pistons just have some carbon build up on em other than that they are fine almost a shame to take em out. I'm going 2.3, but i am thinkin its pre-ignition though. I also was running nology hotwires but i am switching to a COP setup now.

 

after some light grinding and polishing i got most of em out

 

dont you log knock? how can you not know if your cars detonating or not? even with a pocketlogger you can tell if its detonating, because the ecu would retard the timing to hell in attempt to fix it. id set your ecu up to where the check engine light flickers on knock.

 

looks like a job for the pros. call a good shop in ur area and ask them what to do.

 

What's going on between the two valves (near the sparkplug?). The pits look like detonation to me.

I'd probably deck the head - decent bit of firering wear it looks like.

 

car was on stock boost running on "93" Texaco . Pistons are perfect which makes me wonder why the head is the only damaged part.

 

nm dont think you can leakdown with head off. should have done a comp test before you broke the seal on the head. just because the top of the pistons dont look bad doesn't mean the rings didn't get fried a bit.

 

it looked like bad casting, if it was hot spots your pistons would of caught some dents too,..
and if not then at least the carbon would of been blown off that side of the piston,..

next time take it to a shop that specializes in heads before grinding your combustion chamber, or at least take out your spark plugs.

 

Forgot to take em out ( a bit tired from working on my motor ) i think its bad casting too due to the other side having a ruff pitted finish.

 

don't worry about it...run it. Usually detonation shows up on the squish (quench) area and not in the chamber itself. It certainly looks like someone tried to polish it so maybe your just seeing the casting flash. Either way, I wouldn't do anything but mill that head and stick it back on unless you really want to rebuild it and do the chambers over. you would have to grind it out, and make them all the same. Certainly not something you would want to try at home.