Plug Indexing

[midnightSun]

So i had a mis on my way home this early AM WOT @ 120MPH. So i was going to gap and index the plugs then it occurred to me this engine has 4 valves....In the past on 2 valve heads ive always side indexed. So on this 4 valve does one intake valve open before another? I mean the plug is basically in the center of all 4 valves.....maybe ill shield the spark from the intake keeping the back to the injector as a test. Humm decisions, decisions.

 

[midnightSun]

I guess i should really be asking...which side is the squish side?

 

[Rockstar04]

Everything that I have read is that indexing doesn't do nearly as much as it used to (compared to the OHV motors of yester-year). If you are dead set on trying to index your plugs I would point the ground strap towards the exhaust side, so the flame front will travel best into the pocket on the piston.

In this picture the ground strap is opposite of what I would expect would be optimal.