Iridium Plugs ok or not???

Message

s80wkr · #1 Post by **s80wkr** » Wed Feb 01, 2006 11:11 am

I have read that Platinum plugs can give an adverse reaction when run on LPG Are Iridium Plugs ok?

badger · #2 Post by **badger** » Wed Feb 01, 2006 11:24 am

I run my 2000 Discovery 4.0 V8 on NGK irridium plugs, the platinum ones don't seem to like LPG, with an accumulation of misfire detection codes being stored in the vehicle's ecu. The irridiums have been fitted for 6 months with no probs.

richy_boy · #3 Post by **richy_boy** » Wed Feb 01, 2006 11:36 am

I run NGK Iridium plugs in mine (cooler grade too due to higher boost levels) I;ve had no ignition problems at all, although saying that I've not pulled a plug out and had a look at what state it's in <IMG SRC="http://www.my90.co.uk/lpgforum/clipart/happy.gif" ALT=":-)" BORDER=0> Rich

garysutherland · #4 Post by **garysutherland** » Wed Feb 01, 2006 12:09 pm

What grade/code of plugs are you using? I'm just about to order a new set for my 3.5l V8i Discovery and might give these a try. Regards Gary

richy_boy · #5 Post by **richy_boy** » Wed Feb 01, 2006 12:19 pm

NGK BKR7EIX (Iridium) I think was the model. Grade 6 is the normal spark plug type. To convert this into Denso talk... I moved from a IK20 to an IK22 Rich

richy_boy · #6 Post by **richy_boy** » Wed Feb 01, 2006 12:21 pm

Just to add, obviously you will need the right plugs for your car though! (i.e. model number) Check out <a href="http://www.sparkplugs.co.uk" target=_top>www.sparkplugs.co.uk</a> <IMG SRC="http://www.my90.co.uk/lpgforum/clipart/happy.gif" ALT=":-)" BORDER=0> Rich

garysutherland · #7 Post by **garysutherland** » Wed Feb 01, 2006 12:46 pm

Thanks, I'll get some ordered. Only problem with the sparkplugs.co.uk site is that their plug-finder doesn't list LPG as a fuel. Cheers Gary

garysutherland · #8 Post by **garysutherland** » Wed Feb 01, 2006 12:51 pm

Are you sure that's BKR and not BPR ? Cheers Gary

richy_boy · #9 Post by **richy_boy** » Wed Feb 01, 2006 12:59 pm

Yup sure, but then those numbers are engine specific for a Nissan 200sx S14a (SR20DET engine) A quick look suggests the Iridium plugs for your Landy are 'BPR6EIX' @ £6.99 each (obviously don't take my word for it!) Rich

sm200sx · #10 Post by **sm200sx** » Mon Feb 06, 2006 11:45 am

I've used Iridiums for around 40,000miles on my 200SX also.

steve_96 · #12 Post by **steve_96** » Mon Feb 06, 2006 11:14 pm

Be very aware of any type of plug that claims a 'long life'. The erosion of plug electrodes has attracted much attention from plug and engine designers alike, they all want to reduce erosion to lengthen plug change intervals for different reasons. When they succeed in their quest, they call it a 'long life' plug. BUT! They pay little or no attention to the corrosion and erosion of the threaded portion of the plug. New ones have a nice shiny gold or silver coloured thread coating, designed to stem both effects. The ones you take out do not look so good because the coating has been burned /eroded/ corroded and the lack of it is the principle cause of plugs snapping off upon removal. So, the electrodes may last longer but you may not get the things out of the head when its time to change them. Much better to stick to standard plugs and change them more often, in many cases you can buy 3 or 4 sets for the price of the whizz bang types. Unless, of course, you have a car with silly plug positions (Chrysler Voyager and many, many others). Then you do not want to change them often, if at all! In that case, coat the threads with Copper based grease before fitting. The compound acts as a sacrifice, extending thread coating life and just prey they will come out when their time is done.

sm200sx · #13 Post by **sm200sx** » Tue Feb 07, 2006 8:53 am

I would say Iridiums are well worth it on a LPG. They are know, and proven to produced a better spark, and LPG is known to be harder to ignite. "All a spark plug does is light the fire" Not true, it is also the main conduction point to take heat away from your engine, however whatever type of plug you use will do this job fine if the correct rating is used. And surely igniting the mixture is one of the most important things in the internal combustion engine? They became very popular when the emmissions laws were tightened up as they help with a much better burn and therefore extend the life of catalysts and reduce emmsions. Of course on a car not designed to run them there will be minimal gains, from a tuning background however the gains are very evident and as stated as LPG is harder to ignite well worth the money.

richy_boy · #14 Post by **richy_boy** » Tue Feb 07, 2006 9:02 am

"So, the electrodes may last longer but you may not get the things out of the head when its time to change them. " I like to put a dab of copper grease in the thread before inserting. Never had a problem yet... Rich

badger · #15 Post by **badger** » Tue Feb 07, 2006 10:59 am

It's also worth noting, guys, that sometimes a Platinum (or irridium) plug is specified due to the way in which the spark discharges, to allow certain onboard diagnostics to work correctly. On a Landrover V8 "thor" engine with the Bosch Motronic management system, for example, the individual cylinder missfire detection facility will not operate correctly unless you fit Platinum or Irridium plugs. I discovered this after I inadvertantly fitted a set of std NGK BPR6ES plugs to my own vehicle, and had some gas set-up issues which turned out to be a failing coil pack. With normal plugs, there was no fault code indication for the missfiring, but with Platinums re-installed the fault codes were present, the individual cylinders concerned led me to the correct coil pack. I replaced the platinums with irridiums to run on LPG, obviously.

richy_boy · #18 Post by **richy_boy** » Tue Feb 07, 2006 7:51 pm

Indeed, but then, some of use run quite high boost on our turbos with maximum advance and do the odd track day. Often you can see the 'cheaper' variety of plugs fail in these extreme conditions and when running LPG on top it's especially important to put something half decent in the car you can rely on. Call me marketing dream, but I'd rather not throw a £2 spark plug in a car I have spent a small fortune putting together... Rich

sm200sx · #19 Post by **sm200sx** » Wed Feb 08, 2006 11:39 am

I definatly noticed an improvment when I dropped a set of Denso iridiums in my new trackday car and pulled out and binned the 2000 mile old copper denso's last week. I'm not saying everyone, and everycar would notice the differance, but a better spark can only be a good thing. Iridiums arent that long life - platinums are, iridiums give the best spark. F1 cars use iridium plugs, extreme example, but I bet they dont use them so they'll last a season ....