Plug readers: What would you do??

RockinRobin said

Setup:
Gen3 Hemi racing motor NA 13.5:1 compression running on 110 racing fuel which has purple dye in it.
Holly Sniper 4500 TBI fuel injection and Mopar Drag Pak intake. Ported Eagle heads. Brisk ER14S plugs.
After 5 passes it slows down by 20 numbers and the plugs look like this:
left bank (2468):
View attachment 1716122298
And they look like this after a quick clean with a wire wheel:
View attachment 1716122299
Right bank (1357) Looks like this before cleaning:
View attachment 1716122300

I clean them all and put them back in and the car runs it's number again.
1. Too rich?
2. Why the difference between banks?

Would you clean them and keep using them (what I've been doing) or replace them (these plugs aren't cheap, $180 for a set and there are only 2 companies making a cold enough plug for this motor) or something else?

Click to expand...

Definately eroding the plugs. Is this happening to both plugs in each cylinder. The waste spark fires one from the ground to electrode and the other electrode to ground.
By the ceramic the plug temp appears good but the electrode could be a bit hot. Spark likes to jump from square corners, so I agree it is time for new plugs.
I would be inclined to get water injection. Being a drag engine you could set it up to inject when you let the brakes off. Inject about 1/3 to 1/2 the volume of fuel and then add 2° ignition advance. The water slows and cools the burn in the cylinder which is why the ignition needs to be advanced a bit. Trial and error with reading the plugs. The water expands 1,600X converting during the combustion, adding to cylinder pressure and torque.