My 1990 348 ts is ready for new set of spark plugs; any recommendations? Thank you.
Where does such incorrect advice come from? NGK say to gap them. That plug fits a lot of stuff. When NGK makes them they have no idea what the proper gap is and do not set them for your needs. https://www.ngk.com/proper-ngk-gapping-instructions#:~:text=NGK doesn't recommend adjusting,and drastically reducing plug life.
OK... let me qualify that. Its a plug they can be gapped sure, 7EIX comes pre gapped at .044 so yes that should be gapped. If it was a platinum or copper plug, definitely gap them. The 8EIX come factory gapped at .032". and 348 spec is below. I suppose if one really wanted they would try and close it .01mm (That's the difference). But you risk damaging the tip, the Iridium plugs are more efficient and at the factory gap seems to work well. Could you close the gap on 8EIX that tiny .01mm? Sure. Should you, well up to you. If you re gap them manually, would you have 01mm difference between them anyhow, ohh most likely as you cant really apply pressure to the tip. Especially if one uses that stupid quarter sized edge slider gap tool. Now if you use feeler gauges and specialty gap tools you can do it especially if your carful. Can Brian do it correct, yes. Will most folks? Probably not and not even realize the tip broke off after the gap tool is removed. Most folks will just hoark on them and make things worse is all which is why I say for most folks don't gap the 8EIX.
The factory spec is between 24-28 and anyone with any brains or Ferrari experience knows the lower end is better and yes it does make a difference. I have gapped thousands of iridium plugs without damaging a single one. Yes I understand some people can break a steel ball so if you have that problem you should quit working on your own car. Now, to the OP. Should we take this idiots advice or should we take the advice of NGK and Ferrari?
This is all I am saying regarding Iridium plugs, Denso and NGK sites say this. SHOULD you gap... sure why not. The Ferrari 348 manual existed before Iridium's even existed, manual recommends Champion A-6g. LOL ok sure what ever. But yes, I am in Idiot some so gap them please, always. At least it will be within the spec. Can't hurt unless you break them. Will you notice it, no you wont. But then again I am an idiot so there's that. Image Unavailable, Please Login
Reigniting this thread . I purchased a 94 , 348 SP with under 24000 miles regularly ( read annually serviced ) . The book is just stamped and the invoices just vague “ serviced to manufacture recommended specifications “ , with the belt services mentioned where applicable. I got it December back , and have done about 1000 miles in regular short ish 20-50 mile chunks . At the beginning I got a lot of SDL s and even the odd cylinder bank shut down . Some days it ran perfectly but never felt that responsive under and around 2000 rpm in the pick up . As a barometer I run a flat 6 Porsche and carb 208 GT 4 ….it felt worse than these two . So I systematically went around cleaning as many contacts with Stabilent 22 as I could find . Did the relays and fuses in the passenger foot well, the front hood FWIW ? . Did all the connections in the engine bay , MAF ,throttle etc etc . Kinda improved the bank shut down ended but occasionally ( done 500 miles now ) the SDL would flicker or intermittently come on . Recently it felt lumpy as if running on 7 maybe intermittently…say 8 for 5 secs them missing a pot , then back to 8 . It also sounded odd . Not nice as a Tubi should . Even the wife [ typically car numpty female ] said it felt + sounded funny . So I took randomly 2 plugs out of each bank to inspect and bought a IR temp gun . The plugs were these, the originals I suspect . Image Unavailable, Please Login Image Unavailable, Please Login RHS bank a bit fuelled up darker . The IR temp guage when the SDL flickers was way in excess of the un lit LHS . The tail pipe temps different the LHS which is the RHS bank ( cross over in the can ) were way hotter after the engine shut down .I diagnosed unburnt fuel in the right bank , the flickering SDL ? So I ordered a set of NGK Iridium Core DR8EIX . The NGK are 18 mm and the original Champions a lot smaller so needed a different plug socket . Crucially before fitting ( awaiting del ) I cleaned the contacts of each plug lead and applied the Stablient 22 . This immediately cured the SDL issue and the CAT / tail pipe temps equalised + it ran better and sounded better . The NGK Iridium Core DR8EIX Arrived and I was in two minds wether to hold out or fit them ? No idea how old the champions were ? But under 24 K miles . Having read only +ve reports I went ahead and swapped out the champions to NGK Iridium Core DR8EIX WOW WHAT A IMPROVEMENT!!! The cars feels completely different, picks up equally as the Porsche where the PO fitted iridium’s , runs so much smoother as it a turbine and sounds even better than ever . Gapping . Concerned and conscious of the rows on here ,differences in opinion etc I measured one carefully sos not to break the tip at 0.6 mm . Near enough I thought .So just threw them in out of the box . It’s new tech relatively for a 94 modal car so I suspect there’s different gapping then the copper core OEM Champions . [ incidentally those OEM plugs when googled , a lot of Ducati bike motors come up ] . A lot of U.K. lads confirmed just “ throw them in “. Anyhow I had booked it in @ my Indy to go through the plug leads , coil packs , etc possibly other issues to get it running better . Thats cancelled now . It s made such a huge difference the iridium plugs . One thing to note the caps on the OEM Champions were loose easily moved . I had to remove them and put them on the iridium’s as they came without caps . So the problem was likely partly connectivity of the leads at both ends with a few plugs . Partly the caps = not tight for what ever reason ? , Partly the actual OEM plug(s) . I wish I knew there age ?
Sorry can’t seem to remove the bottom pic . It’s an error . Fat finger . If interested it from the Dino rallye in the alps = see more on the 308 and Dino groups . It’s a 208 and runs fine on trad copper cores with its Webers . Diff Stone Age tech plugs / points / Dizzy .
