Thread: Blew tops of pistons

So my top swap grand prix blew up and the guy i have swapping motors for me now said that i had holes in the top of my pistons. What would cause this? I had a 3.8 pulley, zzp pcm, headers,1.9 zzp rockers, autolite 104s, and 180 thermostat. The motor i had the stuff on had 205k. Could it of just been the high mileage?

Might be a silly question for you but did you run premium or regular?

Premium

Well the mods look alright (but I'd get a second opinion) except the fact you used a canned tune.

Well my scanner would go max 3.5 kr but it would only do that sometimes. Does the kr 1 reading on an aeroforce gauge read constantly or do i need to setup up to read constantly?

Actually it did hit 6kr but that was after it was miss firing.

Ok thanks i'd been wodering about that cause i was knock free for awhile then it would hit 3.5 kr and back to zero. Also when i would go all out when shifting into third it would stutter or miss could that be a sign of bad tune causing a lean condition?

Well im planning on a new tune but i cant afford a dyno tune right now since all this just happened and idk how to tune myself. Anyone know another can tune company i could check? Also is there a way to tell if im running lean on my scan gauge? Also any other possibilities on why i was running lean?

Central Ill.

Alright thanks for the help i hope its just a tune cause i dont want to have to go threw this again any time soon.