Platinum/Iridium Spark Plug Maint

[PRO_32]

Just wanna know if these can be cleaned up a little if so what should i use back in ol school days i would have given them a lite sand but platinum/iridium no idea what this wil do to them maybe bit off petrol ????

cheers

andrew...

[MegaGTS4]

Dont sand them, as most platinum plugs are only platinum coated and not a solid platinum electrode, sometimes even gaping the coated plugs can damage the thin platinum coating causing early failure. Platinum plugs are also self cleaning, this is achieved when the plug electrode reaches a certain temperature it burns off any chemical residue, if the plug is not in the right temp range the plug might not self clean and chemical residue will build up causing the plug to foul. The solid platinum electrode plugs reach the self cleaning temp more quicker making them more reliable over a longer service life. Electrode edges need to be sharp and not rounded as this will reduce plug performance.

The following is taken from http://www.ngkntk.com.br/site_ingles/direct/p19.html

Cleaning procedure:

1. If the ignition end is weat or humid, clean it first with a dissolver and dry it before continuing cleaning.

2. After cleaning, apply an air jet to eliminate cleaning product traces in the ignition end.

3. Clean the thread and the spark plug metal cover with a little wire brush. Be careful and make sure to eliminate all traces of the cleaning product in the threads because it could damage the breech thread when installing the spark plug.

4. Finally, adjust the electrodes caliber as recommended by the engine manufacturer.

(Note) To clean V type or platinum electrodes spark plugs, apply a smaller air pressure and realize cleaning in a shorter time.

MEGA

[MegaGTS4]

Bosch recommends when installing spark plugs to use a torque wrench and the correct torque in ft.-lbs. As listed below:

10mm With Gasket - 8-11 FT.-LBS

12mm With Gasket - 12-15 FT.-LBS

14mm With Gasket - 19-22 FT.-LBS

14mm Tapered Seat - 12-15 FT.-LBS

18mm With Gasket - 20-23 FT.-LBS

18mm Tapered Seat - 14-17 FT.-LBS

If a torque wrench is not available, hand tighten the plug until it is seated in the cylinder head. Spark plugs with gaskets should be tightened an additional 90°. Spark plugs with tapered seats should be tightened an additional 15°.

This PDF file shows how to read the faces of used standard electrode plugs:

http://www.boschusa.com/images/Sparkplugfaces.pdf

MEGA

[PRO_32]

Dude thanks heaps plent of info there...

Man those picks of plugs...lol...Some are in REALLY bad shape...

Cheers..

[benm]

Hrmm I might check my plugs tomorrow and see how they look compared to the plugs in that PDF.

Thanks for that info MegaGTS4

[predator]

If you've got problems, i'd just go back to coppers - @$23 or so for 6x you can replace a hell of a lot of them to match one set of platinums.

I checked mine today and they turned up somewhere between 1. and 2. on those pics which is fine in a skyline. You'll find that the RB engines tend to run a bit richer, therefore the plugs will get dirty a bit easier than with some other cars.

[PRO_32]

I always thought the Platinums were used not so much for their lifespan rather for there performance?? is this wrong

[predator]

Platinums will make absolutely no difference to performance. People running 300rwkw setups often still use coppers.

although some say they are recommended about "spark efficiency" and rubbish, i think its often b.s to sell you a $200 set of plugs, rather than a $30 set.

They will last longer though.

[JimX]

I always thought the Platinums were used not so much for their lifespan rather for there performance?? is this wrong

The reason I use iridiums isn't because of more power, but because they last a lot longer and are more consistent over their lifetime. Mostly because of their self-cleaning ability. Whenever I've used coppers in the past, the plugs just deteriorate slowly and I was never sure of when to replace the plugs. I could take the easy way out and just replace them every 5000km as many people do, but after 20000km of coppers I could have paid for one set of iridiums. And iridiums last a lot longer than 20000km.

Pred, where did you get quoted $200 for platinums? I paid $17 each for my iridiums, and platinums are usually a tad cheaper.

[predator]

I don't have too much problems with fouling and run 10psi consistanly. I think this latest set of plugs has done 15k or so and they've still got another good 5-10k in them. But really, up to you.

i think it was repco at the time that quoted me that so no wonder !

[benm]

My plugs haven't been checked in 35,000km, thats why I plan on checking them later tonight or tomorrow night when everything cools down abit just to see what condition they are in and what they are gapped to.

[MegaGTS4]

I prefer platinum's because every time a spark plug fires, a tiny bit of metal is lost in the electrical discharge. Over the course of 1000 km at 10,000 rpm – or 80 000 km at 2500 rpm in a car – this can degrade the plug’s performance because the gap between the center electrode and ground electrode gets larger. The larger the gap, the more voltage is required to produce a spark, until the capability of the ignition system is exceeded and the plug misfires. It was found that the multiple ground electrode and precious metals such as platinum reduces gap erosion. Small diameter electrodes make it easier for spark to be produced also reducing the gap has the same effect and reduces the ignition voltage reqirements.

Platinum's are a direct result of development and testing in long distance racing.

IMHO expense of the platinums can be justified if you take into account the performance, life-span , reliability , labour saving aspects.

MEGA

[siu_loong_bao]

The reason I use iridiums isn't because of more power, but because they last a lot longer and are more consistent over their lifetime. Mostly because of their self-cleaning ability. Whenever I've used coppers in the past, the plugs just deteriorate slowly and I was never sure of when to replace the plugs. I could take the easy way out and just replace them every 5000km as many people do, but after 20000km of coppers I could have paid for one set of iridiums. And iridiums last a lot longer than 20000km.

Pred, where did you get quoted $200 for platinums? I paid $17 each for my iridiums, and platinums are usually a tad cheaper.

Where did u buy them at? I am looking to buy a set and I got quoted $30/each!!!!

[Bobjones]

I am using iridiums at the moment, only cause I am a fan and have used them on various cars with good performance and at $35 for a set who could argue (yes they are NGK and no I am not telling where I got them)

I only use platinums in N/A cars because the less strain on the plugs ie heat and boost etc. If you can change your plugs regular use Copper they conduct better, if you ever speak to a sparkie do they use platinum in wires???

[JimX]

Where did u buy them at? I am looking to buy a set and I got quoted $30/each!!!!

Auto 1.

[JimX]

I am using iridiums at the moment, only cause I am a fan and have used them on various cars with good performance and at $35 for a set who could argue (yes they are NGK and no I am not telling where I got them)

Why bother telling us how cheap you got them if you don't say where? Are we suppoed to be impressed?

[samuri]

The reason I use iridiums isn't because of more power, but because they last a lot longer and are more consistent over their lifetime. Mostly because of their self-cleaning ability. Whenever I've used coppers in the past, the plugs just deteriorate slowly and I was never sure of when to replace the plugs. I could take the easy way out and just replace them every 5000km as many people do, but after 20000km of coppers I could have paid for one set of iridiums. And iridiums last a lot longer than 20000km.

Pred, where did you get quoted $200 for platinums? I paid $17 each for my iridiums, and platinums are usually a tad cheaper.

Mine lasted 105,000k and I only replaced them because it was convenient with a major service

[jrm]

6-year thread bump for pointless post ftl

[Galois]

wow old thread, my coppers are fading at like 4000km, will switch to bosch plats at $38 for 6 soon.

should also point out that the metal used doesn't impact the explostion of the fuel, ie: the power. and the metal lost is kind of insignificant, the bigger problems are damage to the plug by using a plug which is too hot or crap forming all over the plug from running rich etc

[Cain82]

has anybody used Bosch plugs?

Repco don't stock NGK and sold me a set of "platinum iridium super plus" plugs, wanted to know if anybody had any experiences to share??

...I haven't put them in yet, probably next weekend with the full service

Edited February 5, 2012 by Cain82