More Spark Plug advice....or am I going over the top?

[superspit]

Taken from another SKYLINE internet page.............

New Plugs (30/12/00):Blah blah blah: On recommendation by another Skyline owner I installed some Nissan platinum plugs. I have for years been using NGK copper plugs simply because they are cheap and new copper plugs deliver stronger sparks than platinums. The down side is that copper plugs need to be changed every 5000kms to retain optimum performance, mine hadnt been changed for 10,000kms and were pretty fouled up.

The Nissan platinum plugs are the same as Nissan Exa spark plugs (22401-58S16, NKG PRF6A-11), benefits are; more consistent plug performance over a longer period of time and less plug changes. As plug changes in the RB20 take about 40mins, this was a huge bonus. The serviceable life of the plugs is 100,000kms, but I think I will still change them after 20,000kms, depending on the condition. Downside is that they are $100 for a set, compared to $15 for the copper ones.

Perfomance: Initially there was a huge difference in power, the engine was more tractable at low revs and came on boost earlier, however after the second day, it developed a miss above 5000rpm on high boost. This was familiar problem...... plug gaps were too big!

The plug gaps on the Nissan plugs were 1.1mm which in my experience is too large when running high boost (+15psi), the theory is that the higher the pressures in the combustion chamber, the harder it is to light the charge, so you either need stronger coils or close the gaps on the plugs to about 0.9mm.

Reducing the plug gaps on the Platinum plugs is a delicate operation, because the layer of platinum is very thin, you have to becareful not to damage this with the feeler gauge. All I did was place the electrode on to a rubber mat and tap the end gently with a rubber mallet untill the gap was sufficiently closed, do not close the gap too much as opening the gap is alot harder.

After the gap was reduced to 0.9mm the miss was gone, but there was some loss of outright power, based on my gut feeling. Maybe the optimal gap is around 1mm, but this will depend on the health of your coils. Never the less the car does feel stronger with the new Nissan plugs, time will tell if they work better than the standard copper NGKs.

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The last paragraph interests me the most........your thoughts on this simple but 'faskinating' subject!!!!!!!!!!??????????

Mark.

[2fardown]

When I had my r33 I gapped the plugs to 0.7mm to stop it hesitating and missing.... POS. They were copper plugs. I can't justify paying $23 for a spark plug, that's nearly a carton of beer.

[WLD747]

Mark, ive been through this process before and learnt the expensive way. See below for my findings.

Platinums:

Last longer max 20,000

Idles Better

0.80 gap loss in power & misfire problems begin

Very expensive

Coppers:

Very strong spark

0.80 gap

lasts 5000 - 8000Km

No misfire and no loss in power

Cheap as Chips

Conclusion:

Stick with coppers.

[superspit]

Mark, ive been through this process before and learnt the expensive way.  See below for my findings.

Platinums:

Last longer max 20,000

Idles Better

0.80 gap loss in power & misfire problems begin

Very expensive

Coppers:

Very strong spark

0.80 gap  

lasts 5000 - 8000Km

No misfire and no loss in power

Cheap as Chips    

Conclusion:

Stick with coppers.  

Hey W747!

mmmmmmmmm..My new plugs (2 weeks old @ $26.50 each) were installed at 1.1mm (pre-extra boost). Boost increased to 9-10 psi, now misfiring when gunning on take off (POP POP Blurble...POP!). So from all the info I see, I figured that .8mm was the fix. Now the 'type' of plug could be a cause???

mmmmmm...I need to get this right before the weekend, as I plan on doing the 'gaps' on my 33 (wot a stuff around with all those pipes ' sh1t).

I'm hoping it's just the gap 747 (?)

Thankyou so much!!

[superspit]

When I had my r33 I gapped the plugs to 0.7mm to stop it hesitating and missing.... POS.  They were copper plugs.  I can't justify paying $23 for a spark plug, that's nearly a carton of beer.

hey 2far.. you don't think the extra cash on plugs is worth the less messing around in the engine bay every few months, just to change darn plugs?

Thanx man.

[Busky2k]

Use NGK V-Power plugs (The ones with the groove in the electrode).

They're probably the best bang for your buck plugs. Or you can waste $100 and hope you can feel the difference on the iridiums/plats IMO.

Fact: I can run bigger gaps w/o misfire on my V-Power plugs than my 10k old Platinums they replaced.

[superspit]

Use NGK V-Power plugs (The ones with the groove in the electrode).  

They're probably the best bang for your buck plugs. Or you can waste $100 and hope you can feel the difference on the iridiums/plats IMO.

Fact: I can run bigger gaps w/o misfire on my V-Power plugs than my 10k old Platinums they replaced.

Is V-Power "copper", will I still need to replace them regularly?

Also, I'm NOT LOOKING FOR POWER GAINS FROM SPARK PLUGS, looking for longevity and reliability, I've never felt more power from a certain type of plug in 20 years of driving. Don't like the idea of 'stripping' the top of my motor out too much just 4 da plugs!!

Thanx so much for your input mate.

[2fardown]

hey 2far.. you don't think the extra cash on plugs is worth the less messing around in the engine bay every few months, just to change darn plugs?

Thanx man.

Not when the plugs cost a mint and hinder performance.... I'll stick with my coppers.

[WLD747]

Check your coils first, could be a lose ground wire. But my car did not like platinums and i bought a heap of sets and realised that plats are bad. Coppers all the way

[superspit]

Check your coils first, could be a lose ground wire. But my car did not like platinums and i bought a heap of sets and realised that plats are bad. Coppers all the way  

Mannnnnnnnn!!!!!!!!!! Looks like I've just blown $100 plus on the Nissan Platinums!!!

Thanks guys!!

[JimX]

I put NGK Iridiums in mine almost 30000km ago, very soon after I got my car. I haven't had a single spark-related problem ever since, and I have never needed to waste time/effort changing my plugs at service time. In effect, they were essentially free. I still had the 8 Iridiums from my Commodore, which I had removed before selling the car. I sold those to a mate who had a V8 Commodore for $100, which covered the entire cost of the 6 replacement ones for the Skyline (they were about $16 each).

[sidewaymambo]

I got some TRUST Iridiums from Belperformance, they are pre-gapped at 0.7, about $21 each..you might able to find some which already gapped 0.7 somewhere else..

[Jay95R33]

Re: the gap size and loss of power. Basically the best thing you can do is run the biggest gap you can without it missing (of course there are limits to this ).

The bigger the gap, the bigger the spark = more/better/faster burn.

It'd be great to run 1.1mm and have a high energy ignition thingy, but the fact is that they are big bucks. But reduce the gap down to 0.8mm and it should be fine for most of our power levels

J

[knore]

im with jimx,

I was a little iffy about iridiums when i went to get new spark plugs.

I actually had NGK Vpower plugs before that, but couldnt find them again anywhere so went on iridiums

Mine are gapped at 1.1mm, and are perfect, ive never had a miss, backfire.. nothing

I am running standard boost tho at the moment.

To me, Iridiums make alot of sense. Iridiums cost 5x more than coppers, but coppers need to be changed 5x more than Iridiums.

Ide rather change my plugs once every xx instead of 5x every xx with coppers.

Plus the design of iridium was purely for performance applications. When u really look at the plug, u can see how it makes a better spark from its design.

I say if you can afford them, buy them.

Sidewaymambo: Where abouts its belperformance?

And gapping iridiums isnt that hard, u just have to be gentle.

[JimX]

You can get NGK Iridiums already gapped to 0.8mm. By pure luck when I ordered mine in, the shop guy got the 0.8mm ones. I knew nothing about spark plug gap back then.

[superspit]

im with jimx,  

I was a little iffy about iridiums when i went to get new spark plugs.  

I actually had NGK Vpower plugs before that, but couldnt find them again anywhere so went on iridiums

Mine are gapped at 1.1mm, and are perfect, ive never had a miss, backfire.. nothing  

I am running standard boost tho at the moment.  

To me, Iridiums make alot of sense. Iridiums cost 5x more than coppers, but coppers need to be changed 5x more than Iridiums.  

Ide rather change my plugs once every xx instead of 5x every xx with coppers.

Plus the design of iridium was purely for performance applications. When u really look at the plug, u can see how it makes a better spark from its design.

I say if you can afford them, buy them.

Sidewaymambo: Where abouts its belperformance?

And gapping iridiums isnt that hard, u just have to be gentle.

ahh yes.....Knore, this is making me feel better already....and ready for the weekend when I re-gap to compensate for my extra boost!! I am more than confident now of 33 running better than ever (no misfire) after I've gone to .8mm.

Thankyou my virtual friend!