An internal combustion engine and method of operating such an engine are disclosed. In some embodiments, the engine includes a piston provided within a cylinder, wherein a combustion chamber is defined within the cylinder at least in part by a face of the piston, and an intake valve within the cylinder capable of allowing access to the combustion chamber. The engine further includes a source of compressed air, where the source is external of the cylinder and is coupled to the cylinder by way of the intake valve, and where the piston does not ever operate so as to compress therewithin an amount of uncombusted fuel/air mixture, whereby the engine is capable of operating without a starter. In further embodiments, the piston is rigidly coupled to another, oppositely-orientated second piston, and the two pistons move in unison in response to combustion events to drive hydraulic fluid to a hydraulic motor.