NGK Iridium plugs - anyone?

[zodiac3813]

How did you change it Terry? By tapping? Very carefully I imagine! Did you set it at .010" ?

 

Cheers, Jim

 

 

[Guest terry]

Hi Jim, I set them the same as the usual plugs in a 582. Seem to work fine. However I would be happy to be informed otherwise.

 

Regards Terry.

 

 

[wizzard1964]

From the other "Fouled plugs" thread seems $15 ea on special @ SCAutoSome were bought for $12.75 ea from UK

So this $10.50 looks cheap.

 

Sould last way longer than conventional ones, which are around $6 ea locally I think

I pay $3.50 each for the standard (NGK) ones, and change them every 25 hours.

 

I was considering changing to Iridium plugs and better leads, but no-one has sugessted it is worthwhile...

 

 

[Dieselten]

Friend of mine had 'em in his J230. After some engine issues he removed them, cleaned and tested them. None sparked in the tester. He's gone back to D9EAs.

 

Use at your own risk in home-built Jabs, afaik not approved for factory-built.

 

 

[jetjr]

Folks at Jabiru engines recommend them.

 

 

[gas man]

I have been running iridium plugs for 100 hours apparently without problems. The plugs still look good. I forget how I did it but I did carefully narrow the gaps partially but I am not sure if this is necessary. The insulator and central electrode are horribly delicate.

 

The surface area of the central electrode (the bit in the middle)of an iridium plug is a fraction of the conventional plug equivalent due to the robust properties of the metal. The electrode looks more like a pin than a rod.

 

My understanding is that the charge density on this tiny point is therefore very high and that this enhances the spark and also allows it to jump a bigger gap.

 

I do not think that it is possible for the average guy to assess small diferences in engine performance but I am sure that my cold starting has improved with these plugs.

 

It would be important to hear from anyone who has had problems with these plugs.

 

At this stage I am planning to monitor their condition but I guess I will want to retire tham after a couple of hundred hours.

 

 

[theoy]

350+ hours with my Iridiums and still Ok

 

 

[compsci]

Free 12 mew Iridium plugs to a deserving Australian

 

Gentlemen,

 

I had bought 12 Iridium plugs to be installed during my annual J230 inspection, but the mechanic recommended not to use them. I would be happy to mail them to an Australian Jabiru owner in appreciation for all the good advice I have received over the past year.

 

COMPSCI

 

Wilmette, Illinois, USA

 

 

[jetjr]

OK Ill have them

 

[email protected]

 

Cheers

 

JR

 

 

[compsci]

Free Iridium plugs

 

JETJR was the first to respond and I will be sending the plugs to him.

 

COMPSCI

 

 

[theoy]

Just replaced my 380 hour Iridium plugs with a new set. My old set looked like would go of another 100 hour easy. For me personally 380 - 400 hours enough from one set. Cheers

 

 

[Modest Pilot]

The latest EAA Sport Aviation mag has an article by Mike Busch (44 as year an USA A & P) on mag checks and plugs. While saying that fine wire plugs have as much as three times the life of normal plugs I thought his comment worth thinking about before rushing out and buying plugs that cost what they do.

 

 

 

 

 



Quote: I am not a big fan of fine wireplugs and use conventional massive-electrode plugs in my airplane. In recent years, we’ve seen an epidemic of insulator failures in fine-wire plugs. Mike also hosts free maintenance webinars on the first Wednesday of each month at 8p.m. (Central). To sign up or access the archives, visit www.Savvymx.com/webinar

 

 

 

 

 

 

 

 

[Alan]

Just changed to Iridium plugs (engine 330 hrs) out of curiosity. Previous plugs were normal NGKs and had been changed out after about 100 hours with no problems. However, the Iridium plugs have presented some noticeable changes. In the circuit there was no noticeable difference, but when set up to cruise there were distinct changes.

 

Normal Spark Plugs

 

Typically I cruise at 2850 rpm which gives just over 110 knots at 20.5 litres per hour, the EGTs (cyl 3 and 4) were level at about 1250°F - I was happy with this. Use more revs to go faster, fuel burn went up and EGTs reduced slightly. Been like this for 330 hours.

 

Iridium Spark Plugs

 

Setting 2850 rpm still gave about 110+, but the fuel flow was now at 19.2 L/hr, the EGTs Cyl 3 was approaching 1300°F and Cyl 4 was now 1275°F. I was two up close to MTOW. Hmmmmm.

 

Resetting the throttle to give 20.5 L/hr now gave me nearly 2950rpm and 120 knots, the EGTs were back down to normalish but No 3 Cyl still leads by about 25°F.

 

With the change to Iridium plugs I will still adjust the fuel flow to maintain low EGTs (and am currently considering fitting a 2 X six channel temperature monitor), it just means I fly faster or change back to normal plugs.

 

Even though I only have two cylinders with EGT sensors I have always flown setting the fuel flow to keep these below 1250°F and have found that going below 20L/hr will slowly have the EGTs climbing.

 

Are these Iridium plugs really that much more efficient? anybody else experienced this? Gauge error? Any suggestions.

 

Regards

 

Alan

 

 

[robinsm]

Alan, vry interested in your experiences with iridium plugs. We had a discussion the hanger today re the merits or otherwise of std NGK v's Platinum tips v's iridium plugs. Most use the std ones but I am interested in hearing your, and any other experieces with the other plugs be they for 4 stroke or 2 stroke us.

 

Cheers

 

Maynard

 

 

[Alan]

Have only done 14 hours flying since fitting iridium plugs and the same result; there does seem to be an efficiency increase. However, I had forgotten that I had the wheel spats put back on the plane at the same service as the change to iridium plugs. This may explain or contribute to the changes observed.

 

Alan

 

 

[bushpilot]

Have only done 14 hours flying since fitting iridium plugs and the same result; there does seem to be an efficiency increase. However, I had forgotten that I had the wheel spats put back on the plane at the same service as the change to iridium plugs. This may explain or contribute to the changes observed.Alan

Clearly the spats would make a difference to the performance criteria you are looking at. How about cold-starting? Has that got better or not? ie cranking time until fires.

 

 

[Jabiru Phil]

First winter that I have not had to use hot water, jumperleads etc.

 

I have not used the choke at all, turns over a few times and always starts.

 

Irridium plugs make some difference I'me sure.

 

I installed mainly after talking to Don at Jabiru and local pilot Theroy who is having a good run with them.

 

Regards Phil.

 

 

[Alan]

No noticeable change in cranking or starting after the change to iridium plugs. But it has never been a problem before; it never really gets cold up here (FNQ).

 

Alan

 

 

[bushpilot]

I spoke to Jab Engine Shop about them today. Bottom line: They cannot be used legally in a certified Jab. So of no use to schools.

 

 

[Zank]

I get the iridiums for 10 bucks (mates rates tho) at local auto parts place and highly reccomend them.

 

Seems they are recomended for LPG engines, so with all the LPG converstions in the last few years they have tacked on a nice margin.

 

 

[jetjr]

They are under $6 ea from US still

 

 

[Jabiru Phil]

Irridium Plugs

 

Anyone know where to purchase.

 

Looking for 12 DR9EIX

 

I got my last set through a member who does not seem to be on the forum anymore.

 

Regards,

 

Phil

 

 

[jetjr]

Phil, I think maybe I got them for you from here, http://www.ecrater.com/p/5196545/4-dr9eix-4772-ngk-iridium-ix-spark?keywords=DR9EIX

 

More plugs in order reduces price of freight a lot

 

 

[Jabiru Phil]

Thanks jetjr

 

They only have 8 in stock at this time. I will try again later

 

Much appreciated.

 

Phil.

 

 

[jetjr]

Yeah they had to order them in last time too, we ordered 32x, they dont keep many in stock.

 

Dont forget to request the screw on tips for them