the hot rodders used to use 'indexing shims' under their plugs to make them face the right way, but i havent seen those in 20 years.. pep boys maybe?
the things look like spark plug seals but they vary slightly in length, and guys would spend hours messing around getting all eight just right....
if i read that right....2.5 horse...it sounds like i wont be the ONLY one looking around for them! LOL

[img]i/expressions/face-icon-small-happy.gif[/img]

 

if i'm not mistaken you can get index shims from Jegs or Summit Racing. I can't find my catalog at the moment but they both have web sites[img]i/expressions/face-icon-small-happy.gif[/img] Jegs
Summit Racing

 

Would the pop top of a beer can work as a sim?

I got plenty of them.

Chet[img]i/expressions/face-icon-small-tongue.gif[/img]

 

Alright guys, here is my opinions. Indexing plugs alone won't add power, but when you are already spending hours correctly degreeing cams, checking deck height, playing with jetting, etc, it can't hurt. The shop that does my machining for my auto engines is owned by a man that was racing street as a teenager in the 60's, played with drag in the 70's, and now races late model dirt track. He explained that he has almost 2000 hours in the portwork on his heads, so why not spend 30 minutes to index plugs. His dyno results have never indicated a horsepower increase. He runs small block fords on alky. You want the ground strap to point to the intake valve in two valve engines, between the valve on 4 valves, and I guess the center valve on the 5 valve raptor.


If you decide to index, indexing shims...worthless. Using them will pull you plug up out of the chamber (yeah, I know its not much). The best way is to buy a box of 4 and find one that points to the valve when it is tightened down. The threads in the head and the threads on the plug will be different for each one. (like raptoryfm660r asked) One autos, a box of ten you will find eight that will work.

As for the plugs. I just bought a box of the Iridium NGK's. They seem to be a great plug. The platium is probably the better buy for the money. Any plug that ends in the VG or VX is awesome. They have a small center electrode and produce a consistant hot kernel. Remember, gap at .018.