Indexing plugs

Dave-R · Post by **Dave-R** » Wed Feb 25, 15 5:00 pm

No I am sure it is worth doing on some heads. I just don't see how it can make a difference on a Mopar Wedge.

Pete · Post by **Pete** » Wed Feb 25, 15 5:29 pm

I assume you have to Shim the plug to achieve this affect, not that I could ever be arsed...............

Les Szabo · Post by **Les Szabo** » Wed Feb 25, 15 5:44 pm

Mostly you want to index the gap towards the inlet so it ignites the freshly entered fuel mix at the point of entry, not the exhaust where there can still be some exhaust gases left over, however sometimes it can work on the ex, = head design etc. etc. I tried it on the 340 and it made no difference but it should be checked on a dyno to really see if any and how much gains are made. You can buy Moroso indexing washers to do this if you wanna have a go.