In accordance with various embodiments of the present invention, a system and method are provided for converting a conventional automobile engine into a gas compressor. In various embodiments, the system and method may provide an economical and efficient gas compressor by modification of a balance-opposed internal-combustion engine to provide a balance-opposed gas compressor. More specifically, in some embodiments, the modification may include a uniquely designed cylinder head adapted to convert an automobile engine into a gas compressor for the recovery, gathering, transfer, or staged compression of natural gas. In one embodiment, a four-cylinder balance-opposed engine is utilized.