Cylinder Liner Cuts Oil Consumption 40%

Federal-Mogul Corp. says its "hybrid liner" system for engine cylinders reduces wear, improves heat transfer and reduces oil consumption as much as 40%.

The dual-material liner, which is designed for aluminum blocks, consists of a cast iron sleeve with an aluminum-coated exterior that is applied using a proprietary wire arc thermal spray process. The aluminum coating has a melting point below that of the aluminum block and closely controlled surface roughness and microporosity that helps it bond to the block itself.

The resulting liner is more uniform and rigid than conventional cylinder liners, according to Gian Maria Olivetti, Federal-Mogul's vice president for powertrain technology. He says the system reduces bore distortion in a running engine by two-thirds, thus reducing wear and oil consumption. Heat transfer rates from cylinder wall to engine block are as much as 30% higher, which reduces cylinder wall temperature by as much as 40 C (104 F). Olivetti says the dynamic strength of the Federal-Mogul liner system is about twice that of a standard design.

The performance improvements allow lighter engine designs with as little as 3 millimeters between the cylinder bores. Olivetti says the dual-material structure limits the formation of cracks when a water channel is drilled between adjacent cylinders.