Denso Iridium...gap?

[CRUZTAKER]

Hello to all:

I installed my Iridium plugs today. They did not come with instructions as most plugs do not. They assume if you can change them, you should know the details.

I examined my new plugs and discovered they were shipped with a gap of approx. .040 I have read several posts on this site, some said use a .054 gap, others said use a .050 gap, and as far as Dennis, he said don't screw with them. Well, I did not ruin them, but I did change the gap to .050. Nothing seems unusual, but when I called Dennis and told him what I did, he nearly had a coniption.

WE HAVE GOT TO GET THIS STRAIGHT!

If I had just visited this site...... http://www.densoiridium.com/index.php?flash=1....I would not have made this mistake. Now I don't know if I should take them out and re-gap again, try to buy new ones at the local parts store and return these falsly, or what.

This sucks......a c-note and no prior warning.............

This post is so the NEXT guy doesn't make the same mistake as I, and probably a lot of others as well.

The ship preset GAP for the IP20 is .044

[Fourth Horseman]

Ok, educate the newbie here (me)... that text you posted from Denso says you can re-gap them if you want. They say you don't need to but you can if you insist on staying factory-spec... or am I not reading that correctly?

If that's the case, then what's the problem? Why would you want to take them back? I'm confused. :confused:

[CRUZTAKER]

Ever have someone warn you about something.......and you did it anyway......except once you have done it...........with no apparent consequence.........you get this erie feeling that something is wrong.........but maybe there isn't.

:confused:

Thats where I'm at! Hopefully other members comments and input as to what THEY did, will make it alllll better.

:alone:

[Fourth Horseman]

Ah, I gotcha. Well, of course I don't really know, but with all due respect to DR, if Denso says it's ok to gap them to factory spec then I'd say don't worry about it. Or, pull them out and put them back to DR's recommended gap. That might be the best call, actually.

[gonzo50]

Fourth Horseman, I think CRUZTAKER is a bit unsure if the gap he changed will do more harm than good, 30,000 miles between replacements is good but that is with the factory gap of .044, any deviation from this might give the plugs a shorter life span. And also not to damage the fine center electrode. I hope all is good. When in doubt, redo the whole process.

[FordNut]

I didn't mess with mine, just went ahead and put them in straight out of the box. I did notice some squeaking of the threads when I took out the old ones and thought it seemed like only a few threads are catching. This is also evident in looking at the threaded part of the plug. The OEM plugs are only threaded about 1/2 as much as the Denso plugs. To help prevent and/or reduce the possiblility of stripped threads I used a small application of Neolube No. 2 on the threads. Neolube is a dry film lubricant consisting of super fine graphite in isopropanol. Brush it on the threads, wipe off the excess and let the isopropanol evaporate for a very light layer of graphite lube. I also used a torque wrench to tighten the plugs evenly without over-tightening them. I believe they are supposed to be 7-9 ft-lbs but the lowest setting on my torque wrench is 10 so I went with that. It's amazing how much tighter than that you can easily go with a 3/8" drive ratchet.

I digress... if it were my decision to make I would leave them gapped where you have them. It says plainly in the instructions that you can if you want to. As long as they are all gapped the same you should be ok.

[SergntMac]

CRUZ, ease up, bud, I don't think you have upset things much, but only time will tell.

I'd say cut your losses right now, leave them in and enjoy them. Next set, you can do differently. Besides, we're all experimenting with a new automotive design, and it's dynamic. Things change, even with Dennis. Six months ago, it was the cooler Motorcraft plugs that worked, now it's the Denso IT20 that the latest hot 411. Tomorrow? S**t, who knows? As long as you have them in, and their gaps match, drive 'em. Not being a smart ass here, but this is why the wise advisors say "your results may vary."

[Macon Marauder]

I left mine just as they came. I thought I read somewhere on this site not to mess with them.

Like CRUZ, I checked 'em and they seemed to be gapped at 40. I just shrugged and put 'em in.

Didn't I also read on here that lube for these plugs was a no-no? Or was that something else?

Anyway, plug access is such a breeze in this engine. I'd yank 'em and set 'em back. Unless they're a pain to adjust. If so, I'd leave 'em for now and check back after 10-12K miles.

[CRUZTAKER]

Originally posted by SergntMac
.........we're all experimenting with a new automotive design, and it's dynamic.

No doubt Mac..........., and it was nice to get such a response. Also nice to see a variety of scenarios.

I agree, it's not that big of a deal as long as (any) negative results get posted. I don't notice much change yet. I did notice though, that if I idle the motor at 2500 sitting still, I get some vibration. The very slightest of shake, noticable utilizing the 'but-o-meter' technique.

I will watch it, otherwise no issue. Gonna watch the fuel milage as well. Last check I managed 17.8, which was a vast improvement from the FIRST week I owned the car.....16.1.




:cool:

[LincMercLover]

LOL, I got 11.8MPG last tank...

*cough* I think I set the trip meter late though... *cough* :D

[WolfeBros]

Leave those poor ricers alone.........mileage will improve......:D

[CRUZTAKER]

Yeah.... ^^^^^^what he said^^^^^^

And some robitussin for that cough......:)

[FordNut]

Yes, it was posted that anti-sieze lube shouldn't be used on plug threads. Reasons were electrical resistance and contamination. The lube I used is basically graphite (pure carbon) and is conductive. It was kept clear of the plug tip and only applied to the threads. I just can't stand the thought of stripped threads in the aluminum heads.

[Macon Marauder]

Fordnut,

Thanks for clearing that up. And good luck with the silver MM for the missus. Hoping for a Dark Toreador Red one for mine! :)

[prchrman]

The other and probably most important issue is that with the low torque required on spark plugs combined with the motor vibration they will back
out when lub is applied..not always but it can and has happened..

[FordNut]

Good point. I'll re-check the torque after a week or so of driving. The plugs are SO easy to get access to in this engine. Glad it's not the 5.4 Lightning engine! If you haven't seen where the plugs are located in one of those you ought to look at one. Looks like you have to pull off fuel rails and everything.

Another tip... The rubber insert is missing from my plug wrench so I used a piece of (new, clean) fuel line to slip down on the insulator to remove the old and insert the new plugs.

[Flash]

On the Denso plugs, does that "U" groove ( approx. .008 deep ) in the ground electrode on the plugs contribute or have anything to do or effect on the gap?

[SergntMac]

Originally posted by Flash
On the Denso plugs, does that "U" groove ( approx. .008 deep ) in the ground electrode on the plugs contribute or have anything to do or effect on the gap?

When I first heard of the Denso spark plug, this site answered a lot of my Q&A...

http://www.denso.co.jp/PLUG/iridium-e/index.html

Hope it helps, y'all too.

[cutt]

anyone have any recorded performance gains with just the plugs.are they hotter or colder than stock?

[FordNut]

They are colder. Somebody posted a 7 hp gain from the plugs alone.

[WolfeBros]

I think Logan said they were good for a couple of HP on his Lightning.
If you got 1-2 hp difference on a stock setup it would be about right.
Sparkplugs usually are used to compliment your setup.
ie......heatrange and gap settings for induction and ignition improvements and are not typically installed by themselves for HP gains.

[SergntMac]

Originally posted by cutt
anyone have any recorded performance gains with just the plugs.are they hotter or colder than stock?

The IT20 plugs are colder than what Denso recommends, and Dennis suggests we use colder plugs. I did some independent testing of the IT 20 plugs on a dyno, and noted a gain of 4 RWHP and 6 ftlb RWTQ, as well as shaving a point from my AFR, from 14.97, down to 13.47. I think they are worth the money, read more here;

http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=1783

[WolfeBros]

That is a very nice gain for about $100
Mine are now ordered. Thanks again Sarge. Lunch, or dinner is definitely on me if we ever get the chance to hookup. :up:

[RF Overlord]

Sarge: I'm this close >< to ordering a set myself, but with all the discussion on gaps, I have to ask...you got the biggest gain from the Densos, what gap are you running?

Also, was that gain from the stock plugs, or from the A12Cs?

Thanks...

[SergntMac]

I only checked for consistency among the set, and they were a perfect match at 0.40. I'd like to add that the gains I verified are very pleasing, but it didn't change anything in driving. Just nice to know I'm getting a clean burn, and I needed to get my AFR down. They do that, and for what they cost, the Denso IT20 are a good investment. I'd estimate their effective life span will be 25-30K miles on the s**t gas we get here in the Big Windy.