On this article we are going to share with you causes of abnormal and excessive cylinder liner wear , ways to minimise cylinder liner wear on marine engines.
Understanding cylinder liner Material
- The liner can be manufactured using a superior material to the cylinder block. While the cylinder block is made from a grey cast iron.
- the liner is manufactured from a cast iron alloyed with chromium, vanadium and molybdenum. (cast iron contains graphite, a lubricant. The alloying elements help resist corrosion and improve the wear resistance at high temperatures.)
Abnormal and excessive cylinder liner wear can be caused by a variety of factors, including:
- Poor lubrication: Inadequate lubrication can lead to increased friction between the piston rings and the cylinder liner, causing excessive wear.
- Contaminants in the lubricating oil: Dirt, metal particles, or other contaminants in the lubricating oil can accelerate wear on the cylinder liner.
- Incompatible cylinder oil.
- Incorrect oil viscosity or oil type.
- Usage of low sulphur fuel oil.
- Overheating: Excessive temperatures can lead to thermal expansion and distortion of the cylinder liner, causing accelerated wear.
- Improper maintenance: Neglecting regular maintenance, such as oil changes and filter replacements, can contribute to abnormal wear of the cylinder liner.
- Misalignment: Misalignment of the piston and cylinder can lead to uneven wear on the liner.
- Material defects: Poor quality materials or manufacturing defects in the cylinder liner can also result in abnormal wear.
Talking about wear on the cyliner liner, abrasion is also type of cylinder liner wear which is due to the hard particles present and formed during combustion. Catalytic fines in the fuel, the ash formed during the combustion, metal swarf, dust and accumulated wear particles in the lube oil cause abrasive wear.
It wear rate is higher at TDC and BDC of the liner. Once the abrasive wear hits the surface, due to exposure of metal without protection, it is highly susceptible to corrosion wear too.
How Can Cylinder Liner Wear be avoid?
1) By avoiding any ingress of water inside the liner by properly treating the fuel oil.
2) By maintaining the correct grade of cylinder oil.
3) By supplying correct feed rate with load change dependent lubrication system
4) By avoiding ingress of moisture from the charge air.
5) By maintaining proper jacket water temperature.
6) By supplying good quality purified fuel oil inside the combustion chamber
7) By properly maintaining the fuel injector and fuel system for correct atomization and injection of fuel inside the chamber
8) By doing regular scavenge port inspection for early detection of piston ring wear and liner surface wear
