artificial 1 those wear marks show that the piston has not been manufactured with the correct sizings. the high spot is in the centre of the piston (ie that wear ring) as well as a high spot on one side of the piston the backplate scratches are normal.

but that piston looks ugly

i think there was one of these engines at my track last clubby. a fellow racer called Tommy Lee raced one at MoorebankRaceway. it was a pritty good motor admitedly mine was quicker, but at the same time my engine was highly worked though.

not dissing picco, another racer at my track who races 8ths has a solaroli tuned picco... that thing is a bullet!