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MG MGB Technical - NGK Iridium spark plugs

Just wondering if anyone has used them, and are the worth the difference in cost??

NGK Iridium IX spark plugs provide unsurpassed performance in auto/light truck and powersports applications. The iridium alloy electrode is extremely durable to heat, corrosion and electrical wear. The fine wire electrode reduces the amount of energy required to create a spark while providing increased ignition efficiency and superior ignitability. The center electrode of Iridium IX spark plugs has an extra anti-fouling mechanism. A thermo edge between the center electrode and the insulator nose provides a gap for a secondary micro-discharge to jump and initiate a self-cleaning process.

https://www.amsoil.com/storefront/ngk_iridium_ix.aspx
DCM McCullough

hi if everything is set up you don't need these fancy plugs , i use ngk cheap as chips and i allso use the same plugs in my v8
daZ

Thanks Daz. I'll stick with the standard NGK's on my 'B' as I now have a Electromotive distributurless ignition.
SF
Dwight


DCM McCullough

To be honest, for the little extra they cost, it can be worth trying different plugs. I've found big differences between certain plugs, and technology is always moving on: if they've found some improved material technology, why not take advantage of it?

In this case, the plugs may last longer, or be less prone to fouling. Iridium is, I think, an alternative to platinum-coating the electrodes, which is done reduce spark erosion and increase plug life (came about out of necessity on modern cars, where engines have to meet emission regs for longer).

D Ainsworth

Dwight,
How do you like your Electromotive? Which model? How did you mount the timing wheel?
I have used a early model on my race B for about 10 years and have had one pick-up sensor fail.
I use NGKs from a RX-7; four ground electrodes and uncovered center electrode. Heat range eight
Leland Bradley

I never understood the multi electrode plugs. You'd only ever get one spark I think since it will just jump the shortest distance. Are the extra electrodes just so they last longer? One erodes so the gap gets bigger so it moves to the next closest?

Simon
Simon Jansen

I use them in my modern MG TF - they're the factory spec, but the reason is that due to the awkward (in terms of access) position of the engine on the TF the plugs are specified for a 60k mile service life. In reality their performance drops off noticably around 40k. They're expensive (much cheaper online though) and for the B I just use cheap NGK or Champion plugs. For a couple of quid each and a few minutes to change it's no hassle, especially as I like to check their condition regularly anyway.

I would say that the multi electrodes are really to ensure even wear and extend life. Note also that if you intend to try a "new fangled plug" in the B they come pre-gapped usually to something much wider than the B's normal spec. Furthermore, the manufacturers often don't recommend attempting to re-gap them.

Cheers,
Tim
T Jenner

Simon,
There is probably something to the wear switching but I don't leave them in the race car that long as they lead foul, from the fuel I use, before much wear takes place. The standard plug shadows the spark and should be indexed for maxmium preformance. If you have the voltage/current available to avoid the spark being blown out, you can use the uncovered center electrode plugs and not worry about indexing.
Leland Bradley

I experimented a long time ago with various plugs in the race car and the regular old NGK BP series did as well as any of the more expensive variants.

The only thing I bother using platinum tip plugs in is my turboed GM V6, as they are reputed to last longer under boost conditions and the front bank are a swine to change....
Bill Spohn

With the introduction of east west V6 engines, the plugs at the back of the engine became very inaccessible. In some cases,this also applied to some 4 cyl. engines. So the answer was to fit long life plugs, usually good for 100K klms. Mitsubishi used long life plugs in the rear cyls. & normal plugs in the front cyls. I doubt there is any difference in performance, you just get a longer life cycle out of the expensive plugs. Barrie E
Barrie Egerton

Platinum at least is said to make plugs last for 60k, although several people have said they had problems with them in an MGB.

I put 4-electrode NGKs in my 4-cylinder MGB some 15-18k miles ago, they have never given a moments trouble and there is no sign of electrode wear yet.

If you run gaps bigger than about 32 thou you can get failures elsewhere in the HT circuit as the voltage rises with increasing gap, and these can be very difficult to locate.
Paul Hunt

This thread was discussed between 10/10/2008 and 21/10/2008

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