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Microseizure and Cloverleafing

Cloverleafing will be caused when the supply of lube oil is not uniform around the 
radial bore of the liner. The normal effect is for the oil to reduce in alkalinity away 
from the injection point, thus if the oil becomes acidic then high corrosive wear rates 
will result. This will cause uneven bore wear rates, with heavy wear in the areas 
furthest away from the oil injection points 

Microseizure is caused when the liner and piston ring material is pressed together 
causing localised welding of the material in the absence of sufficient lube oil. The 
causes are insufficient oil and/or excessive cylinder pressures causes heavy ring/liner 
contact forces. The appearance is heavy scratching/tearing in the vertical direction, 
together with a localised hardening of the ring and liner material. 

The cylinder oil will require 
• Ample viscosity to separate the surfaces under high loading conditions 
• Sufficient alkaline reserve to neutralise the acids formed by combustion of 
residual fuel oil 
• High levels of detergent to maintain piston ring cleanliness and free ring 
movement 
• A level of anti wear properties to minimise micro seizure 
• The ability to burn without resid

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