Cylinder Bore & Piston Rings

Cylinder Bore & Piston Rings Points : cylinder bore & piston rings, problems in internal combustion engines, ic, engine We can divide this subject into two specific problems first-Oil Migration (combustion chamber). Excessive oil film thickness deposited on the cylinder wall will allow the piston rings to hydroplane on this oil film, which allows oil to migrate into the combustion chamber to be burned and can he caused by one or more of the following:

• Oil pan overfill
• Wrong cylinder/bore cross hatch honing method (too flat causing oil “piddling”).
• Inadequate piston oil control ring wiping, due to low tension and probably due to excessive oil rail and gaps.
• Piston skirt fit in cylinder/bore (excessive clearance) resulting in piston skirt not effectively shearing the oil film, thereby allowing oil to be scraped to the combustion chamber on the upward stroke.
• Worn or tapered cylinder/bores.
• Cylinder/bore distortion.
• “Windage” due to wave motion of oil in the oil pan being whipped up and deposited onto the cylinder walls as in the case of oil pan overfills.
• Piston tilt due to piston skirt design protruding below cylinder/bore, which results in the piston ring’s inability to provide proper contact with cylinder walls.