Side sealing oil rings and valve guide seals are keeping oil economy at a satisfactory level in contemporary passenger car engines. Barrel face compression ring designs show improvement in oil and blowby control over traditional configurations.
Metallized molybdenum coated compression rings offer improved ring life where chromium plate scuffing is present. Chromium plate, though, is still unsurpassed for abrasive wear resistance.
A new technique, using sonic energy for measuring ring conformability, is being used for research and development. A high magnification automatic ring face contour gage allows better production control and more accurate experimental ring evaluation.