Patent ID: 8857401

Claim:
An improved efficiency piston for a reciprocating engine, comprising: a piston having an upper crown region, a lower skirt region and a central skirt portion; said piston having a cylindrical shape, wherein said upper crown region and said lower skirt region are of equal diameter; said upper crown region having an upper surface with four indentations; wherein each of said four indentations is circular in shape and equal in size; said central skirt portion comprising a recessed surface being inwardly concave, wherein said central skirt portion employs a reduced diameter with respect to said crown and lower skirt region; said central skirt portion further comprising a pin boss connection; said upper crown region having at least one compression ring groove; said upper crown region having a first oil control ring groove; said lower skirt region having a second oil control ring groove; said lower skirt region having a pair of upward protruding tabs on opposing sides of said lower skirt region.