7.Antipolishing ring

*In a diesel engine burning residual fuel, the piston top land (the area between the top ring and the top of the piston crown) can be subject to a build up of carbon.

*This build up of carbon will have the effect of polishing the bore of the liner, reducing its oil retention capabilities and increasing wear.

*To prevent this happening, the liner can be fitted with a replaceable anti polishing ring.

*This is a steel ring which fits in the top of the liner and is of smaller diameter than the liner, but slightly larger than the piston crown.

*As the piston passes over TDC the ring removes any build up of carbon.

*This encourages a build up of carbon on the liner circumference above the top ring position at TDC.

*This build up of carbon removes from the piston top land.