Abstract: A cast cylinder block for an internal combustion engine includes a first and a second cylinder bore and a shared bore wall. The first cylinder bore includes a first bore wall and the second cylinder bore includes a second bore wall. The shared cylinder bore wall includes a first portion and a second portion. A portion of the first bore wall combines with a portion of the second bore wall to form the shared cylinder bore wall. The first portion of the shared bore wall is an as-cast portion. The second portion of the shared bore wall is a metal matrix composite.

Abstract: A humidity sensing device for measuring a humidity of a reactant stream in a fuel cell system is provided. The humidity sensing device includes a humidity sensor coupled to a sensor housing. The sensor housing is adapted to selectively move the humidity sensor to an operating position and to a non-operating position in the fuel cell system. A fuel cell system and a method employing the humidity sensing device in the fuel cell system is also provided.