NGK iridium Spark plugs

[Berin]

I've bought some iridium spark plugs for both my 1200GSA and Mrs Berins 800GS.

The specs are DCPR8EIX, but there are suffix numbers 3606 one one set and 6546 on the other. After lots of searching (the NGK website only goes as far as 1150's...) I can't find out either a) what these mean or b) which is for which bike.

Anyone know?

 

[Steptoe]

Have you taken a plug out from the 800 or 1200 to compare ?

 

[Berin]

No - but the new plugs with the different suffixes look exactly the same. The only designation is the DCPR8EIX.

if I hadn't taken them from different boxes I wouldn't know which was which.

 

[alimey4u2]

http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm

 

[Berin]

Thanks, useful, but still doesn't say what the suffix numbers are for - just gives details of the DCPR8EIX.

http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm

 

[alimey4u2]

http://www.ngk-sparkplugs.jp/english/techinfo/iridium/03/

 

[MrIFan]

Mmmm, me thinks things mechanical is not your destiny

 

[King Rat]

In an understressed engine like the boxer, I think the benefit of the Iridium plug would be largely masked by the limited power anyway. Maybe in one of Jim Cray's souped up engines, but in a standard bike?

The beauty of the boxer is its understressed nature, large volume to low power.
A 1 litre + engine producing 100hp (or much less in some cases), and when riding, how much of the available power do you actually use?

Peak power is at 6750 rpm - how often and for how long do you run at 6500rpm? I would be willing to bet you are more likely to be running around using between 50hp and 75hp of the available 100hp. - 3500rpm-5000rpm.

We used to run Iridium plugs in one of the race boats, inboard petrol V8s, and in the Honda 225hp raceboat too (petrol outboard 4-stroke). We also used to mark the position of the electrode on the outside of the plug and turn them in so that all the electrodes lined up facing away from the inlet tract, to put the biggest spark front facing the incoming charge. It might have made 1hp difference, when racing you need every 0.1% gain you can get, from wherever you can get it, including crew weight! But on a road bike bimbling around the lanes - it won't show up.

 

[Berin]

You could well be right - although these guys think they make a difference.

However, I thought I'd try them, and I will as soon as I can figure out which ones go in which bike, as per the original question

In an understressed engine like the boxer, I think the benefit of the Iridium plug would be largely masked by the limited power anyway. Maybe in one of Jim Cray's souped up engines, but in a standard bike?

 

[LEIGH]

I use Iridium Plugs in my Aprilia enduro, Not to improve power but to help with cold start. The Aprilia doesnt have a choke but a fast idle for cold starts and the throttle bodies have to be between 11 and 12 deg's open to start or you'll be there all day frying the starter and it wont even cough.

so If you have poor electrics then Iridium plugs might help here. A bit of a band-aid solution though

 

[Magwych]

Hi Berin,

before this is diverted and hits full-on "which spark-plug proportions", the 4 digit number is a manufacturers batch code. All plugs produced in one batch have the same number.

One DCPR8EIX should behave exactly the same as another, irrespective of any other markings. There is no need to match these codes, they are usually used by manufacturers in the event of a warranty return.

 

[Berin]

Citybum, thanks a bundle. That's what I need to know!

Everyone else, feel free to hijack away on the merits of iridium plugs

 

[cookie]

Everyone else, feel free to hijack away on the merits of iridium plugs

i shall express my opinion of fancy spark plugs through the medium of photography...

 

[Steptoe]

i shall express my opinion of fancy spark plugs through the medium of photography...

Can i join in ....

 

[King Rat]

That last pic is of Steptoe's own hand after a single round of Poker......or is he about to buy a round?

 

[Tarka]

Mmmm, me thinks things mechanical is not your destiny

Can I quote that line throughout the 'technical' forums ???