the pistons in this engine had cut outs in them no raised bits and on the 1800 head there is a bit that is raiesed around valves i heard it pink the other day but my charge temp was 43 as i had been sat with it running talking to my brother and he wanted to hear what it soundid like so i booted it and it pinked normaly carge temp is about 28 when ive been driven around at the moment in the heat and never heard it pink