 Share Posted January 18, 2006 yeah I try to work as little as possible, as evidenced by my number of posts that fall between midnight and 8:00am. Quote Link to comment Share on other sites More sharing options...
jrdxx Posted January 18, 2006 Share Posted January 18, 2006 Platinum and Iridium are both catalytic elements. Catalysts accelerate chemical reactions (combustion is a chemical reaction), so the electrode tips of the plugs resist the contamination from deposits and combustion by-products. Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted January 18, 2006 Share Posted January 18, 2006 That may be true...can't find any documentation that reads quite that way. However, I find plenty of documentation that indicates I'm wrong. Apparently, the plugs can be gapped. The best reason I can find for the manufacturers to generically tell you otherwise is concern for damaging the very brittle center electrode. And the iridium alloy electrode is all iridium, not a plating. The reason for the use of iridium is that due to the strength of it in this application, the center electrode can be made much smaller and still be strong enough to do its job. Why would you want the electrode to be smaller? Two reasons....one, to concentrate the spark in a smaller and more consistant area, and two, to decrease resistance....effectively allowing you to make a stronger spark, or to make a good spark with less voltage. Add to that the hardness, durability, and heat resistance of the metal (and possibly the chemical reaction jrd described, although there's no mention of that on the NGK or Denso sites), and iridium seems like a really good thing to make spark plugs with. Sorry for the misinformation. Quote Link to comment Share on other sites More sharing options...
jrdxx Posted January 18, 2006 Share Posted January 18, 2006 All I know for sure is that I still remember the days of breaker points/coil ignition systems, leaded gasoline, and all the PITA changing/cleaning of plugs every 2000 miles or so, and resetting the timing and points gaps, and I don't miss a bit of it. With modern electronic ignitions, plug gap is certainly less critical, and if the plug gap is close, I wouldn't mess with it. Quote Link to comment Share on other sites More sharing options...
blackhawkxx Posted January 18, 2006 Share Posted January 18, 2006 All I know for sure is that I still remember the days of breaker points/coil ignition systems, leaded gasoline, and all the PITA changing/cleaning of plugs every 2000 miles or so, and resetting the timing and points gaps, and I don't miss a bit of it. With modern electronic ignitions, plug gap is certainly less critical, and if the plug gap is close, I wouldn't mess with it. True but I also remember buying a brand new car for $5,000. Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted January 18, 2006 Share Posted January 18, 2006 Heh, heh. Youngster. Quote Link to comment Share on other sites More sharing options...
fredx Posted January 19, 2006 Share Posted January 19, 2006 The company for whom I work manufactures both massive electrode and iridium fine wire sparks plugs for reciprocating aircraft engines. Rockmeupto125 is correct in his 2nd post. Iridium is a great material for long life as it sacrifices less material to ionize the gap between the outer and center electrode hence the "long life" ads you may have seen from various manufacturers. It also resists lead attack better than almost any other precious metal (much better than platinum) which is not as big of a deal in auto/mc engines but is a BIG deal in aircraft engines that use 100LL (low-lead, which is actually a heavily leaded gas). The outer electrode is solid iridium, not plated as iridium is a poor electrolytic (or electroless) plating material. The outer tip of the center electrode is typically a small piece of iridium welded onto a copper center electrode. Gapping iridium plugs is totally do-able. What we, as a manufacturer, worry about is some idjit who applies too much force (ever hear of a "calibrated elbow"?) when gapping the iridium plug that he/she breaks the weld between the outer electrode and shell. If you're curious, we created a website with a decent amount of info on our aviation spark plugs at www.autoliteannie.com. Might answer a lot of your questions about spark plugs. Not trying to sell anything here, just providing some more insight into spark plugs. Don't hate me because I'm in sales... Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted January 20, 2006 Share Posted January 20, 2006 Should I gap my Iridium Plugs? The manufacturers say NO. This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode. Personally, we at sparkplugs.com, gap our iridium plugs for our own vehicles (we’re rebels). If you insist on gapping your iridium plug, please refer to Proper Gapping for instruction. This is from sparkplugs.com's FAQ section. I personally gapped my plugs. Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted January 20, 2006 Share Posted January 20, 2006 We have such a great knowledge base here. Thanks for the insider words and the link, Fred! Quote Link to comment Share on other sites More sharing options...
shovelstrokeed Posted January 20, 2006 Share Posted January 20, 2006 Why bother? Eyeball the things to make sure the gap isn't closed up and toss them in there. Modern ignition systems are not at all sensitve to plug gap. Anything between 0.030 and 0.045 is fine. I played with plug gap changes and plug indexing on my old drag bike and never found any difference that could not be accounted for by changes to temperature and barometric pressure over the time it took to pull the plugs and make the changes. That was on a motor that, believe me, had far tougher combustion conditions than you will ever encounter on a street motorcycle. ie 14:1 pistons, nitrous oxide and race gas which is a whole bunch harder to light off. Quote Link to comment Share on other sites More sharing options...
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