Seizure and scoring are two different stages of the same problem. When the oil film on a cylinder is
momentarily burned or brushed away, the metal surfaces of the piston and the cylinder wall will
actually touch. When this happens, there is a sort of scraping that takes place between them. When
the oil film is resumed, the marks from this scraping will often remain on the piston and (or) the
cylinder wall. This momentary scraping or "scoring" seldom causes any permanent or performance
robbing damage. No significant damage takes place because the oil film is resumed before the piston and cylinder have a chance to start exchanging material onto one another.
Scoring is commonly seen on the piston face directly below the piston ring end gaps. The blast of
combustion can get between the large end gap of a worn out ring and burn the oil off the piston and
cylinder in that area...Hence the surface scoring. In most cases, score marks can simply be sanded
off of the piston and cylinder. However when ever you see scoring, it's a good idea to find the
source so that it doesn't develop into a full blown seizure.