Supposedly the one "NOT" under the coil (or fed by the spark plug wire) is the waste spark plug (used to burn waste gases)

Not sure how a performance plug would aid this ? NGK V plugs are cheap and fine. No performance to gain with better plugs. And from what I've seen , it's not necessary to religiously change the plugs each 30,000 miles. Seems going slightly longer is fine.

Honestly I think every 30k miles on tranny service, plugs etc etc is excessive on a modern vehicle, even truck......unless you tow or use it for hauling. Yet I do like to pamper my truck and certainly understand those that do to.

 

All the plugs are fired by a coil pack. The "other" plug should be the same as the one directly under the coil. In '06 they went from coils with a plug wire firing a plug on the other side of the engine to a dual coil pack on each cylinder, still all the same type plug.

The "by the book" interval is 30K for all 16. My Ram had 87K on its plugs when they were removed. The gap was not pretty. My C got plugs at 49K. Those gaps were in the .050-.053 range.

The 4.7 went to dual plugs in '07 (I think). Uppers changed at 30K, lowers at 90K or 102K.

 

The 08 4.7L has upper and lower plugs. 07-back just the 8 coppers up top.

 

Don't mean to hijack the thread but I have an 04 Ram with the 5.7 and I was curious if the plug under the coil pack the primary or the waste spark? There is one just infront of it that looks like a standard plug wire.

I was going to put double plat in the waste and copper as primary.

 

The one under the coil is the primary.

 

Ive got the copper OEMs in mine and Im at 80k. They have been changed but Im still using OEMs

 

Thanks. Time to have fun changing them (not looking forward to the back plugs)

 

Hemi engines are NOT waste spark engines. Both plugs fire at exactly the same time.

Taylor makes a "shorty" plug wire that drives the plug directly next to the coil. Cleans up the bay and less resistance on the coil.

The reason for the wires was a resistance issue from Chrysler, that was updated on the 06 and later trucks.

You can swap in the dual plug coil packs, but you would have to change the electrical conections on the stock wire harness to the '06 and later connector.

The MSD direct replacement coilpacks, along with the Taylor Shorty wires, is a super clean install, and prevents any fouling due to race fuel, nitrous applications or forced induction. Definately overkill, but they look badass.

 

It's not too bad. I have done mine once already. Took less than 1.5hrs. The back 2 cylinders on the driver side are a little tight under the brake booster. I have the larger double coils used since 06 that are a little harder to maneuver out then the older ones are I believe. Weedahoe upgraded his from the old style with plug wires to the 06-up set-up. He can verify if this is true or not. I've never done the plug wired style Hemi before.
Regardless, just take your time. A short and long extension is helpful. I would also recommend a little anti-seize on the plug threads since they are aluminum heads.

Edit, the early system with plug wires was a wasted spark system that fired the plug with a plug wire on the exhaust stroke to help completely burn the fuel. It was for emissions purposes. The 06-up, does not do this and fires both plugs together. Weedahoe has done this conversion already.

 

hmmm.. how then would you not get a "misfire" CEL code when using the shortys or swapping to 06 coils?