Bull. Motorcraft are just average. And have short thread wich leads to problems.
Autolite XP104.
Bull. Motorcraft are just average. And have short thread wich leads to problems.
Autolite XP104.
Of coarse a platinum coating might have worn off at close to 100k miles (the end of their life cycle)... do you really think its made out of a chunk of platinum? As for earlier comments... if they moved the thread up you would still be left with an area that can rust to the block, it would just be higher. And of coarse there is a tb that says to use sleeves on a blown out plug... what other option is there?My original Motorcrafts, at 90k had a perfectly rounded tip with increased gap. That puts a strain on the ingition coils and leads to misfires, increased fuel consumption...
Didn't look like "platinum" tip to me.
Not even close of what a fine wire tip on the iridium plugs looks like.
Electrical sparks also prefers copper to platinum/iridium.The iridium one have the tip made of iridium and the ground side is platinum plating or wire. There are very tiny - only 0.4-0.6 mm for the tip - but that's what electrical spark likes!
Of course, everybody chooses what he thinks is better
I have on all my cars something better than OEM plugs. I am not attached to a certain brand - in my Mercury Sable V6 DOHC the Bosch "Iridium Fusion +4" worked great, in Hyunday Sonata V6 I did try the Bosch and didn't like them, but NGK "Iridium IX" where great, in the 302 engine the Autolite "XP104" are perfect.
PS: And no, the thread would not leave the moisture get in there because the thread metal is compressed on metal (when you tight it), unlike the micro-gap that is present in the original plug (where I circled it with red). If you use in that port a long thread plug you will still be better since the contact surface is smaller and you can fill it with silicon lube (the special one for sperk plug thread) easier.
You have explained why 'you think' condensation won't get into the threaded part, but I guess you are naive to the fact that condensation will accumulate on the threads when cooled. This is thermal dynamics... just because an area has threads does not somehow make it immune to condensation. More threads = more surface area = more surface area to rust. At this point we could get real technical on the amount of force required to break rust of varying surface areas vs thickness, but it's really a moot point.I don't have to have 4 tips on my spark plugs. The Autolite have just one tip and one ground.
Temperatures inside the chamber are so high and gases so reactive that the Copper would be eaten very soon. That's why iridium and platinum are used. Basic stuff...
Also I have explained why the condensation won't get in the threaded part, and I won't repeat it.
You can keep buying spark plugs with short thread in an iron block. Maybe you don't have salt on your roads. maybe you don't care that the center electrode lost it's shape and cause your MPG to increase with some 5%. Maybe you won't mind spending 600$ (like I had to) o fix problems with seized Motorcraft plugs.
That was just my opinion - that the Motorcraft plugs are just a bare-minimum plugs - and everybody can think different.
Why don't you prove me wrong and post some sources that confirm any of this.Threads have the surfaces PRESSED together with tones per square inch. Metal to metal gap is therfore extremly small.
The cylindical straight face puts no pressure on the block hole. Interstitial gap is probably 10000 bigger than the one between two threads.
Also, a smaller tip, like the iridium one, cools less the flame nucleus. A biger metalic (usual tip) tip will cool the flame nucleus a lot, leading to incomplete burn.
So why do you mention temperature as a cause here?As for the copper chemical oxidation resistance in the presence of 1000-2000 degree combustion gases and air (right to the tip), compared with the one of platinum or iridium... Nickel is the least resistent material that is used for the tip. No copper in the exposed tip.
Temperatures inside the chamber are so high and gases so reactive that the Copper would be eaten very soon. That's why iridium and platinum are used.