ok guys i have problem, look at pix below, i have b16a2, 500miles ago i put darton 200series sleeves, cp pistons, clerance was 0.0035, egt was 1400F, no knock, afr good, plugs good, i never overheat engine - what it can be?
we couldn't tune it becouse of water inside exhoust, after couple minutes it started to smoke white (not blue) we took head and saw this:

 

I had the same issue on a LS/Vtec with no miles on it full rebuild turned out to the the bores were a bit over sized for the pistons and the piston rings expanded more than they were supposed to and caused this. No I am building a GS-R. you could bore it out and get bigger pistons to fit it and make sure your piston rings are properly gaped and clocked. GL

 

0.0035 seems a little tight for cp pistons. what kind of power were you putting down?

 

i was plannig something around 350-400

 

how do the pistons look?

 

right now we take off only the head, so i don't know how they look like