probabily tired old plug vs new plug.

 

from what I understand, platinum is really not the greatest conductor
for spark plugs-- its just long lasting. copper is a better choice-just short lived

I really dont know about iridium---is it the best of both worlds?

any one tried E3 plugs?
I got some for my car- but havent finished the motor yet

 

Platinum plugs date back to the 1920's and 1930's when spark plugs could be rebuilt. Yes, at one time you could rebuild your spark plugs. Copper is a cheaper mineral than platinum, which is most likely the reason copper plugs became prevalent. Auto companies cut costs by the thousandth of a cent, because when multiplied by a few hundred thousand units, the costs add up.

The number one issue they fought with for years was how to increase the maintenance period, meaning eliminate tune-ups. That's how electronic ignition systems and platinum plugs solved that problem.

 

The Magnum motors absolutely LOVE Iridium plugs, however, the fuel/air ratio needs to be at least close to whatever the ECM has programed for a stock reading. If you've done the aluminum plenum upgrade, and no more vacuum leaks can be found, you then buy a bottle of Enzyme Fuel Treatment, as Im sure you, like everyone else and their mother, cheaps out on your fuel fill up, and you're probably running 87 Octane. Well this causes premature combustion of the fuel, as stock magnums don't quite make the cut to be considered "High Compression Motors", their Compression ratio is enough to make the cheap stuff ignite before your spark. Can cause a "knock" that they call an engine ping. Run the full bottle of treatment when you fill up and use the 91 octane(Or 89, depending where youre at, but essentially midgrade is what you're looking for. 93 is too much unless you have aftermarket performance parts, or you're rocking that legendary V12. I promise, buy some NGK or Champion Iridiums, get the correct wires to match, Mopar cap n rotor, and clean your damn fuel system with the hint I just left, and watch your trucks performance completely transform. You'll thank me later, I promise!

 

Erm, no. I have seen WAY too many folks with mystery misfires, that were caused by rare-earth plugs. Sure, not EVERYONE has that problem, but, more often than not, the plugs are the problem.